drivers/edac: new i82443bxgz MC driver

This is a NEW EDAC Memory Controller driver for the 440BX chipset (I82443BXGX)
created and submitted by Timm Small

Signed-off-by: Tim Small <tim@buttersideup.com>
Signed-off-by: Douglas Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 408 insertions, 0 deletions

diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig
index 772a290..b56e478 100644
--- a/drivers/edac/Kconfig
+++ b/drivers/edac/Kconfig
@@ -73,6 +73,13 @@ config EDAC_E752X
 	  Support for error detection and correction on the Intel
 	  E7520, E7525, E7320 server chipsets.
 
+config EDAC_I82443BXGX
+	tristate "Intel 82443BX/GX (440BX/GX)"
+	depends on EDAC_MM_EDAC && PCI && X86_32
+	help
+	  Support for error detection and correction on the Intel
+	  82443BX/GX memory controllers (440BX/GX chipsets).
+
 config EDAC_I82875P
 	tristate "Intel 82875p (D82875P, E7210)"
 	depends on EDAC_MM_EDAC && PCI && X86_32
diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile
index d2674fb..773472c 100644
--- a/drivers/edac/Makefile
+++ b/drivers/edac/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_EDAC_AMD76X)		+= amd76x_edac.o
 obj-$(CONFIG_EDAC_I5000)		+= i5000_edac.o
 obj-$(CONFIG_EDAC_E7XXX)		+= e7xxx_edac.o
 obj-$(CONFIG_EDAC_E752X)		+= e752x_edac.o
+obj-$(CONFIG_EDAC_I82443BXGX)		+= i82443bxgx_edac.o
 obj-$(CONFIG_EDAC_I82875P)		+= i82875p_edac.o
 obj-$(CONFIG_EDAC_I82860)		+= i82860_edac.o
 obj-$(CONFIG_EDAC_R82600)		+= r82600_edac.o
diff --git a/drivers/edac/i82443bxgx_edac.c b/drivers/edac/i82443bxgx_edac.c
new file mode 100644
index 0000000..ecf2ba8
--- /dev/null
+++ b/drivers/edac/i82443bxgx_edac.c
@@ -0,0 +1,400 @@
+/*
+ * Intel 82443BX/GX (440BX/GX chipset) Memory Controller EDAC kernel
+ * module (C) 2006 Tim Small
+ *
+ * This file may be distributed under the terms of the GNU General
+ * Public License.
+ *
+ * Written by Tim Small <tim@buttersideup.com>, based on work by Linux
+ * Networx, Thayne Harbaugh, Dan Hollis <goemon at anime dot net> and
+ * others.
+ *
+ * 440GX fix by Jason Uhlenkott <juhlenko@akamai.com>.
+ *
+ * Written with reference to 82443BX Host Bridge Datasheet:
+ * http://www.intel.com/design/chipsets/440/documentation.htm
+ * references to this document given in [].
+ *
+ * This module doesn't support the 440LX, but it may be possible to
+ * make it do so (the 440LX's register definitions are different, but
+ * not completely so - I haven't studied them in enough detail to know
+ * how easy this would be).
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+
+#include <linux/slab.h>
+
+#include "edac_mc.h"
+
+#define I82443_REVISION	"0.1"
+
+#define EDAC_MOD_STR    "i82443bxgx_edac"
+
+
+/* The 82443BX supports SDRAM, or EDO (EDO for mobile only), "Memory
+ * Size: 8 MB to 512 MB (1GB with Registered DIMMs) with eight memory
+ * rows" "The 82443BX supports multiple-bit error detection and
+ * single-bit error correction when ECC mode is enabled and
+ * single/multi-bit error detection when correction is disabled.
+ * During writes to the DRAM, the 82443BX generates ECC for the data
+ * on a QWord basis. Partial QWord writes require a read-modify-write
+ * cycle when ECC is enabled."
