[PATCH v3 5/6] edac: Add support for Krait CPU cache error detection

Stephen Boyd
2013-11-01T16:33:19Z

Add support for the Krait CPU cache error detection. This is a
simplified version of the code originally written by Stepan
Moskovchenko[1] ported to the EDAC device framework.

[1] https://www.codeaurora.org/cgit/quic/la/kernel/msm/tree/arch/arm/mach-msm/cache_erp.c?h=msm-3.4

Cc: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
drivers/edac/Kconfig | 8 ++
drivers/edac/Makefile | 2 +
drivers/edac/krait_edac.c | 346 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 356 insertions(+)
create mode 100644 drivers/edac/krait_edac.c

diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 878f090..68f612d 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -368,4 +368,12 @@ config EDAC_OCTEON_PCI
Support for error detection and correction on the
Cavium Octeon family of SOCs.

+config EDAC_KRAIT_CACHE
+ tristate "Krait L1/L2 Cache"
+ depends on EDAC_MM_EDAC && ARCH_MSM
+ select KRAIT_L2_ACCESSORS
+ help
+ Support for error detection and correction on the
+ Krait L1/L2 cache controller.
+
endif # EDAC
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index 4154ed6..b6ea505 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -64,3 +64,5 @@ obj-$(CONFIG_EDAC_OCTEON_PC) += octeon_edac-pc.o
obj-$(CONFIG_EDAC_OCTEON_L2C) += octeon_edac-l2c.o
obj-$(CONFIG_EDAC_OCTEON_LMC) += octeon_edac-lmc.o
obj-$(CONFIG_EDAC_OCTEON_PCI) += octeon_edac-pci.o
+
+obj-$(CONFIG_EDAC_KRAIT_CACHE) += krait_edac.o
diff --git a/drivers/edac/krait_edac.c b/drivers/edac/krait_edac.c
new file mode 100644
index 0000000..b1d9f52
--- /dev/null
+++ b/drivers/edac/krait_edac.c
@@ -0,0 +1,346 @@
+/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/cpu.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+
+#include <asm/krait-l2-accessors.h>
+
+#include "edac_core.h"
+
+#define CESR_DCTPE BIT(0)
+#define CESR_DCDPE BIT(1)
+#define CESR_ICTPE BIT(2)
+#define CESR_ICDPE BIT(3)
+#define CESR_DCTE (BIT(4) | BIT(5))
+#define CESR_ICTE (BIT(6) | BIT(7))
+#define CESR_TLBMH BIT(16)
+#define CESR_I_MASK 0x000000cc
+/* Print a message for everything but TLB MH events */
+#define CESR_PRINT_MASK 0x000000ff
+
+#define L2ESR 0x204
+#define L2ESR_MPDCD BIT(0)
+#define L2ESR_MPSLV BIT(1)
+#define L2ESR_TSESB BIT(2)
+#define L2ESR_TSEDB BIT(3)
+#define L2ESR_DSESB BIT(4)
+#define L2ESR_DSEDB BIT(5)
+#define L2ESR_MSE BIT(6)
+#define L2ESR_MPLDREXNOK BIT(8)
+#define L2ESR_CPU_MASK 0xf
+#define L2ESR_CPU_SHIFT 16
+#define L2ESR_SP BIT(20)
+
+#define L2ESYNR0 0x208
+#define L2ESYNR1 0x209
+#define L2EAR0 0x20c
+#define L2EAR1 0x20d
+
+struct krait_edac {
+ int l1_irq;
+ struct edac_device_ctl_info * __percpu *edev;
+ struct notifier_block notifier;
+};
+
+struct krait_edac_error {
+ const char * const msg;
+ void (*func)(struct edac_device_ctl_info *edac_dev,
+ int inst_nr, int block_nr, const char *msg);
+};
+
+static unsigned int read_cesr(void)
+{
+ unsigned int cesr;
+
+ asm volatile ("mrc p15, 7, %0, c15, c0, 1 @ cesr" : "=r" (cesr));
+ return cesr;
+}
+
+static void write_cesr(unsigned int cesr)
+{
+ asm volatile ("mcr p15, 7, %0, c15, c0, 1 @ cesr" : : "r" (cesr));
+}
+
+static unsigned int read_cesynr(void)
+{
+ unsigned int cesynr;
+
+ asm volatile ("mrc p15, 7, %0, c15, c0, 3 @ cesynr" : "=r" (cesynr));
+ return cesynr;
+}
+
