Now that we have an explanation to Amir's issue, we can re-spin this
series.
---
Changes since v3:
- Do not use memblock_start_of_DRAM()
Changes since v2:
- Go back to v1's behavior for patch #2
Changes since v1:
- Make cma_in_zone() more strict, GFP_KERNEL doesn't default to true
now
- Check if phys_addr_ok() exists prior calling it
Christoph Hellwig (1):
dma-pool: fix coherent pool allocations for IOMMU mappings
Nicolas Saenz Julienne (1):
dma-pool: Only allocate from CMA when in same memory zone
drivers/iommu/dma-iommu.c | 4 +-
include/linux/dma-direct.h | 3 -
include/linux/dma-mapping.h | 5 +-
kernel/dma/direct.c | 13 +++-
kernel/dma/pool.c | 145 +++++++++++++++++++-----------------
5 files changed, 92 insertions(+), 78 deletions(-)
--
2.28.0
There is no guarantee to CMA's placement, so allocating a zone specific
atomic pool from CMA might return memory from a completely different
memory zone. To get around this double check CMA's placement before
allocating from it.
Signed-off-by: Nicolas Saenz Julienne <[email protected]>
[hch: rebased, added a fallback to the page allocator, allow dipping into
lower CMA pools]
Signed-off-by: Christoph Hellwig <[email protected]>
---
Changes since v3:
- Do not use memblock_start_of_DRAM()
Changes since v2:
- Go back to v1 behavior
kernel/dma/pool.c | 31 ++++++++++++++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
index 6bc74a2d5127..57f4a0f32a92 100644
--- a/kernel/dma/pool.c
+++ b/kernel/dma/pool.c
@@ -3,7 +3,9 @@
* Copyright (C) 2012 ARM Ltd.
* Copyright (C) 2020 Google LLC
*/
+#include <linux/cma.h>
#include <linux/debugfs.h>
+#include <linux/dma-contiguous.h>
#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
#include <linux/init.h>
@@ -55,6 +57,29 @@ static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
pool_size_kernel += size;
}
+static bool cma_in_zone(gfp_t gfp)
+{
+ unsigned long size;
+ phys_addr_t end;
+ struct cma *cma;
+
+ cma = dev_get_cma_area(NULL);
+ if (!cma)
+ return false;
+
+ size = cma_get_size(cma);
+ if (!size)
+ return false;
+
+ /* CMA can't cross zone boundaries, see cma_activate_area() */
+ end = cma_get_base(cma) + size - 1;
+ if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
+ return end <= DMA_BIT_MASK(zone_dma_bits);
+ if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
+ return end <= DMA_BIT_MASK(32);
+ return true;
+}
+
static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
gfp_t gfp)
{
@@ -68,7 +93,11 @@ static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
do {
pool_size = 1 << (PAGE_SHIFT + order);
- page = alloc_pages(gfp, order);
+ if (cma_in_zone(gfp))
+ page = dma_alloc_from_contiguous(NULL, 1 << order,
+ order, false);
+ if (!page)
+ page = alloc_pages(gfp, order);
} while (!page && order-- > 0);
if (!page)
goto out;
--
2.28.0
From: Christoph Hellwig <[email protected]>
When allocating coherent pool memory for an IOMMU mapping we don't care
about the DMA mask. Move the guess for the initial GFP mask into the
dma_direct_alloc_pages and pass dma_coherent_ok as a function pointer
argument so that it doesn't get applied to the IOMMU case.
