Re: [PATCH v1 3/4] drivers: edac: Add EDAC driver support for QCOM SoCs

From: vnkgutta
Date: Fri Aug 10 2018 - 19:13:09 EST


On 2018-08-10 10:23, Evan Green wrote:
On Wed, Aug 1, 2018 at 1:34 PM Venkata Narendra Kumar Gutta
<vnkgutta@xxxxxxxxxxxxxx> wrote:

From: Channagoud Kadabi <ckadabi@xxxxxxxxxxxxxx>

Add error reporting driver for SBEs and DBEs. As of now, this driver
supports erp for Last Level Cache Controller (LLCC). This driver takes
care of dumping registers and adding config options to enable and
disable panic when the errors happen in cache.

Co-developed-by: Venkata Narendra Kumar Gutta <vnkgutta@xxxxxxxxxxxxxx>
Signed-off-by: Venkata Narendra Kumar Gutta <vnkgutta@xxxxxxxxxxxxxx>
Signed-off-by: Channagoud Kadabi <ckadabi@xxxxxxxxxxxxxx>
---
MAINTAINERS | 7 +
drivers/edac/Kconfig | 28 +++
drivers/edac/Makefile | 1 +
drivers/edac/qcom_edac.c | 507 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 543 insertions(+)
create mode 100644 drivers/edac/qcom_edac.c

...
diff --git a/drivers/edac/qcom_edac.c b/drivers/edac/qcom_edac.c
new file mode 100644
index 0000000..cf3e2b0
--- /dev/null
+++ b/drivers/edac/qcom_edac.c
@@ -0,0 +1,507 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/edac.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/smp.h>
+#include <linux/regmap.h>
+#include <linux/interrupt.h>
+#include <linux/soc/qcom/llcc-qcom.h>

Please alphabetize these includes, and remove any unneeded ones.
Ok, I'll update it in the next version. I didn't know that it's mandatory to have in alphabetic order.
Is it recommended or a strict rule that we have includes in alphabetize order?

