Hi all!
Ok, I hope that this is the last update of the patches which add basic
support for dynamic allocation of memory reserved regions defined in
device tree.
This time I've mainly sliced the main patch into several smaller pieces
to make the changes easier to understand and fixes some minor coding
style issues.
The initial code for this feature were posted here [1], merged as commit
9d8eab7af79cb4ce2de5de39f82c455b1f796963 ("drivers: of: add
initialization code for dma reserved memory") and later reverted by
commit 1931ee143b0ab72924944bc06e363d837ba05063. For more information,
see [2]. Finally a new bindings has been proposed [3] and Josh
Cartwright a few days ago prepared some code which implements those
bindings [4]. This finally pushed me again to find some time to finish
this task and review the code. Josh agreed to give me the ownership of
this series to continue preparing them for mainline inclusion.
For more information please refer to the changlelog and links below.
[1]: http://lkml.kernel.org/g/[email protected]
[2]: http://lkml.kernel.org/g/[email protected]
[3]: http://lkml.kernel.org/g/[email protected]
[4]: http://thread.gmane.org/gmane.linux.documentation/19579
Changelog:
v5:
- sliced main patch into several smaller patches on Grant's request
- fixed coding style issues pointed by Grant
- use node->phandle value directly instead of parsing properties manually
v4: https://lkml.org/lkml/2014/2/20/150
- dynamic allocations are processed after all static reservations has been
done
- moved code for handling static reservations to drivers/of/fdt.c
- removed node matching by string comparison, now phandle values are used
directly
- moved code for DMA and CMA handling directly to
drivers/base/dma-{coherent,contiguous}.c
- added checks for proper #size-cells, #address-cells, ranges properties
in /reserved-memory node
- even more code cleanup
- added init code for ARM64 and PowerPC
v3: http://article.gmane.org/gmane.linux.documentation/20169/
- refactored memory reservation code, created common code to parse reg, size,
align, alloc-ranges properties
- added support for multiple tuples in 'reg' property
- memory is reserved regardless of presence of the driver for its compatible
- prepared arch specific hooks for memory reservation (defaults use memblock
calls)
- removed node matching by string during device initialization
- CMA init code: added checks for required region alignment
- more code cleanup here and there
v2: http://thread.gmane.org/gmane.linux.documentation/19870/
- removed copying of the node name
- split shared-dma-pool handling into separate files (one for CMA and one
for dma_declare_coherent based implementations) for making the code easier
to understand
- added support for AMBA devices, changed prototypes to use struct decice
instead of struct platform_device
- renamed some functions to better match other names used in drivers/of/
- restructured the rest of the code a bit for better readability
- added 'reusable' property to exmaple linux,cma node in documentation
- exclusive dma (dma_coherent) is used for only handling 'shared-dma-pool'
regions without 'reusable' property and CMA is used only for handling
'shared-dma-pool' regions with 'reusable' property.
v1: http://thread.gmane.org/gmane.linux.documentation/19579
- initial version prepared by Josh Cartwright
Summary:
Grant Likely (1):
of: document bindings for reserved-memory nodes
Marek Szyprowski (10):
drivers: of: add initialization code for static reserved memory
drivers: of: add initialization code for dynamic reserved memory
drivers: of: add support for custom reserved memory drivers
drivers: of: add automated assignment of reserved regions to client
devices
drivers: of: initialize and assign reserved memory to newly created
devices
drivers: dma-coherent: add initialization from device tree
drivers: dma-contiguous: add initialization from device tree
arm: add support for reserved memory defined by device tree
arm64: add support for reserved memory defined by device tree
powerpc: add support for reserved memory defined by device tree
.../bindings/reserved-memory/reserved-memory.txt | 138 ++++++++++
arch/arm/Kconfig | 1 +
arch/arm/mm/init.c | 2 +
arch/arm64/Kconfig | 1 +
arch/arm64/mm/init.c | 1 +
arch/powerpc/Kconfig | 1 +
arch/powerpc/kernel/prom.c | 3 +
drivers/base/dma-coherent.c | 41 +++
drivers/base/dma-contiguous.c | 130 +++++++--
drivers/of/Kconfig | 6 +
drivers/of/Makefile | 1 +
drivers/of/fdt.c | 134 +++++++++
drivers/of/of_reserved_mem.c | 291 ++++++++++++++++++++
drivers/of/platform.c | 7 +
include/asm-generic/vmlinux.lds.h | 11 +
include/linux/of_fdt.h | 3 +
include/linux/of_reserved_mem.h | 61 ++++
17 files changed, 810 insertions(+), 22 deletions(-)
create mode 100644 Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
create mode 100644 drivers/of/of_reserved_mem.c
create mode 100644 include/linux/of_reserved_mem.h
--
1.7.9.5
Refactor internal dma_contiguous_init_reserved_mem() function, which
creates CMA area from previously reserved memory region and add support
for handling 'shared-dma-pool' reserved-memory device tree nodes.
Based on previous code provided by Josh Cartwright <[email protected]>
Signed-off-by: Marek Szyprowski <[email protected]>
---
drivers/base/dma-contiguous.c | 130 ++++++++++++++++++++++++++++++++++-------
1 file changed, 108 insertions(+), 22 deletions(-)
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index 165c2c299e57..5dfcc3743d9b 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -182,6 +182,49 @@ static int __init cma_init_reserved_areas(void)
core_initcall(cma_init_reserved_areas);
/**
+ * dma_contiguous_init_reserved_mem() - reserve custom contiguous area
+ * @size: Size of the reserved area (in bytes),
+ * @base: Base address of the reserved area optional, use 0 for any
+ * @limit: End address of the reserved memory (optional, 0 for any).
+ * @res_cma: Pointer to store the created cma region.
+ *
+ * This function reserves memory from early allocator. It should be
+ * called by arch specific code once the early allocator (memblock or bootmem)
+ * has been activated and all other subsystems have already allocated/reserved
+ * memory. This function allows to create custom reserved areas for specific
+ * devices.
+ */
+static int __init dma_contiguous_init_reserved_mem(phys_addr_t size,
+ phys_addr_t base, struct cma **res_cma)
+{
+ struct cma *cma = &cma_areas[cma_area_count];
+ phys_addr_t alignment;
+
+ /* Sanity checks */
+ if (cma_area_count == ARRAY_SIZE(cma_areas)) {
+ pr_err("Not enough slots for CMA reserved regions!\n");
+ return -ENOSPC;
+ }
+
+ if (!size || !memblock_is_region_reserved(base, size))
+ return -EINVAL;
+
+ /* Sanitise input arguments */
+ alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
+ if (ALIGN(base, alignment) != base || ALIGN(size, alignment) != size)
+ return -EINVAL;
+
+ cma->base_pfn = PFN_DOWN(base);
+ cma->count = size >> PAGE_SHIFT;
+ *res_cma = cma;
+ cma_area_count++;
+
+ /* Architecture specific contiguous memory fixup. */
+ dma_contiguous_early_fixup(base, size);
+ return 0;
+}
+
+/**
* dma_contiguous_reserve_area() - reserve custom contiguous area
* @size: Size of the reserved area (in bytes),
* @base: Base address of the reserved area optional, use 0 for any
@@ -197,7 +240,6 @@ core_initcall(cma_init_reserved_areas);
int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
phys_addr_t limit, struct cma **res_cma)
{
- struct cma *cma = &cma_areas[cma_area_count];
phys_addr_t alignment;
int ret = 0;
@@ -205,12 +247,6 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
(unsigned long)size, (unsigned long)base,
(unsigned long)limit);
- /* Sanity checks */
- if (cma_area_count == ARRAY_SIZE(cma_areas)) {
- pr_err("Not enough slots for CMA reserved regions!\n");
- return -ENOSPC;
- }
-
if (!size)
return -EINVAL;
@@ -241,21 +277,12 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
}
}
- /*
- * Each reserved area must be initialised later, when more kernel
- * subsystems (like slab allocator) are available.
- */
- cma->base_pfn = PFN_DOWN(base);
- cma->count = size >> PAGE_SHIFT;
- *res_cma = cma;
- cma_area_count++;
-
- pr_info("CMA: reserved %ld MiB at %08lx\n", (unsigned long)size / SZ_1M,
- (unsigned long)base);
-
- /* Architecture specific contiguous memory fixup. */
- dma_contiguous_early_fixup(base, size);
- return 0;
+ ret = dma_contiguous_init_reserved_mem(size, base, res_cma);
+ if (ret == 0) {
+ pr_info("CMA: reserved %ld MiB at %08lx\n",
+ (unsigned long)size / SZ_1M, (unsigned long)base);
+ return 0;
+ }
err:
pr_err("CMA: failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
return ret;
@@ -357,3 +384,62 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
return true;
}
+
+/*
+ * Support for reserved memory regions defined in device tree
+ */
+#ifdef CONFIG_OF_RESERVED_MEM
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) fmt
+
+static void rmem_cma_device_init(struct reserved_mem *rmem,
+ struct device *dev, struct of_phandle_args *args)
+{
+ struct cma *cma = rmem->priv;
+ dev_set_cma_area(dev, cma);
+}
+
+static const struct reserved_mem_ops rmem_cma_ops = {
+ .device_init = rmem_cma_device_init,
+};
+
+static int __init rmem_cma_setup(struct reserved_mem *rmem,
+ unsigned long node,
+ const char *uname)
+{
+ phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
+ phys_addr_t mask = align - 1;
+ struct cma *cma;
+ int err;
+
+ if (!of_get_flat_dt_prop(node, "reusable", NULL))
+ return -EINVAL;
+
+ if ((rmem->base & mask) || (rmem->size & mask)) {
+ pr_err("Reserved memory: incorrect alignment of CMA region\n");
+ return -EINVAL;
+ }
+
+ err = dma_contiguous_init_reserved_mem(rmem->size, rmem->base, &cma);
+ if (err) {
+ pr_err("Reserved memory: unable to setup CMA region\n");
+ return err;
+ }
+
+ if (of_get_flat_dt_prop(node, "linux,cma-default", NULL))
+ dma_contiguous_set_default(cma);
+
+ rmem->ops = &rmem_cma_ops;
+ rmem->priv = cma;
+
+ pr_info("Reserved memory: created CMA memory pool at %pa, size %ld MiB\n",
+ &rmem->base, (unsigned long)rmem->size / SZ_1M);
+
+ return 0;
+}
+RESERVEDMEM_OF_DECLARE(cma, "shared-dma-pool", rmem_cma_setup);
+#endif
--
1.7.9.5
Enable reserved memory initialization from device tree.
