mm: cache-pl310-erp: Add support for PL310 Error Reporting
PL310 is an external L2 Cache controller which reports
any errors such as decode on master/slave, read/write
parity errors on data/tag RAM using the L2CC interrupt
connected to the processor.
Once we receive interrupt we can read the status register
to determine the type of error occurred.
Change-Id: I66957d4bbd67a11b2bffbf919cf5aa177b5d2ebc
Signed-off-by: Taniya Das <tdas@codeaurora.org>
diff --git a/arch/arm/mm/cache-pl310-erp.c b/arch/arm/mm/cache-pl310-erp.c
new file mode 100644
index 0000000..ad75143
--- /dev/null
+++ b/arch/arm/mm/cache-pl310-erp.c
@@ -0,0 +1,283 @@
+/* Copyright (c) 2012, 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/errno.h>
+#include <linux/cpu.h>
+#include <linux/io.h>
+#include <asm/cputype.h>
+#include <asm/hardware/cache-l2x0.h>
+
+#define MODULE_NAME "pl310_erp"
+
+struct pl310_drv_data {
+ unsigned int irq;
+ unsigned int ecntr;
+ unsigned int parrt;
+ unsigned int parrd;
+ unsigned int errwd;
+ unsigned int errwt;
+ unsigned int errrt;
+ unsigned int errrd;
+ unsigned int slverr;
+ unsigned int decerr;
+ void __iomem *base;
+};
+
+#define ECNTR BIT(0)
+#define PARRT BIT(1)
+#define PARRD BIT(2)
+#define ERRWT BIT(3)
+#define ERRWD BIT(4)
+#define ERRRT BIT(5)
+#define ERRRD BIT(6)
+#define SLVERR BIT(7)
+#define DECERR BIT(8)
+
+static irqreturn_t pl310_erp_irq(int irq, void *dev_id)
+{
+ struct pl310_drv_data *p = platform_get_drvdata(dev_id);
+ uint16_t mask_int_stat, int_clear = 0, error = 0;
+
+ mask_int_stat = readl_relaxed(p->base + L2X0_MASKED_INTR_STAT);
+
+ if (mask_int_stat & ECNTR) {
+ pr_alert("Event Counter1/0 Overflow Increment error\n");
+ p->ecntr++;
+ int_clear = mask_int_stat & ECNTR;
+ }
+
+ if (mask_int_stat & PARRT) {
+ pr_alert("Read parity error on L2 Tag RAM\n");
+ p->parrt++;
+ error = 1;
+ int_clear = mask_int_stat & PARRT;
+ }
+
+ if (mask_int_stat & PARRD) {
+ pr_alert("Read parity error on L2 Tag RAM\n");
+ p->parrd++;
+ error = 1;
+ int_clear = mask_int_stat & PARRD;
+ }
+
+ if (mask_int_stat & ERRWT) {
+ pr_alert("Write error on L2 Tag RAM\n");
+ p->errwt++;
+ int_clear = mask_int_stat & ERRWT;
+ }
+
+ if (mask_int_stat & ERRWD) {
+ pr_alert("Write error on L2 Data RAM\n");
+ p->errwd++;
+ int_clear = mask_int_stat & ERRWD;
+ }
+
+ if (mask_int_stat & ERRRT) {
+ pr_alert("Read error on L2 Tag RAM\n");
+ p->errrt++;
+ int_clear = mask_int_stat & ERRRT;
+ }
+
+ if (mask_int_stat & ERRRD) {
+ pr_alert("Read error on L2 Data RAM\n");
+ p->errrd++;
+ int_clear = mask_int_stat & ERRRD;
+ }
+
+ if (mask_int_stat & DECERR) {
+ pr_alert("L2 master port decode error\n");
+ p->decerr++;
+ int_clear = mask_int_stat & DECERR;
+ }
+
+ if (mask_int_stat & SLVERR) {
+ pr_alert("L2 slave port error\n");
+ p->slverr++;
+ int_clear = mask_int_stat & SLVERR;
+ }
+
+ writel_relaxed(int_clear, p->base + L2X0_INTR_CLEAR);
+
+ /* Make sure the interrupts are cleared */
+ mb();
+
+ /* WARNING will be thrown whenever we receive any L2 interrupt.
+ * Other than parity on tag/data ram, irrespective of the bits
+ * set we will throw a warning.