+#include "edac_mc.h"
+#include "edac_device.h"
+
+#ifdef CONFIG_EDAC_QCOM_LLCC_PANIC_ON_UE
+#define LLCC_ERP_PANIC_ON_UE 1
+#else
+#define LLCC_ERP_PANIC_ON_UE 0
+#endif
+
+#define EDAC_LLCC "qcom_llcc"
+
+#define TRP_SYN_REG_CNT 6
+
+#define DRP_SYN_REG_CNT 8
+
+#define LLCC_COMMON_STATUS0 0x0003000C
+#define LLCC_LB_CNT_MASK GENMASK(31, 28)
+#define LLCC_LB_CNT_SHIFT 28
+
+/* single & Double Bit syndrome register offsets */
+#define TRP_ECC_SB_ERR_SYN0 0x0002304C
+#define TRP_ECC_DB_ERR_SYN0 0x00020370
+#define DRP_ECC_SB_ERR_SYN0 0x0004204C
+#define DRP_ECC_DB_ERR_SYN0 0x00042070
+
+/* Error register offsets */
+#define TRP_ECC_ERROR_STATUS1 0x00020348
+#define TRP_ECC_ERROR_STATUS0 0x00020344
+#define DRP_ECC_ERROR_STATUS1 0x00042048
+#define DRP_ECC_ERROR_STATUS0 0x00042044
+
+/* TRP, DRP interrupt register offsets */
+#define DRP_INTERRUPT_STATUS 0x00041000
+#define TRP_INTERRUPT_0_STATUS 0x00020480
+#define DRP_INTERRUPT_CLEAR 0x00041008
+#define DRP_ECC_ERROR_CNTR_CLEAR 0x00040004
+#define TRP_INTERRUPT_0_CLEAR 0x00020484
+#define TRP_ECC_ERROR_CNTR_CLEAR 0x00020440
+
+/* Mask and shift macros */
+#define ECC_DB_ERR_COUNT_MASK GENMASK(4, 0)
+#define ECC_DB_ERR_WAYS_MASK GENMASK(31, 16)
+#define ECC_DB_ERR_WAYS_SHIFT BIT(4)
+
+#define ECC_SB_ERR_COUNT_MASK GENMASK(23, 16)
+#define ECC_SB_ERR_COUNT_SHIFT BIT(4)
+#define ECC_SB_ERR_WAYS_MASK GENMASK(15, 0)
+
+#define SB_ECC_ERROR BIT(0)
+#define DB_ECC_ERROR BIT(1)
+
+#define DRP_TRP_INT_CLEAR GENMASK(1, 0)
+#define DRP_TRP_CNT_CLEAR GENMASK(1, 0)
+
+/* Config registers offsets*/
+#define DRP_ECC_ERROR_CFG 0x00040000
+
+/* TRP, DRP interrupt register offsets */
+#define CMN_INTERRUPT_0_ENABLE 0x0003001C
+#define CMN_INTERRUPT_2_ENABLE 0x0003003C
+#define TRP_INTERRUPT_0_ENABLE 0x00020488
+#define DRP_INTERRUPT_ENABLE 0x0004100C
+
+#define SB_ERROR_THRESHOLD 0x1
+#define SB_ERROR_THRESHOLD_SHIFT 24
+#define SB_DB_TRP_INTERRUPT_ENABLE 0x3
+#define TRP0_INTERRUPT_ENABLE 0x1
+#define DRP0_INTERRUPT_ENABLE BIT(6)
+#define SB_DB_DRP_INTERRUPT_ENABLE 0x3
+
+
+enum {
+ LLCC_DRAM_CE = 0,
+ LLCC_DRAM_UE,
+ LLCC_TRAM_CE,
+ LLCC_TRAM_UE,
+};
+
+struct errors_edac {
+ const char *msg;
+ void (*func)(struct edac_device_ctl_info *edev_ctl,
+ int inst_nr, int block_nr, const char *msg);
+};
+
+static const struct errors_edac errors[] = {
+ {"LLCC Data RAM correctable Error", edac_device_handle_ce},
+ {"LLCC Data RAM uncorrectable Error", edac_device_handle_ue},
+ {"LLCC Tag RAM correctable Error", edac_device_handle_ce},
+ {"LLCC Tag RAM uncorrectable Error", edac_device_handle_ue},
+};
+
+static int qcom_llcc_core_setup(struct regmap *llcc_bcast_regmap)
+{
+ u32 sb_err_threshold;
+ int ret;
+
+ /* Enable TRP in instance 2 of common interrupt enable register */
+ ret = regmap_update_bits(llcc_bcast_regmap, CMN_INTERRUPT_2_ENABLE,
+ TRP0_INTERRUPT_ENABLE,
+ TRP0_INTERRUPT_ENABLE);
+ if (ret)
+ return ret;
+
+ /* Enable ECC interrupts on Tag Ram */
+ ret = regmap_update_bits(llcc_bcast_regmap, TRP_INTERRUPT_0_ENABLE,
+ SB_DB_TRP_INTERRUPT_ENABLE,
+ SB_DB_TRP_INTERRUPT_ENABLE);
+ if (ret)
+ return ret;
+
+ /* Enable SB error for Data RAM */
+ sb_err_threshold = (SB_ERROR_THRESHOLD << SB_ERROR_THRESHOLD_SHIFT);
+ ret = regmap_write(llcc_bcast_regmap, DRP_ECC_ERROR_CFG,
+ sb_err_threshold);
+ if (ret)
+ return ret;
+
+ /* Enable DRP in instance 2 of common interrupt enable register */
+ ret = regmap_update_bits(llcc_bcast_regmap, CMN_INTERRUPT_2_ENABLE,
+ DRP0_INTERRUPT_ENABLE,
+ DRP0_INTERRUPT_ENABLE);
+ if (ret)
+ return ret;
+
+ /* Enable ECC interrupts on Data Ram */
+ ret = regmap_write(llcc_bcast_regmap, DRP_INTERRUPT_ENABLE,
+ SB_DB_DRP_INTERRUPT_ENABLE);
+ return ret;
+}
+
+/* Clear the error interrupt and counter registers */
+static int qcom_llcc_clear_errors(int err_type, struct llcc_drv_data *drv)
+{
+ int ret = 0;
+
+ switch (err_type) {
+ case LLCC_DRAM_CE:
+ case LLCC_DRAM_UE:
+ /* Clear the interrupt */
+ ret = regmap_write(drv->bcast_regmap, DRP_INTERRUPT_CLEAR,
+ DRP_TRP_INT_CLEAR);
+ if (ret)
+ return ret;
+
+ /* Clear the counters */
+ ret = regmap_write(drv->bcast_regmap, DRP_ECC_ERROR_CNTR_CLEAR,
+ DRP_TRP_CNT_CLEAR);
+ if (ret)
+ return ret;
+ break;
+ case LLCC_TRAM_CE:
+ case LLCC_TRAM_UE:
+ ret = regmap_write(drv->bcast_regmap, TRP_INTERRUPT_0_CLEAR,