Signed-off-by: Marek Szyprowski <[email protected]>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/kernel/prom.c | 3 +++
2 files changed, 4 insertions(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 957bf344c0f5..3b6617fed8fc 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -90,6 +90,7 @@ config PPC
select BINFMT_ELF
select OF
select OF_EARLY_FLATTREE
+ select OF_RESERVED_MEM
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_DYNAMIC_FTRACE
select HAVE_FUNCTION_TRACER
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index f58c0d3aaeb4..591986215801 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -33,6 +33,7 @@
#include <linux/irq.h>
#include <linux/memblock.h>
#include <linux/of.h>
+#include <linux/of_fdt.h>
#include <asm/prom.h>
#include <asm/rtas.h>
@@ -588,6 +589,8 @@ static void __init early_reserve_mem_dt(void)
memblock_reserve(base, size);
}
}
+
+ early_init_fdt_scan_reserved_mem();
}
static void __init early_reserve_mem(void)
--
1.7.9.5
Add support for handling 'shared-dma-pool' reserved-memory device tree
nodes.
Based on previous code provided by Josh Cartwright <[email protected]>
Signed-off-by: Marek Szyprowski <[email protected]>
---
drivers/base/dma-coherent.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c
index bc256b641027..2343ba5d6d43 100644
--- a/drivers/base/dma-coherent.c
+++ b/drivers/base/dma-coherent.c
@@ -218,3 +218,44 @@ int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
return 0;
}
EXPORT_SYMBOL(dma_mmap_from_coherent);
+
+/*
+ * Support for reserved memory regions defined in device tree
+ */
+#ifdef CONFIG_OF_RESERVED_MEM
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
+
+static void rmem_dma_device_init(struct reserved_mem *rmem,
+ struct device *dev, struct of_phandle_args *args)
+{
+ dma_declare_coherent_memory(dev, rmem->base, rmem->base,
+ rmem->size, DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE);
+}
+
+static void rmem_dma_device_release(struct reserved_mem *rmem,
+ struct device *dev)
+{
+ dma_release_declared_memory(dev);
+}
+
+static const struct reserved_mem_ops rmem_dma_ops = {
+ .device_init = rmem_dma_device_init,
+ .device_release = rmem_dma_device_release,
+};
+
+static int __init rmem_dma_setup(struct reserved_mem *rmem,
+ unsigned long node,
+ const char *uname)
+{
+ if (of_get_flat_dt_prop(node, "reusable", NULL))
+ return -EINVAL;
+
+ rmem->ops = &rmem_dma_ops;
+ pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n",
+ &rmem->base, (unsigned long)rmem->size / SZ_1M);
+ return 0;
+}
+RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup);
+#endif
--
1.7.9.5
Enable reserved memory initialization from device tree.
Signed-off-by: Marek Szyprowski <[email protected]>
---
arch/arm64/Kconfig | 1 +
arch/arm64/mm/init.c | 1 +
2 files changed, 2 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 27bbcfc7202a..6abf15407dca 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -43,6 +43,7 @@ config ARM64
select NO_BOOTMEM
select OF
select OF_EARLY_FLATTREE
+ select OF_RESERVED_MEM
select PERF_USE_VMALLOC
select POWER_RESET
select POWER_SUPPLY
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index d0b4c2efda90..3fb8d50dfdaa 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -160,6 +160,7 @@ void __init arm64_memblock_init(void)
memblock_reserve(base, size);
}
+ early_init_fdt_scan_reserved_mem();
dma_contiguous_reserve(0);
memblock_allow_resize();
--
1.7.9.5
Enable reserved memory initialization from device tree.
Signed-off-by: Marek Szyprowski <[email protected]>
---
arch/arm/Kconfig | 1 +
arch/arm/mm/init.c | 2 ++
2 files changed, 3 insertions(+)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e25419817791..d0262bea8020 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1918,6 +1918,7 @@ config USE_OF
select IRQ_DOMAIN
select OF
select OF_EARLY_FLATTREE
+ select OF_RESERVED_MEM
help
Include support for flattened device tree machine descriptions.
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 804d61566a53..2a77ba8796ae 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -323,6 +323,8 @@ void __init arm_memblock_init(struct meminfo *mi,
if (mdesc->reserve)
mdesc->reserve();
+ early_init_fdt_scan_reserved_mem();
+
/*
* reserve memory for DMA contigouos allocations,
* must come from DMA area inside low memory
--
1.7.9.5
From: Grant Likely <[email protected]>
Reserved memory nodes allow for the reservation of static (fixed
address) regions, or dynamically allocated regions for a specific
purpose.
Signed-off-by: Grant Likely <[email protected]>
[joshc: Based on binding document proposed (in non-patch form) here:
http://lkml.kernel.org/g/[email protected]
adapted to support #memory-region-cells]
Signed-off-by: Josh Cartwright <[email protected]>
Signed-off-by: Marek Szyprowski <[email protected]>
---
.../bindings/reserved-memory/reserved-memory.txt | 138 ++++++++++++++++++++
1 file changed, 138 insertions(+)
create mode 100644 Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
new file mode 100644
index 000000000000..a606ce90c9c4
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
@@ -0,0 +1,138 @@
+*** Reserved memory regions ***
+
+Reserved memory is specified as a node under the /reserved-memory node.
+The operating system shall exclude reserved memory from normal usage
+one can create child nodes describing particular reserved (excluded from
+normal use) memory regions. Such memory regions are usually designed for
+the special usage by various device drivers.
+
+Parameters for each memory region can be encoded into the device tree
+with the following nodes:
+
+/reserved-memory node
+---------------------
+#address-cells, #size-cells (required) - standard definition
+ - Should use the same values as the root node
+#memory-region-cells (required) - dictates number of cells used in the child
+ nodes memory-region specifier
+ranges (required) - standard definition
+ - Should be empty
+
+/reserved-memory/ child nodes
+-----------------------------
+Each child of the reserved-memory node specifies one or more regions of
+reserved memory. Each child node may either use a 'reg' property to
+specify a specific range of reserved memory, or a 'size' property with
+optional constraints to request a dynamically allocated block of memory.
+
+Following the generic-names recommended practice, node names should
+reflect the purpose of the node (ie. "framebuffer" or "dma-pool"). Unit
+address (@<address>) should be appended to the name if the node is a
+static allocation.
+
+Properties:
+Requires either a) or b) below.
+a) static allocation
+ reg (required) - standard definition
+b) dynamic allocation
+ size (required) - length based on parent's #size-cells
+ - Size in bytes of memory to reserve.
+ alignment (optional) - length based on parent's #size-cells
+ - Address boundary for alignment of allocation.
+ alloc-ranges (optional) - prop-encoded-array (address, length pairs).
+ - Specifies regions of memory that are
+ acceptable to allocate from.
+
+If both reg and size are present, then the reg property takes precedence
+and size is ignored.
+
+Additional properties:
+compatible (optional) - standard definition
+ - may contain the following strings:
+ - shared-dma-pool: This indicates a region of memory meant to be
+ used as a shared pool of DMA buffers for a set of devices. It can
+ be used by an operating system to instanciate the necessary pool
+ management subsystem if necessary.
+ - vendor specific string in the form <vendor>,[<device>-]<usage>
+no-map (optional) - empty property
+ - Indicates the operating system must not create a virtual mapping
+ of the region as part of its standard mapping of system memory,
+ nor permit speculative access to it under any circumstances other
+ than under the control of the device driver using the region.
+reusable (optional) - empty property
+ - The operating system can use the memory in this region with the
+ limitation that the device driver(s) owning the region need to be
+ able to reclaim it back. Typically that means that the operating
+ system can use that region to store volatile or cached data that
+ can be otherwise regenerated or migrated elsewhere.
+
+Linux implementation note:
+- If a "linux,cma-default" property is present, then Linux will use the
+ region for the default pool of the contiguous memory allocator.
+
+Device node references to reserved memory
+-----------------------------------------
+Regions in the /reserved-memory node may be referenced by other device
+nodes by adding a memory-region property to the device node.
+
+memory-region (optional) - phandle, specifier pairs to children of /reserved-memory
+
+Example
+-------
+This example defines 3 contiguous regions are defined for Linux kernel:
+one default of all device drivers (named linux,cma@72000000 and 64MiB in size),
+one dedicated to the framebuffer device (named framebuffer@78000000, 8MiB), and
+one for multimedia processing (named multimedia-memory@77000000, 64MiB).
+
+/ {
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ memory {
+ reg = <0x40000000 0x40000000>;
+ };
+
+ reserved-memory {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges;
+
+ /* global autoconfigured region for contiguous allocations */
+ linux,cma {
+ compatible = "shared-dma-pool";
+ reusable;
+ #memory-region-cells = <0>;
+ size = <0x4000000>;
+ alignment = <0x2000>;
+ linux,cma-default;
+ };
+
+ display_reserved: framebuffer@78000000 {
+ #memory-region-cells = <0>;
+ reg = <0x78000000 0x800000>;
+ };
+
+ multimedia_reserved: multimedia@77000000 {
+ compatible = "acme,multimedia-memory";
+ #memory-region-cells = <1>;
+ reg = <0x77000000 0x4000000>;
+ };
+ };
+
+ /* ... */
+
+ fb0: video@12300000 {
+ memory-region = <&display_reserved>;
+ /* ... */
+ };
+
+ scaler: scaler@12500000 {
+ memory-region = <&multimedia_reserved 0xdeadbeef>;
+ /* ... */
+ };
+
+ codec: codec@12600000 {
+ memory-region = <&multimedia_reserved 0xfeebdaed>;
+ /* ... */
+ };
+};
--
1.7.9.5
Use recently introduced of_reserved_mem_device_init() function to
automatically assign respective reserved memory region to the newly created
platform and amba device.
Signed-off-by: Marek Szyprowski <[email protected]>
---
drivers/of/platform.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 404d1daebefa..3df0b1826e8b 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -21,6 +21,7 @@
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
+#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
const struct of_device_id of_default_bus_match_table[] = {
@@ -220,6 +221,8 @@ static struct platform_device *of_platform_device_create_pdata(
dev->dev.bus = &platform_bus_type;
dev->dev.platform_data = platform_data;
+ of_reserved_mem_device_init(&dev->dev);
+
/* We do not fill the DMA ops for platform devices by default.
