Update the v7 cache_clean_flush routine to take into account the
memory range passed in r0/r1, and perform cache maintenance by
virtual address on this range instead of set/way maintenance, which
is inappropriate for the purpose of maintaining the cached state of
memory contents.
Since this removes any use of the stack in the implementation of
cache_clean_flush(), we can also drop some code that manages the
value of the stack pointer before calling it.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/arm/boot/compressed/head.S | 83 +++++++-------------
1 file changed, 30 insertions(+), 53 deletions(-)
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 5060a623e0d7..90de5404f402 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -524,11 +524,6 @@ dtb_check_done:
ldr r1, [sp], #4 @ end of target region
ldr r0, [sp], #4 @ start of target region
-#ifndef CONFIG_ZBOOT_ROM
- /* cache_clean_flush may use the stack, so relocate it */
- add sp, sp, r6
-#endif
-
bl cache_clean_flush
badr r0, restart
@@ -685,6 +680,24 @@ params: ldr r0, =0x10000100 @ params_phys for RPC
.align
#endif
+/*
+ * dcache_line_size - get the minimum D-cache line size from the CTR register
+ * on ARMv7.
+ */
+ .macro dcache_line_size, reg, tmp
+#ifdef CONFIG_CPU_V7M
+ movw \tmp, #:lower16:BASEADDR_V7M_SCB + V7M_SCB_CTR
+ movt \tmp, #:upper16:BASEADDR_V7M_SCB + V7M_SCB_CTR
+ ldr \tmp, [\tmp]
+#else
+ mrc p15, 0, \tmp, c0, c0, 1 @ read ctr
+#endif
+ lsr \tmp, \tmp, #16
+ and \tmp, \tmp, #0xf @ cache line size encoding
+ mov \reg, #4 @ bytes per word
+ mov \reg, \reg, lsl \tmp @ actual cache line size
+ .endm
+
/*
* Turn on the cache. We need to setup some page tables so that we
* can have both the I and D caches on.
@@ -1177,8 +1190,6 @@ __armv7_mmu_cache_off:
bic r0, r0, #0x000c
#endif
mcr p15, 0, r0, c1, c0 @ turn MMU and cache off
- mov r12, lr
- bl __armv7_mmu_cache_flush
mov r0, #0
#ifdef CONFIG_MMU
mcr p15, 0, r0, c8, c7, 0 @ invalidate whole TLB
@@ -1186,7 +1197,7 @@ __armv7_mmu_cache_off:
mcr p15, 0, r0, c7, c5, 6 @ invalidate BTC
mcr p15, 0, r0, c7, c10, 4 @ DSB
mcr p15, 0, r0, c7, c5, 4 @ ISB
- mov pc, r12
+ mov pc, lr
/*
* Clean and flush the cache to maintain consistency.
@@ -1202,6 +1213,7 @@ __armv7_mmu_cache_off:
.align 5
cache_clean_flush:
mov r3, #16
+ mov r11, r1
b call_cache_fn
__armv4_mpu_cache_flush:
@@ -1252,51 +1264,16 @@ __armv7_mmu_cache_flush:
mcr p15, 0, r10, c7, c14, 0 @ clean+invalidate D
b iflush
hierarchical:
- mcr p15, 0, r10, c7, c10, 5 @ DMB
- stmfd sp!, {r0-r7, r9-r11}
- mrc p15, 1, r0, c0, c0, 1 @ read clidr
- ands r3, r0, #0x7000000 @ extract loc from clidr
- mov r3, r3, lsr #23 @ left align loc bit field
- beq finished @ if loc is 0, then no need to clean
- mov r10, #0 @ start clean at cache level 0
-loop1:
- add r2, r10, r10, lsr #1 @ work out 3x current cache level
- mov r1, r0, lsr r2 @ extract cache type bits from clidr
- and r1, r1, #7 @ mask of the bits for current cache only
- cmp r1, #2 @ see what cache we have at this level
- blt skip @ skip if no cache, or just i-cache
- mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
- mcr p15, 0, r10, c7, c5, 4 @ isb to sych the new cssr&csidr
- mrc p15, 1, r1, c0, c0, 0 @ read the new csidr
- and r2, r1, #7 @ extract the length of the cache lines
- add r2, r2, #4 @ add 4 (line length offset)
- ldr r4, =0x3ff
- ands r4, r4, r1, lsr #3 @ find maximum number on the way size
- clz r5, r4 @ find bit position of way size increment
- ldr r7, =0x7fff
- ands r7, r7, r1, lsr #13 @ extract max number of the index size
-loop2:
- mov r9, r4 @ create working copy of max way size
-loop3:
- ARM( orr r11, r10, r9, lsl r5 ) @ factor way and cache number into r11
- ARM( orr r11, r11, r7, lsl r2 ) @ factor index number into r11
- THUMB( lsl r6, r9, r5 )
- THUMB( orr r11, r10, r6 ) @ factor way and cache number into r11
- THUMB( lsl r6, r7, r2 )
- THUMB( orr r11, r11, r6 ) @ factor index number into r11
- mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way
- subs r9, r9, #1 @ decrement the way
- bge loop3
- subs r7, r7, #1 @ decrement the index
- bge loop2
-skip:
- add r10, r10, #2 @ increment cache number
- cmp r3, r10
- bgt loop1
-finished:
- ldmfd sp!, {r0-r7, r9-r11}
- mov r10, #0 @ switch back to cache level 0
- mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
+ dcache_line_size r1, r2 @ r1 := dcache min line size
+ sub r2, r1, #1 @ r2 := line size mask
+ bic r0, r0, r2 @ round down start to line size
+ sub r11, r11, #1 @ end address is exclusive
+ bic r11, r11, r2 @ round down end to line size
+0: cmp r0, r11 @ finished?
+ bgt iflush
+ mcr p15, 0, r0, c7, c14, 1 @ Dcache clean/invalidate by VA
+ add r0, r0, r1
+ b 0b
iflush:
mcr p15, 0, r10, c7, c10, 4 @ DSB
mcr p15, 0, r10, c7, c5, 0 @ invalidate I+BTB
--
2.17.1
