[PATCH] drivers/edac: provide support for tile architecture

[Chris Metcalf <cmetcalf@tilera.com>]

Add tile support for the EDAC driver, which provides unified system
error (memory, PCI, etc.) reporting. For now, the TILEPro port
reports memory correctable error (CE) only.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
---
 arch/tile/include/asm/edac.h |   29 +++++
 drivers/edac/Kconfig         |   10 ++-
 drivers/edac/Makefile        |    1 +
 drivers/edac/tile_edac.c     |  254 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 293 insertions(+), 1 deletions(-)
 create mode 100644 arch/tile/include/asm/edac.h
 create mode 100644 drivers/edac/tile_edac.c

diff --git a/arch/tile/include/asm/edac.h b/arch/tile/include/asm/edac.h
new file mode 100644
index 0000000..87fc83e
--- /dev/null
+++ b/arch/tile/include/asm/edac.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2011 Tilera Corporation. 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
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   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, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#ifndef _ASM_TILE_EDAC_H
+#define _ASM_TILE_EDAC_H
+
+/* ECC atomic, DMA, SMP and interrupt safe scrub function */
+
+static inline void atomic_scrub(void *va, u32 size)
+{
+	/*
+	 * These is nothing to be done here because CE is
+	 * corrected by the mshim.
+	 */
+	return;
+}
+
+#endif /* _ASM_TILE_EDAC_H */
diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index fe70a34..fac1a20 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -7,7 +7,7 @@
 menuconfig EDAC
 	bool "EDAC (Error Detection And Correction) reporting"
 	depends on HAS_IOMEM
-	depends on X86 || PPC
+	depends on X86 || PPC || TILE
 	help
 	  EDAC is designed to report errors in the core system.
 	  These are low-level errors that are reported in the CPU or
@@ -282,4 +282,12 @@ config EDAC_CPC925
 	  a companion chip to the PowerPC 970 family of
 	  processors.
 
+config EDAC_TILE
+	tristate "Tilera Memory Controller"
+	depends on EDAC_MM_EDAC && TILE
+	default y
+	help
+	  Support for error detection and correction on the
+	  Tilera memory controller.
+
 endif # EDAC
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index ba2898b..3e23913 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -54,3 +54,4 @@ obj-$(CONFIG_EDAC_PPC4XX)		+= ppc4xx_edac.o
 obj-$(CONFIG_EDAC_AMD8111)		+= amd8111_edac.o
 obj-$(CONFIG_EDAC_AMD8131)		+= amd8131_edac.o
 