* This is currently the responsibility of the platform code
* to do such, possibly using a device notifier
@@ -227,6 +230,7 @@ static struct platform_device *of_platform_device_create_pdata(
if (of_device_add(dev) != 0) {
platform_device_put(dev);
+ of_reserved_mem_device_release(&dev->dev);
return NULL;
}
@@ -282,6 +286,8 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
else
of_device_make_bus_id(&dev->dev);
+ of_reserved_mem_device_init(&dev->dev);
+
/* Allow the HW Peripheral ID to be overridden */
prop = of_get_property(node, "arm,primecell-periphid", NULL);
if (prop)
@@ -308,6 +314,7 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
return dev;
err_free:
+ of_reserved_mem_device_release(&dev->dev);
amba_device_put(dev);
return NULL;
}
--
1.7.9.5
This patch adds code for automated assignment of reserved memory regions
to struct device. reserved_mem->ops->device_init()/device_cleanup()
callbacks are called to perform reserved memory driver specific
initialization and cleanup. The code looks for 'memory-region' property
in the client device node and assigns region pointed by the found
phandle.
Based on previous code provided by Josh Cartwright <[email protected]>
Signed-off-by: Marek Szyprowski <[email protected]>
---
drivers/of/of_reserved_mem.c | 74 +++++++++++++++++++++++++++++++++++++++
include/linux/of_reserved_mem.h | 7 ++++
2 files changed, 81 insertions(+)
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 97de6f882f85..b02a7f0a54c8 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -206,8 +206,16 @@ void __init fdt_init_reserved_mem(void)
for (i = 0; i < reserved_mem_count; i++) {
struct reserved_mem *rmem = &reserved_mem[i];
unsigned long node = rmem->fdt_node;
+ unsigned long len;
+ __be32 *prop;
int err = 0;
+ prop = of_get_flat_dt_prop(node, "phandle", &len);
+ if (!prop)
+ prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
+ if (prop)
+ rmem->phandle = of_read_number(prop, len/4);
+
if (rmem->size == 0)
err = __reserved_mem_alloc_size(node, rmem->name,
&rmem->base, &rmem->size);
@@ -215,3 +223,69 @@ void __init fdt_init_reserved_mem(void)
__reserved_mem_init_node(rmem);
}
}
+
+static inline struct reserved_mem *__find_rmem(struct device_node *node)
+{
+ unsigned int i;
+
+ if (!node->phandle)
+ return NULL;
+
+ for (i = 0; i < reserved_mem_count; i++)
+ if (reserved_mem[i].phandle == node->phandle)
+ return &reserved_mem[i];
+ return NULL;
+}
+
+/**
+ * of_reserved_mem_device_init() - assign reserved memory region to given device
+ *
+ * This function assign memory region pointed by "memory-region" device tree
+ * property to the given device.
+ */
+void of_reserved_mem_device_init(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct reserved_mem *rmem;
+ struct of_phandle_args s;
+ unsigned int i;
+
+ for (i = 0; of_parse_phandle_with_args(np, "memory-region",
+ "#memory-region-cells", i, &s) == 0; i++) {
+
+ rmem = __find_rmem(s.np);
+ if (!rmem || !rmem->ops || !rmem->ops->device_init) {
+ of_node_put(s.np);
+ continue;
+ }
+
+ rmem->ops->device_init(rmem, dev, &s);
+ dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
+ of_node_put(s.np);
+ break;
+ }
+}
+
+/**
+ * of_reserved_mem_device_release() - release reserved memory device structures
+ *
+ * This function releases structures allocated for memory region handling for
+ * the given device.
+ */
+void of_reserved_mem_device_release(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct reserved_mem *rmem;
+ struct of_phandle_args s;
+ unsigned int i;
+
+ for (i = 0; of_parse_phandle_with_args(np, "memory-region",
+ "#memory-region-cells", i, &s) == 0; i++) {
+
+ rmem = __find_rmem(s.np);
+ if (rmem && rmem->ops && rmem->ops->device_release)
+ rmem->ops->device_release(rmem, dev);
+
+ of_node_put(s.np);
+ }
+}
diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
index f707176619a3..a2a25de297de 100644
--- a/include/linux/of_reserved_mem.h
+++ b/include/linux/of_reserved_mem.h
@@ -8,6 +8,7 @@ struct reserved_mem_ops;
struct reserved_mem {
const char *name;
unsigned long fdt_node;
+ unsigned long phandle;
const struct reserved_mem_ops *ops;
phys_addr_t base;
phys_addr_t size;
@@ -26,6 +27,9 @@ typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem,
unsigned long node, const char *uname);
#ifdef CONFIG_OF_RESERVED_MEM
+void of_reserved_mem_device_init(struct device *dev);
+void of_reserved_mem_device_release(struct device *dev);
+
void fdt_init_reserved_mem(void);
void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
phys_addr_t base, phys_addr_t size);
@@ -38,6 +42,9 @@ void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
init : init }
#else
+static inline void of_reserved_mem_device_init(struct device *dev) { }
+static inline void of_reserved_mem_device_release(struct device *pdev) { }
+
static inline void fdt_init_reserved_mem(void) { }
static inline void fdt_reserved_mem_save_node(unsigned long node,
const char *uname, phys_addr_t base, phys_addr_t size) { }
--
1.7.9.5
Add support for custom reserved memory drivers. Call their init() function
for each reserved region and prepare for using operations provided by them
with by the reserved_mem->ops array.
Based on previous code provided by Josh Cartwright <[email protected]>
Signed-off-by: Marek Szyprowski <[email protected]>
---
drivers/of/of_reserved_mem.c | 29 +++++++++++++++++++++++++++++
include/asm-generic/vmlinux.lds.h | 11 +++++++++++
include/linux/of_reserved_mem.h | 33 +++++++++++++++++++++++++++++++++
3 files changed, 73 insertions(+)
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index c7ca6a4a42d1..97de6f882f85 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -170,6 +170,33 @@ static int __init __reserved_mem_alloc_size(unsigned long node,
return 0;
}
+static const struct of_device_id __rmem_of_table_sentinel
+ __used __section(__reservedmem_of_table_end);
+
+/**
+ * res_mem_init_node() - call region specific reserved memory init code
+ */
+static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
+{
+ extern const struct of_device_id __reservedmem_of_table[];
+ const struct of_device_id *i;
+
+ for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
+ reservedmem_of_init_fn initfn = i->data;
+ const char *compat = i->compatible;
+
+ if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
+ continue;
+
+ if (initfn(rmem, rmem->fdt_node, rmem->name) == 0) {
+ pr_info("Reserved memory: initialized node %s, compatible id %s\n",
+ rmem->name, compat);
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
/**
* fdt_init_reserved_mem - allocate and init all saved reserved memory regions
*/
@@ -184,5 +211,7 @@ void __init fdt_init_reserved_mem(void)
if (rmem->size == 0)
err = __reserved_mem_alloc_size(node, rmem->name,
&rmem->base, &rmem->size);
+ if (err == 0)
+ __reserved_mem_init_node(rmem);
}
}
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index bc2121fa9132..f10f64fcc815 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -167,6 +167,16 @@
#define CLK_OF_TABLES()
#endif
+#ifdef CONFIG_OF_RESERVED_MEM
+#define RESERVEDMEM_OF_TABLES() \
+ . = ALIGN(8); \
+ VMLINUX_SYMBOL(__reservedmem_of_table) = .; \
+ *(__reservedmem_of_table) \
+ *(__reservedmem_of_table_end)
+#else
+#define RESERVEDMEM_OF_TABLES()
+#endif
+
#define KERNEL_DTB() \
STRUCT_ALIGN(); \
VMLINUX_SYMBOL(__dtb_start) = .; \
@@ -490,6 +500,7 @@
TRACE_SYSCALLS() \
MEM_DISCARD(init.rodata) \
CLK_OF_TABLES() \
+ RESERVEDMEM_OF_TABLES() \
CLKSRC_OF_TABLES() \
KERNEL_DTB() \
IRQCHIP_OF_MATCH_TABLE()
diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
index 89226ed7d954..f707176619a3 100644
--- a/include/linux/of_reserved_mem.h
+++ b/include/linux/of_reserved_mem.h
@@ -1,21 +1,54 @@
#ifndef __OF_RESERVED_MEM_H
#define __OF_RESERVED_MEM_H
+struct device;
+struct of_phandle_args;
+struct reserved_mem_ops;
+
struct reserved_mem {
const char *name;
unsigned long fdt_node;
+ const struct reserved_mem_ops *ops;
phys_addr_t base;
phys_addr_t size;
+ void *priv;
+};
+
+struct reserved_mem_ops {
+ void (*device_init)(struct reserved_mem *rmem,
+ struct device *dev,
+ struct of_phandle_args *args);
+ void (*device_release)(struct reserved_mem *rmem,
+ struct device *dev);
};
+typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem,
+ unsigned long node, const char *uname);
+
#ifdef CONFIG_OF_RESERVED_MEM
void fdt_init_reserved_mem(void);
void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
phys_addr_t base, phys_addr_t size);
+
+#define RESERVEDMEM_OF_DECLARE(name, compat, init) \
+ static const struct of_device_id __reservedmem_of_table_##name \
+ __used __section(__reservedmem_of_table) \
+ = { .compatible = compat, \
+ .data = (init == (reservedmem_of_init_fn)NULL) ? \
+ init : init }
+
#else
static inline void fdt_init_reserved_mem(void) { }
static inline void fdt_reserved_mem_save_node(unsigned long node,
const char *uname, phys_addr_t base, phys_addr_t size) { }
+
+#define RESERVEDMEM_OF_DECLARE(name, compat, init) \
+ static const struct of_device_id __reservedmem_of_table_##name \
+ __attribute__((unused)) \
+ = { .compatible = compat, \
+ .data = (init == (reservedmem_of_init_fn)NULL) ? \
+ init : init }
+
#endif
#endif /* __OF_RESERVED_MEM_H */
--
1.7.9.5
This patch adds support for dynamically allocated reserved memory regions
declared in device tree. Such regions are defined by 'size', 'alignment'
and 'alloc-ranges' properties.
