Thanks Will for reporting it. > -----Original Message----- > From: linux-arm-kernel-boun...@lists.infradead.org [mailto:linux- > arm-kernel-boun...@lists.infradead.org] On Behalf Of Will Deacon > Sent: Monday, March 07, 2011 5:38 PM > To: 'Santosh Shilimkar'; Russell King - ARM Linux > Cc: t...@atomide.com; Catalin Marinas; linux-omap@vger.kernel.org; > linux-arm-ker...@lists.infradead.org > Subject: RE: [PATCH 1/2] ARM: l2x0: Errata fix for flush by > Wayoperationcan cause data corruption > > Hi Santosh, > > > > On Sun, Feb 27, 2011 at 12:00:21PM +0000, Russell King - ARM > Linux > > > wrote: > > > > > +#else > > > > > +/* Optimised out for non-errata case */ > > > > > +static inline void debug_writel(unsigned long val) > > > > > +{ > > > > > } > > > > > > > > #define l2x0_set_debug NULL > > > > > > > > > +#endif > > > > > > I notice you got rid of the inline function. Have you tried > > > building this without the errata enabled? > > > > I accidently dropped the inline function while > > incorporating the comment from you. :( > > > > Fixed it. Updated version # 6770/1 > > This version of the patch (as it appears in -next) is broken: > > > +#define debug_writel(val) outer_cache.set_debug(val) > + > +static void l2x0_set_debug(unsigned long val) > +{ > + writel(val, l2x0_base + L2X0_DEBUG_CTRL);
This should have been "writel_relaxed()" to avoid the
cache sync.
> }
>
> [...]
>
> @@ -119,9 +120,11 @@ static void l2x0_flush_all(void)
>
> /* clean all ways */
> spin_lock_irqsave(&l2x0_lock, flags);
> + debug_writel(0x03);
> writel_relaxed(l2x0_way_mask, l2x0_base + L2X0_CLEAN_INV_WAY);
> cache_wait_way(l2x0_base + L2X0_CLEAN_INV_WAY, l2x0_way_mask);
> cache_sync();
> + debug_writel(0x00);
> spin_unlock_irqrestore(&l2x0_lock, flags);
> }
>
>
> This deadlocks because the writel forces an outer cache sync, which
> then tries to acquire the spinlock which is held by the calling
> function.
>
> If you change l2x0_set_debug to use writel_relaxed then you can
> avoid the problem.
>
Ya understood. I couldn't test non-errata case because
direct right doesn't work because of security and henced missed
it.
Below is the updated version. Also attached.
Russell,
Do you want me to push this to patch system or you can
apply this one?
Regards,
Santosh
------
>From 9167fd4eff8adf1f8be772cdb734bfc0f2061354 Mon Sep 17 00:00:00 2001
From: Santosh Shilimkar <santosh.shilim...@ti.com>
Date: Mon, 28 Feb 2011 13:31:09 +0100
Subject: [PATCH] ARM: 6770/1: l2x0: Errata fix for flush by Way operation
can cause data corruption
PL310 implements the Clean & Invalidate by Way L2 cache maintenance
operation (offset 0x7FC). This operation runs in background so that
PL310 can handle normal accesses while it is in progress. Under very
rare circumstances, due to this erratum, write data can be lost when
PL310 treats a cacheable write transaction during a Clean & Invalidate
by Way operation.
Workaround:
Disable Write-Back and Cache Linefill (Debug Control Register)
Clean & Invalidate by Way (0x7FC)
Re-enable Write-Back and Cache Linefill (Debug Control Register)
This patch also removes any OMAP dependency on PL310 Errata's
Signed-off-by: Santosh Shilimkar <santosh.shilim...@ti.com>
Acked-by: Catalin Marinas <catalin.mari...@arm.com>
Signed-off-by: Russell King <rmk+ker...@arm.linux.org.uk>
---
arch/arm/Kconfig | 15 ++++++++++++---
arch/arm/include/asm/outercache.h | 1 +
arch/arm/mm/cache-l2x0.c | 32 ++++++++++++++++++--------------
3 files changed, 31 insertions(+), 17 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 65ea7bb..ef41f7e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1135,7 +1135,7 @@ config ARM_ERRATA_742231
config PL310_ERRATA_588369
bool "Clean & Invalidate maintenance operations do not invalidate
clean lines"
- depends on CACHE_L2X0 && ARCH_OMAP4
+ depends on CACHE_L2X0
help
The PL310 L2 cache controller implements three types of Clean &
Invalidate maintenance operations: by Physical Address
@@ -1144,8 +1144,7 @@ config PL310_ERRATA_588369
clean operation followed immediately by an invalidate
operation,
both performing to the same memory location. This functionality
is not correctly implemented in PL310 as clean lines are not
- invalidated as a result of these operations. Note that this
errata
- uses Texas Instrument's secure monitor api.