+static irqreturn_t krait_l1_irq(int irq, void *dev_id)
+{
+ struct edac_device_ctl_info *edac = dev_id;
+ unsigned int cesr = read_cesr();
+ unsigned int i_cesynr, d_cesynr;
+ unsigned int cpu = smp_processor_id();
+ int print_regs = cesr & CESR_PRINT_MASK;
+ int i;
+ static const struct krait_edac_error errors[] = {
+ { "D-cache tag parity error", edac_device_handle_ue },
+ { "D-cache data parity error", edac_device_handle_ue },
+ { "I-cache tag parity error", edac_device_handle_ce },
+ { "I-cache data parity error", edac_device_handle_ce },
+ { "D-cache tag timing error", edac_device_handle_ue },
+ { "D-cache data timing error", edac_device_handle_ue },
+ { "I-cache tag timing error", edac_device_handle_ce },
+ { "I-cache data timing error", edac_device_handle_ce }
+ };
+
+ if (print_regs) {
+ pr_alert("L1 / TLB Error detected on CPU %d!\n", cpu);
+ pr_alert("CESR = 0x%08x\n", cesr);
+ pr_alert("MIDR = 0x%08x\n", read_cpuid_id());
+ }
+
+ for (i = 0; i < ARRAY_SIZE(errors); i++)
+ if (BIT(i) & cesr)
+ errors[i].func(edac, cpu, 0, errors[i].msg);
+
+ if (cesr & CESR_TLBMH) {
+ asm ("mcr p15, 0, r0, c8, c7, 0");
+ edac_device_handle_ce(edac, cpu, 0, "TLB Multi-Hit error");
+ }
+
+ if (cesr & (CESR_ICTPE | CESR_ICDPE | CESR_ICTE)) {
+ i_cesynr = read_cesynr();
+ pr_alert("I-side CESYNR = 0x%08x\n", i_cesynr);
+ write_cesr(CESR_I_MASK);
+
+ /*
+ * Clear the I-side bits from the captured CESR value so that we
+ * don't accidentally clear any new I-side errors when we do
+ * the CESR write-clear operation.
+ */
+ cesr &= ~CESR_I_MASK;
+ }
+
+ if (cesr & (CESR_DCTPE | CESR_DCDPE | CESR_DCTE)) {
+ d_cesynr = read_cesynr();
+ pr_alert("D-side CESYNR = 0x%08x\n", d_cesynr);
+ }
+
+ /* Clear the interrupt bits we processed */
+ write_cesr(cesr);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t krait_l2_irq(int irq, void *dev_id)
+{
+ struct edac_device_ctl_info *edac = dev_id;
+ unsigned int l2esr;
+ unsigned int l2esynr0;
+ unsigned int l2esynr1;
+ unsigned int l2ear0;
+ unsigned int l2ear1;
+ unsigned long cpu;
+ int i;
+ static const struct krait_edac_error errors[] = {
+ { "master port decode error", edac_device_handle_ce },
+ { "master port slave error", edac_device_handle_ce },
+ { "tag soft error, single-bit", edac_device_handle_ce },
+ { "tag soft error, double-bit", edac_device_handle_ue },
+ { "data soft error, single-bit", edac_device_handle_ce },
+ { "data soft error, double-bit", edac_device_handle_ue },
+ { "modified soft error", edac_device_handle_ce },
+ { "slave port exclusive monitor not available",
+ edac_device_handle_ue},
+ { "master port LDREX received Normal OK response",
+ edac_device_handle_ce },
+ };
+
+ l2esr = get_l2_indirect_reg(L2ESR);
+ pr_alert("Error detected!\n");
+ pr_alert("L2ESR = 0x%08x\n", l2esr);
+
+ if (l2esr & (L2ESR_TSESB | L2ESR_TSEDB | L2ESR_MSE | L2ESR_SP)) {
+ l2esynr0 = get_l2_indirect_reg(L2ESYNR0);
+ l2esynr1 = get_l2_indirect_reg(L2ESYNR1);
+ l2ear0 = get_l2_indirect_reg(L2EAR0);
+ l2ear1 = get_l2_indirect_reg(L2EAR1);
+
+ pr_alert("L2ESYNR0 = 0x%08x\n", l2esynr0);
+ pr_alert("L2ESYNR1 = 0x%08x\n", l2esynr1);
+ pr_alert("L2EAR0 = 0x%08x\n", l2ear0);
+ pr_alert("L2EAR1 = 0x%08x\n", l2ear1);
+ }
+
+ cpu = (l2esr >> L2ESR_CPU_SHIFT) & L2ESR_CPU_MASK;
+ cpu = __ffs(cpu);
+ if (cpu)
+ cpu--;
+ for (i = 0; i < ARRAY_SIZE(errors); i++)
+ if (BIT(i) & l2esr)
