edac: add CPC925 Memory Controller driver
authorHarry Ciao <qingtao.cao@windriver.com>
Wed, 17 Jun 2009 23:27:58 +0000 (16:27 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 18 Jun 2009 20:03:56 +0000 (13:03 -0700)
Introduce IBM CPC925 EDAC driver, which makes use of ECC, CPU and
HyperTransport Link error detections and corrections on the IBM
CPC925 Bridge and Memory Controller.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/edac/Kconfig
drivers/edac/Makefile
drivers/edac/cpc925_edac.c [new file with mode: 0644]

index ab4f3592a11c58bcf48137afa6fedb5030cca8d3..ea3a75ee3fa3d41a4b5ab3718b373124e10f4bea 100644 (file)
@@ -232,4 +232,13 @@ config EDAC_AMD8111
          Note, add more Kconfig dependency if it's adopted
          on some machine other than Maple.
 
+config EDAC_CPC925
+       tristate "IBM CPC925 Memory Controller (PPC970FX)"
+       depends on EDAC_MM_EDAC && PPC64
+       help
+         Support for error detection and correction on the
+         IBM CPC925 Bridge and Memory Controller, which is
+         a companion chip to the PowerPC 970 family of
+         processors.
+
 endif # EDAC
index 633dc5604ee32e1d49acf2a7b9057b5c6e0a7e1f..98aa4a7db41292413b18006da300017fe8d04373 100644 (file)
@@ -18,6 +18,7 @@ edac_core-objs        += edac_pci.o edac_pci_sysfs.o
 endif
 
 obj-$(CONFIG_EDAC_AMD76X)              += amd76x_edac.o
+obj-$(CONFIG_EDAC_CPC925)              += cpc925_edac.o
 obj-$(CONFIG_EDAC_I5000)               += i5000_edac.o
 obj-$(CONFIG_EDAC_I5100)               += i5100_edac.o
 obj-$(CONFIG_EDAC_I5400)               += i5400_edac.o
diff --git a/drivers/edac/cpc925_edac.c b/drivers/edac/cpc925_edac.c
new file mode 100644 (file)
index 0000000..8c54196
--- /dev/null
@@ -0,0 +1,1017 @@
+/*
+ * cpc925_edac.c, EDAC driver for IBM CPC925 Bridge and Memory Controller.
+ *
+ * Copyright (c) 2008 Wind River Systems, Inc.
+ *
+ * Authors:    Cao Qingtao <qingtao.cao@windriver.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/edac.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include "edac_core.h"
+#include "edac_module.h"
+
+#define CPC925_EDAC_REVISION   " Ver: 1.0.0 " __DATE__
+#define CPC925_EDAC_MOD_STR    "cpc925_edac"
+
+#define cpc925_printk(level, fmt, arg...) \
+       edac_printk(level, "CPC925", fmt, ##arg)
+
+#define cpc925_mc_printk(mci, level, fmt, arg...) \
+       edac_mc_chipset_printk(mci, level, "CPC925", fmt, ##arg)
+
+/*
+ * CPC925 registers are of 32 bits with bit0 defined at the
+ * most significant bit and bit31 at that of least significant.
+ */
+#define CPC925_BITS_PER_REG    32
+#define CPC925_BIT(nr)         (1UL << (CPC925_BITS_PER_REG - 1 - nr))
+
+/*
+ * EDAC device names for the error detections of
+ * CPU Interface and Hypertransport Link.
+ */
+#define CPC925_CPU_ERR_DEV     "cpu"
+#define CPC925_HT_LINK_DEV     "htlink"
+
+/* Suppose DDR Refresh cycle is 15.6 microsecond */
+#define CPC925_REF_FREQ                0xFA69
+#define CPC925_SCRUB_BLOCK_SIZE 64     /* bytes */
+#define CPC925_NR_CSROWS       8
+
+/*
+ * All registers and bits definitions are taken from
+ * "CPC925 Bridge and Memory Controller User Manual, SA14-2761-02".
