ARM: mm: implement LoUIS API for cache maintenance ops

ARM v7 architecture introduced the concept of cache levels and related
control registers. New processors like A7 and A15 embed an L2 unified cache
controller that becomes part of the cache level hierarchy. Some operations in
the kernel like cpu_suspend and __cpu_disable do not require a flush of the
entire cache hierarchy to DRAM but just the cache levels belonging to the
Level of Unification Inner Shareable (LoUIS), which in most of ARM v7 systems
correspond to L1.

The current cache flushing API used in cpu_suspend and __cpu_disable,
flush_cache_all(), ends up flushing the whole cache hierarchy since for
v7 it cleans and invalidates all cache levels up to Level of Coherency
(LoC) which cripples system performance when used in hot paths like hotplug
and cpuidle.

Therefore a new kernel cache maintenance API must be added to cope with
latest ARM system requirements.

This patch adds flush_cache_louis() to the ARM kernel cache maintenance API.

This function cleans and invalidates all data cache levels up to the
Level of Unification Inner Shareable (LoUIS) and invalidates the instruction
cache for processors that support it (> v7).

This patch also creates an alias of the cache LoUIS function to flush_kern_all
for all processor versions prior to v7, so that the current cache flushing
behaviour is unchanged for those processors.

v7 cache maintenance code implements a cache LoUIS function that cleans and
invalidates the D-cache up to LoUIS and invalidates the I-cache, according
to the new API.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>

diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index e4448e1..e1489c5 100644 (file)
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -49,6 +49,13 @@
  *
  *             Unconditionally clean and invalidate the entire cache.
  *
+ *     flush_kern_louis()
+ *
+ *             Flush data cache levels up to the level of unification
+ *             inner shareable and invalidate the I-cache.
+ *             Only needed from v7 onwards, falls back to flush_cache_all()
+ *             for all other processor versions.
+ *
  *     flush_user_all()
  *
  *             Clean and invalidate all user space cache entries
@@ -97,6 +104,7 @@
 struct cpu_cache_fns {
        void (*flush_icache_all)(void);
        void (*flush_kern_all)(void);
+       void (*flush_kern_louis)(void);
        void (*flush_user_all)(void);
        void (*flush_user_range)(unsigned long, unsigned long, unsigned int);
 
@@ -119,6 +127,7 @@ 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_kern_louis                cpu_cache.flush_kern_louis
 #define __cpuc_flush_user_all          cpu_cache.flush_user_all
 #define __cpuc_flush_user_range                cpu_cache.flush_user_range
 #define __cpuc_coherent_kern_range     cpu_cache.coherent_kern_range
@@ -139,6 +148,7 @@ extern struct cpu_cache_fns cpu_cache;
 
 extern void __cpuc_flush_icache_all(void);
 extern void __cpuc_flush_kern_all(void);
+extern void __cpuc_flush_kern_louis(void);
 extern void __cpuc_flush_user_all(void);
 extern void __cpuc_flush_user_range(unsigned long, unsigned long, unsigned int);
 extern void __cpuc_coherent_kern_range(unsigned long, unsigned long);
@@ -204,6 +214,11 @@ static inline void __flush_icache_all(void)
        __flush_icache_preferred();
 }
 
+/*
+ * Flush caches up to Level of Unification Inner Shareable
+ */
+#define flush_cache_louis()            __cpuc_flush_kern_louis()
+
 #define flush_cache_all()              __cpuc_flush_kern_all()
 
 static inline void vivt_flush_cache_mm(struct mm_struct *mm)