+*/
+
+/* "Additionally, the 82443BX ensures that the data is corrected in
+ * main memory so that accumulation of errors is prevented. Another
+ * error within the same QWord would result in a double-bit error
+ * which is unrecoverable. This is known as hardware scrubbing since
+ * it requires no software intervention to correct the data in memory."
+ */
+
+/* [Also see page 100 (section 4.3), "DRAM Interface"]
+ * [Also see page 112 (section 4.6.1.4), ECC]
+ */
+
+#define I82443BXGX_NR_CSROWS 8
+#define I82443BXGX_NR_CHANS  1
+#define I82443BXGX_NR_DIMMS  4
+
+
+
+/* 82443 PCI Device 0 */
+#define I82443BXGX_NBXCFG 0x50   /* 32bit register starting at this PCI
+				* config space offset */
+#define I82443BXGX_NBXCFG_OFFSET_NON_ECCROW 24 /* Array of bits, zero if
+					      * row is non-ECC */
+#define I82443BXGX_NBXCFG_OFFSET_DRAM_FREQ 12 /* 2 bits,00=100MHz,10=66 MHz */
+
+#define I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY 7 /* 2 bits:       */
+#define I82443BXGX_NBXCFG_INTEGRITY_NONE   0x0    /* 00 = Non-ECC */
+#define I82443BXGX_NBXCFG_INTEGRITY_EC     0x1    /* 01 = EC (only) */
+#define I82443BXGX_NBXCFG_INTEGRITY_ECC    0x2    /* 10 = ECC */
+#define I82443BXGX_NBXCFG_INTEGRITY_SCRUB  0x3    /* 11 = ECC + HW Scrub */
+
+#define I82443BXGX_NBXCFG_OFFSET_ECC_DIAG_ENABLE  6
+
+
+/* 82443 PCI Device 0 */
+#define I82443BXGX_EAP   0x80   /* 32bit register starting at this PCI
+				* config space offset, Error Address
+				* Pointer Register */
+#define I82443BXGX_EAP_OFFSET_EAP  12   /* High 20 bits of error address */
+#define I82443BXGX_EAP_OFFSET_MBE  BIT(1) /* Err at EAP was multi-bit (W1TC) */
+#define I82443BXGX_EAP_OFFSET_SBE  BIT(0) /* Err at EAP was single-bit (W1TC)*/
+
+#define I82443BXGX_ERRCMD  0x90   /* 8bit register starting at this PCI
+				 * config space offset. */
+#define I82443BXGX_ERRCMD_OFFSET_SERR_ON_MBE BIT(1) /* 1 = enable */
+#define I82443BXGX_ERRCMD_OFFSET_SERR_ON_SBE BIT(0) /* 1 = enable */
+
+#define I82443BXGX_ERRSTS  0x91   /* 16bit register starting at this PCI
+				 * config space offset. */
+#define I82443BXGX_ERRSTS_OFFSET_MBFRE 5 /* 3 bits - first err row multibit */
+#define I82443BXGX_ERRSTS_OFFSET_MEF   BIT(4) /* 1 = MBE occurred */
+#define I82443BXGX_ERRSTS_OFFSET_SBFRE 1 /* 3 bits - first err row singlebit */
+#define I82443BXGX_ERRSTS_OFFSET_SEF   BIT(0) /* 1 = SBE occurred */
+
+
+#define I82443BXGX_DRAMC 0x57   /* 8bit register starting at this PCI
+			       * config space offset. */
+#define I82443BXGX_DRAMC_OFFSET_DT 3      /* 2 bits, DRAM Type */
+#define I82443BXGX_DRAMC_DRAM_IS_EDO 0    /* 00 = EDO */
+#define I82443BXGX_DRAMC_DRAM_IS_SDRAM 1	/* 01 = SDRAM */
+#define I82443BXGX_DRAMC_DRAM_IS_RSDRAM 2 /* 10 = Registered SDRAM */
+
+
