2014-07-17 16:39:54

by Tomasz Figa

[permalink] [raw]
Subject: [PATCH v3 0/7] Enable L2 cache support on Exynos4210/4x12 SoCs

This series intends to add support for L2 cache on Exynos4 SoCs on boards
running under secure firmware, which requires certain initialization steps
to be done with help of firmware, as selected registers are writable only
from secure mode.

First four patches extend existing support for secure write in L2C driver
to account for design of secure firmware running on Exynos. Namely:
1) direct read access to certain registers is needed on Exynos, because
secure firmware calls set several registers at once,
2) not all boards are running secure firmware, so .write_sec callback
needs to be installed in Exynos firmware ops initialization code,
3) write access to {DATA,TAG}_LATENCY_CTRL registers fron non-secure world
is not allowed and so must use l2c_write_sec as well,
4) on certain boards, default value of prefetch register is incorrect
and must be overridden at L2C initialization.
For boards running with firmware that provides access to individual
L2C registers this series should introduce no functional changes. However
since the driver is widely used on other platforms I'd like to kindly ask
any interested people for testing.

Further two patches add impelmentation of .write_sec for Exynos secure
firmware and necessary DT nodes to enable L2 cache.

Tested on Exynos4210-based Universal C210 and Trats (both without secure
firmware) and Exynos4412-based TRATS2 and ODROID-U3 boards (both with secure
firmware).

Depends on:
- [PATCH] ARM: make it easier to check the CPU part number correctly
(http://thread.gmane.org/gmane.linux.ports.arm.kernel/335126
already in linux-next)
- [PATCH v2 0/2] Firmware-assisted suspend/resume of Exynos SoCs
(https://lkml.org/lkml/2014/7/17/431)

Changes since v2:
(https://lkml.org/lkml/2014/6/25/416)
- refactored L2C driver to use commit-like interface and make it no longer
depend on availability of writes to individual registers,
- moved L2C resume to assembly code, because doing it later makes some
systems unstable - this is also needed for deeper cpuidle modes,
- dropped unnecessary patch hacking around the .write_sec interface,
- dropped patch making the driver use l2c_write_sec() for LATENCY_CTRL
registers as Exynos is no longer affected and I'm not aware of any
reports that this is also needed on other platforms (can be applied
separately if it turns out to be so),
- rebased onto next-20140717 tag of linux-next tree.

Changes since v1:
(https://www.mail-archive.com/[email protected]/msg106323.html)
- rebased onto for-next branch of linux-samsung tree,
- changed argument order of outer_cache.write_sec() callback to match
l2c_write_sec() function in cache-l2x0.c,
- added support of overriding of prefetch settings to work around incorrect
default settings on certain Exynos4x12-based boards,
- added call to firmware to invalidate whole L2 cache before setting enable
bit in L2C control register (required by Exynos secure firmware).

Tomasz Figa (7):
ARM: l2c: Refactor the driver to use commit-like interface
ARM: l2c: Add interface to ask hypervisor to configure L2C
ARM: l2c: Get outer cache .write_sec callback from mach_desc only if
not NULL
ARM: l2c: Add support for overriding prefetch settings
ARM: EXYNOS: Add .write_sec outer cache callback for L2C-310
ARM: EXYNOS: Add support for non-secure L2X0 resume
ARM: dts: exynos4: Add nodes for L2 cache controller

Documentation/devicetree/bindings/arm/l2cc.txt | 10 +
arch/arm/boot/dts/exynos4210.dtsi | 9 +
arch/arm/boot/dts/exynos4x12.dtsi | 14 ++
arch/arm/include/asm/outercache.h | 3 +
arch/arm/kernel/irq.c | 3 +-
arch/arm/mach-exynos/common.h | 1 +
arch/arm/mach-exynos/firmware.c | 40 ++++
arch/arm/mach-exynos/sleep.S | 41 +++++
arch/arm/mm/cache-l2x0.c | 245 ++++++++++++++++---------
9 files changed, 274 insertions(+), 92 deletions(-)

--
1.9.3


2014-07-17 16:39:58

by Tomasz Figa

[permalink] [raw]
Subject: [PATCH v3 6/7] ARM: EXYNOS: Add support for non-secure L2X0 resume

On Exynos SoCs it is necessary to resume operation of L2C early in
assembly code, because otherwise certain systems will crash. This patch
adds necessary code to non-secure resume handler.

Signed-off-by: Tomasz Figa <[email protected]>
---
arch/arm/mach-exynos/common.h | 1 +
arch/arm/mach-exynos/firmware.c | 2 ++
arch/arm/mach-exynos/sleep.S | 41 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 44 insertions(+)

diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h
index a3f3061..2540827 100644
--- a/arch/arm/mach-exynos/common.h
+++ b/arch/arm/mach-exynos/common.h
@@ -113,6 +113,7 @@ IS_SAMSUNG_CPU(exynos5800, EXYNOS5800_SOC_ID, EXYNOS5_SOC_MASK)

extern u32 cp15_save_diag;
extern u32 cp15_save_power;
+extern unsigned long l2x0_regs_phys;

extern void __iomem *sysram_ns_base_addr;
extern void __iomem *sysram_base_addr;
diff --git a/arch/arm/mach-exynos/firmware.c b/arch/arm/mach-exynos/firmware.c
index 554b350..09131d3 100644
--- a/arch/arm/mach-exynos/firmware.c
+++ b/arch/arm/mach-exynos/firmware.c
@@ -103,6 +103,8 @@ static int exynos_suspend(void)
writel(virt_to_phys(exynos_cpu_resume_ns),
sysram_ns_base_addr + EXYNOS_BOOT_ADDR);