diff --git a/arch/arm/include/asm/glue-cache.h b/arch/arm/include/asm/glue-cache.h
index 7e30874..2d6a7de 100644 (file)
--- a/arch/arm/include/asm/glue-cache.h
+++ b/arch/arm/include/asm/glue-cache.h
@@ -132,6 +132,7 @@
 #ifndef MULTI_CACHE
 #define __cpuc_flush_icache_all                __glue(_CACHE,_flush_icache_all)
 #define __cpuc_flush_kern_all          __glue(_CACHE,_flush_kern_cache_all)
+#define __cpuc_flush_kern_louis                __glue(_CACHE,_flush_kern_cache_louis)
 #define __cpuc_flush_user_all          __glue(_CACHE,_flush_user_cache_all)
 #define __cpuc_flush_user_range                __glue(_CACHE,_flush_user_cache_range)
 #define __cpuc_coherent_kern_range     __glue(_CACHE,_coherent_kern_range)

diff --git a/arch/arm/mm/cache-fa.S b/arch/arm/mm/cache-fa.S
index 0720163..e505bef 100644 (file)
--- a/arch/arm/mm/cache-fa.S
+++ b/arch/arm/mm/cache-fa.S
@@ -240,6 +240,9 @@ ENTRY(fa_dma_unmap_area)
        mov     pc, lr
 ENDPROC(fa_dma_unmap_area)
 
+       .globl  fa_flush_kern_cache_louis
+       .equ    fa_flush_kern_cache_louis, fa_flush_kern_cache_all
+
        __INITDATA
 
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)

diff --git a/arch/arm/mm/cache-v3.S b/arch/arm/mm/cache-v3.S
index 52e35f3..8a3fade 100644 (file)
--- a/arch/arm/mm/cache-v3.S
+++ b/arch/arm/mm/cache-v3.S
@@ -128,6 +128,9 @@ ENTRY(v3_dma_map_area)
 ENDPROC(v3_dma_unmap_area)
 ENDPROC(v3_dma_map_area)
 
+       .globl  v3_flush_kern_cache_louis
+       .equ    v3_flush_kern_cache_louis, v3_flush_kern_cache_all
+
        __INITDATA
 
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)

diff --git a/arch/arm/mm/cache-v4.S b/arch/arm/mm/cache-v4.S
index 022135d..43e5d77 100644 (file)
--- a/arch/arm/mm/cache-v4.S
+++ b/arch/arm/mm/cache-v4.S
@@ -140,6 +140,9 @@ ENTRY(v4_dma_map_area)
 ENDPROC(v4_dma_unmap_area)
 ENDPROC(v4_dma_map_area)
 
+       .globl  v4_flush_kern_cache_louis
+       .equ    v4_flush_kern_cache_louis, v4_flush_kern_cache_all
+
        __INITDATA
 
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)

diff --git a/arch/arm/mm/cache-v4wb.S b/arch/arm/mm/cache-v4wb.S
index 8f1eeae..cd49453 100644 (file)
--- a/arch/arm/mm/cache-v4wb.S
+++ b/arch/arm/mm/cache-v4wb.S
@@ -251,6 +251,9 @@ ENTRY(v4wb_dma_unmap_area)
        mov     pc, lr
 ENDPROC(v4wb_dma_unmap_area)
 
+       .globl  v4wb_flush_kern_cache_louis
+       .equ    v4wb_flush_kern_cache_louis, v4wb_flush_kern_cache_all
+
        __INITDATA
 
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)

diff --git a/arch/arm/mm/cache-v4wt.S b/arch/arm/mm/cache-v4wt.S
index b34a5f9..11e5e58 100644 (file)
--- a/arch/arm/mm/cache-v4wt.S
+++ b/arch/arm/mm/cache-v4wt.S
@@ -196,6 +196,9 @@ ENTRY(v4wt_dma_map_area)
 ENDPROC(v4wt_dma_unmap_area)
 ENDPROC(v4wt_dma_map_area)
 
+       .globl  v4wt_flush_kern_cache_louis
+       .equ    v4wt_flush_kern_cache_louis, v4wt_flush_kern_cache_all
+
        __INITDATA
 
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)

diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
index 4b10760..d8fd4d4 100644 (file)
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -326,6 +326,9 @@ ENTRY(v6_dma_unmap_area)
        mov     pc, lr
 ENDPROC(v6_dma_unmap_area)
 