Based on previous code provided by Josh Cartwright <[email protected]>
Signed-off-by: Marek Szyprowski <[email protected]>
---
drivers/of/Kconfig | 6 ++
drivers/of/Makefile | 1 +
drivers/of/fdt.c | 13 ++-
drivers/of/of_reserved_mem.c | 188 +++++++++++++++++++++++++++++++++++++++
include/linux/of_reserved_mem.h | 21 +++++
5 files changed, 227 insertions(+), 2 deletions(-)
create mode 100644 drivers/of/of_reserved_mem.c
create mode 100644 include/linux/of_reserved_mem.h
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index c6973f101a3e..30a7d87a8077 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -75,4 +75,10 @@ config OF_MTD
depends on MTD
def_bool y
+config OF_RESERVED_MEM
+ depends on OF_EARLY_FLATTREE
+ bool
+ help
+ Helpers to allow for reservation of memory regions
+
endmenu # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index efd05102c405..ed9660adad77 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_OF_MDIO) += of_mdio.o
obj-$(CONFIG_OF_PCI) += of_pci.o
obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o
obj-$(CONFIG_OF_MTD) += of_mtd.o
+obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 12809e20ef71..eafe5805257a 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -15,6 +15,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/slab.h>
@@ -449,7 +450,7 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
phys_addr_t base, size;
unsigned long len;
__be32 *prop;
- int nomap;
+ int nomap, first = 1;
prop = of_get_flat_dt_prop(node, "reg", &len);
if (!prop)
@@ -476,6 +477,10 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
uname, &base, (unsigned long)size / SZ_1M);
len -= t_len;
+ if (first) {
+ fdt_reserved_mem_save_node(node, uname, base, size);
+ first = 0;
+ }
}
return 0;
}
@@ -506,6 +511,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
{
static int found;
const char *status;
+ int err;
if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
if (__reserved_mem_check_root(node) != 0) {
@@ -528,7 +534,9 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
return 0;
- __reserved_mem_reserve_reg(node, uname);
+ err = __reserved_mem_reserve_reg(node, uname);
+ if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
+ fdt_reserved_mem_save_node(node, uname, 0, 0);
/* scan next node */
return 0;
@@ -544,6 +552,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
void __init early_init_fdt_scan_reserved_mem(void)
{
of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
+ fdt_init_reserved_mem();
}
/**
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
new file mode 100644
index 000000000000..c7ca6a4a42d1
--- /dev/null
+++ b/drivers/of/of_reserved_mem.c
@@ -0,0 +1,188 @@
+/*
+ * Device tree based initialization code for reserved memory.
+ *
+ * Copyright (c) 2013, The Linux Foundation. All Rights Reserved.
+ * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com
+ * Author: Marek Szyprowski <[email protected]>
+ * Author: Josh Cartwright <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License or (at your optional) any later version of the license.
+ */
+
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+#include <linux/mm.h>
+#include <linux/sizes.h>
+#include <linux/of_reserved_mem.h>
+
+#define MAX_RESERVED_REGIONS 16
+static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
+static int reserved_mem_count;
+
+#if defined(CONFIG_HAVE_MEMBLOCK)
+#include <linux/memblock.h>
+int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
+ phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
+ phys_addr_t *res_base)
+{
+ /*
+ * We use __memblock_alloc_base() because memblock_alloc_base()
+ * panic()s on allocation failure.
+ */
+ phys_addr_t base = __memblock_alloc_base(size, align, end);
+ if (!base)
+ return -ENOMEM;
+
+ /*
+ * Check if the allocated region fits in to start..end window
+ */
+ if (base < start) {
+ memblock_free(base, size);
+ return -ENOMEM;
+ }
+
+ *res_base = base;
+ if (nomap)
+ return memblock_remove(base, size);
+ return 0;
+}
+#else
+int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
+ phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
+ phys_addr_t *res_base)
+{
+ pr_error("Reserved memory not supported, ignoring region 0x%llx%s\n",
+ size, nomap ? " (nomap)" : "");
+ return -ENOSYS;
+}
+#endif
+
+/**
+ * res_mem_save_node() - save fdt node for second pass initialization
+ */
+void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
+ phys_addr_t base, phys_addr_t size)
+{
+ struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
+
+ if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
+ pr_err("Reserved memory: not enough space all defined regions.\n");
+ return;
+ }
+
+ rmem->fdt_node = node;
+ rmem->name = uname;
+ rmem->base = base;
+ rmem->size = size;
+
+ reserved_mem_count++;
+ return;
+}
+
+/**
+ * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
+ * and 'alloc-ranges' properties
+ */
+static int __init __reserved_mem_alloc_size(unsigned long node,
+ const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
+{
+ int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+ phys_addr_t start = 0, end = 0;
+ phys_addr_t base = 0, align = 0, size;
+ unsigned long len;
+ __be32 *prop;
+ int nomap;
+ int ret;
+
+ prop = of_get_flat_dt_prop(node, "size", &len);
+ if (!prop)
+ return -EINVAL;
+
+ if (len != dt_root_size_cells * sizeof(__be32)) {
+ pr_err("Reserved memory: invalid size property in '%s' node.\n",
+ uname);
+ return -EINVAL;
+ }
+ size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+ nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+ prop = of_get_flat_dt_prop(node, "alignment", &len);
+ if (prop) {
+ if (len != dt_root_addr_cells * sizeof(__be32)) {
+ pr_err("Reserved memory: invalid alignment property in '%s' node.\n",
+ uname);
+ return -EINVAL;
+ }
+ align = dt_mem_next_cell(dt_root_addr_cells, &prop);
+ }
+
+ prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
+ if (prop) {
+
+ if (len % t_len != 0) {
+ pr_err("Reserved memory: invalid alloc-ranges property in '%s', skipping node.\n",
+ uname);
+ return -EINVAL;
+ }
+
+ base = 0;
+
+ while (len > 0) {
+ start = dt_mem_next_cell(dt_root_addr_cells, &prop);
+ end = start + dt_mem_next_cell(dt_root_size_cells,
+ &prop);
+
+ ret = early_init_dt_alloc_reserved_memory_arch(size,
+ align, start, end, nomap, &base);
+ if (ret == 0) {
+ pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
+ uname, &base,
+ (unsigned long)size / SZ_1M);
+ break;
+ }
+ len -= t_len;
+ }
+
+ } else {
+ ret = early_init_dt_alloc_reserved_memory_arch(size, align,
+ 0, 0, nomap, &base);
+ if (ret == 0)
+ pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
+ uname, &base, (unsigned long)size / SZ_1M);
+ }
+
+ if (base == 0) {
+ pr_info("Reserved memory: failed to allocate memory for node '%s'\n",
+ uname);
+ return -ENOMEM;
+ }
+
+ *res_base = base;
+ *res_size = size;
+
+ return 0;
+}
+
+/**
+ * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
+ */
+void __init fdt_init_reserved_mem(void)
+{
+ int i;
+ for (i = 0; i < reserved_mem_count; i++) {
+ struct reserved_mem *rmem = &reserved_mem[i];
+ unsigned long node = rmem->fdt_node;
+ int err = 0;
+
+ if (rmem->size == 0)
+ err = __reserved_mem_alloc_size(node, rmem->name,
+ &rmem->base, &rmem->size);
+ }
+}
diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
new file mode 100644
index 000000000000..89226ed7d954
--- /dev/null
+++ b/include/linux/of_reserved_mem.h
@@ -0,0 +1,21 @@
+#ifndef __OF_RESERVED_MEM_H
+#define __OF_RESERVED_MEM_H
+
+struct reserved_mem {
+ const char *name;
+ unsigned long fdt_node;
+ phys_addr_t base;
+ phys_addr_t size;
+};
+
+#ifdef CONFIG_OF_RESERVED_MEM
+void fdt_init_reserved_mem(void);
+void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
+ phys_addr_t base, phys_addr_t size);
+#else
+static inline void fdt_init_reserved_mem(void) { }
+static inline void fdt_reserved_mem_save_node(unsigned long node,
+ const char *uname, phys_addr_t base, phys_addr_t size) { }
+#endif
+
+#endif /* __OF_RESERVED_MEM_H */
--
1.7.9.5
This patch adds support for static (defined by 'reg' property) reserved
memory regions declared in device tree.
Memory blocks can be reliably reserved only during early boot. This must
happen before the whole memory management subsystem is initialized,
because we need to ensure that the given contiguous blocks are not yet
allocated by kernel. Also it must happen before kernel mappings for the
whole low memory are created, to ensure that there will be no mappings
(for reserved blocks). Typically, all this happens before device tree
structures are unflattened, so we need to get reserved memory layout
directly from fdt.
Based on previous code provided by Josh Cartwright <[email protected]>
Signed-off-by: Marek Szyprowski <[email protected]>
---
drivers/of/fdt.c | 125 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of_fdt.h | 3 ++
2 files changed, 128 insertions(+)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 758b4f8b30b7..12809e20ef71 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -440,6 +440,113 @@ struct boot_param_header *initial_boot_params;
#ifdef CONFIG_OF_EARLY_FLATTREE
/**
+ * res_mem_reserve_reg() - reserve all memory described in 'reg' property
+ */
+static int __init __reserved_mem_reserve_reg(unsigned long node,
+ const char *uname)
+{
+ int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+ phys_addr_t base, size;
+ unsigned long len;
+ __be32 *prop;
+ int nomap;
+
+ prop = of_get_flat_dt_prop(node, "reg", &len);
+ if (!prop)
+ return -ENOENT;
+
+ if (len && len % t_len != 0) {
+ pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
+ uname);
+ return -EINVAL;
+ }
+
+ nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+ while (len > 0) {
+ base = dt_mem_next_cell(dt_root_addr_cells, &prop);
+ size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+ if (base && size &&
+ early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
+ pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
+ uname, &base, (unsigned long)size / SZ_1M);
+ else
+ pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
+ uname, &base, (unsigned long)size / SZ_1M);
+
+ len -= t_len;
+ }
+ return 0;
+}
+
+static int __reserved_mem_check_root(unsigned long node)
+{
+ __be32 *prop;
+
+ prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+ if (prop && be32_to_cpup(prop) != dt_root_size_cells)
+ return -EINVAL;
+
+ prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+ if (prop && be32_to_cpup(prop) != dt_root_addr_cells)
+ return -EINVAL;
+
+ prop = of_get_flat_dt_prop(node, "ranges", NULL);
+ if (!prop)
+ return -EINVAL;
+ return 0;
+}
+
+/**
+ * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
+ */
+static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
+ int depth, void *data)
+{
+ static int found;
+ const char *status;
+
+ if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
+ if (__reserved_mem_check_root(node) != 0) {
+ pr_err("Reserved memory: unsupported node format, ignoring\n");
+ /* break scan */
+ return 1;
+ }
+ found = 1;
+ /* scan next node */
+ return 0;
+ } else if (!found) {
+ /* scan next node */
+ return 0;
+ } else if (found && depth < 2) {
+ /* scanning of /reserved-memory has been finished */
+ return 1;
+ }
+
+ status = of_get_flat_dt_prop(node, "status", NULL);
+ if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
+ return 0;
+
+ __reserved_mem_reserve_reg(node, uname);
+
+ /* scan next node */
+ return 0;
+}
+
+/**
+ * early_init_fdt_scan_reserved_mem() - create reserved memory regions
+ *
+ * This function grabs memory from early allocator for device exclusive use
+ * defined in device tree structures. It should be called by arch specific code
+ * once the early allocator (i.e. memblock) has been fully activated.