+ */
+
+/*
+ * CPU and Memory Controller Registers
+ */
+/************************************************************
+ *     Processor Interface Exception Mask Register (APIMASK)
+ ************************************************************/
+#define REG_APIMASK_OFFSET     0x30070
+enum apimask_bits {
+       APIMASK_DART    = CPC925_BIT(0), /* DART Exception */
+       APIMASK_ADI0    = CPC925_BIT(1), /* Handshake Error on PI0_ADI */
+       APIMASK_ADI1    = CPC925_BIT(2), /* Handshake Error on PI1_ADI */
+       APIMASK_STAT    = CPC925_BIT(3), /* Status Exception */
+       APIMASK_DERR    = CPC925_BIT(4), /* Data Error Exception */
+       APIMASK_ADRS0   = CPC925_BIT(5), /* Addressing Exception on PI0 */
+       APIMASK_ADRS1   = CPC925_BIT(6), /* Addressing Exception on PI1 */
+                                        /* BIT(7) Reserved */
+       APIMASK_ECC_UE_H = CPC925_BIT(8), /* UECC upper */
+       APIMASK_ECC_CE_H = CPC925_BIT(9), /* CECC upper */
+       APIMASK_ECC_UE_L = CPC925_BIT(10), /* UECC lower */
+       APIMASK_ECC_CE_L = CPC925_BIT(11), /* CECC lower */
+
+       CPU_MASK_ENABLE = (APIMASK_DART | APIMASK_ADI0 | APIMASK_ADI1 |
+                          APIMASK_STAT | APIMASK_DERR | APIMASK_ADRS0 |
+                          APIMASK_ADRS1),
+       ECC_MASK_ENABLE = (APIMASK_ECC_UE_H | APIMASK_ECC_CE_H |
+                          APIMASK_ECC_UE_L | APIMASK_ECC_CE_L),
+};
+
+/************************************************************
+ *     Processor Interface Exception Register (APIEXCP)
+ ************************************************************/
+#define REG_APIEXCP_OFFSET     0x30060
+enum apiexcp_bits {
+       APIEXCP_DART    = CPC925_BIT(0), /* DART Exception */
+       APIEXCP_ADI0    = CPC925_BIT(1), /* Handshake Error on PI0_ADI */
+       APIEXCP_ADI1    = CPC925_BIT(2), /* Handshake Error on PI1_ADI */
+       APIEXCP_STAT    = CPC925_BIT(3), /* Status Exception */
+       APIEXCP_DERR    = CPC925_BIT(4), /* Data Error Exception */
+       APIEXCP_ADRS0   = CPC925_BIT(5), /* Addressing Exception on PI0 */
+       APIEXCP_ADRS1   = CPC925_BIT(6), /* Addressing Exception on PI1 */
+                                        /* BIT(7) Reserved */
+       APIEXCP_ECC_UE_H = CPC925_BIT(8), /* UECC upper */
+       APIEXCP_ECC_CE_H = CPC925_BIT(9), /* CECC upper */
+       APIEXCP_ECC_UE_L = CPC925_BIT(10), /* UECC lower */
+       APIEXCP_ECC_CE_L = CPC925_BIT(11), /* CECC lower */
+
+       CPU_EXCP_DETECTED = (APIEXCP_DART | APIEXCP_ADI0 | APIEXCP_ADI1 |
+                            APIEXCP_STAT | APIEXCP_DERR | APIEXCP_ADRS0 |
+                            APIEXCP_ADRS1),
+       UECC_EXCP_DETECTED = (APIEXCP_ECC_UE_H | APIEXCP_ECC_UE_L),
+       CECC_EXCP_DETECTED = (APIEXCP_ECC_CE_H | APIEXCP_ECC_CE_L),
+       ECC_EXCP_DETECTED = (UECC_EXCP_DETECTED | CECC_EXCP_DETECTED),
+};
+
+/************************************************************
+ *     Memory Bus Configuration Register (MBCR)
+************************************************************/
+#define REG_MBCR_OFFSET                0x2190
+#define MBCR_64BITCFG_SHIFT    23
+#define MBCR_64BITCFG_MASK     (1UL << MBCR_64BITCFG_SHIFT)
+#define MBCR_64BITBUS_SHIFT    22
+#define MBCR_64BITBUS_MASK     (1UL << MBCR_64BITBUS_SHIFT)
+
+/************************************************************
+ *     Memory Bank Mode Register (MBMR)
+************************************************************/
+#define REG_MBMR_OFFSET                0x21C0
+#define MBMR_MODE_MAX_VALUE    0xF
+#define MBMR_MODE_SHIFT                25
+#define MBMR_MODE_MASK         (MBMR_MODE_MAX_VALUE << MBMR_MODE_SHIFT)
+#define MBMR_BBA_SHIFT         24
+#define MBMR_BBA_MASK          (1UL << MBMR_BBA_SHIFT)
+
+/************************************************************
+ *     Memory Bank Boundary Address Register (MBBAR)
+ ************************************************************/
+#define REG_MBBAR_OFFSET       0x21D0
+#define MBBAR_BBA_MAX_VALUE    0xFF
+#define MBBAR_BBA_SHIFT                24
+#define MBBAR_BBA_MASK         (MBBAR_BBA_MAX_VALUE << MBBAR_BBA_SHIFT)
+
+/************************************************************
+ *     Memory Scrub Control Register (MSCR)
+ ************************************************************/
+#define REG_MSCR_OFFSET                0x2400
+#define MSCR_SCRUB_MOD_MASK    0xC0000000 /* scrub_mod - bit0:1*/
+#define MSCR_BACKGR_SCRUB      0x40000000 /* 01 */
+#define MSCR_SI_SHIFT          16      /* si - bit8:15*/
+#define MSCR_SI_MAX_VALUE      0xFF
+#define MSCR_SI_MASK           (MSCR_SI_MAX_VALUE << MSCR_SI_SHIFT)
+
+/************************************************************
+ *     Memory Scrub Range Start Register (MSRSR)
+ ************************************************************/
+#define REG_MSRSR_OFFSET       0x2410
+
+/************************************************************
+ *     Memory Scrub Range End Register (MSRER)
+ ************************************************************/
