From: Will Deacon <will.deacon@xxxxxxx> To speed up decompression, the decompressor sets up a flat, cacheable mapping of memory. However, when there is insufficient space to hold the page tables for this mapping, we don't bother to enable the caches and subsequently skip all the cache maintenance hooks. Skipping the cache maintenance before jumping to the relocated code allows the processor to predict the branch and populate the I-cache with stale data before the relocation loop has completed (since a bootloader may have SCTLR.I set, which permits normal, cacheable instruction fetches regardless of SCTLR.M). This patch moves the cache maintenance check into the maintenance routines themselves, allowing the v6/v7 versions to invalidate the I-cache regardless of the MMU state. Cc: <stable@xxxxxxxxxxxxxxx> Reported-by: Marc Carino <marc.ceeeee@xxxxxxxxx> Tested-by: Julien Grall <julien.grall@xxxxxxxxxx> Signed-off-by: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> (cherry picked from commit 238962ac71910d6c20162ea5230685fead1836a4) Buglink: https://stintbugzilla.st.com/show_bug.cgi?id=89771 Signed-off-by: Sudeep Biswas <sudeep.biswas@xxxxxx> --- arch/arm/boot/compressed/head.S | 20 ++++++++++++++++---- 1 files changed, 16 insertions(+), 4 deletions(-) diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index e806479..8f966918 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -431,8 +431,7 @@ dtb_check_done: add sp, sp, r6 #endif - tst r4, #1 - bleq cache_clean_flush + bl cache_clean_flush adr r0, BSYM(restart) add r0, r0, r6 @@ -1096,6 +1095,8 @@ cache_clean_flush: b call_cache_fn __armv4_mpu_cache_flush: + tst r4, #1 + movne pc, lr mov r2, #1 mov r3, #0 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache @@ -1113,6 +1114,8 @@ __armv4_mpu_cache_flush: mov pc, lr __fa526_cache_flush: + tst r4, #1 + movne pc, lr mov r1, #0 mcr p15, 0, r1, c7, c14, 0 @ clean and invalidate D cache mcr p15, 0, r1, c7, c5, 0 @ flush I cache @@ -1121,13 +1124,16 @@ __fa526_cache_flush: __armv6_mmu_cache_flush: mov r1, #0 - mcr p15, 0, r1, c7, c14, 0 @ clean+invalidate D + tst r4, #1 + mcreq p15, 0, r1, c7, c14, 0 @ clean+invalidate D mcr p15, 0, r1, c7, c5, 0 @ invalidate I+BTB - mcr p15, 0, r1, c7, c15, 0 @ clean+invalidate unified + mcreq p15, 0, r1, c7, c15, 0 @ clean+invalidate unified mcr p15, 0, r1, c7, c10, 4 @ drain WB mov pc, lr __armv7_mmu_cache_flush: + tst r4, #1 + bne iflush mrc p15, 0, r10, c0, c1, 5 @ read ID_MMFR1 tst r10, #0xf << 16 @ hierarchical cache (ARMv7) mov r10, #0 @@ -1188,6 +1194,8 @@ iflush: mov pc, lr __armv5tej_mmu_cache_flush: + tst r4, #1 + movne pc, lr 1: mrc p15, 0, r15, c7, c14, 3 @ test,clean,invalidate D cache bne 1b mcr p15, 0, r0, c7, c5, 0 @ flush I cache @@ -1195,6 +1203,8 @@ __armv5tej_mmu_cache_flush: mov pc, lr __armv4_mmu_cache_flush: + tst r4, #1 + movne pc, lr mov r2, #64*1024 @ default: 32K dcache size (*2) mov r11, #32 @ default: 32 byte line size mrc p15, 0, r3, c0, c0, 1 @ read cache type @@ -1228,6 +1238,8 @@ no_cache_id: __armv3_mmu_cache_flush: __armv3_mpu_cache_flush: + tst r4, #1 + movne pc, lr mov r1, #0 mcr p15, 0, r1, c7, c0, 0 @ invalidate whole cache v3 mov pc, lr -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html