[PATCH 1/2] EDAC, altera: Less Intrusive Error Injection

From: thor . thayer
Date: Tue Mar 26 2019 - 17:27:13 EST


From: Thor Thayer <thor.thayer@xxxxxxxxxxxxxxx>

Improve the Arria10 and Stratix10 error injection routine
by reading the data and changing just 1 bit before writing
back out. Previous routine would overwrite the first bytes
to 0 then change 1 bit but this method is less intrusive.

Signed-off-by: Thor Thayer <thor.thayer@xxxxxxxxxxxxxxx>
---
drivers/edac/altera_edac.c | 30 +++++++++++++-----------------
drivers/edac/altera_edac.h | 2 +-
2 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
index 5ff263850cc7..acb3006df631 100644
--- a/drivers/edac/altera_edac.c
+++ b/drivers/edac/altera_edac.c
@@ -1762,28 +1762,24 @@ static ssize_t altr_edac_a10_device_trig2(struct file *file,
if (trig_type == ALTR_UE_TRIGGER_CHAR) {
writel(priv->ue_set_mask, set_addr);
} else {
- /* Setup write of 0 to first 4 bytes */
- writel(0x0, drvdata->base + ECC_BLK_WDATA0_OFST);
- writel(0x0, drvdata->base + ECC_BLK_WDATA1_OFST);
- writel(0x0, drvdata->base + ECC_BLK_WDATA2_OFST);
- writel(0x0, drvdata->base + ECC_BLK_WDATA3_OFST);
- /* Setup write of 4 bytes */
+ /* Setup read/write of 4 bytes */
writel(ECC_WORD_WRITE, drvdata->base + ECC_BLK_DBYTECTRL_OFST);
/* Setup Address to 0 */
- writel(0x0, drvdata->base + ECC_BLK_ADDRESS_OFST);
- /* Setup accctrl to write & data override */
- writel(ECC_WRITE_DOVR, drvdata->base + ECC_BLK_ACCCTRL_OFST);
- /* Kick it. */
- writel(ECC_XACT_KICK, drvdata->base + ECC_BLK_STARTACC_OFST);
- /* Setup accctrl to read & ecc override */
- writel(ECC_READ_EOVR, drvdata->base + ECC_BLK_ACCCTRL_OFST);
+ writel(0, drvdata->base + ECC_BLK_ADDRESS_OFST);
+ /* Setup accctrl to read & ecc & data override */
+ writel(ECC_READ_EDOVR, drvdata->base + ECC_BLK_ACCCTRL_OFST);
/* Kick it. */
writel(ECC_XACT_KICK, drvdata->base + ECC_BLK_STARTACC_OFST);
/* Setup write for single bit change */
- writel(0x1, drvdata->base + ECC_BLK_WDATA0_OFST);
- writel(0x0, drvdata->base + ECC_BLK_WDATA1_OFST);
- writel(0x0, drvdata->base + ECC_BLK_WDATA2_OFST);
- writel(0x0, drvdata->base + ECC_BLK_WDATA3_OFST);
+ writel(readl(drvdata->base + ECC_BLK_RDATA0_OFST) ^ 0x1,
+ drvdata->base + ECC_BLK_WDATA0_OFST);
+ writel(readl(drvdata->base + ECC_BLK_RDATA1_OFST),
+ drvdata->base + ECC_BLK_WDATA1_OFST);
+ writel(readl(drvdata->base + ECC_BLK_RDATA2_OFST),
+ drvdata->base + ECC_BLK_WDATA2_OFST);
+ writel(readl(drvdata->base + ECC_BLK_RDATA3_OFST),
+ drvdata->base + ECC_BLK_WDATA3_OFST);
+
/* Copy Read ECC to Write ECC */
writel(readl(drvdata->base + ECC_BLK_RECC0_OFST),
drvdata->base + ECC_BLK_WECC0_OFST);
diff --git a/drivers/edac/altera_edac.h b/drivers/edac/altera_edac.h
index 60513f201ffb..1532ec9c3510 100644
--- a/drivers/edac/altera_edac.h
+++ b/drivers/edac/altera_edac.h
@@ -321,7 +321,7 @@ struct altr_sdram_mc_data {
#define ECC_BLK_STARTACC_OFST 0x7C

#define ECC_XACT_KICK 0x10000
-#define ECC_WORD_WRITE 0xF
+#define ECC_WORD_WRITE 0xFF
#define ECC_WRITE_DOVR 0x101
#define ECC_WRITE_EDOVR 0x103
#define ECC_READ_EOVR 0x2
--
2.7.4