+       .globl  v6_flush_kern_cache_louis
+       .equ    v6_flush_kern_cache_louis, v6_flush_kern_cache_all
+
        __INITDATA
 
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)

diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index 39e3fb3..d1fa2f6 100644 (file)
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -33,6 +33,24 @@ ENTRY(v7_flush_icache_all)
        mov     pc, lr
 ENDPROC(v7_flush_icache_all)
 
+ /*
+ *     v7_flush_dcache_louis()
+ *
+ *     Flush the D-cache up to the Level of Unification Inner Shareable
+ *
+ *     Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
+ */
+
+ENTRY(v7_flush_dcache_louis)
+       dmb                                     @ ensure ordering with previous memory accesses
+       mrc     p15, 1, r0, c0, c0, 1           @ read clidr, r0 = clidr
+       ands    r3, r0, #0xe00000               @ extract LoUIS from clidr
+       mov     r3, r3, lsr #20                 @ r3 = LoUIS * 2
+       moveq   pc, lr                          @ return if level == 0
+       mov     r10, #0                         @ r10 (starting level) = 0
+       b       loop1                           @ start flushing cache levels
+ENDPROC(v7_flush_dcache_louis)
+
 /*
  *     v7_flush_dcache_all()
  *
@@ -120,6 +138,24 @@ ENTRY(v7_flush_kern_cache_all)
        mov     pc, lr
 ENDPROC(v7_flush_kern_cache_all)
 
+ /*
+ *     v7_flush_kern_cache_louis(void)
+ *
+ *     Flush the data cache up to Level of Unification Inner Shareable.
+ *     Invalidate the I-cache to the point of unification.
+ */
+ENTRY(v7_flush_kern_cache_louis)
+ ARM(  stmfd   sp!, {r4-r5, r7, r9-r11, lr}    )
+ THUMB(        stmfd   sp!, {r4-r7, r9-r11, lr}        )
+       bl      v7_flush_dcache_louis
+       mov     r0, #0
+       ALT_SMP(mcr     p15, 0, r0, c7, c1, 0)  @ invalidate I-cache inner shareable
+       ALT_UP(mcr      p15, 0, r0, c7, c5, 0)  @ I+BTB cache invalidate
+ ARM(  ldmfd   sp!, {r4-r5, r7, r9-r11, lr}    )
+ THUMB(        ldmfd   sp!, {r4-r7, r9-r11, lr}        )
+       mov     pc, lr
+ENDPROC(v7_flush_kern_cache_louis)
+
 /*
  *     v7_flush_cache_all()
  *

diff --git a/arch/arm/mm/proc-arm1020.S b/arch/arm/mm/proc-arm1020.S
index 0650bb8..2bb61e7 100644 (file)
--- a/arch/arm/mm/proc-arm1020.S
+++ b/arch/arm/mm/proc-arm1020.S
@@ -368,6 +368,9 @@ ENTRY(arm1020_dma_unmap_area)
        mov     pc, lr
 ENDPROC(arm1020_dma_unmap_area)
 
+       .globl  arm1020_flush_kern_cache_louis
+       .equ    arm1020_flush_kern_cache_louis, arm1020_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions arm1020
 

diff --git a/arch/arm/mm/proc-arm1020e.S b/arch/arm/mm/proc-arm1020e.S
index 4188478..8f96aa4 100644 (file)
--- a/arch/arm/mm/proc-arm1020e.S
+++ b/arch/arm/mm/proc-arm1020e.S
@@ -354,6 +354,9 @@ ENTRY(arm1020e_dma_unmap_area)
        mov     pc, lr
 ENDPROC(arm1020e_dma_unmap_area)
 
