This patch adds workaround for ARM errata 798870 which says "If back-to-back speculative cache line fills (fill A and fill B) are issued from the L1 data cache of a CPU to the L2 cache, the second request (fill B) is then cancelled, and the second request would have detected a hazard against a recent write or eviction (write B) to the same cache line as fill B then the L2 logic might deadlock."
Signed-off-by: Kimoon Kim kimoon.kim@samsung.com Signed-off-by: Akshay Saraswat akshay.s@samsung.com Reviewed-by: Simon Glass sjg@chromium.org Tested-by: Simon Glass sjg@chromium.org --- Changes since v2: - No change.
Changes since v1: - Added Reviewed-by & Tested-by. - Added space before */ on line # 40.
arch/arm/cpu/armv7/exynos/lowlevel_init.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/arch/arm/cpu/armv7/exynos/lowlevel_init.c b/arch/arm/cpu/armv7/exynos/lowlevel_init.c index e36f2fa..7335a1e 100644 --- a/arch/arm/cpu/armv7/exynos/lowlevel_init.c +++ b/arch/arm/cpu/armv7/exynos/lowlevel_init.c @@ -46,6 +46,28 @@ enum {
#ifdef CONFIG_EXYNOS5420 /* + * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been + * stalled for 1024 cycles to verify that its hazard condition still exists. + */ +void set_l2cache(void) +{ + uint32_t val; + + /* Read MIDR for Primary Part Number */ + mrc_midr(val); + val = (val >> 4); + val &= 0xf; + + /* L2ACTLR[7]: Enable hazard detect timeout for A15 */ + if (val == 0xf) { + mrc_l2_aux_ctlr(val); + val |= (1 << 7); + mcr_l2_aux_ctlr(val); + mrc_l2_ctlr(val); + } +} + +/* * Pointer to this function is stored in iRam which is used * for jump and power down of a specific core. */