msm: Add support for EBI error reporting

Add support for reporting EBI errors to the kernel log to
help with debugging problems where memory configuration or
access permissions may be incorrect.

Change-Id: I58b46459384f39a813bfaa225b44259c8d9121d7
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>

arch/arm/mach-msm/Kconfig

@@ -2257,6 +2257,16 @@ config MSM_RTB_SEPARATE_CPUS
 	  separately. This will guarantee that the last acesses for each cpu
 	  will be logged but there will be fewer entries per cpu
 
+config MSM_EBI_ERP
+	bool "External Bus Interface (EBI) error reporting"
+	help
+	  Say 'Y' here to enable reporting of external bus interface errors to
+	  the kernel log. Information such as the offending address and
+	  transaction type will be logged. This may be useful for debugging
+	  seemingly broken memory accesses.
+
+	  For production builds, you should probably say 'N' here.
+
 config MSM_CACHE_ERP
 	bool "Cache / CPU error reporting"
 	depends on ARCH_MSM_KRAIT

arch/arm/mach-msm/Makefile

@@ -364,6 +364,7 @@ endif
 obj-$(CONFIG_ARCH_MSM8960) += mdm2.o mdm_common.o
 obj-$(CONFIG_MSM_RTB) += msm_rtb.o
 obj-$(CONFIG_MSM_CACHE_ERP) += cache_erp.o
+obj-$(CONFIG_MSM_EBI_ERP) += ebi_erp.o
 obj-$(CONFIG_MSM_CACHE_DUMP) += msm_cache_dump.o
 
