From 041d42e789aba20296ffcde92173f100a9592880 Mon Sep 17 00:00:00 2001 From: Siarhei Siamashka Date: Tue, 23 Feb 2010 23:56:36 -0500 Subject: [PATCH] OMAP3: workaround for ARM Cortex-A8 erratum 725233 725233: PLD instructions executed with PLD data forwarding enabled can result in a processor deadlock This deadlock can happen when NEON load instructions are used together with cache preload instructions (PLD). The problematic conditions can be triggered in-the-wild by NEON optimized functions from pixman library (http://cgit.freedesktop.org/pixman), which perform dynamic adjustment of prefetch distance. The workaround disables PLD data forwarding by setting PLD_FWD bit in L2 Cache Auxiliary Control Register as recommended in ARM Cortex-A8 errata list. The deadlock can only happen on r1pX revisions of Cortex-A8 (used in OMAP34xx/OMAP35xx). Performance impact of the workaround is practically non-existant. Signed-off-by: Siarhei Siamashka Signed-off-by: Sandeep Paulraj --- cpu/arm_cortexa8/omap3/board.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/cpu/arm_cortexa8/omap3/board.c b/cpu/arm_cortexa8/omap3/board.c index 2aa69b383b..7b78fa448b 100644 --- a/cpu/arm_cortexa8/omap3/board.c +++ b/cpu/arm_cortexa8/omap3/board.c @@ -146,6 +146,12 @@ void setup_auxcr() __asm__ __volatile__("orr r0, r0, #1 << 5"); /* SMI instruction to call ROM Code API */ __asm__ __volatile__(".word 0xE1600070"); + /* Set PLD_FWD bit in L2AUXCR (Cortex-A8 erratum 725233 workaround) */ + __asm__ __volatile__("mov r12, #0x2"); + __asm__ __volatile__("mrc p15, 1, r0, c9, c0, 2"); + __asm__ __volatile__("orr r0, r0, #1 << 27"); + /* SMI instruction to call ROM Code API */ + __asm__ __volatile__(".word 0xE1600070"); __asm__ __volatile__("mov r0, %0":"=r"(i)); __asm__ __volatile__("mov r12, %0":"=r"(j)); } -- 2.39.5