+ */
+ WARN_ON(!error);
+
+ /* Panic in case we encounter parity error in TAG/DATA Ram */
+ BUG_ON(error);
+
+ return IRQ_HANDLED;
+}
+
+static void pl310_mask_int(struct pl310_drv_data *p, bool enable)
+{
+ uint16_t mask;
+
+ if (enable)
+ mask = 0x1FF;
+ else
+ mask = 0x0;
+
+ writel_relaxed(mask, p->base + L2X0_INTR_MASK);
+
+ /* Make sure Mask is updated */
+ mb();
+
+ pr_debug("Mask interrupt %x\n",
+ readl_relaxed(p->base + L2X0_INTR_MASK));
+}
+
+static int pl310_erp_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct pl310_drv_data *p = dev_get_drvdata(dev);
+
+ return snprintf(buf, PAGE_SIZE,
+ "L2CC Interrupt Number:\t\t\t%d\n"\
+ "Event Counter1/0 Overflow Increment:\t%u\n"\
+ "Parity Error on L2 Tag RAM (Read):\t%u\n"\
+ "Parity Error on L2 Data RAM (Read):\t%u\n"\
+ "Error on L2 Tag RAM (Write):\t\t%u\n"\
+ "Error on L2 Data RAM (Write):\t\t%u\n"\
+ "Error on L2 Tag RAM (Read):\t\t%u\n"\
+ "Error on L2 Data RAM (Read):\t\t%u\n"\
+ "SLave Error from L3 Port:\t\t%u\n"\
+ "Decode Error from L3 Port:\t\t%u\n",
+ p->irq, p->ecntr, p->parrt, p->parrd, p->errwt, p->errwd,
+ p->errrt, p->errrd, p->slverr, p->decerr);
+}
+
+static DEVICE_ATTR(cache_erp, 0664, pl310_erp_show, NULL);
+
+static int __init pl310_create_sysfs(struct device *dev)
+{
+ /* create a sysfs entry at
+ * /sys/devices/platform/pl310_erp/cache_erp
+ */
+ return device_create_file(dev, &dev_attr_cache_erp);
+}
+
+static int __devinit pl310_cache_erp_probe(struct platform_device *pdev)
+{
+ struct resource *r;
+ struct pl310_drv_data *drv_data;
+ int ret;
+
+ drv_data = devm_kzalloc(&pdev->dev, sizeof(struct pl310_drv_data),
+ GFP_KERNEL);
+ if (drv_data == NULL) {
+ dev_err(&pdev->dev, "cannot allocate memory\n");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r) {
+ dev_err(&pdev->dev, "No L2 base address\n");
+ ret = -ENODEV;
+ goto error;
+ }
+
+ if (!devm_request_mem_region(&pdev->dev, r->start, resource_size(r),
+ "erp")) {
+ ret = -EBUSY;
+ goto error;
+ }
+
+ drv_data->base = devm_ioremap_nocache(&pdev->dev, r->start,
+ resource_size(r));
+ if (!drv_data->base) {
+ dev_err(&pdev->dev, "errored to ioremap 0x%x\n", r->start);
+ ret = -ENOMEM;
+ goto error;
+ }
+ dev_dbg(&pdev->dev, "L2CC base 0x%p\n", drv_data->base);
+
+ r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "l2_irq");
+ if (!r) {
+ dev_err(&pdev->dev, "No L2 IRQ resource\n");
+ ret = -ENODEV;
+ goto error;
+ }
+
+ drv_data->irq = r->start;
+
+ ret = devm_request_irq(&pdev->dev, drv_data->irq, pl310_erp_irq,
+ IRQF_TRIGGER_RISING, "l2cc_intr", pdev);
+ if (ret) {
+ dev_err(&pdev->dev, "request irq for L2 interrupt failed\n");
+ goto error;
+ }
+
+ platform_set_drvdata(pdev, drv_data);
+
+ pl310_mask_int(drv_data, true);
+
+ ret = pl310_create_sysfs(&pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to create sysfs entry\n");
+ goto sysfs_err;
+ }
+
+ return 0;
+
+sysfs_err:
+ platform_set_drvdata(pdev, NULL);
+ pl310_mask_int(drv_data, false);
+error:
+ return ret;
+}
+
+static int __devexit pl310_cache_erp_remove(struct platform_device *pdev)
+{
+ struct pl310_drv_data *p = platform_get_drvdata(pdev);
+
+ pl310_mask_int(p, false);
+
+ device_remove_file(&pdev->dev, &dev_attr_cache_erp);
+
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+static struct platform_driver pl310_cache_erp_driver = {
+ .probe = pl310_cache_erp_probe,
+ .remove = __devexit_p(pl310_cache_erp_remove),
+ .driver = {
+ .name = MODULE_NAME,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init pl310_cache_erp_init(void)
+{
+ return platform_driver_register(&pl310_cache_erp_driver);
+}
+module_init(pl310_cache_erp_init);
+
+static void __exit pl310_cache_erp_exit(void)
+{
+ platform_driver_unregister(&pl310_cache_erp_driver);
+}
+module_exit(pl310_cache_erp_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("PL310 cache error reporting driver");