+ */
+void __init early_init_fdt_scan_reserved_mem(void)
+{
+ of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
+}
+
+/**
* of_scan_flat_dt - scan flattened tree blob and call callback on each.
* @it: callback function
* @data: context data pointer
@@ -856,6 +963,16 @@ void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
memblock_add(base, size);
}
+int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
+ phys_addr_t size, bool nomap)
+{
+ if (memblock_is_region_reserved(base, size))
+ return -EBUSY;
+ if (nomap)
+ return memblock_remove(base, size);
+ return memblock_reserve(base, size);
+}
+
/*
* called from unflatten_device_tree() to bootstrap devicetree itself
* Architectures can override this definition if memblock isn't used
@@ -864,6 +981,14 @@ void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
{
return __va(memblock_alloc(size, align));
}
+#else
+int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
+ phys_addr_t size, bool nomap)
+{
+ pr_error("Reserved memory not supported, ignoring range 0x%llx - 0x%llx%s\n",
+ base, size, nomap ? " (nomap)" : "");
+ return -ENOSYS;
+}
#endif
bool __init early_init_dt_scan(void *params)
diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
index 2b77058a7335..8610ad8d77d2 100644
--- a/include/linux/of_fdt.h
+++ b/include/linux/of_fdt.h
@@ -98,7 +98,10 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
int depth, void *data);
extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
int depth, void *data);
+extern void early_init_fdt_scan_reserved_mem(void);
extern void early_init_dt_add_memory_arch(u64 base, u64 size);
+extern int early_init_dt_reserve_memory_arch(phys_addr_t base, phys_addr_t size,
+ bool no_map);
extern void * early_init_dt_alloc_memory_arch(u64 size, u64 align);
extern u64 dt_mem_next_cell(int s, __be32 **cellp);
--
1.7.9.5
On Fri, 21 Feb 2014 13:25:17 +0100, Marek Szyprowski <[email protected]> wrote:
> From: Grant Likely <[email protected]>
>
> Reserved memory nodes allow for the reservation of static (fixed
> address) regions, or dynamically allocated regions for a specific
> purpose.
>
> Signed-off-by: Grant Likely <[email protected]>
> [joshc: Based on binding document proposed (in non-patch form) here:
> http://lkml.kernel.org/g/[email protected]
> adapted to support #memory-region-cells]
> Signed-off-by: Josh Cartwright <[email protected]>
> Signed-off-by: Marek Szyprowski <[email protected]>
> ---
> .../bindings/reserved-memory/reserved-memory.txt | 138 ++++++++++++++++++++
> 1 file changed, 138 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
>
> diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
> new file mode 100644
> index 000000000000..a606ce90c9c4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
> @@ -0,0 +1,138 @@
> +*** Reserved memory regions ***
> +
> +Reserved memory is specified as a node under the /reserved-memory node.
> +The operating system shall exclude reserved memory from normal usage
> +one can create child nodes describing particular reserved (excluded from
> +normal use) memory regions. Such memory regions are usually designed for
> +the special usage by various device drivers.
> +
> +Parameters for each memory region can be encoded into the device tree
> +with the following nodes:
> +
> +/reserved-memory node
> +---------------------
> +#address-cells, #size-cells (required) - standard definition
> + - Should use the same values as the root node
> +#memory-region-cells (required) - dictates number of cells used in the child
> + nodes memory-region specifier
I still don't like this portion of the binding. I'm not convinced that
it is necessary in the majority of cases and it is going to be very
driver specific. I would rather drop it entirely from the common
binding. If a specific driver needs to do something like the above then
it can have a driver specific binding. Otherwise I think the default
should be a simple phandle with no arguments to a single reserved memory
node.
Ben, can you weigh in on the current state of this document. I'm mostly
happy with it aside from my comment above. Do you think this is ready to
be merged?
> +ranges (required) - standard definition
> + - Should be empty
> +
> +/reserved-memory/ child nodes
> +-----------------------------
> +Each child of the reserved-memory node specifies one or more regions of
> +reserved memory. Each child node may either use a 'reg' property to
> +specify a specific range of reserved memory, or a 'size' property with
> +optional constraints to request a dynamically allocated block of memory.
> +
> +Following the generic-names recommended practice, node names should
> +reflect the purpose of the node (ie. "framebuffer" or "dma-pool"). Unit
> +address (@<address>) should be appended to the name if the node is a
> +static allocation.
> +
> +Properties:
> +Requires either a) or b) below.
> +a) static allocation
> + reg (required) - standard definition
> +b) dynamic allocation
> + size (required) - length based on parent's #size-cells
> + - Size in bytes of memory to reserve.
> + alignment (optional) - length based on parent's #size-cells
> + - Address boundary for alignment of allocation.
> + alloc-ranges (optional) - prop-encoded-array (address, length pairs).
> + - Specifies regions of memory that are
> + acceptable to allocate from.
> +
> +If both reg and size are present, then the reg property takes precedence
> +and size is ignored.
> +
> +Additional properties:
> +compatible (optional) - standard definition
> + - may contain the following strings:
> + - shared-dma-pool: This indicates a region of memory meant to be
> + used as a shared pool of DMA buffers for a set of devices. It can
> + be used by an operating system to instanciate the necessary pool
> + management subsystem if necessary.
> + - vendor specific string in the form <vendor>,[<device>-]<usage>
Add "Use vendor strings to identify regions dedicates for a specific
vendor device. For example: 'acme,framebuffer'. Platform code can use vendor
strings to identify device specific regions"
> +no-map (optional) - empty property
> + - Indicates the operating system must not create a virtual mapping
> + of the region as part of its standard mapping of system memory,
> + nor permit speculative access to it under any circumstances other
> + than under the control of the device driver using the region.
> +reusable (optional) - empty property
> + - The operating system can use the memory in this region with the
> + limitation that the device driver(s) owning the region need to be
> + able to reclaim it back. Typically that means that the operating
> + system can use that region to store volatile or cached data that
> + can be otherwise regenerated or migrated elsewhere.
> +
> +Linux implementation note:
> +- If a "linux,cma-default" property is present, then Linux will use the
> + region for the default pool of the contiguous memory allocator.
> +
> +Device node references to reserved memory
> +-----------------------------------------
> +Regions in the /reserved-memory node may be referenced by other device
> +nodes by adding a memory-region property to the device node.
> +
> +memory-region (optional) - phandle, specifier pairs to children of /reserved-memory
> +
> +Example
> +-------
> +This example defines 3 contiguous regions are defined for Linux kernel:
> +one default of all device drivers (named linux,cma@72000000 and 64MiB in size),
> +one dedicated to the framebuffer device (named framebuffer@78000000, 8MiB), and
> +one for multimedia processing (named multimedia-memory@77000000, 64MiB).
> +
> +/ {
> + #address-cells = <1>;
> + #size-cells = <1>;
> +
> + memory {
> + reg = <0x40000000 0x40000000>;
> + };
> +
> + reserved-memory {
> + #address-cells = <1>;
> + #size-cells = <1>;
> + ranges;
> +
> + /* global autoconfigured region for contiguous allocations */
> + linux,cma {
> + compatible = "shared-dma-pool";
> + reusable;
> + #memory-region-cells = <0>;
> + size = <0x4000000>;
> + alignment = <0x2000>;
> + linux,cma-default;
> + };
> +
> + display_reserved: framebuffer@78000000 {
> + #memory-region-cells = <0>;
> + reg = <0x78000000 0x800000>;
> + };
> +
> + multimedia_reserved: multimedia@77000000 {
> + compatible = "acme,multimedia-memory";
> + #memory-region-cells = <1>;
> + reg = <0x77000000 0x4000000>;
> + };
> + };
> +
> + /* ... */
> +
> + fb0: video@12300000 {
> + memory-region = <&display_reserved>;
> + /* ... */
> + };
> +
> + scaler: scaler@12500000 {
> + memory-region = <&multimedia_reserved 0xdeadbeef>;
> + /* ... */
> + };
> +
> + codec: codec@12600000 {
> + memory-region = <&multimedia_reserved 0xfeebdaed>;
> + /* ... */
> + };
> +};
> --
> 1.7.9.5
>
On Fri, 21 Feb 2014 13:25:18 +0100, Marek Szyprowski <[email protected]> wrote:
> This patch adds support for static (defined by 'reg' property) reserved
> memory regions declared in device tree.
>
> Memory blocks can be reliably reserved only during early boot. This must
> happen before the whole memory management subsystem is initialized,
> because we need to ensure that the given contiguous blocks are not yet
> allocated by kernel. Also it must happen before kernel mappings for the
> whole low memory are created, to ensure that there will be no mappings
> (for reserved blocks). Typically, all this happens before device tree
> structures are unflattened, so we need to get reserved memory layout
> directly from fdt.