+ l2x0_regs_phys = virt_to_phys(&l2x0_saved_regs);
+
return cpu_suspend(0, exynos_cpu_suspend);
}

diff --git a/arch/arm/mach-exynos/sleep.S b/arch/arm/mach-exynos/sleep.S
index e3c3730..b8ce8f0 100644
--- a/arch/arm/mach-exynos/sleep.S
+++ b/arch/arm/mach-exynos/sleep.S
@@ -16,6 +16,8 @@
*/

#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/hardware/cache-l2x0.h>
#include "smc.h"

#define CPU_MASK 0xff0ffff0
@@ -74,6 +76,40 @@ ENTRY(exynos_cpu_resume_ns)
mov r0, #SMC_CMD_C15RESUME
dsb
smc #0
+#ifdef CONFIG_CACHE_L2X0
+ adr r0, l2x0_regs_phys
+ ldr r0, [r0]
+ cmp r0, #0
+ beq skip_l2x0
+
+ ldr r1, [r0, #L2X0_R_PHY_BASE]
+ ldr r2, [r1, #L2X0_CTRL]
+ tst r2, #0x1
+ bne skip_l2x0
+
+ ldr r1, [r0, #L2X0_R_TAG_LATENCY]
+ ldr r2, [r0, #L2X0_R_DATA_LATENCY]
+ ldr r3, [r0, #L2X0_R_PREFETCH_CTRL]
+ mov r0, #SMC_CMD_L2X0SETUP1
+ smc #0
+
+ /* Reload saved regs pointer because smc corrupts registers. */
+ adr r0, l2x0_regs_phys
+ ldr r0, [r0]
+
+ ldr r1, [r0, #L2X0_R_PWR_CTRL]
+ ldr r2, [r0, #L2X0_R_AUX_CTRL]
+ mov r0, #SMC_CMD_L2X0SETUP2
+ smc #0
+
+ mov r0, #SMC_CMD_L2X0INVALL
+ smc #0
+
+ mov r1, #1
+ mov r0, #SMC_CMD_L2X0CTRL
+ smc #0
+skip_l2x0:
+#endif /* CONFIG_CACHE_L2X0 */
skip_cp15:
b cpu_resume
ENDPROC(exynos_cpu_resume_ns)
@@ -83,3 +119,8 @@ cp15_save_diag:
.globl cp15_save_power
cp15_save_power:
.long 0 @ cp15 power control
+#ifdef CONFIG_CACHE_L2X0
+ .globl l2x0_regs_phys
+l2x0_regs_phys:
+ .long 0 @ phys address of l2x0 save struct
+#endif /* CONFIG_CACHE_L2X0 */
--
1.9.3

2014-07-17 16:39:56

by Tomasz Figa

[permalink] [raw]
Subject: [PATCH v3 1/7] ARM: l2c: Refactor the driver to use commit-like interface

Certain implementations of secure hypervisors (namely the one found on
Samsung Exynos-based boards) do not provide access to individual L2C
registers. This makes the .write_sec()-based interface insufficient and
provoking ugly hacks.

This patch is first step to make the driver not rely on availability of
writes to individual registers. This is achieved by refactoring the
driver to use a commit-like operation scheme: all register values are
prepared first and stored in an instance of l2x0_regs struct and then a
single callback is responsible to flush those values to the hardware.

Signed-off-by: Tomasz Figa <[email protected]>
---
arch/arm/mm/cache-l2x0.c | 201 ++++++++++++++++++++++++++---------------------
1 file changed, 110 insertions(+), 91 deletions(-)

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 5f2c988..385c047 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -40,12 +40,14 @@ struct l2c_init_data {
void (*enable)(void __iomem *, u32, unsigned);
void (*fixup)(void __iomem *, u32, struct outer_cache_fns *);
void (*save)(void __iomem *);
+ void (*configure)(void __iomem *);
struct outer_cache_fns outer_cache;
};

#define CACHE_LINE_SIZE 32

static void __iomem *l2x0_base;
+static const struct l2c_init_data *l2x0_data;
static DEFINE_RAW_SPINLOCK(l2x0_lock);
static u32 l2x0_way_mask; /* Bitmask of active ways */
static u32 l2x0_size;
@@ -105,6 +107,14 @@ static inline void l2c_unlock(void __iomem *base, unsigned num)
}
}

+static void l2c_configure(void __iomem *base)
+{
+ if (l2x0_data->configure)
+ l2x0_data->configure(base);
+
+ l2c_write_sec(l2x0_saved_regs.aux_ctrl, base, L2X0_AUX_CTRL);
+}
+
/*
* Enable the L2 cache controller. This function must only be
* called when the cache controller is known to be disabled.
@@ -113,7 +123,12 @@ static void l2c_enable(void __iomem *base, u32 aux, unsigned num_lock)
{
unsigned long flags;

- l2c_write_sec(aux, base, L2X0_AUX_CTRL);
+ /* Do not touch the controller if already enabled. */
+ if (readl_relaxed(base + L2X0_CTRL) & L2X0_CTRL_EN)
+ return;
+
+ l2x0_saved_regs.aux_ctrl = aux;
+ l2c_configure(base);

l2c_unlock(base, num_lock);

@@ -207,6 +222,12 @@ static void l2c_save(void __iomem *base)
l2x0_saved_regs.aux_ctrl = readl_relaxed(l2x0_base + L2X0_AUX_CTRL);
}