+#define REG_MSRER_OFFSET       0x2420
+
+/************************************************************
+ *     Memory Scrub Pattern Register (MSPR)
+ ************************************************************/
+#define REG_MSPR_OFFSET                0x2430
+
+/************************************************************
+ *     Memory Check Control Register (MCCR)
+ ************************************************************/
+#define REG_MCCR_OFFSET                0x2440
+enum mccr_bits {
+       MCCR_ECC_EN     = CPC925_BIT(0), /* ECC high and low check */
+};
+
+/************************************************************
+ *     Memory Check Range End Register (MCRER)
+ ************************************************************/
+#define REG_MCRER_OFFSET       0x2450
+
+/************************************************************
+ *     Memory Error Address Register (MEAR)
+ ************************************************************/
+#define REG_MEAR_OFFSET                0x2460
+#define MEAR_BCNT_MAX_VALUE    0x3
+#define MEAR_BCNT_SHIFT                30
+#define MEAR_BCNT_MASK         (MEAR_BCNT_MAX_VALUE << MEAR_BCNT_SHIFT)
+#define MEAR_RANK_MAX_VALUE    0x7
+#define MEAR_RANK_SHIFT                27
+#define MEAR_RANK_MASK         (MEAR_RANK_MAX_VALUE << MEAR_RANK_SHIFT)
+#define MEAR_COL_MAX_VALUE     0x7FF
+#define MEAR_COL_SHIFT         16
+#define MEAR_COL_MASK          (MEAR_COL_MAX_VALUE << MEAR_COL_SHIFT)
+#define MEAR_BANK_MAX_VALUE    0x3
+#define MEAR_BANK_SHIFT                14
+#define MEAR_BANK_MASK         (MEAR_BANK_MAX_VALUE << MEAR_BANK_SHIFT)
+#define MEAR_ROW_MASK          0x00003FFF
+
+/************************************************************
+ *     Memory Error Syndrome Register (MESR)
+ ************************************************************/
+#define REG_MESR_OFFSET                0x2470
+#define MESR_ECC_SYN_H_MASK    0xFF00
+#define MESR_ECC_SYN_L_MASK    0x00FF
+
+/************************************************************
+ *     Memory Mode Control Register (MMCR)
+ ************************************************************/
+#define REG_MMCR_OFFSET                0x2500
+enum mmcr_bits {
+       MMCR_REG_DIMM_MODE = CPC925_BIT(3),
+};
+
+/*
+ * HyperTransport Link Registers
+ */
+/************************************************************
+ *  Error Handling/Enumeration Scratch Pad Register (ERRCTRL)
+ ************************************************************/
+#define REG_ERRCTRL_OFFSET     0x70140
+enum errctrl_bits {                     /* nonfatal interrupts for */
+       ERRCTRL_SERR_NF = CPC925_BIT(0), /* system error */
+       ERRCTRL_CRC_NF  = CPC925_BIT(1), /* CRC error */
+       ERRCTRL_RSP_NF  = CPC925_BIT(2), /* Response error */
+       ERRCTRL_EOC_NF  = CPC925_BIT(3), /* End-Of-Chain error */
+       ERRCTRL_OVF_NF  = CPC925_BIT(4), /* Overflow error */
+       ERRCTRL_PROT_NF = CPC925_BIT(5), /* Protocol error */
+
+       ERRCTRL_RSP_ERR = CPC925_BIT(6), /* Response error received */
+       ERRCTRL_CHN_FAL = CPC925_BIT(7), /* Sync flooding detected */
+
+       HT_ERRCTRL_ENABLE = (ERRCTRL_SERR_NF | ERRCTRL_CRC_NF |
+                            ERRCTRL_RSP_NF | ERRCTRL_EOC_NF |
+                            ERRCTRL_OVF_NF | ERRCTRL_PROT_NF),
+       HT_ERRCTRL_DETECTED = (ERRCTRL_RSP_ERR | ERRCTRL_CHN_FAL),
+};
+
+/************************************************************
+ *  Link Configuration and Link Control Register (LINKCTRL)
+ ************************************************************/
+#define REG_LINKCTRL_OFFSET    0x70110
+enum linkctrl_bits {
+       LINKCTRL_CRC_ERR        = (CPC925_BIT(22) | CPC925_BIT(23)),
+       LINKCTRL_LINK_FAIL      = CPC925_BIT(27),
+
+       HT_LINKCTRL_DETECTED    = (LINKCTRL_CRC_ERR | LINKCTRL_LINK_FAIL),
+};
+
+/************************************************************
+ *  Link FreqCap/Error/Freq/Revision ID Register (LINKERR)
+ ************************************************************/
+#define REG_LINKERR_OFFSET     0x70120
+enum linkerr_bits {
+       LINKERR_EOC_ERR         = CPC925_BIT(17), /* End-Of-Chain error */
+       LINKERR_OVF_ERR         = CPC925_BIT(18), /* Receive Buffer Overflow */
+       LINKERR_PROT_ERR        = CPC925_BIT(19), /* Protocol error */
+
+       HT_LINKERR_DETECTED     = (LINKERR_EOC_ERR | LINKERR_OVF_ERR |
+                                  LINKERR_PROT_ERR),
+};
+
+/************************************************************
+ *     Bridge Control Register (BRGCTRL)
+ ************************************************************/
+#define REG_BRGCTRL_OFFSET     0x70300
+enum brgctrl_bits {
+       BRGCTRL_DETSERR = CPC925_BIT(0), /* SERR on Secondary Bus */
+       BRGCTRL_SECBUSRESET = CPC925_BIT(9), /* Secondary Bus Reset */
+};
+
+/* Private structure for edac memory controller */
+struct cpc925_mc_pdata {
+       void __iomem *vbase;
+       unsigned long total_mem;
+       const char *name;
+       int edac_idx;
+};
+
+/* Private structure for common edac device */