+obj-$(CONFIG_EDAC_TILE)			+= tile_edac.o
diff --git a/drivers/edac/tile_edac.c b/drivers/edac/tile_edac.c
new file mode 100644
index 0000000..1d5cf06
--- /dev/null
+++ b/drivers/edac/tile_edac.c
@@ -0,0 +1,254 @@
+/*
+ * Copyright 2011 Tilera Corporation. 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
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   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, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ * Tilera-specific EDAC driver.
+ *
+ * This source code is derived from the following driver:
+ *
+ * Cell MIC driver for ECC counting
+ *
+ * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
+ *                <benh@kernel.crashing.org>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/edac.h>
+#include <hv/hypervisor.h>
+#include <hv/drv_mshim_intf.h>
+
+#include "edac_core.h"
+
+#define DRV_NAME	"tile-edac"
+
+/* Number of cs_rows needed per memory controller on TILEPro. */
+#define TILE_EDAC_NR_CSROWS	1
+
+/* Number of channels per memory controller on TILEPro. */
+#define TILE_EDAC_NR_CHANS	1
+
+/* Granularity of reported error in bytes on TILEPro. */
+#define TILE_EDAC_ERROR_GRAIN	8
+
+/* TILE processor has multiple independent memory controllers. */
+struct platform_device *mshim_pdev[TILE_MAX_MSHIMS];
+
+struct tile_edac_priv {
+	int		hv_devhdl;	/* Hypervisor device handle. */
+	int		node;		/* Memory controller instance #. */
+	unsigned int	ce_count;	/*
+					 * Correctable-error counter
+					 * kept by the driver.
+					 */
+};
+
+static void tile_edac_check(struct mem_ctl_info *mci)
+{
+	struct tile_edac_priv	*priv = mci->pvt_info;
+	struct mshim_mem_error	mem_error;
+
+	if (hv_dev_pread(priv->hv_devhdl, 0, (HV_VirtAddr)&mem_error,
+		sizeof(struct mshim_mem_error), MSHIM_MEM_ERROR_OFF) !=
+		sizeof(struct mshim_mem_error)) {
+		pr_err(DRV_NAME ": MSHIM_MEM_ERROR_OFF pread failure.\n");
+		return;
+	}
+
+	/* Check if the current error count is different from the saved one. */
+	if (mem_error.sbe_count != priv->ce_count) {
+		dev_dbg(mci->dev, "ECC CE err on node %d\n", priv->node);
+		priv->ce_count = mem_error.sbe_count;
+		edac_mc_handle_ce(mci, 0, 0, 0, 0, 0, mci->ctl_name);
+	}
+}
+
+/*
+ * Initialize the 'csrows' table within the mci control structure with the
+ * addressing of memory.
+ */
+static int __devinit tile_edac_init_csrows(struct mem_ctl_info *mci)
+{
+	struct csrow_info	*csrow = &mci->csrows[0];
+	struct tile_edac_priv	*priv = mci->pvt_info;
+	struct mshim_mem_info	mem_info;
+
+	if (hv_dev_pread(priv->hv_devhdl, 0, (HV_VirtAddr)&mem_info,
+		sizeof(struct mshim_mem_info), MSHIM_MEM_INFO_OFF) !=
+		sizeof(struct mshim_mem_info)) {
+		pr_err(DRV_NAME ": MSHIM_MEM_INFO_OFF pread failure.\n");
+		return -1;
+	}
+
+	if (mem_info.mem_ecc)
+		csrow->edac_mode = EDAC_SECDED;
+	else
+		csrow->edac_mode = EDAC_NONE;
+	switch (mem_info.mem_type) {
+	case DDR2:
+		csrow->mtype = MEM_DDR2;
+		break;
+
+	case DDR3:
+		csrow->mtype = MEM_DDR3;
+		break;
+
+	default:
+		return -1;
+	}
+
+	csrow->first_page = 0;
+	csrow->nr_pages = mem_info.mem_size >> PAGE_SHIFT;
+	csrow->last_page = csrow->first_page + csrow->nr_pages - 1;
+	csrow->grain = TILE_EDAC_ERROR_GRAIN;
+	csrow->dtype = DEV_UNKNOWN;
+
+	return 0;
+}
+
+static int __devinit tile_edac_mc_probe(struct platform_device *pdev)
+{
+	char			hv_file[32];
+	int			hv_devhdl;
+	struct mem_ctl_info	*mci;
+	struct tile_edac_priv	*priv;
+	int			rc;
+
+	sprintf(hv_file, "mshim/%d", pdev->id);
+	hv_devhdl = hv_dev_open((HV_VirtAddr)hv_file, 0);
+	if (hv_devhdl < 0)
+		return -EINVAL;
+
+	/* A TILE MC has a single channel and one chip-select row. */
+	mci = edac_mc_alloc(sizeof(struct tile_edac_priv),
+		TILE_EDAC_NR_CSROWS, TILE_EDAC_NR_CHANS, pdev->id);
+	if (mci == NULL)
+		return -ENOMEM;
+	priv = mci->pvt_info;
+	priv->node = pdev->id;
+	priv->hv_devhdl = hv_devhdl;
+
+	mci->dev = &pdev->dev;
+	mci->mtype_cap = MEM_FLAG_DDR2;
+	mci->edac_ctl_cap = EDAC_FLAG_SECDED;
+
+	mci->mod_name = DRV_NAME;
+	mci->ctl_name = "TILEPro_Memory_Controller";
+	mci->dev_name = dev_name(&pdev->dev);
+	mci->edac_check = tile_edac_check;
+
+	/*
+	 * Initialize the MC control structure 'csrows' table
+	 * with the mapping and control information.
+	 */
+	if (tile_edac_init_csrows(mci)) {
+		/* No csrows found. */
+		mci->edac_cap = EDAC_FLAG_NONE;
+	} else {
+		mci->edac_cap = EDAC_FLAG_SECDED;
+	}
+
+	platform_set_drvdata(pdev, mci);
+
+	/* Register with EDAC core */
+	rc = edac_mc_add_mc(mci);
+	if (rc) {
+		dev_err(&pdev->dev, "failed to register with EDAC core\n");
+		edac_mc_free(mci);
+		return rc;
+	}
+
+	return 0;
+}
+
+static int __devexit tile_edac_mc_remove(struct platform_device *pdev)
+{
+	struct mem_ctl_info *mci = platform_get_drvdata(pdev);
+
+	edac_mc_del_mc(&pdev->dev);
+	if (mci)
+		edac_mc_free(mci);
+	return 0;
+}
+
+static struct platform_driver tile_edac_mc_driver = {
+	.driver		= {
+		.name	= DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= tile_edac_mc_probe,
+	.remove		= __devexit_p(tile_edac_mc_remove),
+};
+
+/*
+ * Driver init routine.
+ */
+static int __init tile_edac_init(void)
+{
+	char	hv_file[32];
+	struct platform_device *pdev;
+	int i, err, num = 0;
+
+	/* Only support POLL mode. */
+	edac_op_state = EDAC_OPSTATE_POLL;
+
+	err = platform_driver_register(&tile_edac_mc_driver);
+	if (err)
+		return err;
+
+	for (i = 0; i < TILE_MAX_MSHIMS; i++) {
+		/*
+		 * Not all memory controllers are configured such as in the
+		 * case of a simulator. So we register only those mshims
+		 * that are configured by the hypervisor.
+		 */
+		sprintf(hv_file, "mshim/%d", i);
+		if (hv_dev_open((HV_VirtAddr)hv_file, 0) < 0)
+			continue;
+
+		pdev = platform_device_register_simple(DRV_NAME, i, NULL, 0);
+		if (IS_ERR(pdev))
+			continue;
+		mshim_pdev[i] = pdev;
+		num++;
+	}
+
+	if (num == 0) {
+		platform_driver_unregister(&tile_edac_mc_driver);
+		return -ENODEV;
+	}
+	return 0;
+}
+
+/*
+ * Driver cleanup routine.
+ */
+static void __exit tile_edac_exit(void)
+{
+	int i;
+
+	for (i = 0; i < TILE_MAX_MSHIMS; i++) {
+		struct platform_device *pdev = mshim_pdev[i];
+		if (!pdev)
+			continue;
+
+		platform_set_drvdata(pdev, NULL);
+		platform_device_unregister(pdev);
+	}
+	platform_driver_unregister(&tile_edac_mc_driver);
+}
+
+module_init(tile_edac_init);
+module_exit(tile_edac_exit);
-- 
1.6.5.2