+#define I82443BXGX_DRB 0x60   /* 8x 8bit registers starting at this PCI
+			     * config space offset. */
+
+
+/* FIXME - don't poll when ECC disabled? */
+
+
+struct i82443bxgx_edacmc_error_info {
+	u32 eap;
+};
+
+
+static void i82443bxgx_edacmc_get_error_info (struct mem_ctl_info *mci,
+		struct i82443bxgx_edacmc_error_info *info)
+{
+	struct pci_dev *pdev;
+	pdev = to_pci_dev(mci->dev);
+	pci_read_config_dword(pdev, I82443BXGX_EAP, &info->eap);
+	if (info->eap & I82443BXGX_EAP_OFFSET_SBE)
+		/* Clear error to allow next error to be reported [p.61] */
+		pci_write_bits32(pdev, I82443BXGX_EAP,
+				 I82443BXGX_EAP_OFFSET_SBE,
+				 I82443BXGX_EAP_OFFSET_SBE);
+
+	if (info->eap & I82443BXGX_EAP_OFFSET_MBE)
+		/* Clear error to allow next error to be reported [p.61] */
+		pci_write_bits32(pdev, I82443BXGX_EAP,
+				 I82443BXGX_EAP_OFFSET_MBE,
+				 I82443BXGX_EAP_OFFSET_MBE);
+}
+
+
+static int i82443bxgx_edacmc_process_error_info (struct mem_ctl_info *mci,
+		struct i82443bxgx_edacmc_error_info *info, int handle_errors)
+{
+	int error_found = 0;
+	u32 eapaddr, page, pageoffset;
+
+	/* bits 30:12 hold the 4kb block in which the error occurred
+	 * [p.61] */
+	eapaddr = (info->eap & 0xfffff000);
+	page = eapaddr >> PAGE_SHIFT;
+	pageoffset = eapaddr - (page << PAGE_SHIFT);
+
+	if (info->eap  & I82443BXGX_EAP_OFFSET_SBE) {
+		error_found = 1;
+		if (handle_errors)
+			edac_mc_handle_ce(
+				mci, page, pageoffset,
+				/* 440BX/GX don't make syndrome information available */
+				0,
+				edac_mc_find_csrow_by_page(mci, page),
+				0,	/* channel */
+				mci->ctl_name);
+	}
+
+	if (info->eap  & I82443BXGX_EAP_OFFSET_MBE) {
+		error_found = 1;
+		if (handle_errors)
+			edac_mc_handle_ue(
+				mci, page, pageoffset,
+				edac_mc_find_csrow_by_page(mci, page),
+				mci->ctl_name);
+	}
+
+	return error_found;
+}
+
+
+static void i82443bxgx_edacmc_check(struct mem_ctl_info *mci)
+{
+	struct i82443bxgx_edacmc_error_info info;
+
+	debugf1("MC%d: " __FILE__ ": %s()\n", mci->mc_idx, __func__);
+	i82443bxgx_edacmc_get_error_info(mci, &info);
+	i82443bxgx_edacmc_process_error_info(mci, &info, 1);
+}
+
+
+static void i82443bxgx_init_csrows(struct mem_ctl_info *mci,
+					struct pci_dev *pdev,
+					enum edac_type edac_mode,
+					enum mem_type mtype)
+{
+	struct csrow_info *csrow;
+	int index;
+	u8 drbar, dramc;
+	u32 row_base, row_high_limit, row_high_limit_last;
+
+	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
+	row_high_limit_last = 0;
+	for (index = 0; index < mci->nr_csrows; index++) {
+		csrow = &mci->csrows[index];
+		pci_read_config_byte(pdev, I82443BXGX_DRB + index, &drbar);
+		debugf1("MC%d: " __FILE__ ": %s() Row=%d DRB = %#0x\n",
+			mci->mc_idx, __func__, index, drbar);
+		row_high_limit = ((u32) drbar << 23);
+		/* find the DRAM Chip Select Base address and mask */
