Thread (115 messages) 115 messages, 8 authors, 2010-10-06
STALE5718d

[PATCH] ARM: Handle __flush_icache_all for CONFIG_SMP_ON_UP

From: tony@atomide.com (Tony Lindgren)
Date: 2010-09-14 18:59:08
Also in: linux-omap
Subsystem: arm port, the rest · Maintainers: Russell King, Linus Torvalds

* Russell King - ARM Linux [off-list ref] [100906 03:36]:
Here's my latest patch (which is combined from two patches.)
I think that patch is now done assuming the fixes I've posted are
merged, so here's my S-O-B for the bits I've contributed:

Signed-off-by: Tony Lindgren <tony@atomide.com>

Anybody else care to ack?
2. __flush_icache_all()

Note that (2) seems to be complicated by the instruction only being
available on ARMv7 and later.

Also note that this should only be used for comparing SMP vs UP versions
of the same architecture - in other words, not ARMv6 vs ARMv6K.
Here's a patch for __flush_icache_all. I believe this is the last
remaining patch we need.

The only other thing I can think of are the conflicts with
CONFIG_CPU_32v6K, on early ARM1136 and later ARM11 systems if somebody
wants to compile a kernel that supports both. But that's not needed for
omap2, so we can boot now omap2, 3 and 4 with a single defconfig :)

Regards,

Tony

From: Tony Lindgren <tony@atomide.com>
Date: Tue, 14 Sep 2010 11:33:09 -0700
Subject: [PATCH] ARM: Handle __flush_icache_all for CONFIG_SMP_ON_UP

Do this by adding flush_icache_all to cache_fns for ARMv6 and 7.
As flush_icache_all may neeed to be called from flush_kern_cache_all,
add it as the first entry in the cache_fns.

Note that now we can remove the ARM_ERRATA_411920 dependency
to !SMP so it can be selected on UP ARMv6 processors, such
as omap2.

Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index f274300..8853cc0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1003,7 +1003,7 @@ endif
 
 config ARM_ERRATA_411920
 	bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
-	depends on CPU_V6 && !SMP
+	depends on CPU_V6
 	help
 	  Invalidation of the Instruction Cache operation can
 	  fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index 4656a24..22902b5 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -156,6 +156,12 @@
  *	Please note that the implementation of these, and the required
  *	effects are cache-type (VIVT/VIPT/PIPT) specific.
  *
+ *	flush_icache_all()
+ *
+ *		Unconditionally clean and invalidate the entire icache.
+ *		Currently only needed for cache-v6.S and cache-v7.S, see
+ *		__flush_icache_all for the generic implementation.
+ *
  *	flush_kern_all()
  *
  *		Unconditionally clean and invalidate the entire cache.
@@ -206,6 +212,7 @@
  */
 
 struct cpu_cache_fns {
+	void (*flush_icache_all)(void);
 	void (*flush_kern_all)(void);
 	void (*flush_user_all)(void);
 	void (*flush_user_range)(unsigned long, unsigned long, unsigned int);
@@ -227,6 +234,7 @@ struct cpu_cache_fns {
 
 extern struct cpu_cache_fns cpu_cache;
 
+#define __cpuc_flush_icache_all		cpu_cache.flush_icache_all
 #define __cpuc_flush_kern_all		cpu_cache.flush_kern_all
 #define __cpuc_flush_user_all		cpu_cache.flush_user_all
 #define __cpuc_flush_user_range		cpu_cache.flush_user_range
@@ -246,6 +254,7 @@ extern struct cpu_cache_fns cpu_cache;
 
 #else
 
+#define __cpuc_flush_icache_all		__glue(_CACHE,_flush_icache_all)
 #define __cpuc_flush_kern_all		__glue(_CACHE,_flush_kern_cache_all)
 #define __cpuc_flush_user_all		__glue(_CACHE,_flush_user_cache_all)
 #define __cpuc_flush_user_range		__glue(_CACHE,_flush_user_cache_range)
@@ -253,6 +262,7 @@ extern struct cpu_cache_fns cpu_cache;
 #define __cpuc_coherent_user_range	__glue(_CACHE,_coherent_user_range)
 #define __cpuc_flush_dcache_area	__glue(_CACHE,_flush_kern_dcache_area)
 
+extern void __cpuc_flush_icache_all(void);
 extern void __cpuc_flush_kern_all(void);
 extern void __cpuc_flush_user_all(void);
 extern void __cpuc_flush_user_range(unsigned long, unsigned long, unsigned int);
@@ -291,6 +301,37 @@ extern void copy_to_user_page(struct vm_area_struct *, struct page *,
 /*
  * Convert calls to our calling convention.
  */
+
+/* Invalidate I-cache */
+#define __flush_icache_all_generic()					\
+	asm("mcr	p15, 0, %0, c7, c5, 0"				\
+	    : : "r" (0));
+
+/* Invalidate I-cache inner shareable */
+#define __flush_icache_all_v7_smp()					\
+	asm("mcr	p15, 0, %0, c7, c1, 0"				\
+	    : : "r" (0));
+
+/*
+ * Optimized __flush_icache_all for the common cases. Note that UP ARMv7
+ * will fall through to use __flush_icache_all_generic.
+ */
+#if (defined(CONFIG_CPU_V7) && defined(CONFIG_CPU_V6)) ||		\
+	defined(CONFIG_SMP_ON_UP)
+#define __flush_icache_preferred	__cpuc_flush_icache_all
+#elif __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
+#define __flush_icache_preferred	__flush_icache_all_v7_smp
+#elif __LINUX_ARM_ARCH__ == 6 && defined(CONFIG_ARM_ERRATA_411920)
+#define __flush_icache_preferred	__cpuc_flush_icache_all
+#else
+#define __fluch_icache_preferred	__flush_icache_all_generic
+#endif
+
+static inline void __flush_icache_all(void)
+{
+	__flush_icache_preferred();
+}
+
 #define flush_cache_all()		__cpuc_flush_kern_all()
 
 static inline void vivt_flush_cache_mm(struct mm_struct *mm)
@@ -366,21 +407,6 @@ extern void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 extern void flush_dcache_page(struct page *);
 