+struct cpc925_dev_info {
+       void __iomem *vbase;
+       struct platform_device *pdev;
+       char *ctl_name;
+       int edac_idx;
+       struct edac_device_ctl_info *edac_dev;
+       void (*init)(struct cpc925_dev_info *dev_info);
+       void (*exit)(struct cpc925_dev_info *dev_info);
+       void (*check)(struct edac_device_ctl_info *edac_dev);
+};
+
+/* Get total memory size from Open Firmware DTB */
+static void get_total_mem(struct cpc925_mc_pdata *pdata)
+{
+       struct device_node *np = NULL;
+       const unsigned int *reg, *reg_end;
+       int len, sw, aw;
+       unsigned long start, size;
+
+       np = of_find_node_by_type(NULL, "memory");
+       if (!np)
+               return;
+
+       aw = of_n_addr_cells(np);
+       sw = of_n_size_cells(np);
+       reg = (const unsigned int *)of_get_property(np, "reg", &len);
+       reg_end = reg + len/4;
+
+       pdata->total_mem = 0;
+       do {
+               start = of_read_number(reg, aw);
+               reg += aw;
+               size = of_read_number(reg, sw);
+               reg += sw;
+               debugf1("%s: start 0x%lx, size 0x%lx\n", __func__,
+                       start, size);
+               pdata->total_mem += size;
+       } while (reg < reg_end);
+
+       of_node_put(np);
+       debugf0("%s: total_mem 0x%lx\n", __func__, pdata->total_mem);
+}
+
+static void cpc925_init_csrows(struct mem_ctl_info *mci)
+{
+       struct cpc925_mc_pdata *pdata = mci->pvt_info;
+       struct csrow_info *csrow;
+       int index;
+       u32 mbmr, mbbar, bba;
+       unsigned long row_size, last_nr_pages = 0;
+
+       get_total_mem(pdata);
+
+       for (index = 0; index < mci->nr_csrows; index++) {
+               mbmr = __raw_readl(pdata->vbase + REG_MBMR_OFFSET +
+                                  0x20 * index);
+               mbbar = __raw_readl(pdata->vbase + REG_MBBAR_OFFSET +
+                                  0x20 + index);
+               bba = (((mbmr & MBMR_BBA_MASK) >> MBMR_BBA_SHIFT) << 8) |
+                      ((mbbar & MBBAR_BBA_MASK) >> MBBAR_BBA_SHIFT);
+
+               if (bba == 0)
+                       continue; /* not populated */
+
+               csrow = &mci->csrows[index];
+
+               row_size = bba * (1UL << 28);   /* 256M */
+               csrow->first_page = last_nr_pages;
+               csrow->nr_pages = row_size >> PAGE_SHIFT;
+               csrow->last_page = csrow->first_page + csrow->nr_pages - 1;
+               last_nr_pages = csrow->last_page + 1;
+
+               csrow->mtype = MEM_RDDR;
+               csrow->edac_mode = EDAC_SECDED;
+
+               switch (csrow->nr_channels) {
+               case 1: /* Single channel */
+                       csrow->grain = 32; /* four-beat burst of 32 bytes */
+                       break;
+               case 2: /* Dual channel */
+               default:
+                       csrow->grain = 64; /* four-beat burst of 64 bytes */
+                       break;
+               }
+
+               switch ((mbmr & MBMR_MODE_MASK) >> MBMR_MODE_SHIFT) {
+               case 6: /* 0110, no way to differentiate X8 VS X16 */
+               case 5: /* 0101 */
+               case 8: /* 1000 */
+                       csrow->dtype = DEV_X16;
+                       break;
+               case 7: /* 0111 */
+               case 9: /* 1001 */
+                       csrow->dtype = DEV_X8;
+                       break;
+               default:
+                       csrow->dtype = DEV_UNKNOWN;
+                       break;
+               }
+       }
+}
+
+/* Enable memory controller ECC detection */
+static void cpc925_mc_init(struct mem_ctl_info *mci)
+{
+       struct cpc925_mc_pdata *pdata = mci->pvt_info;
+       u32 apimask;
+       u32 mccr;
+
+       /* Enable various ECC error exceptions */
+       apimask = __raw_readl(pdata->vbase + REG_APIMASK_OFFSET);
+       if ((apimask & ECC_MASK_ENABLE) == 0) {
+               apimask |= ECC_MASK_ENABLE;
+               __raw_writel(apimask, pdata->vbase + REG_APIMASK_OFFSET);
+       }
+
+       /* Enable ECC detection */
+       mccr = __raw_readl(pdata->vbase + REG_MCCR_OFFSET);
+       if ((mccr & MCCR_ECC_EN) == 0) {
+               mccr |= MCCR_ECC_EN;
+               __raw_writel(mccr, pdata->vbase + REG_MCCR_OFFSET);
+       }
+}
+
+/* Disable memory controller ECC detection */
+static void cpc925_mc_exit(struct mem_ctl_info *mci)
+{
+       /*
+        * WARNING:
+        * We are supposed to clear the ECC error detection bits,
+        * and it will be no problem to do so. However, once they
+        * are cleared here if we want to re-install CPC925 EDAC
+        * module later, setting them up in cpc925_mc_init() will
+        * trigger machine check exception.
+        * Also, it's ok to leave ECC error detection bits enabled,
+        * since they are reset to 1 by default or by boot loader.
+        */
+
+       return;
+}
+
+/*
+ * Revert DDR column/row/bank addresses into page frame number and
+ * offset in page.