>
> Based on previous code provided by Josh Cartwright <[email protected]>
>
> Signed-off-by: Marek Szyprowski <[email protected]>
> ---
> drivers/of/fdt.c | 125 ++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/of_fdt.h | 3 ++
> 2 files changed, 128 insertions(+)
>
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index 758b4f8b30b7..12809e20ef71 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -440,6 +440,113 @@ struct boot_param_header *initial_boot_params;
> #ifdef CONFIG_OF_EARLY_FLATTREE
>
> /**
> + * res_mem_reserve_reg() - reserve all memory described in 'reg' property
> + */
> +static int __init __reserved_mem_reserve_reg(unsigned long node,
> + const char *uname)
> +{
> + int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
> + phys_addr_t base, size;
> + unsigned long len;
> + __be32 *prop;
> + int nomap;
> +
> + prop = of_get_flat_dt_prop(node, "reg", &len);
> + if (!prop)
> + return -ENOENT;
> +
> + if (len && len % t_len != 0) {
> + pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
> + uname);
> + return -EINVAL;
> + }
> +
> + nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
> +
> + while (len > 0) {
This is safer: while (len >= t_len) {
> + base = dt_mem_next_cell(dt_root_addr_cells, &prop);
> + size = dt_mem_next_cell(dt_root_size_cells, &prop);
> +
> + if (base && size &&
> + early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
> + pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
> + uname, &base, (unsigned long)size / SZ_1M);
> + else
> + pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
> + uname, &base, (unsigned long)size / SZ_1M);
> +
> + len -= t_len;
> + }
> + return 0;
> +}
> +
> +static int __reserved_mem_check_root(unsigned long node)
Please document the purpose of this function. This function reflects a Linux
implementation limitation because it is easier than parsing a correctly
formed ranges property. Sometime in the future it may be fixed. It is
worth capturing all of that in a comment.
> +{
> + __be32 *prop;
> +
> + prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
> + if (prop && be32_to_cpup(prop) != dt_root_size_cells)
> + return -EINVAL;
> +
> + prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
> + if (prop && be32_to_cpup(prop) != dt_root_addr_cells)
> + return -EINVAL;
> +
> + prop = of_get_flat_dt_prop(node, "ranges", NULL);
> + if (!prop)
> + return -EINVAL;
> + return 0;
> +}
> +
> +/**
> + * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
> + */
> +static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
> + int depth, void *data)
> +{
> + static int found;
> + const char *status;
> +
> + if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
> + if (__reserved_mem_check_root(node) != 0) {
> + pr_err("Reserved memory: unsupported node format, ignoring\n");
> + /* break scan */
> + return 1;
> + }
> + found = 1;
> + /* scan next node */
> + return 0;
> + } else if (!found) {
> + /* scan next node */
> + return 0;
> + } else if (found && depth < 2) {
> + /* scanning of /reserved-memory has been finished */
> + return 1;
> + }
> +
> + status = of_get_flat_dt_prop(node, "status", NULL);
> + if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
> + return 0;
> +
> + __reserved_mem_reserve_reg(node, uname);
> +
> + /* scan next node */
> + return 0;
> +}
> +
> +/**
> + * early_init_fdt_scan_reserved_mem() - create reserved memory regions
> + *
> + * This function grabs memory from early allocator for device exclusive use
> + * defined in device tree structures. It should be called by arch specific code
> + * once the early allocator (i.e. memblock) has been fully activated.
> + */
> +void __init early_init_fdt_scan_reserved_mem(void)
> +{
> + of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
> +}
Looks good.
> +
> +/**
> * of_scan_flat_dt - scan flattened tree blob and call callback on each.
> * @it: callback function
> * @data: context data pointer
> @@ -856,6 +963,16 @@ void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
> memblock_add(base, size);
> }
>
> +int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
> + phys_addr_t size, bool nomap)
> +{
> + if (memblock_is_region_reserved(base, size))
> + return -EBUSY;
> + if (nomap)
> + return memblock_remove(base, size);
> + return memblock_reserve(base, size);
> +}
> +
> /*
> * called from unflatten_device_tree() to bootstrap devicetree itself
> * Architectures can override this definition if memblock isn't used
> @@ -864,6 +981,14 @@ void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
> {
> return __va(memblock_alloc(size, align));
> }
> +#else
> +int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
> + phys_addr_t size, bool nomap)
> +{
> + pr_error("Reserved memory not supported, ignoring range 0x%llx - 0x%llx%s\n",
> + base, size, nomap ? " (nomap)" : "");
> + return -ENOSYS;
> +}
> #endif
>
> bool __init early_init_dt_scan(void *params)
> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
> index 2b77058a7335..8610ad8d77d2 100644
> --- a/include/linux/of_fdt.h
> +++ b/include/linux/of_fdt.h
> @@ -98,7 +98,10 @@ extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
> int depth, void *data);
> extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
> int depth, void *data);
> +extern void early_init_fdt_scan_reserved_mem(void);
> extern void early_init_dt_add_memory_arch(u64 base, u64 size);
> +extern int early_init_dt_reserve_memory_arch(phys_addr_t base, phys_addr_t size,
> + bool no_map);
> extern void * early_init_dt_alloc_memory_arch(u64 size, u64 align);
> extern u64 dt_mem_next_cell(int s, __be32 **cellp);
I think I'm happy with this one. Address my comments above and add my
Acked-by (so I remember I was okay with this one when you repost it) :-)
Acked-by: Grant Likely <[email protected]>
>
> --
> 1.7.9.5
>
On Fri, 21 Feb 2014 13:25:19 +0100, Marek Szyprowski <[email protected]> wrote:
> This patch adds support for dynamically allocated reserved memory regions
> declared in device tree. Such regions are defined by 'size', 'alignment'
> and 'alloc-ranges' properties.
>
> Based on previous code provided by Josh Cartwright <[email protected]>
>
> Signed-off-by: Marek Szyprowski <[email protected]>
Acked-by: Grant Likely <[email protected]>
> ---
> drivers/of/Kconfig | 6 ++
> drivers/of/Makefile | 1 +
> drivers/of/fdt.c | 13 ++-
> drivers/of/of_reserved_mem.c | 188 +++++++++++++++++++++++++++++++++++++++
> include/linux/of_reserved_mem.h | 21 +++++
> 5 files changed, 227 insertions(+), 2 deletions(-)
> create mode 100644 drivers/of/of_reserved_mem.c
> create mode 100644 include/linux/of_reserved_mem.h
>
> diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> index c6973f101a3e..30a7d87a8077 100644
> --- a/drivers/of/Kconfig
> +++ b/drivers/of/Kconfig
> @@ -75,4 +75,10 @@ config OF_MTD
> depends on MTD
> def_bool y
>
> +config OF_RESERVED_MEM
> + depends on OF_EARLY_FLATTREE
> + bool
> + help
> + Helpers to allow for reservation of memory regions
> +
> endmenu # OF
> diff --git a/drivers/of/Makefile b/drivers/of/Makefile
> index efd05102c405..ed9660adad77 100644
> --- a/drivers/of/Makefile
> +++ b/drivers/of/Makefile
> @@ -9,3 +9,4 @@ obj-$(CONFIG_OF_MDIO) += of_mdio.o
> obj-$(CONFIG_OF_PCI) += of_pci.o
> obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o
> obj-$(CONFIG_OF_MTD) += of_mtd.o
> +obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index 12809e20ef71..eafe5805257a 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -15,6 +15,7 @@
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/of_fdt.h>
> +#include <linux/of_reserved_mem.h>
> #include <linux/string.h>
> #include <linux/errno.h>
> #include <linux/slab.h>
> @@ -449,7 +450,7 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
> phys_addr_t base, size;
> unsigned long len;
> __be32 *prop;
> - int nomap;
> + int nomap, first = 1;
>
> prop = of_get_flat_dt_prop(node, "reg", &len);
> if (!prop)
> @@ -476,6 +477,10 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
> uname, &base, (unsigned long)size / SZ_1M);
>
> len -= t_len;
> + if (first) {
> + fdt_reserved_mem_save_node(node, uname, base, size);
> + first = 0;
> + }
> }
> return 0;
> }
> @@ -506,6 +511,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
> {
> static int found;
> const char *status;
> + int err;
>
> if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
> if (__reserved_mem_check_root(node) != 0) {
> @@ -528,7 +534,9 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
> if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
> return 0;
>
> - __reserved_mem_reserve_reg(node, uname);
> + err = __reserved_mem_reserve_reg(node, uname);
> + if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
> + fdt_reserved_mem_save_node(node, uname, 0, 0);
>
> /* scan next node */
> return 0;
> @@ -544,6 +552,7 @@ static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
> void __init early_init_fdt_scan_reserved_mem(void)
> {
> of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
> + fdt_init_reserved_mem();
> }
>
> /**
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> new file mode 100644
> index 000000000000..c7ca6a4a42d1
> --- /dev/null
> +++ b/drivers/of/of_reserved_mem.c
> @@ -0,0 +1,188 @@
> +/*
> + * Device tree based initialization code for reserved memory.
> + *
> + * Copyright (c) 2013, The Linux Foundation. All Rights Reserved.
> + * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
> + * http://www.samsung.com
> + * Author: Marek Szyprowski <[email protected]>
> + * Author: Josh Cartwright <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of the
> + * License or (at your optional) any later version of the license.
> + */
> +
> +#include <linux/err.h>
> +#include <linux/of.h>
> +#include <linux/of_fdt.h>
> +#include <linux/of_platform.h>
> +#include <linux/mm.h>
> +#include <linux/sizes.h>
> +#include <linux/of_reserved_mem.h>
> +
> +#define MAX_RESERVED_REGIONS 16
> +static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
> +static int reserved_mem_count;
> +
> +#if defined(CONFIG_HAVE_MEMBLOCK)
> +#include <linux/memblock.h>
> +int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
> + phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
> + phys_addr_t *res_base)
> +{
> + /*
> + * We use __memblock_alloc_base() because memblock_alloc_base()
> + * panic()s on allocation failure.