+ DRP_TRP_INT_CLEAR);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(drv->bcast_regmap, TRP_ECC_ERROR_CNTR_CLEAR,
+ DRP_TRP_CNT_CLEAR);
+ if (ret)
+ return ret;
+ break;
+ }
+ return ret;
+}
+
+/* Dump syndrome registers for tag Ram Double bit errors */
+static int dump_trp_db_syn_reg(struct llcc_drv_data *drv, u32 bank)
+{
+ int db_err_cnt, db_err_ways, ret, i;
+ u32 synd_reg, synd_val;
+
+ for (i = 0; i < TRP_SYN_REG_CNT; i++) {
+ synd_reg = TRP_ECC_DB_ERR_SYN0 + (i * 4);
+ ret = regmap_read(drv->regmap, drv->offsets[bank] + synd_reg,
+ &synd_val);
+ if (ret)
+ return ret;
+ edac_printk(KERN_CRIT, EDAC_LLCC, "TRP_ECC_SYN%d: 0x%8x\n",
+ i, synd_val);
+ }
+
+ ret = regmap_read(drv->regmap,
+ drv->offsets[bank] + TRP_ECC_ERROR_STATUS1,
+ &db_err_cnt);
+ if (ret)
+ return ret;
+ db_err_cnt = (db_err_cnt & ECC_DB_ERR_COUNT_MASK);
+ edac_printk(KERN_CRIT, EDAC_LLCC, "Double-Bit error count: 0x%4x\n",
+ db_err_cnt);
+
+ ret = regmap_read(drv->regmap,
+ drv->offsets[bank] + TRP_ECC_ERROR_STATUS0,
+ &db_err_ways);
+ if (ret)
+ return ret;
+ db_err_ways = (db_err_ways & ECC_DB_ERR_WAYS_MASK);
+ db_err_ways >>= ECC_DB_ERR_WAYS_SHIFT;
+
+ edac_printk(KERN_CRIT, EDAC_LLCC, "Double-Bit error ways: 0x%4x\n",
+ db_err_ways);
+
+ return ret;
+}
+
+/* Dump syndrome register for tag Ram Single Bit Errors */
+static int dump_trp_sb_syn_reg(struct llcc_drv_data *drv, u32 bank)
+{
+ int sb_err_cnt, sb_err_ways, ret, i;
+ u32 synd_reg, synd_val;
+
+ for (i = 0; i < TRP_SYN_REG_CNT; i++) {
+ synd_reg = TRP_ECC_SB_ERR_SYN0 + (i * 4);
+ ret = regmap_read(drv->regmap, drv->offsets[bank] + synd_reg,
+ &synd_val);
+ if (ret)
+ return ret;
+ edac_printk(KERN_CRIT, EDAC_LLCC, "TRP_ECC_SYN%d: 0x%8x\n", i,
+ synd_val);
+ }
+
+ ret = regmap_read(drv->regmap,
+ drv->offsets[bank] + TRP_ECC_ERROR_STATUS1,
+ &sb_err_cnt);
+ if (ret)
+ return ret;
+ sb_err_cnt = (sb_err_cnt & ECC_SB_ERR_COUNT_MASK);
+ sb_err_cnt >>= ECC_SB_ERR_COUNT_SHIFT;
+ edac_printk(KERN_CRIT, EDAC_LLCC, "Single-Bit error count: 0x%4x\n",
+ sb_err_cnt);
+
+ ret = regmap_read(drv->regmap,
+ drv->offsets[bank] + TRP_ECC_ERROR_STATUS0,
+ &sb_err_ways);
+ if (ret)
+ return ret;
+
+ sb_err_ways = sb_err_ways & ECC_SB_ERR_WAYS_MASK;
+
+ edac_printk(KERN_CRIT, EDAC_LLCC, "Single-Bit error ways: 0x%4x\n",
+ sb_err_ways);
+
+ return ret;
+}
+
+/* Dump syndrome registers for Data Ram Double bit errors */
+static int dump_drp_db_syn_reg(struct llcc_drv_data *drv, u32 bank)
+{
+ int db_err_cnt, db_err_ways, ret, i;
+ u32 synd_reg, synd_val;
+
+ for (i = 0; i < DRP_SYN_REG_CNT; i++) {
+ synd_reg = DRP_ECC_DB_ERR_SYN0 + (i * 4);
+ ret = regmap_read(drv->regmap, drv->offsets[bank] + synd_reg,
+ &synd_val);
+ if (ret)
+ return ret;
+ edac_printk(KERN_CRIT, EDAC_LLCC, "DRP_ECC_SYN%d: 0x%8x\n", i,
+ synd_val);
+ }
+
+ ret = regmap_read(drv->regmap,
+ drv->offsets[bank] + DRP_ECC_ERROR_STATUS1,
+ &db_err_cnt);
+ if (ret)
+ return ret;
+ db_err_cnt = (db_err_cnt & ECC_DB_ERR_COUNT_MASK);
+ edac_printk(KERN_CRIT, EDAC_LLCC, "Double-Bit error count: 0x%4x\n",
+ db_err_cnt);
+
+ ret = regmap_read(drv->regmap,
+ drv->offsets[bank] + DRP_ECC_ERROR_STATUS0,
+ &db_err_ways);
+ if (ret)
+ return ret;
+ db_err_ways &= ECC_DB_ERR_WAYS_MASK;
+ db_err_ways >>= ECC_DB_ERR_WAYS_SHIFT;
+ edac_printk(KERN_CRIT, EDAC_LLCC, "Double-Bit error ways: 0x%4x\n",
+ db_err_ways);
+
+ return ret;
+}
+
+/* Dump Syndrome registers for Data Ram Single bit errors*/
+static int dump_drp_sb_syn_reg(struct llcc_drv_data *drv, u32 bank)
+{
+ int sb_err_cnt, sb_err_ways, ret, i;
+ u32 synd_reg, synd_val;
+
+ for (i = 0; i < DRP_SYN_REG_CNT; i++) {
+ synd_reg = DRP_ECC_SB_ERR_SYN0 + (i * 4);
+ ret = regmap_read(drv->regmap, drv->offsets[bank] + synd_reg,
+ &synd_val);
+ if (ret)
+ return ret;
+ edac_printk(KERN_CRIT, EDAC_LLCC, "DRP_ECC_SYN%d: 0x%8x\n", i,
+ synd_val);
+ }
+
+ ret = regmap_read(drv->regmap,
+ drv->offsets[bank] + DRP_ECC_ERROR_STATUS1,
+ &sb_err_cnt);
+ if (ret)
+ return ret;
+ sb_err_cnt &= ECC_SB_ERR_COUNT_MASK;
+ sb_err_cnt >>= ECC_SB_ERR_COUNT_SHIFT;
+ edac_printk(KERN_CRIT, EDAC_LLCC, "Single-Bit error count: 0x%4x\n",
+ sb_err_cnt);
+
+ ret = regmap_read(drv->regmap,
+ drv->offsets[bank] + DRP_ECC_ERROR_STATUS0,
+ &sb_err_ways);
+ if (ret)
+ return ret;
+ sb_err_ways = sb_err_ways & ECC_SB_ERR_WAYS_MASK;
+
+ edac_printk(KERN_CRIT, EDAC_LLCC, "Single-Bit error ways: 0x%4x\n",
+ sb_err_ways);
+
+ return ret;
+}