+static void l2c_resume(void)
+{
+ l2x0_data->enable(l2x0_base, l2x0_saved_regs.aux_ctrl,
+ l2x0_data->num_lock);
+}
+
/*
* L2C-210 specific code.
*
@@ -287,14 +308,6 @@ static void l2c210_sync(void)
__l2c210_cache_sync(l2x0_base);
}

-static void l2c210_resume(void)
-{
- void __iomem *base = l2x0_base;
-
- if (!(readl_relaxed(base + L2X0_CTRL) & L2X0_CTRL_EN))
- l2c_enable(base, l2x0_saved_regs.aux_ctrl, 1);
-}
-
static const struct l2c_init_data l2c210_data __initconst = {
.type = "L2C-210",
.way_size_0 = SZ_8K,
@@ -308,7 +321,7 @@ static const struct l2c_init_data l2c210_data __initconst = {
.flush_all = l2c210_flush_all,
.disable = l2c_disable,
.sync = l2c210_sync,
- .resume = l2c210_resume,
+ .resume = l2c_resume,
},
};

@@ -465,7 +478,7 @@ static const struct l2c_init_data l2c220_data = {
.flush_all = l2c220_flush_all,
.disable = l2c_disable,
.sync = l2c220_sync,
- .resume = l2c210_resume,
+ .resume = l2c_resume,
},
};

@@ -614,39 +627,29 @@ static void __init l2c310_save(void __iomem *base)
L310_POWER_CTRL);
}

-static void l2c310_resume(void)
+static void l2c310_configure(void __iomem *base)
{
- void __iomem *base = l2x0_base;
+ unsigned revision;

- if (!(readl_relaxed(base + L2X0_CTRL) & L2X0_CTRL_EN)) {
- unsigned revision;
-
- /* restore pl310 setup */
- writel_relaxed(l2x0_saved_regs.tag_latency,
- base + L310_TAG_LATENCY_CTRL);
- writel_relaxed(l2x0_saved_regs.data_latency,
- base + L310_DATA_LATENCY_CTRL);
- writel_relaxed(l2x0_saved_regs.filter_end,
- base + L310_ADDR_FILTER_END);
- writel_relaxed(l2x0_saved_regs.filter_start,
- base + L310_ADDR_FILTER_START);
-
- revision = readl_relaxed(base + L2X0_CACHE_ID) &
- L2X0_CACHE_ID_RTL_MASK;
-
- if (revision >= L310_CACHE_ID_RTL_R2P0)
- l2c_write_sec(l2x0_saved_regs.prefetch_ctrl, base,
- L310_PREFETCH_CTRL);
- if (revision >= L310_CACHE_ID_RTL_R3P0)
- l2c_write_sec(l2x0_saved_regs.pwr_ctrl, base,
- L310_POWER_CTRL);
-
- l2c_enable(base, l2x0_saved_regs.aux_ctrl, 8);
-
- /* Re-enable full-line-of-zeros for Cortex-A9 */
- if (l2x0_saved_regs.aux_ctrl & L310_AUX_CTRL_FULL_LINE_ZERO)
- set_auxcr(get_auxcr() | BIT(3) | BIT(2) | BIT(1));
- }
+ /* restore pl310 setup */
+ writel_relaxed(l2x0_saved_regs.tag_latency,
+ base + L310_TAG_LATENCY_CTRL);
+ writel_relaxed(l2x0_saved_regs.data_latency,
+ base + L310_DATA_LATENCY_CTRL);
+ writel_relaxed(l2x0_saved_regs.filter_end,
+ base + L310_ADDR_FILTER_END);
+ writel_relaxed(l2x0_saved_regs.filter_start,
+ base + L310_ADDR_FILTER_START);
+
+ revision = readl_relaxed(base + L2X0_CACHE_ID) &
+ L2X0_CACHE_ID_RTL_MASK;
+
+ if (revision >= L310_CACHE_ID_RTL_R2P0)
+ l2c_write_sec(l2x0_saved_regs.prefetch_ctrl, base,
+ L310_PREFETCH_CTRL);
+ if (revision >= L310_CACHE_ID_RTL_R3P0)
+ l2c_write_sec(l2x0_saved_regs.pwr_ctrl, base,
+ L310_POWER_CTRL);
}

static int l2c310_cpu_enable_flz(struct notifier_block *nb, unsigned long act, void *data)
@@ -698,6 +701,23 @@ static void __init l2c310_enable(void __iomem *base, u32 aux, unsigned num_lock)
aux &= ~(L310_AUX_CTRL_FULL_LINE_ZERO | L310_AUX_CTRL_EARLY_BRESP);
}

+ /* r3p0 or later has power control register */
+ if (rev >= L310_CACHE_ID_RTL_R3P0)
+ l2x0_saved_regs.pwr_ctrl = L310_DYNAMIC_CLK_GATING_EN |
+ L310_STNDBY_MODE_EN;
+
+ /*
+ * Always enable non-secure access to the lockdown registers -
+ * we write to them as part of the L2C enable sequence so they
+ * need to be accessible.
+ */
+ aux |= L310_AUX_CTRL_NS_LOCKDOWN;
+
+ l2c_enable(base, aux, num_lock);
+
+ /* Read back resulting AUX_CTRL value as it could have been altered. */
+ aux = readl_relaxed(base + L2X0_AUX_CTRL);
+
if (aux & (L310_AUX_CTRL_DATA_PREFETCH | L310_AUX_CTRL_INSTR_PREFETCH)) {
u32 prefetch = readl_relaxed(base + L310_PREFETCH_CTRL);