> + */
> + phys_addr_t base = __memblock_alloc_base(size, align, end);
> + if (!base)
> + return -ENOMEM;
> +
> + /*
> + * Check if the allocated region fits in to start..end window
> + */
> + if (base < start) {
> + memblock_free(base, size);
> + return -ENOMEM;
> + }
> +
> + *res_base = base;
> + if (nomap)
> + return memblock_remove(base, size);
> + return 0;
> +}
> +#else
> +int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
> + phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
> + phys_addr_t *res_base)
> +{
> + pr_error("Reserved memory not supported, ignoring region 0x%llx%s\n",
> + size, nomap ? " (nomap)" : "");
> + return -ENOSYS;
> +}
> +#endif
> +
> +/**
> + * res_mem_save_node() - save fdt node for second pass initialization
> + */
> +void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
> + phys_addr_t base, phys_addr_t size)
> +{
> + struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
> +
> + if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
> + pr_err("Reserved memory: not enough space all defined regions.\n");
> + return;
> + }
> +
> + rmem->fdt_node = node;
> + rmem->name = uname;
> + rmem->base = base;
> + rmem->size = size;
> +
> + reserved_mem_count++;
> + return;
> +}
> +
> +/**
> + * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
> + * and 'alloc-ranges' properties
> + */
> +static int __init __reserved_mem_alloc_size(unsigned long node,
> + const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
> +{
> + int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
> + phys_addr_t start = 0, end = 0;
> + phys_addr_t base = 0, align = 0, size;
> + unsigned long len;
> + __be32 *prop;
> + int nomap;
> + int ret;
> +
> + prop = of_get_flat_dt_prop(node, "size", &len);
> + if (!prop)
> + return -EINVAL;
> +
> + if (len != dt_root_size_cells * sizeof(__be32)) {
> + pr_err("Reserved memory: invalid size property in '%s' node.\n",
> + uname);
> + return -EINVAL;
> + }
> + size = dt_mem_next_cell(dt_root_size_cells, &prop);
> +
> + nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
> +
> + prop = of_get_flat_dt_prop(node, "alignment", &len);
> + if (prop) {
> + if (len != dt_root_addr_cells * sizeof(__be32)) {
> + pr_err("Reserved memory: invalid alignment property in '%s' node.\n",
> + uname);
> + return -EINVAL;
> + }
> + align = dt_mem_next_cell(dt_root_addr_cells, &prop);
> + }
> +
> + prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
> + if (prop) {
> +
> + if (len % t_len != 0) {
> + pr_err("Reserved memory: invalid alloc-ranges property in '%s', skipping node.\n",
> + uname);
> + return -EINVAL;
> + }
> +
> + base = 0;
> +
> + while (len > 0) {
> + start = dt_mem_next_cell(dt_root_addr_cells, &prop);
> + end = start + dt_mem_next_cell(dt_root_size_cells,
> + &prop);
> +
> + ret = early_init_dt_alloc_reserved_memory_arch(size,
> + align, start, end, nomap, &base);
> + if (ret == 0) {
> + pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
> + uname, &base,
> + (unsigned long)size / SZ_1M);
> + break;
> + }
> + len -= t_len;
> + }
> +
> + } else {
> + ret = early_init_dt_alloc_reserved_memory_arch(size, align,
> + 0, 0, nomap, &base);
> + if (ret == 0)
> + pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
> + uname, &base, (unsigned long)size / SZ_1M);
> + }
> +
> + if (base == 0) {
> + pr_info("Reserved memory: failed to allocate memory for node '%s'\n",
> + uname);
> + return -ENOMEM;
> + }
> +
> + *res_base = base;
> + *res_size = size;
> +
> + return 0;
> +}
> +
> +/**
> + * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
> + */
> +void __init fdt_init_reserved_mem(void)
> +{
> + int i;
> + for (i = 0; i < reserved_mem_count; i++) {
> + struct reserved_mem *rmem = &reserved_mem[i];
> + unsigned long node = rmem->fdt_node;
> + int err = 0;
> +
> + if (rmem->size == 0)
> + err = __reserved_mem_alloc_size(node, rmem->name,
> + &rmem->base, &rmem->size);
> + }
> +}
> diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
> new file mode 100644
> index 000000000000..89226ed7d954
> --- /dev/null
> +++ b/include/linux/of_reserved_mem.h
> @@ -0,0 +1,21 @@
> +#ifndef __OF_RESERVED_MEM_H
> +#define __OF_RESERVED_MEM_H
> +
> +struct reserved_mem {
> + const char *name;
> + unsigned long fdt_node;
> + phys_addr_t base;
> + phys_addr_t size;
> +};
> +
> +#ifdef CONFIG_OF_RESERVED_MEM
> +void fdt_init_reserved_mem(void);
> +void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
> + phys_addr_t base, phys_addr_t size);
> +#else
> +static inline void fdt_init_reserved_mem(void) { }
> +static inline void fdt_reserved_mem_save_node(unsigned long node,
> + const char *uname, phys_addr_t base, phys_addr_t size) { }
> +#endif
> +
> +#endif /* __OF_RESERVED_MEM_H */
> --
> 1.7.9.5
>
On Fri, 21 Feb 2014 13:25:22 +0100, Marek Szyprowski <[email protected]> wrote:
> Use recently introduced of_reserved_mem_device_init() function to
> automatically assign respective reserved memory region to the newly created
> platform and amba device.
>
> Signed-off-by: Marek Szyprowski <[email protected]>
I'm wary on this patch. It hides the assignment of regions into the core
code and I worry that it is the wrong level of abstraction. I would
think that drivers should know that they need a reserved memory region
and should be calling the API to obtain the region directly rather than
doing it for them. The reason being is that there may be some situations
where the common code isn't quite right and the driver needs to override
the behaviour. If it is called automatically then the driver cannot do
that.
Is it really a big burden to have the driver call the reserved memory
init function?
g.
> ---
> drivers/of/platform.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 404d1daebefa..3df0b1826e8b 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -21,6 +21,7 @@
> #include <linux/of_device.h>
> #include <linux/of_irq.h>
> #include <linux/of_platform.h>
> +#include <linux/of_reserved_mem.h>
> #include <linux/platform_device.h>
>
> const struct of_device_id of_default_bus_match_table[] = {
> @@ -220,6 +221,8 @@ static struct platform_device *of_platform_device_create_pdata(
> dev->dev.bus = &platform_bus_type;
> dev->dev.platform_data = platform_data;
>
> + of_reserved_mem_device_init(&dev->dev);
> +
> /* We do not fill the DMA ops for platform devices by default.
> * This is currently the responsibility of the platform code
> * to do such, possibly using a device notifier
> @@ -227,6 +230,7 @@ static struct platform_device *of_platform_device_create_pdata(
>
> if (of_device_add(dev) != 0) {
> platform_device_put(dev);
> + of_reserved_mem_device_release(&dev->dev);
> return NULL;
> }
>
> @@ -282,6 +286,8 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
> else
> of_device_make_bus_id(&dev->dev);
>
> + of_reserved_mem_device_init(&dev->dev);
> +
> /* Allow the HW Peripheral ID to be overridden */
> prop = of_get_property(node, "arm,primecell-periphid", NULL);
> if (prop)
> @@ -308,6 +314,7 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
> return dev;
>
> err_free:
> + of_reserved_mem_device_release(&dev->dev);
> amba_device_put(dev);
> return NULL;
> }
> --
> 1.7.9.5
>
Hello,
On 2014-02-26 13:14, Grant Likely wrote:
> On Fri, 21 Feb 2014 13:25:22 +0100, Marek Szyprowski <[email protected]> wrote:
> > Use recently introduced of_reserved_mem_device_init() function to
> > automatically assign respective reserved memory region to the newly created
> > platform and amba device.
> >
> > Signed-off-by: Marek Szyprowski <[email protected]>
>
> I'm wary on this patch. It hides the assignment of regions into the core
> code and I worry that it is the wrong level of abstraction. I would
> think that drivers should know that they need a reserved memory region
> and should be calling the API to obtain the region directly rather than
> doing it for them. The reason being is that there may be some situations
> where the common code isn't quite right and the driver needs to override
> the behaviour. If it is called automatically then the driver cannot do
> that.
>
> Is it really a big burden to have the driver call the reserved memory
> init function?
If a device requires very special handling of the reserved memory region,
it may simply provide its own reserved memory region driver which will do
the required early initialization.
If we assume that driver needs to initialize reserved region manually, then
why do we ever bother with adding support for custom reserved memory drivers
and assigning regions to a device node? We can simply stick with just a set
of reserved regions and tell drivers to use them.
In my opinion for most typical use cases a board designer will assign
'dma-shared-pool' driver to the given set of devices, which in turn ensures
that all memory allocations for dma purposes for those device will be
served from that region. It is really not a driver role to initialize it
in such case. Driver should focus on controlling hw operations, regardless
the way the hardware module has been integrated to the system.
I can perfectly imagine a generic driver which operates the same way in any
of the following cases (depends mainly on the hw version): 1) restricted
dma window, 2) iommu for all dma for the given device, 3) fully featured
memory master for dma for the given device (no restrictions), if the
respective kernel subsystems did the correct initialization and provide
their own methods for managing DMA operation. I already have a working
platform glue code for the above cases tested with Samsung multimedia
drivers. No changes to the drivers were required.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
Hello,
On 2014-02-26 12:51, Grant Likely wrote:
> On Fri, 21 Feb 2014 13:25:17 +0100, Marek Szyprowski <[email protected]> wrote:
> > From: Grant Likely <[email protected]>
> >
> > Reserved memory nodes allow for the reservation of static (fixed
> > address) regions, or dynamically allocated regions for a specific
> > purpose.
> >
> > Signed-off-by: Grant Likely <[email protected]>
> > [joshc: Based on binding document proposed (in non-patch form) here:
> > http://lkml.kernel.org/g/[email protected]
> > adapted to support #memory-region-cells]
> > Signed-off-by: Josh Cartwright <[email protected]>
> > Signed-off-by: Marek Szyprowski <[email protected]>
> > ---
> > .../bindings/reserved-memory/reserved-memory.txt | 138 ++++++++++++++++++++
> > 1 file changed, 138 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
> >
> > diff --git a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
> > new file mode 100644
> > index 000000000000..a606ce90c9c4
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
> > @@ -0,0 +1,138 @@
> > +*** Reserved memory regions ***
> > +
> > +Reserved memory is specified as a node under the /reserved-memory node.
> > +The operating system shall exclude reserved memory from normal usage
> > +one can create child nodes describing particular reserved (excluded from
> > +normal use) memory regions. Such memory regions are usually designed for
> > +the special usage by various device drivers.