As Borislav mentioned, dump_{trp,drp}_{db,sb}_syn_reg are basically
copy/pastes of each other with minor differences. I wonder if there's
a way to refactor this so that there's less boilerplate. Maybe a
helper function for the for loop, and maybe another one to read both
of the status registers (or optionally just one) might help. Or you
might do even better with a table, depending on how things shake out.

Sure, I'll explore that option.


+
+static int dump_syn_reg(struct edac_device_ctl_info *edev_ctl,
+ int err_type, u32 bank)
+{
+ struct llcc_drv_data *drv = edev_ctl->pvt_info;
+ int ret = 0;
+
+ switch (err_type) {
+ case LLCC_DRAM_CE:
+ ret = dump_drp_sb_syn_reg(drv, bank);
+ break;
+ case LLCC_DRAM_UE:
+ ret = dump_drp_db_syn_reg(drv, bank);
+ break;
+ case LLCC_TRAM_CE:
+ ret = dump_trp_sb_syn_reg(drv, bank);
+ break;
+ case LLCC_TRAM_UE:
+ ret = dump_trp_db_syn_reg(drv, bank);
+ break;
+ }
+ if (ret)
+ return ret;
+

If something fails and you return here without clearing errors, would
there be an interrupt storm?

I'm not sure on this. I'll have to go back and check the spec. I can update
it in the next patch set based on the findings.


+ ret = qcom_llcc_clear_errors(err_type, drv);
+ if (ret)
+ return ret;
+
+ errors[err_type].func(edev_ctl, 0, bank, errors[err_type].msg);
+
+ return ret;
+}
+

Whoops, I clipped the rest of this message already, but in probe, the
type of ecc_irq should be int. Also, in patch 2 you directly assigned
platform_get_irq into the ecc_irq member, so the if (!ecc_irq) logic
in probe doesn't quite work if platform_get_irq returns a negative
number. Is 0 a valid irq number? I don't know.

Yeah, I'll update the data type and fix the logic accordingly.