@@ -711,23 +731,12 @@ static void __init l2c310_enable(void __iomem *base, u32 aux, unsigned num_lock)
if (rev >= L310_CACHE_ID_RTL_R3P0) {
u32 power_ctrl;

- l2c_write_sec(L310_DYNAMIC_CLK_GATING_EN | L310_STNDBY_MODE_EN,
- base, L310_POWER_CTRL);
power_ctrl = readl_relaxed(base + L310_POWER_CTRL);
pr_info("L2C-310 dynamic clock gating %sabled, standby mode %sabled\n",
power_ctrl & L310_DYNAMIC_CLK_GATING_EN ? "en" : "dis",
power_ctrl & L310_STNDBY_MODE_EN ? "en" : "dis");
}

- /*
- * Always enable non-secure access to the lockdown registers -
- * we write to them as part of the L2C enable sequence so they
- * need to be accessible.
- */
- aux |= L310_AUX_CTRL_NS_LOCKDOWN;
-
- l2c_enable(base, aux, num_lock);
-
if (aux & L310_AUX_CTRL_FULL_LINE_ZERO) {
set_auxcr(get_auxcr() | BIT(3) | BIT(2) | BIT(1));
cpu_notifier(l2c310_cpu_enable_flz, 0);
@@ -759,11 +768,11 @@ static void __init l2c310_fixup(void __iomem *base, u32 cache_id,

if (revision >= L310_CACHE_ID_RTL_R3P0 &&
revision < L310_CACHE_ID_RTL_R3P2) {
- u32 val = readl_relaxed(base + L310_PREFETCH_CTRL);
+ u32 val = l2x0_saved_regs.prefetch_ctrl;
/* I don't think bit23 is required here... but iMX6 does so */
if (val & (BIT(30) | BIT(23))) {
val &= ~(BIT(30) | BIT(23));
- l2c_write_sec(val, base, L310_PREFETCH_CTRL);
+ l2x0_saved_regs.prefetch_ctrl = val;
errata[n++] = "752271";
}
}
@@ -799,6 +808,15 @@ static void l2c310_disable(void)
l2c_disable();
}

+static void l2c310_resume(void)
+{
+ l2c_resume();
+
+ /* Re-enable full-line-of-zeros for Cortex-A9 */
+ if (l2x0_saved_regs.aux_ctrl & L310_AUX_CTRL_FULL_LINE_ZERO)
+ set_auxcr(get_auxcr() | BIT(3) | BIT(2) | BIT(1));
+}
+
static const struct l2c_init_data l2c310_init_fns __initconst = {
.type = "L2C-310",
.way_size_0 = SZ_8K,
@@ -806,6 +824,7 @@ static const struct l2c_init_data l2c310_init_fns __initconst = {
.enable = l2c310_enable,
.fixup = l2c310_fixup,
.save = l2c310_save,
+ .configure = l2c310_configure,
.outer_cache = {
.inv_range = l2c210_inv_range,
.clean_range = l2c210_clean_range,
@@ -825,6 +844,12 @@ static void __init __l2c_init(const struct l2c_init_data *data,
u32 aux, old_aux;

/*
+ * Save the pointer globally so that callbacks which do not receive
+ * context from callers can access the structure.
+ */
+ l2x0_data = data;
+
+ /*
* Sanity check the aux values. aux_mask is the bits we preserve
* from reading the hardware register, and aux_val is the bits we
* set.
@@ -935,6 +960,10 @@ void __init l2x0_init(void __iomem *base, u32 aux_val, u32 aux_mask)
break;
}

+ /* Read back current (default) hardware configuration */
+ if (data->save)
+ data->save(l2x0_base);
+
__l2c_init(data, aux_val, aux_mask, cache_id);
}

@@ -993,7 +1022,7 @@ static const struct l2c_init_data of_l2c210_data __initconst = {
.flush_all = l2c210_flush_all,
.disable = l2c_disable,
.sync = l2c210_sync,
- .resume = l2c210_resume,
+ .resume = l2c_resume,
},
};

@@ -1011,7 +1040,7 @@ static const struct l2c_init_data of_l2c220_data __initconst = {
.flush_all = l2c220_flush_all,
.disable = l2c_disable,
.sync = l2c220_sync,
- .resume = l2c210_resume,
+ .resume = l2c_resume,
},
};

@@ -1024,28 +1053,26 @@ static void __init l2c310_of_parse(const struct device_node *np,

of_property_read_u32_array(np, "arm,tag-latency", tag, ARRAY_SIZE(tag));
if (tag[0] && tag[1] && tag[2])
- writel_relaxed(
+ l2x0_saved_regs.tag_latency =
L310_LATENCY_CTRL_RD(tag[0] - 1) |
L310_LATENCY_CTRL_WR(tag[1] - 1) |
- L310_LATENCY_CTRL_SETUP(tag[2] - 1),
- l2x0_base + L310_TAG_LATENCY_CTRL);
+ L310_LATENCY_CTRL_SETUP(tag[2] - 1);

of_property_read_u32_array(np, "arm,data-latency",
data, ARRAY_SIZE(data));
if (data[0] && data[1] && data[2])
- writel_relaxed(
+ l2x0_saved_regs.data_latency =
L310_LATENCY_CTRL_RD(data[0] - 1) |
L310_LATENCY_CTRL_WR(data[1] - 1) |
- L310_LATENCY_CTRL_SETUP(data[2] - 1),
- l2x0_base + L310_DATA_LATENCY_CTRL);
+ L310_LATENCY_CTRL_SETUP(data[2] - 1);

of_property_read_u32_array(np, "arm,filter-ranges",
filter, ARRAY_SIZE(filter));
if (filter[1]) {
- writel_relaxed(ALIGN(filter[0] + filter[1], SZ_1M),
- l2x0_base + L310_ADDR_FILTER_END);
- writel_relaxed((filter[0] & ~(SZ_1M - 1)) | L310_ADDR_FILTER_EN,
- l2x0_base + L310_ADDR_FILTER_START);
+ l2x0_saved_regs.filter_end =
+ ALIGN(filter[0] + filter[1], SZ_1M);
+ l2x0_saved_regs.filter_start = (filter[0] & ~(SZ_1M - 1))
+ | L310_ADDR_FILTER_EN;
}
}