> > +
> > +Parameters for each memory region can be encoded into the device tree
> > +with the following nodes:
> > +
> > +/reserved-memory node
> > +---------------------
> > +#address-cells, #size-cells (required) - standard definition
> > + - Should use the same values as the root node
> > +#memory-region-cells (required) - dictates number of cells used in the child
> > + nodes memory-region specifier
>
> I still don't like this portion of the binding. I'm not convinced that
> it is necessary in the majority of cases and it is going to be very
> driver specific. I would rather drop it entirely from the common
> binding. If a specific driver needs to do something like the above then
> it can have a driver specific binding. Otherwise I think the default
> should be a simple phandle with no arguments to a single reserved memory
> node.
>
> Ben, can you weigh in on the current state of this document. I'm mostly
> happy with it aside from my comment above. Do you think this is ready to
> be merged?
>
> > +ranges (required) - standard definition
> > + - Should be empty
> > +
> > +/reserved-memory/ child nodes
> > +-----------------------------
> > +Each child of the reserved-memory node specifies one or more regions of
> > +reserved memory. Each child node may either use a 'reg' property to
> > +specify a specific range of reserved memory, or a 'size' property with
> > +optional constraints to request a dynamically allocated block of memory.
> > +
> > +Following the generic-names recommended practice, node names should
> > +reflect the purpose of the node (ie. "framebuffer" or "dma-pool"). Unit
> > +address (@<address>) should be appended to the name if the node is a
> > +static allocation.
> > +
> > +Properties:
> > +Requires either a) or b) below.
> > +a) static allocation
> > + reg (required) - standard definition
> > +b) dynamic allocation
> > + size (required) - length based on parent's #size-cells
> > + - Size in bytes of memory to reserve.
> > + alignment (optional) - length based on parent's #size-cells
> > + - Address boundary for alignment of allocation.
> > + alloc-ranges (optional) - prop-encoded-array (address, length pairs).
> > + - Specifies regions of memory that are
> > + acceptable to allocate from.
> > +
> > +If both reg and size are present, then the reg property takes precedence
> > +and size is ignored.
> > +
> > +Additional properties:
> > +compatible (optional) - standard definition
> > + - may contain the following strings:
> > + - shared-dma-pool: This indicates a region of memory meant to be
> > + used as a shared pool of DMA buffers for a set of devices. It can
> > + be used by an operating system to instanciate the necessary pool
> > + management subsystem if necessary.
> > + - vendor specific string in the form <vendor>,[<device>-]<usage>
>
> Add "Use vendor strings to identify regions dedicates for a specific
> vendor device. For example: 'acme,framebuffer'. Platform code can use vendor
> strings to identify device specific regions"
So do you want to completely drop phandle based links between device
nodes and
memory regions?
> > +no-map (optional) - empty property
> > + - Indicates the operating system must not create a virtual mapping
> > + of the region as part of its standard mapping of system memory,
> > + nor permit speculative access to it under any circumstances other
> > + than under the control of the device driver using the region.
> > +reusable (optional) - empty property
> > + - The operating system can use the memory in this region with the
> > + limitation that the device driver(s) owning the region need to be
> > + able to reclaim it back. Typically that means that the operating
> > + system can use that region to store volatile or cached data that
> > + can be otherwise regenerated or migrated elsewhere.
> > +
> > +Linux implementation note:
> > +- If a "linux,cma-default" property is present, then Linux will use the
> > + region for the default pool of the contiguous memory allocator.
> > +
> > +Device node references to reserved memory
> > +-----------------------------------------
> > +Regions in the /reserved-memory node may be referenced by other device
> > +nodes by adding a memory-region property to the device node.
> > +
> > +memory-region (optional) - phandle, specifier pairs to children of /reserved-memory
> > +
> > +Example
> > +-------
> > +This example defines 3 contiguous regions are defined for Linux kernel:
> > +one default of all device drivers (named linux,cma@72000000 and 64MiB in size),
> > +one dedicated to the framebuffer device (named framebuffer@78000000, 8MiB), and
> > +one for multimedia processing (named multimedia-memory@77000000, 64MiB).
> > +
> > +/ {
> > + #address-cells = <1>;
> > + #size-cells = <1>;
> > +
> > + memory {
> > + reg = <0x40000000 0x40000000>;
> > + };
> > +
> > + reserved-memory {
> > + #address-cells = <1>;
> > + #size-cells = <1>;
> > + ranges;
> > +
> > + /* global autoconfigured region for contiguous allocations */
> > + linux,cma {
> > + compatible = "shared-dma-pool";
> > + reusable;
> > + #memory-region-cells = <0>;
> > + size = <0x4000000>;
> > + alignment = <0x2000>;
> > + linux,cma-default;
> > + };
> > +
> > + display_reserved: framebuffer@78000000 {
> > + #memory-region-cells = <0>;
> > + reg = <0x78000000 0x800000>;
> > + };
> > +
> > + multimedia_reserved: multimedia@77000000 {
> > + compatible = "acme,multimedia-memory";
> > + #memory-region-cells = <1>;
> > + reg = <0x77000000 0x4000000>;
> > + };
> > + };
> > +
> > + /* ... */
> > +
> > + fb0: video@12300000 {
> > + memory-region = <&display_reserved>;
> > + /* ... */
> > + };
> > +
> > + scaler: scaler@12500000 {
> > + memory-region = <&multimedia_reserved 0xdeadbeef>;
> > + /* ... */
> > + };
> > +
> > + codec: codec@12600000 {
> > + memory-region = <&multimedia_reserved 0xfeebdaed>;
> > + /* ... */
> > + };
> > +};
> > --
> > 1.7.9.5
> >
>
>
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
On 28.02.2014 10:54, Marek Szyprowski wrote:
> Hello,
>
> On 2014-02-26 12:51, Grant Likely wrote:
>> On Fri, 21 Feb 2014 13:25:17 +0100, Marek Szyprowski
>> <[email protected]> wrote:
>> > From: Grant Likely <[email protected]>
>> >
>> > Reserved memory nodes allow for the reservation of static (fixed
>> > address) regions, or dynamically allocated regions for a specific
>> > purpose.
>> >
>> > Signed-off-by: Grant Likely <[email protected]>
>> > [joshc: Based on binding document proposed (in non-patch form) here:
>> >
>> http://lkml.kernel.org/g/[email protected]
>> > adapted to support #memory-region-cells]
>> > Signed-off-by: Josh Cartwright <[email protected]>
>> > Signed-off-by: Marek Szyprowski <[email protected]>
>> > ---
>> > .../bindings/reserved-memory/reserved-memory.txt | 138
>> ++++++++++++++++++++
>> > 1 file changed, 138 insertions(+)
>> > create mode 100644
>> Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
>> >
>> > diff --git
>> a/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
>>
>> > new file mode 100644
>> > index 000000000000..a606ce90c9c4
>> > --- /dev/null
>> > +++
>> b/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
>> > @@ -0,0 +1,138 @@
>> > +*** Reserved memory regions ***
>> > +
>> > +Reserved memory is specified as a node under the /reserved-memory
>> node.
>> > +The operating system shall exclude reserved memory from normal usage
>> > +one can create child nodes describing particular reserved (excluded
>> from
>> > +normal use) memory regions. Such memory regions are usually
>> designed for
>> > +the special usage by various device drivers.
>> > +
>> > +Parameters for each memory region can be encoded into the device tree
>> > +with the following nodes:
>> > +
>> > +/reserved-memory node
>> > +---------------------
>> > +#address-cells, #size-cells (required) - standard definition
>> > + - Should use the same values as the root node
>> > +#memory-region-cells (required) - dictates number of cells used in
>> the child
>> > + nodes memory-region specifier
>>
>> I still don't like this portion of the binding. I'm not convinced that
>> it is necessary in the majority of cases and it is going to be very
>> driver specific. I would rather drop it entirely from the common
>> binding. If a specific driver needs to do something like the above then
>> it can have a driver specific binding. Otherwise I think the default
>> should be a simple phandle with no arguments to a single reserved memory
>> node.
>>
>> Ben, can you weigh in on the current state of this document. I'm mostly
>> happy with it aside from my comment above. Do you think this is ready to
>> be merged?
>>
>> > +ranges (required) - standard definition
>> > + - Should be empty
>> > +
>> > +/reserved-memory/ child nodes
>> > +-----------------------------
>> > +Each child of the reserved-memory node specifies one or more
>> regions of
>> > +reserved memory. Each child node may either use a 'reg' property to
>> > +specify a specific range of reserved memory, or a 'size' property with
>> > +optional constraints to request a dynamically allocated block of
>> memory.
>> > +
>> > +Following the generic-names recommended practice, node names should
>> > +reflect the purpose of the node (ie. "framebuffer" or "dma-pool").
>> Unit
>> > +address (@<address>) should be appended to the name if the node is a
>> > +static allocation.
>> > +
>> > +Properties:
>> > +Requires either a) or b) below.
>> > +a) static allocation
>> > + reg (required) - standard definition
>> > +b) dynamic allocation
>> > + size (required) - length based on parent's #size-cells
>> > + - Size in bytes of memory to reserve.
>> > + alignment (optional) - length based on parent's #size-cells
>> > + - Address boundary for alignment of
>> allocation.
>> > + alloc-ranges (optional) - prop-encoded-array (address, length
>> pairs).
>> > + - Specifies regions of memory that are
>> > + acceptable to allocate from.
>> > +
>> > +If both reg and size are present, then the reg property takes
>> precedence
>> > +and size is ignored.
>> > +
>> > +Additional properties:
>> > +compatible (optional) - standard definition
>> > + - may contain the following strings:
>> > + - shared-dma-pool: This indicates a region of memory meant
>> to be
>> > + used as a shared pool of DMA buffers for a set of
>> devices. It can
>> > + be used by an operating system to instanciate the
>> necessary pool
>> > + management subsystem if necessary.
>> > + - vendor specific string in the form
>> <vendor>,[<device>-]<usage>
>>
>> Add "Use vendor strings to identify regions dedicates for a specific
>> vendor device. For example: 'acme,framebuffer'. Platform code can use
>> vendor
>> strings to identify device specific regions"
>
> So do you want to completely drop phandle based links between device
> nodes and
> memory regions?
Huh? How this would work with regions that have to be used for multiple
(but not all - not a default region) devices?
Best regards,
Tomasz