+ *
+ * Suppose memory mode is 0x0111(128-bit mode, identical DIMM pairs),
+ * physical address(PA) bits to column address(CA) bits mappings are:
+ * CA  0   1   2   3   4   5   6   7   8   9   10
+ * PA  59  58  57  56  55  54  53  52  51  50  49
+ *
+ * physical address(PA) bits to bank address(BA) bits mappings are:
+ * BA  0   1
+ * PA  43  44
+ *
+ * physical address(PA) bits to row address(RA) bits mappings are:
+ * RA  0   1   2   3   4   5   6   7   8   9   10   11   12
+ * PA  36  35  34  48  47  46  45  40  41  42  39   38   37
+ */
+static void cpc925_mc_get_pfn(struct mem_ctl_info *mci, u32 mear,
+               unsigned long *pfn, unsigned long *offset, int *csrow)
+{
+       u32 bcnt, rank, col, bank, row;
+       u32 c;
+       unsigned long pa;
+       int i;
+
+       bcnt = (mear & MEAR_BCNT_MASK) >> MEAR_BCNT_SHIFT;
+       rank = (mear & MEAR_RANK_MASK) >> MEAR_RANK_SHIFT;
+       col = (mear & MEAR_COL_MASK) >> MEAR_COL_SHIFT;
+       bank = (mear & MEAR_BANK_MASK) >> MEAR_BANK_SHIFT;
+       row = mear & MEAR_ROW_MASK;
+
+       *csrow = rank;
+
+#ifdef CONFIG_EDAC_DEBUG
+       if (mci->csrows[rank].first_page == 0) {
+               cpc925_mc_printk(mci, KERN_ERR, "ECC occurs in a "
+                       "non-populated csrow, broken hardware?\n");
+               return;
+       }
+#endif
+
+       /* Revert csrow number */
+       pa = mci->csrows[rank].first_page << PAGE_SHIFT;
+
+       /* Revert column address */
+       col += bcnt;
+       for (i = 0; i < 11; i++) {
+               c = col & 0x1;
+               col >>= 1;
+               pa |= c << (14 - i);
+       }
+
+       /* Revert bank address */
+       pa |= bank << 19;
+
+       /* Revert row address, in 4 steps */
+       for (i = 0; i < 3; i++) {
+               c = row & 0x1;
+               row >>= 1;
+               pa |= c << (26 - i);
+       }
+
+       for (i = 0; i < 3; i++) {
+               c = row & 0x1;
+               row >>= 1;
+               pa |= c << (21 + i);
+       }
+
+       for (i = 0; i < 4; i++) {
+               c = row & 0x1;
+               row >>= 1;
+               pa |= c << (18 - i);
+       }
+
+       for (i = 0; i < 3; i++) {
+               c = row & 0x1;
+               row >>= 1;
+               pa |= c << (29 - i);
+       }
+
+       *offset = pa & (PAGE_SIZE - 1);
+       *pfn = pa >> PAGE_SHIFT;
+
+       debugf0("%s: ECC physical address 0x%lx\n", __func__, pa);
+}
+
+static int cpc925_mc_find_channel(struct mem_ctl_info *mci, u16 syndrome)
+{
+       if ((syndrome & MESR_ECC_SYN_H_MASK) == 0)
+               return 0;
+
+       if ((syndrome & MESR_ECC_SYN_L_MASK) == 0)
+               return 1;
+
+       cpc925_mc_printk(mci, KERN_INFO, "Unexpected syndrome value: 0x%x\n",
+                        syndrome);
+       return 1;
+}
+
+/* Check memory controller registers for ECC errors */
+static void cpc925_mc_check(struct mem_ctl_info *mci)
+{
+       struct cpc925_mc_pdata *pdata = mci->pvt_info;
+       u32 apiexcp;
+       u32 mear;
+       u32 mesr;
+       u16 syndrome;
+       unsigned long pfn = 0, offset = 0;
+       int csrow = 0, channel = 0;
+
+       /* APIEXCP is cleared when read */
+       apiexcp = __raw_readl(pdata->vbase + REG_APIEXCP_OFFSET);
+       if ((apiexcp & ECC_EXCP_DETECTED) == 0)
+               return;
+
+       mesr = __raw_readl(pdata->vbase + REG_MESR_OFFSET);
+       syndrome = mesr | (MESR_ECC_SYN_H_MASK | MESR_ECC_SYN_L_MASK);
+
+       mear = __raw_readl(pdata->vbase + REG_MEAR_OFFSET);
+
+       /* Revert column/row addresses into page frame number, etc */
+       cpc925_mc_get_pfn(mci, mear, &pfn, &offset, &csrow);
+
+       if (apiexcp & CECC_EXCP_DETECTED) {
+               cpc925_mc_printk(mci, KERN_INFO, "DRAM CECC Fault\n");
+               channel = cpc925_mc_find_channel(mci, syndrome);
+               edac_mc_handle_ce(mci, pfn, offset, syndrome,
+                                 csrow, channel, mci->ctl_name);
+       }
+
+       if (apiexcp & UECC_EXCP_DETECTED) {
+               cpc925_mc_printk(mci, KERN_INFO, "DRAM UECC Fault\n");
+               edac_mc_handle_ue(mci, pfn, offset, csrow, mci->ctl_name);
+       }
+
+       cpc925_mc_printk(mci, KERN_INFO, "Dump registers:\n");
+       cpc925_mc_printk(mci, KERN_INFO, "APIMASK               0x%08x\n",
+               __raw_readl(pdata->vbase + REG_APIMASK_OFFSET));
+       cpc925_mc_printk(mci, KERN_INFO, "APIEXCP               0x%08x\n",
+               apiexcp);
+       cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Ctrl        0x%08x\n",
+               __raw_readl(pdata->vbase + REG_MSCR_OFFSET));
+       cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge Start   0x%08x\n",
+               __raw_readl(pdata->vbase + REG_MSRSR_OFFSET));
+       cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Rge End     0x%08x\n",
+               __raw_readl(pdata->vbase + REG_MSRER_OFFSET));
+       cpc925_mc_printk(mci, KERN_INFO, "Mem Scrub Pattern     0x%08x\n",
+               __raw_readl(pdata->vbase + REG_MSPR_OFFSET));
+       cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Ctrl          0x%08x\n",
+               __raw_readl(pdata->vbase + REG_MCCR_OFFSET));
+       cpc925_mc_printk(mci, KERN_INFO, "Mem Chk Rge End       0x%08x\n",
+               __raw_readl(pdata->vbase + REG_MCRER_OFFSET));
+       cpc925_mc_printk(mci, KERN_INFO, "Mem Err Address       0x%08x\n",
+               mesr);
+       cpc925_mc_printk(mci, KERN_INFO, "Mem Err Syndrome      0x%08x\n",
+               syndrome);
+}
+
+/******************** CPU err device********************************/
+/* Enable CPU Errors detection */
+static void cpc925_cpu_init(struct cpc925_dev_info *dev_info)
+{
+       u32 apimask;
+
+       apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
+       if ((apimask & CPU_MASK_ENABLE) == 0) {
+               apimask |= CPU_MASK_ENABLE;
+               __raw_writel(apimask, dev_info->vbase + REG_APIMASK_OFFSET);
+       }
+}
+
+/* Disable CPU Errors detection */
+static void cpc925_cpu_exit(struct cpc925_dev_info *dev_info)
+{
+       /*
+        * WARNING:
+        * We are supposed to clear the CPU error detection bits,
+        * and it will be no problem to do so. However, once they
+        * are cleared here if we want to re-install CPC925 EDAC
+        * module later, setting them up in cpc925_cpu_init() will
+        * trigger machine check exception.