+       .globl  arm1020e_flush_kern_cache_louis
+       .equ    arm1020e_flush_kern_cache_louis, arm1020e_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions arm1020e
 

diff --git a/arch/arm/mm/proc-arm1022.S b/arch/arm/mm/proc-arm1022.S
index 33c6882..8ebe4a4 100644 (file)
--- a/arch/arm/mm/proc-arm1022.S
+++ b/arch/arm/mm/proc-arm1022.S
@@ -343,6 +343,9 @@ ENTRY(arm1022_dma_unmap_area)
        mov     pc, lr
 ENDPROC(arm1022_dma_unmap_area)
 
+       .globl  arm1022_flush_kern_cache_louis
+       .equ    arm1022_flush_kern_cache_louis, arm1022_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions arm1022
 

diff --git a/arch/arm/mm/proc-arm1026.S b/arch/arm/mm/proc-arm1026.S
index fbc1d5f..093fc7e 100644 (file)
--- a/arch/arm/mm/proc-arm1026.S
+++ b/arch/arm/mm/proc-arm1026.S
@@ -337,6 +337,9 @@ ENTRY(arm1026_dma_unmap_area)
        mov     pc, lr
 ENDPROC(arm1026_dma_unmap_area)
 
+       .globl  arm1026_flush_kern_cache_louis
+       .equ    arm1026_flush_kern_cache_louis, arm1026_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions arm1026
 

diff --git a/arch/arm/mm/proc-arm920.S b/arch/arm/mm/proc-arm920.S
index 1a8c138..2c3b942 100644 (file)
--- a/arch/arm/mm/proc-arm920.S
+++ b/arch/arm/mm/proc-arm920.S
@@ -319,6 +319,9 @@ ENTRY(arm920_dma_unmap_area)
        mov     pc, lr
 ENDPROC(arm920_dma_unmap_area)
 
+       .globl  arm920_flush_kern_cache_louis
+       .equ    arm920_flush_kern_cache_louis, arm920_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions arm920
 #endif

diff --git a/arch/arm/mm/proc-arm922.S b/arch/arm/mm/proc-arm922.S
index 4c44d7e..4464c49 100644 (file)
--- a/arch/arm/mm/proc-arm922.S
+++ b/arch/arm/mm/proc-arm922.S
@@ -321,6 +321,9 @@ ENTRY(arm922_dma_unmap_area)
        mov     pc, lr
 ENDPROC(arm922_dma_unmap_area)
 
+       .globl  arm922_flush_kern_cache_louis
+       .equ    arm922_flush_kern_cache_louis, arm922_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions arm922
 #endif

diff --git a/arch/arm/mm/proc-arm925.S b/arch/arm/mm/proc-arm925.S
index ec5b118..281eb9b 100644 (file)
--- a/arch/arm/mm/proc-arm925.S
+++ b/arch/arm/mm/proc-arm925.S
@@ -376,6 +376,9 @@ ENTRY(arm925_dma_unmap_area)
        mov     pc, lr
 ENDPROC(arm925_dma_unmap_area)
 
+       .globl  arm925_flush_kern_cache_louis
+       .equ    arm925_flush_kern_cache_louis, arm925_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions arm925
 

diff --git a/arch/arm/mm/proc-arm926.S b/arch/arm/mm/proc-arm926.S
index c31e62c..f1803f7 100644 (file)
--- a/arch/arm/mm/proc-arm926.S
+++ b/arch/arm/mm/proc-arm926.S
@@ -339,6 +339,9 @@ ENTRY(arm926_dma_unmap_area)
        mov     pc, lr
 ENDPROC(arm926_dma_unmap_area)
 
+       .globl  arm926_flush_kern_cache_louis
+       .equ    arm926_flush_kern_cache_louis, arm926_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions arm926
 

diff --git a/arch/arm/mm/proc-arm940.S b/arch/arm/mm/proc-arm940.S
index a613a7d..8da189d 100644 (file)
--- a/arch/arm/mm/proc-arm940.S
+++ b/arch/arm/mm/proc-arm940.S
@@ -267,6 +267,9 @@ ENTRY(arm940_dma_unmap_area)
        mov     pc, lr
 ENDPROC(arm940_dma_unmap_area)
 