+ errors[i].func(edac, cpu, 1, errors[i].msg);
+
+ set_l2_indirect_reg(L2ESR, l2esr);
+
+ return IRQ_HANDLED;
+}
+
+static void enable_l1_irq(void *info)
+{
+ const struct krait_edac *k = info;
+
+ enable_percpu_irq(k->l1_irq, IRQ_TYPE_LEVEL_HIGH);
+}
+
+static void disable_l1_irq(void *info)
+{
+ const struct krait_edac *k = info;
+
+ disable_percpu_irq(k->l1_irq);
+}
+
+static int
+krait_edac_notify(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+ struct krait_edac *p = container_of(nfb, struct krait_edac, notifier);
+
+ switch (action & ~CPU_TASKS_FROZEN) {
+ case CPU_STARTING:
+ enable_l1_irq(p);
+ break;
+
+ case CPU_DYING:
+ disable_l1_irq(p);
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static int krait_edac_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct edac_device_ctl_info *edev;
+ struct krait_edac *p;
+ int l1_irq, l2_irq;
+ int ret, cpu;
+ struct device_node *node;
+
+ node = of_get_cpu_node(0, NULL);
+ if (!node)
+ return -ENODEV;
+
+ node = of_parse_phandle(node, "next-level-cache", 0);
+ if (!node)
+ return -ENODEV;
+
+ l2_irq = irq_of_parse_and_map(node, 0);
+ of_node_put(node);
+ if (l2_irq < 0)
+ return l2_irq;
+
+ l1_irq = platform_get_irq(pdev, 0);
+ if (l1_irq < 0)
+ return l1_irq;
+
+ p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, p);
+ p->l1_irq = l1_irq;
+
+ p->edev = alloc_percpu(struct edac_device_ctl_info *);
+ if (!p->edev)
+ return -ENOMEM;
+
+ edev = edac_device_alloc_ctl_info(0, "cpu", num_possible_cpus(),
+ "L", 2, 1, NULL, 0,
+ edac_device_alloc_index());
+ if (!edev) {
+ ret = -ENOMEM;
+ goto err_alloc;
+ }
+
+ edev->dev = dev;
+ edev->mod_name = dev_name(dev);
+ edev->dev_name = dev_name(dev);
+ edev->ctl_name = "cache";
+
+ for_each_possible_cpu(cpu)
+ *per_cpu_ptr(p->edev, cpu) = edev;
+
+ ret = edac_device_add_device(edev);
+ if (ret)
+ goto err_add;
+
+ ret = request_percpu_irq(l1_irq, krait_l1_irq, "L1 err",
+ p->edev);
+ if (ret)
+ goto err_l1_irq;
+
+ ret = devm_request_irq(dev, l2_irq, krait_l2_irq, 0, "L2 err",
+ edev);
+ if (ret)
+ goto err_l2_irq;
+
+ p->notifier.notifier_call = krait_edac_notify;
+ register_hotcpu_notifier(&p->notifier);
+ on_each_cpu(enable_l1_irq, p, true);
+
+ return 0;
+err_l2_irq:
+ free_percpu_irq(p->l1_irq, p->edev);
+err_l1_irq:
+ edac_device_del_device(dev);
+err_add:
+ edac_device_free_ctl_info(edev);
+err_alloc:
+ free_percpu(p->edev);
+ return ret;
+}
+
+static int krait_edac_remove(struct platform_device *pdev)
+{
+ struct krait_edac *p = platform_get_drvdata(pdev);
+
+ unregister_hotcpu_notifier(&p->notifier);
+ on_each_cpu(disable_l1_irq, p, true);
+ free_percpu_irq(p->l1_irq, p->edev);
+ edac_device_del_device(&pdev->dev);
+ edac_device_free_ctl_info(*__this_cpu_ptr(p->edev));
+ free_percpu(p->edev);
+
+ return 0;
+}
+
+static const struct of_device_id krait_edac_match_table[] = {
+ { .compatible = "qcom,krait" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, krait_edac_match_table);
+
+static struct platform_driver krait_edac_driver = {
+ .probe = krait_edac_probe,
+ .remove = krait_edac_remove,
+ .driver = {
+ .name = "krait_edac",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(krait_edac_match_table),
+ },
+};
+module_platform_driver(krait_edac_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Krait CPU cache error reporting driver");
+MODULE_ALIAS("platform:krait_edac");