diff options
Diffstat (limited to 'meta/recipes-kernel/linux/linux-omap2-git/beagleboard/no-cortex-deadlock.patch')
| -rw-r--r-- | meta/recipes-kernel/linux/linux-omap2-git/beagleboard/no-cortex-deadlock.patch | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/meta/recipes-kernel/linux/linux-omap2-git/beagleboard/no-cortex-deadlock.patch b/meta/recipes-kernel/linux/linux-omap2-git/beagleboard/no-cortex-deadlock.patch new file mode 100644 index 0000000000..32ec4c2d33 --- /dev/null +++ b/meta/recipes-kernel/linux/linux-omap2-git/beagleboard/no-cortex-deadlock.patch @@ -0,0 +1,75 @@ +From: Mans Rullgard <mans@mansr.com> +Date: Wed, 30 Jul 2008 08:25:51 +0000 (+0100) +Subject: ARM: NEON L1 cache bug workaround (erratum 451034) +X-Git-Url: http://git.mansr.com/?p=linux-omap;a=commitdiff_plain;h=26023493baf13e0a67fd6cf08d87be5ff6f7c56d + +ARM: NEON L1 cache bug workaround (erratum 451034) + +On Cortex-A8 r1p0 and r1p1, executing a NEON store with an integer +store in the store buffer, can cause a processor deadlock under +certain conditions. + +Executing a DMB instruction before saving NEON/VFP registers and before +return to userspace makes it safe to run code which includes similar +counter-measures. Userspace code can still trigger the deadlock, so +a different workaround is required to safely run untrusted code. + +See ARM Cortex-A8 Errata Notice (PR120-PRDC-008070) for full details. +--- + +diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig +index 8c75840..1172e14 100644 +--- a/arch/arm/Kconfig ++++ b/arch/arm/Kconfig +@@ -1071,6 +1071,22 @@ config NEON + Say Y to include support code for NEON, the ARMv7 Advanced SIMD + Extension. + ++config NEON_CACHE_BUG ++ bool "NEON L1 cache bug workaround (erratum 451034)" ++ depends on VFPv3 ++ help ++ On Cortex-A8 r1p0 and r1p1, executing a NEON store with an integer ++ store in the store buffer, can cause a processor deadlock under ++ certain conditions. ++ ++ See ARM Cortex-A8 Errata Notice (PR120-PRDC-008070) for full details. ++ ++ Say Y to include a workaround. ++ ++ WARNING: Even with this option enabled, userspace code can trigger ++ the deadlock. To safely run untrusted code, a different fix is ++ required. ++ + endmenu + + menu "Userspace binary formats" +diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S +index 597ed00..e50094e 100644 +--- a/arch/arm/kernel/entry-common.S ++++ b/arch/arm/kernel/entry-common.S +@@ -68,6 +68,10 @@ no_work_pending: + /* perform architecture specific actions before user return */ + arch_ret_to_user r1, lr + ++#ifdef CONFIG_NEON_CACHE_BUG ++ dmb ++#endif ++ + @ slow_restore_user_regs + ldr r1, [sp, #S_PSR] @ get calling cpsr + ldr lr, [sp, #S_PC]! @ get pc +diff --git a/include/asm-arm/vfpmacros.h b/include/asm-arm/vfpmacros.h +index cccb389..c9d2976 100644 +--- a/include/asm-arm/vfpmacros.h ++++ b/include/asm-arm/vfpmacros.h +@@ -32,6 +32,9 @@ + + @ write all the working registers out of the VFP + .macro VFPFSTMIA, base, tmp ++#ifdef CONFIG_NEON_CACHE_BUG ++ dmb ++#endif + #if __LINUX_ARM_ARCH__ < 6 + STC p11, cr0, [\base],#33*4 @ FSTMIAX \base!, {d0-d15} + #else |