+       .globl  arm940_flush_kern_cache_louis
+       .equ    arm940_flush_kern_cache_louis, arm940_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions arm940
 

diff --git a/arch/arm/mm/proc-arm946.S b/arch/arm/mm/proc-arm946.S
index 9f4f299..f666cf3 100644 (file)
--- a/arch/arm/mm/proc-arm946.S
+++ b/arch/arm/mm/proc-arm946.S
@@ -310,6 +310,9 @@ ENTRY(arm946_dma_unmap_area)
        mov     pc, lr
 ENDPROC(arm946_dma_unmap_area)
 
+       .globl  arm946_flush_kern_cache_louis
+       .equ    arm946_flush_kern_cache_louis, arm946_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions arm946
 

diff --git a/arch/arm/mm/proc-feroceon.S b/arch/arm/mm/proc-feroceon.S
index 23a8e4c..85e5e3b 100644 (file)
--- a/arch/arm/mm/proc-feroceon.S
+++ b/arch/arm/mm/proc-feroceon.S
@@ -415,6 +415,9 @@ ENTRY(feroceon_dma_unmap_area)
        mov     pc, lr
 ENDPROC(feroceon_dma_unmap_area)
 
+       .globl  feroceon_flush_kern_cache_louis
+       .equ    feroceon_flush_kern_cache_louis, feroceon_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions feroceon
 

diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index 2d8ff3a..b29a226 100644 (file)
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -299,6 +299,7 @@ ENTRY(\name\()_processor_functions)
 ENTRY(\name\()_cache_fns)
        .long   \name\()_flush_icache_all
        .long   \name\()_flush_kern_cache_all
+       .long   \name\()_flush_kern_cache_louis
        .long   \name\()_flush_user_cache_all
        .long   \name\()_flush_user_cache_range
        .long   \name\()_coherent_kern_range

diff --git a/arch/arm/mm/proc-mohawk.S b/arch/arm/mm/proc-mohawk.S
index fbb2124..82f9cdc 100644 (file)
--- a/arch/arm/mm/proc-mohawk.S
+++ b/arch/arm/mm/proc-mohawk.S
@@ -303,6 +303,9 @@ ENTRY(mohawk_dma_unmap_area)
        mov     pc, lr
 ENDPROC(mohawk_dma_unmap_area)
 
+       .globl  mohawk_flush_kern_cache_louis
+       .equ    mohawk_flush_kern_cache_louis, mohawk_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions mohawk
 

diff --git a/arch/arm/mm/proc-xsc3.S b/arch/arm/mm/proc-xsc3.S
index b0d5786..eb93d64 100644 (file)
--- a/arch/arm/mm/proc-xsc3.S
+++ b/arch/arm/mm/proc-xsc3.S
@@ -337,6 +337,9 @@ ENTRY(xsc3_dma_unmap_area)
        mov     pc, lr
 ENDPROC(xsc3_dma_unmap_area)
 
+       .globl  xsc3_flush_kern_cache_louis
+       .equ    xsc3_flush_kern_cache_louis, xsc3_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions xsc3
 

diff --git a/arch/arm/mm/proc-xscale.S b/arch/arm/mm/proc-xscale.S
index 4ffebaa..b5ea31d 100644 (file)
--- a/arch/arm/mm/proc-xscale.S
+++ b/arch/arm/mm/proc-xscale.S
@@ -410,6 +410,9 @@ ENTRY(xscale_dma_unmap_area)
        mov     pc, lr
 ENDPROC(xscale_dma_unmap_area)
 
+       .globl  xscale_flush_kern_cache_louis
+       .equ    xscale_flush_kern_cache_louis, xscale_flush_kern_cache_all
+
        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
        define_cache_functions xscale