Signed-off-by: Christoph Hellwig <[email protected]>
---
Changes since v1:
- Check if phys_addr_ok() exists prior calling it
drivers/iommu/dma-iommu.c | 4 +-
include/linux/dma-direct.h | 3 -
include/linux/dma-mapping.h | 5 +-
kernel/dma/direct.c | 13 ++--
kernel/dma/pool.c | 114 +++++++++++++++---------------------
5 files changed, 62 insertions(+), 77 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 4959f5df21bd..5141d49a046b 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1035,8 +1035,8 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
!gfpflags_allow_blocking(gfp) && !coherent)
- cpu_addr = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &page,
- gfp);
+ page = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &cpu_addr,
+ gfp, NULL);
else
cpu_addr = iommu_dma_alloc_pages(dev, size, &page, gfp, attrs);
if (!cpu_addr)
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index 5a3ce2a24794..6e87225600ae 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -73,9 +73,6 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size,
}
u64 dma_direct_get_required_mask(struct device *dev);
-gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
- u64 *phys_mask);
-bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size);
void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs);
void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 016b96b384bd..52635e91143b 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -522,8 +522,9 @@ void *dma_common_pages_remap(struct page **pages, size_t size,
pgprot_t prot, const void *caller);
void dma_common_free_remap(void *cpu_addr, size_t size);
-void *dma_alloc_from_pool(struct device *dev, size_t size,
- struct page **ret_page, gfp_t flags);
+struct page *dma_alloc_from_pool(struct device *dev, size_t size,
+ void **cpu_addr, gfp_t flags,
+ bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t));
bool dma_free_from_pool(struct device *dev, void *start, size_t size);
int
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index bb0041e99659..db6ef07aec3b 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -43,7 +43,7 @@ u64 dma_direct_get_required_mask(struct device *dev)
return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
}
-gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
+static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
u64 *phys_limit)
{
u64 dma_limit = min_not_zero(dma_mask, dev->bus_dma_limit);
@@ -68,7 +68,7 @@ gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
return 0;
}
-bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
+static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
{
return phys_to_dma_direct(dev, phys) + size - 1 <=
min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);
@@ -161,8 +161,13 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
size = PAGE_ALIGN(size);
if (dma_should_alloc_from_pool(dev, gfp, attrs)) {
- ret = dma_alloc_from_pool(dev, size, &page, gfp);
- if (!ret)
+ u64 phys_mask;
+
+ gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
+ &phys_mask);
+ page = dma_alloc_from_pool(dev, size, &ret, gfp,
+ dma_coherent_ok);
+ if (!page)
return NULL;
goto done;
}
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
index 57f4a0f32a92..b0aaba4197ae 100644
--- a/kernel/dma/pool.c
+++ b/kernel/dma/pool.c
@@ -225,93 +225,75 @@ static int __init dma_atomic_pool_init(void)
}
postcore_initcall(dma_atomic_pool_init);
-static inline struct gen_pool *dma_guess_pool_from_device(struct device *dev)
+static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp)
{
- u64 phys_mask;
- gfp_t gfp;
-
- gfp = dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
- &phys_mask);
- if (IS_ENABLED(CONFIG_ZONE_DMA) && gfp == GFP_DMA)
+ if (prev == NULL) {
+ if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
+ return atomic_pool_dma32;
+ if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
+ return atomic_pool_dma;
+ return atomic_pool_kernel;
+ }
+ if (prev == atomic_pool_kernel)
+ return atomic_pool_dma32 ? atomic_pool_dma32 : atomic_pool_dma;
+ if (prev == atomic_pool_dma32)
return atomic_pool_dma;