@@ -1057,6 +1084,7 @@ static const struct l2c_init_data of_l2c310_data __initconst = {
.enable = l2c310_enable,
.fixup = l2c310_fixup,
.save = l2c310_save,
+ .configure = l2c310_configure,
.outer_cache = {
.inv_range = l2c210_inv_range,
.clean_range = l2c210_clean_range,
@@ -1085,6 +1113,7 @@ static const struct l2c_init_data of_l2c310_coherent_data __initconst = {
.enable = l2c310_enable,
.fixup = l2c310_fixup,
.save = l2c310_save,
+ .configure = l2c310_configure,
.outer_cache = {
.inv_range = l2c210_inv_range,
.clean_range = l2c210_clean_range,
@@ -1199,16 +1228,6 @@ static void aurora_save(void __iomem *base)
l2x0_saved_regs.aux_ctrl = readl_relaxed(base + L2X0_AUX_CTRL);
}

-static void aurora_resume(void)
-{
- void __iomem *base = l2x0_base;
-
- if (!(readl(base + L2X0_CTRL) & L2X0_CTRL_EN)) {
- writel_relaxed(l2x0_saved_regs.aux_ctrl, base + L2X0_AUX_CTRL);
- writel_relaxed(l2x0_saved_regs.ctrl, base + L2X0_CTRL);
- }
-}
-
/*
* For Aurora cache in no outer mode, enable via the CP15 coprocessor
* broadcasting of cache commands to L2.
@@ -1270,7 +1289,7 @@ static const struct l2c_init_data of_aurora_with_outer_data __initconst = {
.flush_all = l2x0_flush_all,
.disable = l2x0_disable,
.sync = l2x0_cache_sync,
- .resume = aurora_resume,
+ .resume = l2c_resume,
},
};

@@ -1283,7 +1302,7 @@ static const struct l2c_init_data of_aurora_no_outer_data __initconst = {
.fixup = aurora_fixup,
.save = aurora_save,
.outer_cache = {
- .resume = aurora_resume,
+ .resume = l2c_resume,
},
};

@@ -1431,6 +1450,7 @@ static const struct l2c_init_data of_bcm_l2x0_data __initconst = {
.of_parse = l2c310_of_parse,
.enable = l2c310_enable,
.save = l2c310_save,
+ .configure = l2c310_configure,
.outer_cache = {
.inv_range = bcm_inv_range,
.clean_range = bcm_clean_range,
@@ -1452,18 +1472,12 @@ static void __init tauros3_save(void __iomem *base)
readl_relaxed(base + L310_PREFETCH_CTRL);
}

-static void tauros3_resume(void)
+static void tauros3_configure(void __iomem *base)
{
- void __iomem *base = l2x0_base;
-
- if (!(readl_relaxed(base + L2X0_CTRL) & L2X0_CTRL_EN)) {
- writel_relaxed(l2x0_saved_regs.aux2_ctrl,
- base + TAUROS3_AUX2_CTRL);
- writel_relaxed(l2x0_saved_regs.prefetch_ctrl,
- base + L310_PREFETCH_CTRL);
-
- l2c_enable(base, l2x0_saved_regs.aux_ctrl, 8);
- }
+ writel_relaxed(l2x0_saved_regs.aux2_ctrl,
+ base + TAUROS3_AUX2_CTRL);
+ writel_relaxed(l2x0_saved_regs.prefetch_ctrl,
+ base + L310_PREFETCH_CTRL);
}

static const struct l2c_init_data of_tauros3_data __initconst = {
@@ -1472,9 +1486,10 @@ static const struct l2c_init_data of_tauros3_data __initconst = {
.num_lock = 8,
.enable = l2c_enable,
.save = tauros3_save,
+ .configure = tauros3_configure,
/* Tauros3 broadcasts L1 cache operations to L2 */
.outer_cache = {
- .resume = tauros3_resume,
+ .resume = l2c_resume,
},
};

@@ -1530,6 +1545,10 @@ int __init l2x0_of_init(u32 aux_val, u32 aux_mask)
if (!of_property_read_bool(np, "cache-unified"))
pr_err("L2C: device tree omits to specify unified cache\n");

+ /* Read back current (default) hardware configuration */
+ if (data->save)
+ data->save(l2x0_base);
+
/* L2 configuration can only be changed if the cache is disabled */
if (!(readl_relaxed(l2x0_base + L2X0_CTRL) & L2X0_CTRL_EN))
if (data->of_parse)
--
1.9.3

2014-07-17 16:40:41

by Tomasz Figa

[permalink] [raw]
Subject: [PATCH v3 7/7] ARM: dts: exynos4: Add nodes for L2 cache controller

This patch adds device tree nodes for L2 cache controller present on
Exynos4 SoCs.