-static inline void __flush_icache_all(void)
-{
-#ifdef CONFIG_ARM_ERRATA_411920
-	extern void v6_icache_inval_all(void);
-	v6_icache_inval_all();
-#elif defined(CONFIG_SMP) && __LINUX_ARM_ARCH__ >= 7
-	asm("mcr	p15, 0, %0, c7, c1, 0	@ invalidate I-cache inner shareable\n"
-	    :
-	    : "r" (0));
-#else
-	asm("mcr	p15, 0, %0, c7, c5, 0	@ invalidate I-cache\n"
-	    :
-	    : "r" (0));
-#endif
-}
 static inline void flush_kernel_vmap_range(void *addr, int size)
 {
 	if ((cache_is_vivt() || cache_is_vipt_aliasing()))
diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
index 86aa689..99fa688 100644
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -21,18 +21,22 @@
 #define D_CACHE_LINE_SIZE	32
 #define BTB_FLUSH_SIZE		8
 
-#ifdef CONFIG_ARM_ERRATA_411920
 /*
- * Invalidate the entire I cache (this code is a workaround for the ARM1136
- * erratum 411920 - Invalidate Instruction Cache operation can fail. This
- * erratum is present in 1136, 1156 and 1176. It does not affect the MPCore.
+ *	v6_flush_icache_all()
+ *
+ *	Flush the whole I-cache.
  *
- * Registers:
- *   r0 - set to 0
- *   r1 - corrupted
+ *	ARM1136 erratum 411920 - Invalidate Instruction Cache operation can fail.
+ *	This erratum is present in 1136, 1156 and 1176. It does not affect the
+ *	MPCore.
+ *
+ *	Registers:
+ *	r0 - set to 0
+ *	r1 - corrupted
  */
-ENTRY(v6_icache_inval_all)
+ENTRY(v6_flush_icache_all)
 	mov	r0, #0
+#ifdef CONFIG_ARM_ERRATA_411920
 	mrs	r1, cpsr
 	cpsid	ifa				@ disable interrupts
 	mcr	p15, 0, r0, c7, c5, 0		@ invalidate entire I-cache
@@ -43,8 +47,11 @@ ENTRY(v6_icache_inval_all)
 	.rept	11				@ ARM Ltd recommends at least
 	nop					@ 11 NOPs
 	.endr
-	mov	pc, lr
+#else
+	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I-cache
 #endif
+	mov	pc, lr
+ENDPROC(v6_flush_icache_all)
 
 /*
  *	v6_flush_cache_all()
@@ -60,7 +67,7 @@ ENTRY(v6_flush_kern_cache_all)
 #ifndef CONFIG_ARM_ERRATA_411920
 	mcr	p15, 0, r0, c7, c5, 0		@ I+BTB cache invalidate
 #else
-	b	v6_icache_inval_all
+	b	v6_flush_icache_all
 #endif
 #else
 	mcr	p15, 0, r0, c7, c15, 0		@ Cache clean+invalidate
@@ -138,7 +145,7 @@ ENTRY(v6_coherent_user_range)
 #ifndef CONFIG_ARM_ERRATA_411920
 	mcr	p15, 0, r0, c7, c5, 0		@ I+BTB cache invalidate
 #else
-	b	v6_icache_inval_all
+	b	v6_flush_icache_all
 #endif
 #else
 	mcr	p15, 0, r0, c7, c5, 6		@ invalidate BTB
@@ -312,6 +319,7 @@ ENDPROC(v6_dma_unmap_area)
 
 	.type	v6_cache_fns, #object
 ENTRY(v6_cache_fns)
+	.long	v6_flush_icache_all
 	.long	v6_flush_kern_cache_all
 	.long	v6_flush_user_cache_all
 	.long	v6_flush_user_cache_range
diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index 2aa59d5..2a02ade 100644
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -18,6 +18,21 @@
 #include "proc-macros.S"
 
 /*
+ *	v7_flush_icache_all()
+ *
+ *	Flush the whole I-cache.
+ *
+ *	Registers:
+ *	r0 - set to 0
+ */
+ENTRY(v7_flush_icache_all)
+	mov	r0, #0
+	SMP(mcr	p15, 0, r0, c7, c1, 0)		@ invalidate I-cache inner shareable
+	UP(mcr	p15, 0, r0, c7, c5, 0)		@ I+BTB cache invalidate
+	mov	pc, lr
+ENDPROC(v7_flush_icache_all)
+
+/*
  *	v7_flush_dcache_all()
  *
  *	Flush the whole D-cache.
@@ -303,6 +318,7 @@ ENDPROC(v7_dma_unmap_area)
 
 	.type	v7_cache_fns, #object
 ENTRY(v7_cache_fns)
+	.long	v7_flush_icache_all
 	.long	v7_flush_kern_cache_all
 	.long	v7_flush_user_cache_all
 	.long	v7_flush_user_cache_range
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