+        * Also, it's ok to leave CPU error detection bits enabled,
+        * since they are reset to 1 by default.
+        */
+
+       return;
+}
+
+/* Check for CPU Errors */
+static void cpc925_cpu_check(struct edac_device_ctl_info *edac_dev)
+{
+       struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
+       u32 apiexcp;
+       u32 apimask;
+
+       /* APIEXCP is cleared when read */
+       apiexcp = __raw_readl(dev_info->vbase + REG_APIEXCP_OFFSET);
+       if ((apiexcp & CPU_EXCP_DETECTED) == 0)
+               return;
+
+       apimask = __raw_readl(dev_info->vbase + REG_APIMASK_OFFSET);
+       cpc925_printk(KERN_INFO, "Processor Interface Fault\n"
+                                "Processor Interface register dump:\n");
+       cpc925_printk(KERN_INFO, "APIMASK               0x%08x\n", apimask);
+       cpc925_printk(KERN_INFO, "APIEXCP               0x%08x\n", apiexcp);
+
+       edac_device_handle_ue(edac_dev, 0, 0, edac_dev->ctl_name);
+}
+
+/******************** HT Link err device****************************/
+/* Enable HyperTransport Link Error detection */
+static void cpc925_htlink_init(struct cpc925_dev_info *dev_info)
+{
+       u32 ht_errctrl;
+
+       ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
+       if ((ht_errctrl & HT_ERRCTRL_ENABLE) == 0) {
+               ht_errctrl |= HT_ERRCTRL_ENABLE;
+               __raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
+       }
+}
+
+/* Disable HyperTransport Link Error detection */
+static void cpc925_htlink_exit(struct cpc925_dev_info *dev_info)
+{
+       u32 ht_errctrl;
+
+       ht_errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
+       ht_errctrl &= ~HT_ERRCTRL_ENABLE;
+       __raw_writel(ht_errctrl, dev_info->vbase + REG_ERRCTRL_OFFSET);
+}
+
+/* Check for HyperTransport Link errors */
+static void cpc925_htlink_check(struct edac_device_ctl_info *edac_dev)
+{
+       struct cpc925_dev_info *dev_info = edac_dev->pvt_info;
+       u32 brgctrl = __raw_readl(dev_info->vbase + REG_BRGCTRL_OFFSET);
+       u32 linkctrl = __raw_readl(dev_info->vbase + REG_LINKCTRL_OFFSET);
+       u32 errctrl = __raw_readl(dev_info->vbase + REG_ERRCTRL_OFFSET);
+       u32 linkerr = __raw_readl(dev_info->vbase + REG_LINKERR_OFFSET);
+
+       if (!((brgctrl & BRGCTRL_DETSERR) ||
+             (linkctrl & HT_LINKCTRL_DETECTED) ||
+             (errctrl & HT_ERRCTRL_DETECTED) ||
+             (linkerr & HT_LINKERR_DETECTED)))
+               return;
+
+       cpc925_printk(KERN_INFO, "HT Link Fault\n"
+                                "HT register dump:\n");
+       cpc925_printk(KERN_INFO, "Bridge Ctrl                   0x%08x\n",
+                     brgctrl);
+       cpc925_printk(KERN_INFO, "Link Config Ctrl              0x%08x\n",
+                     linkctrl);
+       cpc925_printk(KERN_INFO, "Error Enum and Ctrl           0x%08x\n",
+                     errctrl);
+       cpc925_printk(KERN_INFO, "Link Error                    0x%08x\n",
+                     linkerr);
+
+       /* Clear by write 1 */
+       if (brgctrl & BRGCTRL_DETSERR)
+               __raw_writel(BRGCTRL_DETSERR,
+                               dev_info->vbase + REG_BRGCTRL_OFFSET);
+
+       if (linkctrl & HT_LINKCTRL_DETECTED)
+               __raw_writel(HT_LINKCTRL_DETECTED,
+                               dev_info->vbase + REG_LINKCTRL_OFFSET);
+
+       /* Initiate Secondary Bus Reset to clear the chain failure */
+       if (errctrl & ERRCTRL_CHN_FAL)
+               __raw_writel(BRGCTRL_SECBUSRESET,
+                               dev_info->vbase + REG_BRGCTRL_OFFSET);
+
+       if (errctrl & ERRCTRL_RSP_ERR)
+               __raw_writel(ERRCTRL_RSP_ERR,
+                               dev_info->vbase + REG_ERRCTRL_OFFSET);
+
+       if (linkerr & HT_LINKERR_DETECTED)
+               __raw_writel(HT_LINKERR_DETECTED,
+                               dev_info->vbase + REG_LINKERR_OFFSET);
+
+       edac_device_handle_ce(edac_dev, 0, 0, edac_dev->ctl_name);
+}
+
+static struct cpc925_dev_info cpc925_devs[] = {
+       {
+       .ctl_name = CPC925_CPU_ERR_DEV,
+       .init = cpc925_cpu_init,
+       .exit = cpc925_cpu_exit,
+       .check = cpc925_cpu_check,
+       },
+       {
+       .ctl_name = CPC925_HT_LINK_DEV,
+       .init = cpc925_htlink_init,
+       .exit = cpc925_htlink_exit,
+       .check = cpc925_htlink_check,
+       },
+       {0}, /* Terminated by NULL */
+};
+
+/*
+ * Add CPU Err detection and HyperTransport Link Err detection
+ * as common "edac_device", they have no corresponding device
+ * nodes in the Open Firmware DTB and we have to add platform
+ * devices for them. Also, they will share the MMIO with that
+ * of memory controller.