+		debugf1("MC%d: " __FILE__ ": %s() Row=%d, "
+			"Boundry Address=%#0x, Last = %#0x \n",
+			mci->mc_idx, __func__, index, row_high_limit,
+			row_high_limit_last);
+
+		/* 440GX goes to 2GB, represented with a DRB of 0. */
+		if (row_high_limit_last && !row_high_limit)
+			row_high_limit = 1UL << 31;
+
+		/* This row is empty [p.49] */
+		if (row_high_limit == row_high_limit_last)
+			continue;
+		row_base = row_high_limit_last;
+		csrow->first_page = row_base >> PAGE_SHIFT;
+		csrow->last_page = (row_high_limit >> PAGE_SHIFT) - 1;
+		csrow->nr_pages = csrow->last_page - csrow->first_page + 1;
+		/* EAP reports in 4kilobyte granularity [61] */
+		csrow->grain = 1 << 12;
+		csrow->mtype = mtype;
+		/* I don't think 440BX can tell you device type? FIXME? */
+		csrow->dtype = DEV_UNKNOWN;
+		/* Mode is global to all rows on 440BX */
+		csrow->edac_mode = edac_mode;
+		row_high_limit_last = row_high_limit;
+	}
+}
+
+
+static int  i82443bxgx_edacmc_probe1(struct pci_dev *pdev, int dev_idx)
+{
+	struct mem_ctl_info *mci;
+	u8 dramc;
+	u32 nbxcfg, ecc_mode;
+	enum mem_type mtype;
+	enum edac_type edac_mode;
+
+	debugf0("MC: " __FILE__ ": %s()\n", __func__);
+
+	/* Something is really hosed if PCI config space reads from
+	   the MC aren't working.  */
+	if (pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg))
+		return -EIO;
+
+	mci = edac_mc_alloc(0, I82443BXGX_NR_CSROWS, I82443BXGX_NR_CHANS);
+
+	if (mci == NULL)
+		return -ENOMEM;
+
+	debugf0("MC: " __FILE__ ": %s(): mci = %p\n", __func__, mci);
+	mci->dev = &pdev->dev;
+	mci->mtype_cap = MEM_FLAG_EDO | MEM_FLAG_SDR | MEM_FLAG_RDR;
+	mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_EC | EDAC_FLAG_SECDED;
+	pci_read_config_byte(pdev, I82443BXGX_DRAMC, &dramc);
+	switch ((dramc >> I82443BXGX_DRAMC_OFFSET_DT) & (BIT(0) | BIT(1))) {
+	case  I82443BXGX_DRAMC_DRAM_IS_EDO:
+		mtype = MEM_EDO;
+		break;
+	case I82443BXGX_DRAMC_DRAM_IS_SDRAM:
+		mtype = MEM_SDR;
+		break;
+	case I82443BXGX_DRAMC_DRAM_IS_RSDRAM:
+		mtype = MEM_RDR;
+		break;
+	default:
+		debugf0("Unknown/reserved DRAM type value in DRAMC register!\n");
+		mtype = -MEM_UNKNOWN;
+	}
+
+	if ((mtype == MEM_SDR) || (mtype == MEM_RDR))
+		mci->edac_cap = mci->edac_ctl_cap;
+	else
+		mci->edac_cap = EDAC_FLAG_NONE;
+
+	mci->scrub_cap = SCRUB_FLAG_HW_SRC;
+	pci_read_config_dword(pdev, I82443BXGX_NBXCFG, &nbxcfg);
+	ecc_mode = ((nbxcfg >> I82443BXGX_NBXCFG_OFFSET_DRAM_INTEGRITY) &
+				(BIT(0) | BIT(1)));
+
+	mci->scrub_mode = (ecc_mode == I82443BXGX_NBXCFG_INTEGRITY_SCRUB)
+		? SCRUB_HW_SRC
+		: SCRUB_NONE;
+
+	switch(ecc_mode) {
+	case I82443BXGX_NBXCFG_INTEGRITY_NONE:
+		edac_mode = EDAC_NONE;
+		break;
+	case I82443BXGX_NBXCFG_INTEGRITY_EC:
+		edac_mode = EDAC_EC;
+		break;