Signed-off-by: Tomasz Figa <[email protected]>
---
arch/arm/boot/dts/exynos4210.dtsi | 9 +++++++++
arch/arm/boot/dts/exynos4x12.dtsi | 14 ++++++++++++++
2 files changed, 23 insertions(+)

diff --git a/arch/arm/boot/dts/exynos4210.dtsi b/arch/arm/boot/dts/exynos4210.dtsi
index ee3001f..99970ab 100644
--- a/arch/arm/boot/dts/exynos4210.dtsi
+++ b/arch/arm/boot/dts/exynos4210.dtsi
@@ -54,6 +54,15 @@
reg = <0x10023CA0 0x20>;
};

+ l2c: l2-cache-controller@10502000 {
+ compatible = "arm,pl310-cache";
+ reg = <0x10502000 0x1000>;
+ cache-unified;
+ cache-level = <2>;
+ arm,tag-latency = <2 2 1>;
+ arm,data-latency = <2 2 1>;
+ };
+
gic: interrupt-controller@10490000 {
cpu-offset = <0x8000>;
};
diff --git a/arch/arm/boot/dts/exynos4x12.dtsi b/arch/arm/boot/dts/exynos4x12.dtsi
index c5a943d..ddffefe 100644
--- a/arch/arm/boot/dts/exynos4x12.dtsi
+++ b/arch/arm/boot/dts/exynos4x12.dtsi
@@ -60,6 +60,20 @@
reg = <0x10023CA0 0x20>;
};

+ l2c: l2-cache-controller@10502000 {
+ compatible = "arm,pl310-cache";
+ reg = <0x10502000 0x1000>;
+ cache-unified;
+ cache-level = <2>;
+ arm,tag-latency = <2 2 1>;
+ arm,data-latency = <3 2 1>;
+ arm,double-linefill = <1>;
+ arm,double-linefill-incr = <0>;
+ arm,double-linefill-wrap = <1>;
+ arm,prefetch-drop = <1>;
+ arm,prefetch-offset = <7>;
+ };
+
clock: clock-controller@10030000 {
compatible = "samsung,exynos4412-clock";
reg = <0x10030000 0x20000>;
--
1.9.3

2014-07-17 16:40:57

by Tomasz Figa

[permalink] [raw]
Subject: [PATCH v3 5/7] ARM: EXYNOS: Add .write_sec outer cache callback for L2C-310

Exynos4 SoCs equipped with an L2C-310 cache controller and running under
secure firmware require certain registers of aforementioned IP to be
accessed only from secure mode. This means that SMC calls are required
for certain register writes. To handle this, an implementation of
.write_sec and .configure callbacks is provided by this patch.

Signed-off-by: Tomasz Figa <[email protected]>
---
arch/arm/mach-exynos/firmware.c | 38 ++++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)

diff --git a/arch/arm/mach-exynos/firmware.c b/arch/arm/mach-exynos/firmware.c
index f5e626d..554b350 100644
--- a/arch/arm/mach-exynos/firmware.c
+++ b/arch/arm/mach-exynos/firmware.c
@@ -17,6 +17,7 @@
#include <asm/cacheflush.h>
#include <asm/cputype.h>
#include <asm/firmware.h>
+#include <asm/hardware/cache-l2x0.h>
#include <asm/suspend.h>

#include <mach/map.h>
@@ -120,6 +121,31 @@ static const struct firmware_ops exynos_firmware_ops = {
.resume = exynos_resume,
};

+static void exynos_l2_write_sec(unsigned long val, unsigned reg)
+{
+ switch (reg) {
+ case L2X0_CTRL:
+ if (val & L2X0_CTRL_EN)
+ exynos_smc(SMC_CMD_L2X0INVALL, 0, 0, 0);
+ exynos_smc(SMC_CMD_L2X0CTRL, val, 0, 0);
+ break;
+
+ case L2X0_DEBUG_CTRL:
+ exynos_smc(SMC_CMD_L2X0DEBUG, val, 0, 0);
+ break;
+
+ default:
+ WARN_ONCE(1, "%s: ignoring write to reg 0x%x\n", __func__, reg);
+ }
+}
+
+static void exynos_l2_configure(const struct l2x0_regs *regs)
+{
+ exynos_smc(SMC_CMD_L2X0SETUP1, regs->tag_latency, regs->data_latency,
+ regs->prefetch_ctrl);
+ exynos_smc(SMC_CMD_L2X0SETUP2, regs->pwr_ctrl, regs->aux_ctrl, 0);
+}
+
void __init exynos_firmware_init(void)
{
struct device_node *nd;
@@ -139,4 +165,16 @@ void __init exynos_firmware_init(void)
pr_info("Running under secure firmware.\n");

register_firmware_ops(&exynos_firmware_ops);
+
+ /*
+ * Exynos 4 SoCs (based on Cortex A9 and equipped with L2C-310),
+ * running under secure firmware, require certain registers of L2
+ * cache controller to be written in secure mode. Here .write_sec
+ * callback is provided to perform necessary SMC calls.
+ */
+ if (IS_ENABLED(CONFIG_CACHE_L2X0)
+ && read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
+ outer_cache.write_sec = exynos_l2_write_sec;
+ outer_cache.configure = exynos_l2_configure;
+ }
}
--
1.9.3

2014-07-17 16:41:25

by Tomasz Figa

[permalink] [raw]
Subject: [PATCH v3 4/7] ARM: l2c: Add support for overriding prefetch settings

Firmware on certain boards (e.g. ODROID-U3) can leave incorrect L2C prefetch
settings configured in registers leading to crashes if L2C is enabled
without overriding them. This patch introduces bindings to enable
prefetch settings to be specified from DT and necessary support in the
driver.