- if (IS_ENABLED(CONFIG_ZONE_DMA32) && gfp == GFP_DMA32)
- return atomic_pool_dma32;
- return atomic_pool_kernel;
+ return NULL;
}
-static inline struct gen_pool *dma_get_safer_pool(struct gen_pool *bad_pool)
+static struct page *__dma_alloc_from_pool(struct device *dev, size_t size,
+ struct gen_pool *pool, void **cpu_addr,
+ bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
{
- if (bad_pool == atomic_pool_kernel)
- return atomic_pool_dma32 ? : atomic_pool_dma;
+ unsigned long addr;
+ phys_addr_t phys;
- if (bad_pool == atomic_pool_dma32)
- return atomic_pool_dma;
+ addr = gen_pool_alloc(pool, size);
+ if (!addr)
+ return NULL;
- return NULL;
-}
+ phys = gen_pool_virt_to_phys(pool, addr);
+ if (phys_addr_ok && !phys_addr_ok(dev, phys, size)) {
+ gen_pool_free(pool, addr, size);
+ return NULL;
+ }
-static inline struct gen_pool *dma_guess_pool(struct device *dev,
- struct gen_pool *bad_pool)
-{
- if (bad_pool)
- return dma_get_safer_pool(bad_pool);
+ if (gen_pool_avail(pool) < atomic_pool_size)
+ schedule_work(&atomic_pool_work);
- return dma_guess_pool_from_device(dev);
+ *cpu_addr = (void *)addr;
+ memset(*cpu_addr, 0, size);
+ return pfn_to_page(__phys_to_pfn(phys));
}
-void *dma_alloc_from_pool(struct device *dev, size_t size,
- struct page **ret_page, gfp_t flags)
+struct page *dma_alloc_from_pool(struct device *dev, size_t size,
+ void **cpu_addr, gfp_t gfp,
+ bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
{
struct gen_pool *pool = NULL;
- unsigned long val = 0;
- void *ptr = NULL;
- phys_addr_t phys;
-
- while (1) {
- pool = dma_guess_pool(dev, pool);
- if (!pool) {
- WARN(1, "Failed to get suitable pool for %s\n",
- dev_name(dev));
- break;
- }
-
- val = gen_pool_alloc(pool, size);
- if (!val)
- continue;
-
- phys = gen_pool_virt_to_phys(pool, val);
- if (dma_coherent_ok(dev, phys, size))
- break;
-
- gen_pool_free(pool, val, size);
- val = 0;
- }
-
-
- if (val) {
- *ret_page = pfn_to_page(__phys_to_pfn(phys));
- ptr = (void *)val;
- memset(ptr, 0, size);
+ struct page *page;
- if (gen_pool_avail(pool) < atomic_pool_size)
- schedule_work(&atomic_pool_work);
+ while ((pool = dma_guess_pool(pool, gfp))) {
+ page = __dma_alloc_from_pool(dev, size, pool, cpu_addr,
+ phys_addr_ok);
+ if (page)
+ return page;
}
- return ptr;
+ WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev));
+ return NULL;
}
bool dma_free_from_pool(struct device *dev, void *start, size_t size)
{
struct gen_pool *pool = NULL;
- while (1) {
- pool = dma_guess_pool(dev, pool);
- if (!pool)
- return false;
-
- if (gen_pool_has_addr(pool, (unsigned long)start, size)) {
- gen_pool_free(pool, (unsigned long)start, size);
- return true;
- }
+ while ((pool = dma_guess_pool(pool, 0))) {
+ if (!gen_pool_has_addr(pool, (unsigned long)start, size))
+ continue;
+ gen_pool_free(pool, (unsigned long)start, size);
+ return true;
}
+
+ return false;
}
--
2.28.0
On Fri, 14 Aug 2020 at 15:56, Nicolas Saenz Julienne
<[email protected]> wrote:
>
> Now that we have an explanation to Amir's issue, we can re-spin this
> series.
Hi, Smoke tested (boots AOSP to UI with Touch/WiFi/BT working) on my
Poco F1 phone, with upstream commit 00e4db51259a (+ 30 odd out of
tree patches [1]) and I see no obvious regressions.
For both the patches in the series:
Tested-by: Amit Pundir <[email protected]>
[1] https://github.com/pundiramit/linux/commits/beryllium-mainline-display
>
> ---
> Changes since v3:
> - Do not use memblock_start_of_DRAM()
>
> Changes since v2:
> - Go back to v1's behavior for patch #2
>
> Changes since v1:
> - Make cma_in_zone() more strict, GFP_KERNEL doesn't default to true
> now
>
> - Check if phys_addr_ok() exists prior calling it
>
> Christoph Hellwig (1):
> dma-pool: fix coherent pool allocations for IOMMU mappings
>
> Nicolas Saenz Julienne (1):
> dma-pool: Only allocate from CMA when in same memory zone
>
> drivers/iommu/dma-iommu.c | 4 +-
> include/linux/dma-direct.h | 3 -
> include/linux/dma-mapping.h | 5 +-
> kernel/dma/direct.c | 13 +++-
> kernel/dma/pool.c | 145 +++++++++++++++++++-----------------
> 5 files changed, 92 insertions(+), 78 deletions(-)
>
> --
> 2.28.0
>