diff options
author | Ard Biesheuvel <ardb@kernel.org> | 2020-02-18 17:06:14 +0100 |
---|---|---|
committer | Ard Biesheuvel <ardb@kernel.org> | 2020-02-27 11:15:50 +0100 |
commit | 401b368caaecdce1cf8f05bab448172752230cb0 (patch) | |
tree | 59714c64290a097c0fd1dc272eab6d21c8e7382c /arch/arm/boot/compressed/head.S | |
parent | e114412f616446708b3d1e559ff4af9db7ade46e (diff) |
ARM: decompressor: switch to by-VA cache maintenance for v7 cores
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.
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'arch/arm/boot/compressed/head.S')
-rw-r--r-- | arch/arm/boot/compressed/head.S | 83 |
1 files changed, 30 insertions, 53 deletions
diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index f90034151aef..4f7c6145e31f 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -530,11 +530,6 @@ dtb_check_done: mov r0, r9 @ start of relocated zImage add r1, sp, r6 @ end of relocated zImage -#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 @@ -684,6 +679,24 @@ params: ldr r0, =0x10000100 @ params_phys for RPC #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. * @@ -1175,8 +1188,6 @@ __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 @@ -1184,7 +1195,7 @@ __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. @@ -1200,6 +1211,7 @@ __armv7_mmu_cache_off: .align 5 cache_clean_flush: mov r3, #16 + mov r11, r1 b call_cache_fn __armv4_mpu_cache_flush: @@ -1250,51 +1262,16 @@ __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 |