Signed-off-by: Tomasz Figa <[email protected]>
---
Documentation/devicetree/bindings/arm/l2cc.txt | 10 +++++++
arch/arm/mm/cache-l2x0.c | 39 ++++++++++++++++++++++++++
2 files changed, 49 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt
index af527ee..3443d2d 100644
--- a/Documentation/devicetree/bindings/arm/l2cc.txt
+++ b/Documentation/devicetree/bindings/arm/l2cc.txt
@@ -47,6 +47,16 @@ Optional properties:
- cache-id-part: cache id part number to be used if it is not present
on hardware
- wt-override: If present then L2 is forced to Write through mode
+- arm,double-linefill : Override double linefill enable setting. Enable if
+ non-zero, disable if zero.
+- arm,double-linefill-incr : Override double linefill on INCR read. Enable
+ if non-zero, disable if zero.
+- arm,double-linefill-wrap : Override double linefill on WRAP read. Enable
+ if non-zero, disable if zero.
+- arm,prefetch-drop : Override prefetch drop enable setting. Enable if non-zero,
+ disable if zero.
+- arm,prefetch-offset : Override prefetch offset value. Valid values are
+ 0-7, 15, 23, and 31.

Example:

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 21a625a0..6274803 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -1055,6 +1055,8 @@ static void __init l2c310_of_parse(const struct device_node *np,
u32 data[3] = { 0, 0, 0 };
u32 tag[3] = { 0, 0, 0 };
u32 filter[2] = { 0, 0 };
+ u32 prefetch;
+ u32 val;

of_property_read_u32_array(np, "arm,tag-latency", tag, ARRAY_SIZE(tag));
if (tag[0] && tag[1] && tag[2])
@@ -1079,6 +1081,43 @@ static void __init l2c310_of_parse(const struct device_node *np,
l2x0_saved_regs.filter_start = (filter[0] & ~(SZ_1M - 1))
| L310_ADDR_FILTER_EN;
}
+
+ prefetch = l2x0_saved_regs.prefetch_ctrl;
+
+ if (!of_property_read_u32(np, "arm,double-linefill", &val)) {
+ if (val)
+ prefetch |= L310_PREFETCH_CTRL_DBL_LINEFILL;
+ else
+ prefetch &= ~L310_PREFETCH_CTRL_DBL_LINEFILL;
+ }
+
+ if (!of_property_read_u32(np, "arm,double-linefill-incr", &val)) {
+ if (val)
+ prefetch |= L310_PREFETCH_CTRL_DBL_LINEFILL_INCR;
+ else
+ prefetch &= ~L310_PREFETCH_CTRL_DBL_LINEFILL_INCR;
+ }
+
+ if (!of_property_read_u32(np, "arm,double-linefill-wrap", &val)) {
+ if (!val)
+ prefetch |= L310_PREFETCH_CTRL_DBL_LINEFILL_WRAP;
+ else
+ prefetch &= ~L310_PREFETCH_CTRL_DBL_LINEFILL_WRAP;
+ }
+
+ if (!of_property_read_u32(np, "arm,prefetch-drop", &val)) {
+ if (val)
+ prefetch |= L310_PREFETCH_CTRL_PREFETCH_DROP;
+ else
+ prefetch &= ~L310_PREFETCH_CTRL_PREFETCH_DROP;
+ }
+
+ if (!of_property_read_u32(np, "arm,prefetch-offset", &val)) {
+ prefetch &= ~L310_PREFETCH_CTRL_OFFSET_MASK;
+ prefetch |= val & L310_PREFETCH_CTRL_OFFSET_MASK;
+ }
+
+ l2x0_saved_regs.prefetch_ctrl = prefetch;
}

static const struct l2c_init_data of_l2c310_data __initconst = {
--
1.9.3

2014-07-17 16:41:58

by Tomasz Figa

[permalink] [raw]
Subject: [PATCH v3 2/7] ARM: l2c: Add interface to ask hypervisor to configure L2C

Because certain secure hypervisor do not allow writes to individual L2C
registers, but rather expect set of parameters to be passed as argument
to secure monitor calls, there is a need to provide an interface for the
L2C driver to ask the firmware to configure the hardware according to
specified parameters. This patch adds such.

Signed-off-by: Tomasz Figa <[email protected]>
---
arch/arm/include/asm/outercache.h | 3 +++
arch/arm/mm/cache-l2x0.c | 5 +++++
2 files changed, 8 insertions(+)

diff --git a/arch/arm/include/asm/outercache.h b/arch/arm/include/asm/outercache.h
index 891a56b..563b92f 100644
--- a/arch/arm/include/asm/outercache.h
+++ b/arch/arm/include/asm/outercache.h
@@ -23,6 +23,8 @@

#include <linux/types.h>

+struct l2x0_regs;
+
struct outer_cache_fns {
void (*inv_range)(unsigned long, unsigned long);
void (*clean_range)(unsigned long, unsigned long);
@@ -36,6 +38,7 @@ struct outer_cache_fns {

/* This is an ARM L2C thing */
void (*write_sec)(unsigned long, unsigned);
+ void (*configure)(const struct l2x0_regs *);
};

extern struct outer_cache_fns outer_cache;
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 385c047..21a625a0 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -109,6 +109,11 @@ static inline void l2c_unlock(void __iomem *base, unsigned num)

static void l2c_configure(void __iomem *base)
{
+ if (outer_cache.configure) {
+ outer_cache.configure(&l2x0_saved_regs);
+ return;
+ }
+
if (l2x0_data->configure)
l2x0_data->configure(base);

--
1.9.3

2014-07-17 16:41:57

by Tomasz Figa

[permalink] [raw]
Subject: [PATCH v3 3/7] ARM: l2c: Get outer cache .write_sec callback from mach_desc only if not NULL

Certain platforms (i.e. Exynos) might need to set .write_sec callback
from firmware initialization which is happenning in .init_early callback
of machine descriptor. However current code will overwrite the pointer
with whatever is present in machine descriptor, even though it can be
already set earlier. This patch fixes this by making the assignment
conditional, depending on whether current .write_sec callback is NULL.

