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....@samsung.com>
Signed-off-by: Akshay Saraswat <aksha...@samsung.com>
Reviewed-by: Simon Glass <s...@chromium.org>
Tested-by: Simon Glass <s...@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.
*/
--
1.9.1
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