+	case I82443BXGX_NBXCFG_INTEGRITY_ECC:
+	case I82443BXGX_NBXCFG_INTEGRITY_SCRUB:
+		edac_mode = EDAC_SECDED;
+		break;
+	default:
+		debugf0("%s(): Unknown/reserved ECC state in NBXCFG register!\n",
+			__func__);
+		edac_mode = EDAC_UNKNOWN;
+		break;
+	}
+
+	i82443bxgx_init_csrows(mci, pdev, edac_mode, mtype);
+
+	/* Many BIOSes don't clear error flags on boot, so do this
+	 * here, or we get "phantom" errors occuring at module-load
+	 * time. */
+	pci_write_bits32(pdev, I82443BXGX_EAP,
+			 (I82443BXGX_EAP_OFFSET_SBE | I82443BXGX_EAP_OFFSET_MBE),
+			 (I82443BXGX_EAP_OFFSET_SBE | I82443BXGX_EAP_OFFSET_MBE));
+
+	mci->mod_name = EDAC_MOD_STR;
+	mci->mod_ver = I82443_REVISION;
+	mci->ctl_name = "I82443BXGX";
+	mci->edac_check = i82443bxgx_edacmc_check;
+	mci->ctl_page_to_phys = NULL;
+
+	if (edac_mc_add_mc(mci, 0)) {
+		debugf3("%s(): failed edac_mc_add_mc()\n", __func__);
+		goto fail;
+	}
+
+	debugf3("MC: " __FILE__ ": %s(): success\n", __func__);
+	return 0;
+
+fail:
+	edac_mc_free(mci);
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_probe1);
+
+/* returns count (>= 0), or negative on error */
+static int __devinit i82443bxgx_edacmc_init_one(struct pci_dev *pdev,
+				     const struct pci_device_id *ent)
+{
+	debugf0("MC: " __FILE__ ": %s()\n", __func__);
+
+	/* don't need to call pci_device_enable() */
+	return  i82443bxgx_edacmc_probe1(pdev, ent->driver_data);
+}
+
+
+static void __devexit i82443bxgx_edacmc_remove_one(struct pci_dev *pdev)
+{
+	struct mem_ctl_info *mci;
+
+	debugf0(__FILE__ ": %s()\n", __func__);
+
+	if ((mci = edac_mc_del_mc(&pdev->dev)) == NULL )
+		return;
+
+	edac_mc_free(mci);
+}
+EXPORT_SYMBOL_GPL(i82443bxgx_edacmc_remove_one);
+
+
+static const struct pci_device_id i82443bxgx_pci_tbl[] __devinitdata = {
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_0)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443BX_2)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_0)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443GX_2)},
+	{0,}			/* 0 terminated list. */
+};
+
+MODULE_DEVICE_TABLE(pci, i82443bxgx_pci_tbl);
+
+
+static struct pci_driver i82443bxgx_edacmc_driver = {
+	.name = EDAC_MOD_STR,
+	.probe = i82443bxgx_edacmc_init_one,
+	.remove = __devexit_p(i82443bxgx_edacmc_remove_one),
+	.id_table = i82443bxgx_pci_tbl,
+};
+
+
+static int __init i82443bxgx_edacmc_init(void)
+{
+	return pci_register_driver(&i82443bxgx_edacmc_driver);
+}
+
+
+static void __exit i82443bxgx_edacmc_exit(void)
+{
+	pci_unregister_driver(&i82443bxgx_edacmc_driver);
+}
+
+
+module_init(i82443bxgx_edacmc_init);
+module_exit(i82443bxgx_edacmc_exit);
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Tim Small <tim@buttersideup.com> - WPAD");
+MODULE_DESCRIPTION("EDAC MC support for Intel 82443BX/GX memory controllers");