Signed-off-by: Tomasz Figa <[email protected]>
---
arch/arm/kernel/irq.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 2c42576..e7383b9 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -125,7 +125,8 @@ void __init init_IRQ(void)

if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
(machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
- outer_cache.write_sec = machine_desc->l2c_write_sec;
+ if (!outer_cache.write_sec)
+ outer_cache.write_sec = machine_desc->l2c_write_sec;
ret = l2x0_of_init(machine_desc->l2c_aux_val,
machine_desc->l2c_aux_mask);
if (ret)
--
1.9.3

2014-07-31 19:09:00

by Tomasz Figa

[permalink] [raw]
Subject: Re: [PATCH v3 0/7] Enable L2 cache support on Exynos4210/4x12 SoCs

On 17.07.2014 18:38, Tomasz Figa wrote:
> This series intends to add support for L2 cache on Exynos4 SoCs on boards
> running under secure firmware, which requires certain initialization steps
> to be done with help of firmware, as selected registers are writable only
> from secure mode.
>
> First four patches extend existing support for secure write in L2C driver
> to account for design of secure firmware running on Exynos. Namely:
> 1) direct read access to certain registers is needed on Exynos, because
> secure firmware calls set several registers at once,
> 2) not all boards are running secure firmware, so .write_sec callback
> needs to be installed in Exynos firmware ops initialization code,
> 3) write access to {DATA,TAG}_LATENCY_CTRL registers fron non-secure world
> is not allowed and so must use l2c_write_sec as well,
> 4) on certain boards, default value of prefetch register is incorrect
> and must be overridden at L2C initialization.
> For boards running with firmware that provides access to individual
> L2C registers this series should introduce no functional changes. However
> since the driver is widely used on other platforms I'd like to kindly ask
> any interested people for testing.
>
> Further two patches add impelmentation of .write_sec for Exynos secure
> firmware and necessary DT nodes to enable L2 cache.
>
> Tested on Exynos4210-based Universal C210 and Trats (both without secure
> firmware) and Exynos4412-based TRATS2 and ODROID-U3 boards (both with secure
> firmware).
>
> Depends on:
> - [PATCH] ARM: make it easier to check the CPU part number correctly
> (http://thread.gmane.org/gmane.linux.ports.arm.kernel/335126
> already in linux-next)
> - [PATCH v2 0/2] Firmware-assisted suspend/resume of Exynos SoCs
> (https://lkml.org/lkml/2014/7/17/431)
>
> Changes since v2:
> (https://lkml.org/lkml/2014/6/25/416)
> - refactored L2C driver to use commit-like interface and make it no longer
> depend on availability of writes to individual registers,
> - moved L2C resume to assembly code, because doing it later makes some
> systems unstable - this is also needed for deeper cpuidle modes,
> - dropped unnecessary patch hacking around the .write_sec interface,
> - dropped patch making the driver use l2c_write_sec() for LATENCY_CTRL
> registers as Exynos is no longer affected and I'm not aware of any
> reports that this is also needed on other platforms (can be applied
> separately if it turns out to be so),
> - rebased onto next-20140717 tag of linux-next tree.
>
> Changes since v1:
> (https://www.mail-archive.com/[email protected]/msg106323.html)
> - rebased onto for-next branch of linux-samsung tree,
> - changed argument order of outer_cache.write_sec() callback to match
> l2c_write_sec() function in cache-l2x0.c,
> - added support of overriding of prefetch settings to work around incorrect
> default settings on certain Exynos4x12-based boards,
> - added call to firmware to invalidate whole L2 cache before setting enable
> bit in L2C control register (required by Exynos secure firmware).
>
> Tomasz Figa (7):
> ARM: l2c: Refactor the driver to use commit-like interface
> ARM: l2c: Add interface to ask hypervisor to configure L2C
> ARM: l2c: Get outer cache .write_sec callback from mach_desc only if
> not NULL
> ARM: l2c: Add support for overriding prefetch settings
> ARM: EXYNOS: Add .write_sec outer cache callback for L2C-310
> ARM: EXYNOS: Add support for non-secure L2X0 resume
> ARM: dts: exynos4: Add nodes for L2 cache controller
>
> Documentation/devicetree/bindings/arm/l2cc.txt | 10 +
> arch/arm/boot/dts/exynos4210.dtsi | 9 +
> arch/arm/boot/dts/exynos4x12.dtsi | 14 ++
> arch/arm/include/asm/outercache.h | 3 +
> arch/arm/kernel/irq.c | 3 +-
> arch/arm/mach-exynos/common.h | 1 +
> arch/arm/mach-exynos/firmware.c | 40 ++++
> arch/arm/mach-exynos/sleep.S | 41 +++++
> arch/arm/mm/cache-l2x0.c | 245 ++++++++++++++++---------
> 9 files changed, 274 insertions(+), 92 deletions(-)
>

Any comments for this series?

Best regards,
Tomasz