+ */
+static void cpc925_add_edac_devices(void __iomem *vbase)
+{
+       struct cpc925_dev_info *dev_info;
+
+       if (!vbase) {
+               cpc925_printk(KERN_ERR, "MMIO not established yet\n");
+               return;
+       }
+
+       for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
+               dev_info->vbase = vbase;
+               dev_info->pdev = platform_device_register_simple(
+                                       dev_info->ctl_name, 0, NULL, 0);
+               if (IS_ERR(dev_info->pdev)) {
+                       cpc925_printk(KERN_ERR,
+                               "Can't register platform device for %s\n",
+                               dev_info->ctl_name);
+                       continue;
+               }
+
+               /*
+                * Don't have to allocate private structure but
+                * make use of cpc925_devs[] instead.
+                */
+               dev_info->edac_idx = edac_device_alloc_index();
+               dev_info->edac_dev =
+                       edac_device_alloc_ctl_info(0, dev_info->ctl_name,
+                               1, NULL, 0, 0, NULL, 0, dev_info->edac_idx);
+               if (!dev_info->edac_dev) {
+                       cpc925_printk(KERN_ERR, "No memory for edac device\n");
+                       goto err1;
+               }
+
+               dev_info->edac_dev->pvt_info = dev_info;
+               dev_info->edac_dev->dev = &dev_info->pdev->dev;
+               dev_info->edac_dev->ctl_name = dev_info->ctl_name;
+               dev_info->edac_dev->mod_name = CPC925_EDAC_MOD_STR;
+               dev_info->edac_dev->dev_name = dev_name(&dev_info->pdev->dev);
+
+               if (edac_op_state == EDAC_OPSTATE_POLL)
+                       dev_info->edac_dev->edac_check = dev_info->check;
+
+               if (dev_info->init)
+                       dev_info->init(dev_info);
+
+               if (edac_device_add_device(dev_info->edac_dev) > 0) {
+                       cpc925_printk(KERN_ERR,
+                               "Unable to add edac device for %s\n",
+                               dev_info->ctl_name);
+                       goto err2;
+               }
+
+               debugf0("%s: Successfully added edac device for %s\n",
+                       __func__, dev_info->ctl_name);
+
+               continue;
+
+err2:
+               if (dev_info->exit)
+                       dev_info->exit(dev_info);
+               edac_device_free_ctl_info(dev_info->edac_dev);
+err1:
+               platform_device_unregister(dev_info->pdev);
+       }
+}
+
+/*
+ * Delete the common "edac_device" for CPU Err Detection
+ * and HyperTransport Link Err Detection
+ */
+static void cpc925_del_edac_devices(void)
+{
+       struct cpc925_dev_info *dev_info;
+
+       for (dev_info = &cpc925_devs[0]; dev_info->init; dev_info++) {
+               if (dev_info->edac_dev) {
+                       edac_device_del_device(dev_info->edac_dev->dev);
+                       edac_device_free_ctl_info(dev_info->edac_dev);
+                       platform_device_unregister(dev_info->pdev);
+               }
+
+               if (dev_info->exit)
+                       dev_info->exit(dev_info);
+
+               debugf0("%s: Successfully deleted edac device for %s\n",
+                       __func__, dev_info->ctl_name);
+       }
+}
+
+/* Convert current back-ground scrub rate into byte/sec bandwith */
+static int cpc925_get_sdram_scrub_rate(struct mem_ctl_info *mci, u32 *bw)
+{
+       struct cpc925_mc_pdata *pdata = mci->pvt_info;
+       u32 mscr;
+       u8 si;
+
+       mscr = __raw_readl(pdata->vbase + REG_MSCR_OFFSET);
+       si = (mscr & MSCR_SI_MASK) >> MSCR_SI_SHIFT;
+
+       debugf0("%s, Mem Scrub Ctrl Register 0x%x\n", __func__, mscr);
+
+       if (((mscr & MSCR_SCRUB_MOD_MASK) != MSCR_BACKGR_SCRUB) ||
+           (si == 0)) {
+               cpc925_mc_printk(mci, KERN_INFO, "Scrub mode not enabled\n");
+               *bw = 0;
+       } else
+               *bw = CPC925_SCRUB_BLOCK_SIZE * 0xFA67 / si;
+
+       return 0;
+}
+
+/* Return 0 for single channel; 1 for dual channel */
+static int cpc925_mc_get_channels(void __iomem *vbase)
+{
+       int dual = 0;
+       u32 mbcr;
+
+       mbcr = __raw_readl(vbase + REG_MBCR_OFFSET);
+
+       /*
+        * Dual channel only when 128-bit wide physical bus
+        * and 128-bit configuration.