 obj-$(CONFIG_MSM_HSIC_SYSMON) += hsic_sysmon.o

arch/arm/mach-msm/ebi_erp.c

@@ -0,0 +1,194 @@
+/* Copyright (c) 2012, Code Aurora Forum. 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/io.h>
+#include <linux/irq.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/proc_fs.h>
+#include <linux/cpu.h>
+
+#define MODULE_NAME "msm_ebi_erp"
+
+#define EBI_ERR_ADDR		0x100
+#define SLV_ERR_APACKET_0	0x108
+#define SLV_ERR_APACKET_1	0x10C
+#define SLV_ERR_CNTL		0x114
+
+#define CNTL_ERR_OCCURRED	BIT(4)
+#define CNTL_CLEAR_ERR		BIT(8)
+#define CNTL_IRQ_EN		BIT(12)
+
+#define AMID_MASK		0xFFFF
+#define ERR_AWRITE		BIT(0)
+#define ERR_AOOOWR		BIT(1)
+#define ERR_AOOORD		BIT(2)
+#define ERR_APTORNS		BIT(3)
+#define ERR_ALOCK_SHIFT		6
+#define ERR_ALOCK_MASK		0x3
+#define ERR_ATYPE_SHIFT		8
+#define ERR_ATYPE_MASK		0xF
+#define ERR_ABURST		BIT(12)
+#define ERR_ASIZE_SHIFT		13
+#define ERR_ASIZE_MASK		0x7
+#define ERR_ATID_SHIFT		16
+#define ERR_ATID_MASK		0xFF
+#define ERR_ALEN_SHIFT		24
+#define ERR_ALEN_MASK		0xF
+
+#define ERR_CODE_DECODE_ERROR	BIT(0)
+#define ERR_CODE_MPU_ERROR	BIT(1)
+
+struct msm_ebi_erp_data {
+	void __iomem *base;
+	struct device *dev;
+};
+
+static const char *err_lock_types[4] = {
+	"normal",
+	"exclusive",
+	"locked",
+	"barrier",
+};
+
+static const char *err_sizes[8] = {
+	"byte",
+	"half word",
+	"word",
+	"double word",
+	"reserved_4",
+	"reserved_5",
+	"reserved_6",
+	"reserved_7",
+};
+
+static irqreturn_t msm_ebi_irq(int irq, void *dev_id)
+{
+	struct msm_ebi_erp_data *drvdata = dev_id;
+	void __iomem *base = drvdata->base;
+	unsigned int err_addr, err_apacket0, err_apacket1, err_cntl;
+
+	err_addr = readl_relaxed(base + EBI_ERR_ADDR);
+	err_apacket0 = readl_relaxed(base + SLV_ERR_APACKET_0);
+	err_apacket1 = readl_relaxed(base + SLV_ERR_APACKET_1);
+	err_cntl = readl_relaxed(base + SLV_ERR_CNTL);
+
+	if (!(err_cntl & CNTL_ERR_OCCURRED))
+		return IRQ_NONE;
+
+	pr_alert("EBI error detected!\n");
+	pr_alert("\tDevice   = %s\n", dev_name(drvdata->dev));
+	pr_alert("\tERR_ADDR = 0x%08x\n", err_addr);
+	pr_alert("\tAPACKET0 = 0x%08x\n", err_apacket0);
+	pr_alert("\tAPACKET1 = 0x%08x\n", err_apacket1);
+	pr_alert("\tERR_CNTL = 0x%08x\n", err_cntl);
+
+	pr_alert("\tAMID     = 0x%08x\n", err_apacket0 & AMID_MASK);
+	pr_alert("\tType     = %s, %s, %s\n",
+		err_apacket1 & ERR_AWRITE ? "write" : "read",
+		err_sizes[(err_apacket1 >> ERR_ASIZE_SHIFT) & ERR_ASIZE_MASK],
+		err_apacket1 & ERR_APTORNS ? "non-secure" : "secure");
+
+	pr_alert("\tALOCK    = %s\n",
+	    err_lock_types[(err_apacket1 >> ERR_ALOCK_SHIFT) & ERR_ALOCK_MASK]);
+
+	pr_alert("\tABURST   = %s\n", err_apacket1 & ERR_ABURST ?
+						"increment" : "wrap");
+
+	pr_alert("\tCODE     = %s %s\n", err_cntl & ERR_CODE_DECODE_ERROR ?
+						"decode error" : "",
+					 err_cntl & ERR_CODE_MPU_ERROR ?
+						"mpu error" : "");
+	err_cntl |= CNTL_CLEAR_ERR;
+	writel_relaxed(err_cntl, base + SLV_ERR_CNTL);
+	mb();	/* Ensure interrupt is cleared before returning */
+	return IRQ_HANDLED;
+}
+
+static int __devinit msm_ebi_erp_probe(struct platform_device *pdev)
+{
+	struct resource *r;
+	struct msm_ebi_erp_data *drvdata;
+	int ret, irq;
+	unsigned int err_cntl;
+
+	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->dev = &pdev->dev;
+	platform_set_drvdata(pdev, drvdata);
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r)
+		return -EINVAL;
+
+	drvdata->base = devm_ioremap(&pdev->dev, r->start, resource_size(r));
+	if (!drvdata->base)
+		return -ENOMEM;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_irq(&pdev->dev, irq, msm_ebi_irq, IRQF_TRIGGER_HIGH,
+			       dev_name(&pdev->dev), drvdata);
+	if (ret)
+		return ret;
+
+	/* Enable the interrupt */
+	err_cntl = readl_relaxed(drvdata->base + SLV_ERR_CNTL);
+	err_cntl |= CNTL_IRQ_EN;
+	writel_relaxed(err_cntl, drvdata->base + SLV_ERR_CNTL);
+	mb();	/* Ensure interrupt is enabled before returning */
+	return 0;
+}
+
+static int msm_ebi_erp_remove(struct platform_device *pdev)
+{
+	struct msm_ebi_erp_data *drvdata = platform_get_drvdata(pdev);
+	unsigned int err_cntl;
+
+	/* Disable the interrupt */
+	err_cntl = readl_relaxed(drvdata->base + SLV_ERR_CNTL);
+	err_cntl &= ~CNTL_IRQ_EN;
+	writel_relaxed(err_cntl, drvdata->base + SLV_ERR_CNTL);
+	mb();	/* Ensure interrupt is disabled before returning */
+	return 0;
+}
+
+static struct platform_driver msm_ebi_erp_driver = {
+	.probe = msm_ebi_erp_probe,
+	.remove = __devexit_p(msm_ebi_erp_remove),
+	.driver = {
+		.name = MODULE_NAME,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init msm_ebi_erp_init(void)
+{
+	return platform_driver_register(&msm_ebi_erp_driver);
+}
+
+static void __exit msm_ebi_erp_exit(void)
+{
+	platform_driver_unregister(&msm_ebi_erp_driver);
+}
+
+
+module_init(msm_ebi_erp_init);
+module_exit(msm_ebi_erp_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MSM cache error reporting driver");