drivers/edac: provide support for tile architecture

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>

1 files changed, 254 insertions, 0 deletions

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);