+ invalidated as a result of these operations.
config ARM_ERRATA_720789
bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can
broadcast a faulty ASID"
@@ -1172,6 +1171,16 @@ config ARM_ERRATA_743622
visible impact on the overall performance or power consumption
of the
processor.
+config PL310_ERRATA_727915
+ bool "Background Clean & Invalidate by Way operation can cause
data corruption"
+ depends on CACHE_L2X0
+ help
+ PL310 implements the Clean & Invalidate by Way L2 cache
maintenance
+ operation (offset 0x7FC). This operation runs in background so
that
+ PL310 can handle normal accesses while it is in progress. Under
very
+ rare circumstances, due to this erratum, write data can be lost
when
+ PL310 treats a cacheable write transaction during a Clean &
+ Invalidate by Way operation.
endmenu
source "arch/arm/common/Kconfig"
diff --git a/arch/arm/include/asm/outercache.h
b/arch/arm/include/asm/outercache.h
index fc19009..348d513 100644
--- a/arch/arm/include/asm/outercache.h
+++ b/arch/arm/include/asm/outercache.h
@@ -31,6 +31,7 @@ struct outer_cache_fns {
#ifdef CONFIG_OUTER_CACHE_SYNC
void (*sync)(void);
#endif
+ void (*set_debug)(unsigned long);
};
#ifdef CONFIG_OUTER_CACHE
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 170c9bb..0986cce 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -67,18 +67,24 @@ static inline void l2x0_inv_line(unsigned long addr)
writel_relaxed(addr, base + L2X0_INV_LINE_PA);
}
-#ifdef CONFIG_PL310_ERRATA_588369
-static void debug_writel(unsigned long val)
-{
- extern void omap_smc1(u32 fn, u32 arg);
+#if defined(CONFIG_PL310_ERRATA_588369) ||
defined(CONFIG_PL310_ERRATA_727915)
- /*
- * Texas Instrument secure monitor api to modify the
- * PL310 Debug Control Register.
- */
- omap_smc1(0x100, val);
+#define debug_writel(val) outer_cache.set_debug(val)
+
+static void l2x0_set_debug(unsigned long val)
+{
+ writel_relaxed(val, l2x0_base + L2X0_DEBUG_CTRL);
}
+#else
+/* Optimised out for non-errata case */
+static inline void debug_writel(unsigned long val)
+{
+}
+
+#define l2x0_set_debug NULL
+#endif
+#ifdef CONFIG_PL310_ERRATA_588369
static inline void l2x0_flush_line(unsigned long addr)
{
void __iomem *base = l2x0_base;
@@ -91,11 +97,6 @@ static inline void l2x0_flush_line(unsigned long addr)
}
#else
-/* Optimised out for non-errata case */
-static inline void debug_writel(unsigned long val)
-{
-}
-
static inline void l2x0_flush_line(unsigned long addr)
{
void __iomem *base = l2x0_base;
@@ -119,9 +120,11 @@ static void l2x0_flush_all(void)
/* clean all ways */
spin_lock_irqsave(&l2x0_lock, flags);
+ debug_writel(0x03);
writel_relaxed(l2x0_way_mask, l2x0_base + L2X0_CLEAN_INV_WAY);
cache_wait_way(l2x0_base + L2X0_CLEAN_INV_WAY, l2x0_way_mask);
cache_sync();
+ debug_writel(0x00);
spin_unlock_irqrestore(&l2x0_lock, flags);
}
@@ -329,6 +332,7 @@ void __init l2x0_init(void __iomem *base, __u32
aux_val, __u32 aux_mask)
outer_cache.flush_all = l2x0_flush_all;
outer_cache.inv_all = l2x0_inv_all;
outer_cache.disable = l2x0_disable;
+ outer_cache.set_debug = l2x0_set_debug;
printk(KERN_INFO "%s cache controller enabled\n", type);
printk(KERN_INFO "l2x0: %d ways, CACHE_ID 0x%08x, AUX_CTRL 0x%08x,
Cache size: %d B\n",
--
1.6.0.4
0001-ARM-6770-1-l2x0-Errata-fix-for-flush-by-Way-opera.patch
Description: Binary data