+        */
+       if (((mbcr & MBCR_64BITCFG_MASK) == 0) &&
+           ((mbcr & MBCR_64BITBUS_MASK) == 0))
+               dual = 1;
+
+       debugf0("%s: %s channel\n", __func__,
+               (dual > 0) ? "Dual" : "Single");
+
+       return dual;
+}
+
+static int __devinit cpc925_probe(struct platform_device *pdev)
+{
+       static int edac_mc_idx;
+       struct mem_ctl_info *mci;
+       void __iomem *vbase;
+       struct cpc925_mc_pdata *pdata;
+       struct resource *r;
+       int res = 0, nr_channels;
+
+       debugf0("%s: %s platform device found!\n", __func__, pdev->name);
+
+       if (!devres_open_group(&pdev->dev, cpc925_probe, GFP_KERNEL)) {
+               res = -ENOMEM;
+               goto out;
+       }
+
+       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!r) {
+               cpc925_printk(KERN_ERR, "Unable to get resource\n");
+               res = -ENOENT;
+               goto err1;
+       }
+
+       if (!devm_request_mem_region(&pdev->dev,
+                                    r->start,
+                                    r->end - r->start + 1,
+                                    pdev->name)) {
+               cpc925_printk(KERN_ERR, "Unable to request mem region\n");
+               res = -EBUSY;
+               goto err1;
+       }
+
+       vbase = devm_ioremap(&pdev->dev, r->start, r->end - r->start + 1);
+       if (!vbase) {
+               cpc925_printk(KERN_ERR, "Unable to ioremap device\n");
+               res = -ENOMEM;
+               goto err2;
+       }
+
+       nr_channels = cpc925_mc_get_channels(vbase);
+       mci = edac_mc_alloc(sizeof(struct cpc925_mc_pdata),
+                       CPC925_NR_CSROWS, nr_channels + 1, edac_mc_idx);
+       if (!mci) {
+               cpc925_printk(KERN_ERR, "No memory for mem_ctl_info\n");
+               res = -ENOMEM;
+               goto err2;
+       }
+
+       pdata = mci->pvt_info;
+       pdata->vbase = vbase;
+       pdata->edac_idx = edac_mc_idx++;
+       pdata->name = pdev->name;
+
+       mci->dev = &pdev->dev;
+       platform_set_drvdata(pdev, mci);
+       mci->dev_name = dev_name(&pdev->dev);
+       mci->mtype_cap = MEM_FLAG_RDDR | MEM_FLAG_DDR;
+       mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
+       mci->edac_cap = EDAC_FLAG_SECDED;
+       mci->mod_name = CPC925_EDAC_MOD_STR;
+       mci->mod_ver = CPC925_EDAC_REVISION;
+       mci->ctl_name = pdev->name;
+
+       if (edac_op_state == EDAC_OPSTATE_POLL)
+               mci->edac_check = cpc925_mc_check;
+
+       mci->ctl_page_to_phys = NULL;
+       mci->scrub_mode = SCRUB_SW_SRC;
+       mci->set_sdram_scrub_rate = NULL;
+       mci->get_sdram_scrub_rate = cpc925_get_sdram_scrub_rate;
+
+       cpc925_init_csrows(mci);
+
+       /* Setup memory controller registers */
+       cpc925_mc_init(mci);
+
+       if (edac_mc_add_mc(mci) > 0) {
+               cpc925_mc_printk(mci, KERN_ERR, "Failed edac_mc_add_mc()\n");
+               goto err3;
+       }
+
+       cpc925_add_edac_devices(vbase);
+
+       /* get this far and it's successful */
+       debugf0("%s: success\n", __func__);
+
+       res = 0;
+       goto out;
+
+err3:
+       cpc925_mc_exit(mci);
+       edac_mc_free(mci);
+err2:
+       devm_release_mem_region(&pdev->dev, r->start, r->end-r->start+1);
+err1:
+       devres_release_group(&pdev->dev, cpc925_probe);
+out:
+       return res;
+}
+
+static int cpc925_remove(struct platform_device *pdev)
+{
+       struct mem_ctl_info *mci = platform_get_drvdata(pdev);
+
+       /*
+        * Delete common edac devices before edac mc, because
+        * the former share the MMIO of the latter.
+        */
+       cpc925_del_edac_devices();
+       cpc925_mc_exit(mci);
+
+       edac_mc_del_mc(&pdev->dev);
+       edac_mc_free(mci);
+
+       return 0;
+}
+
+static struct platform_driver cpc925_edac_driver = {
+       .probe = cpc925_probe,
+       .remove = cpc925_remove,
+       .driver = {
+                  .name = "cpc925_edac",
+       }
+};
+
+static int __init cpc925_edac_init(void)
+{
+       int ret = 0;
+
+       printk(KERN_INFO "IBM CPC925 EDAC driver " CPC925_EDAC_REVISION "\n");
+       printk(KERN_INFO "\t(c) 2008 Wind River Systems, Inc\n");
+
+       /* Only support POLL mode so far */
+       edac_op_state = EDAC_OPSTATE_POLL;
+
+       ret = platform_driver_register(&cpc925_edac_driver);
+       if (ret) {
+               printk(KERN_WARNING "Failed to register %s\n",
+                       CPC925_EDAC_MOD_STR);
+       }
+
+       return ret;
+}
+
+static void __exit cpc925_edac_exit(void)
+{
+       platform_driver_unregister(&cpc925_edac_driver);
+}
+
+module_init(cpc925_edac_init);
+module_exit(cpc925_edac_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Cao Qingtao <qingtao.cao@windriver.com>");
+MODULE_DESCRIPTION("IBM CPC925 Bridge and MC EDAC kernel module");