kernel-fxtec-pro1x/drivers/edac/i82875p_edac.c
Jason Uhlenkott 654ede200f drivers/edac: mod race fix i82875p
If ERRSTS indicates that there's no error then we don't need to bother reading
the other registers.

In addition to making the common case faster, this actually fixes a small race
where we don't see an error but we clear the error bits anyway, potentially
wiping away info on an error that happened in the interim (or where a CE
arrives between the first and second read of ERRSTS, causing us to falsely
claim "UE overwrote CE").

Signed-off-by: Jason Uhlenkott <juhlenko@akamai.com>
Signed-off-by: Douglas Thompson <dougthompson@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:55 -07:00

582 lines
14 KiB
C

/*
* Intel D82875P Memory Controller kernel module
* (C) 2003 Linux Networx (http://lnxi.com)
* This file may be distributed under the terms of the
* GNU General Public License.
*
* Written by Thayne Harbaugh
* Contributors:
* Wang Zhenyu at intel.com
*
* $Id: edac_i82875p.c,v 1.5.2.11 2005/10/05 00:43:44 dsp_llnl Exp $
*
* Note: E7210 appears same as D82875P - zhenyu.z.wang at intel.com
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/slab.h>
#include "edac_core.h"
#define I82875P_REVISION " Ver: 2.0.2 " __DATE__
#define EDAC_MOD_STR "i82875p_edac"
#define i82875p_printk(level, fmt, arg...) \
edac_printk(level, "i82875p", fmt, ##arg)
#define i82875p_mc_printk(mci, level, fmt, arg...) \
edac_mc_chipset_printk(mci, level, "i82875p", fmt, ##arg)
#ifndef PCI_DEVICE_ID_INTEL_82875_0
#define PCI_DEVICE_ID_INTEL_82875_0 0x2578
#endif /* PCI_DEVICE_ID_INTEL_82875_0 */
#ifndef PCI_DEVICE_ID_INTEL_82875_6
#define PCI_DEVICE_ID_INTEL_82875_6 0x257e
#endif /* PCI_DEVICE_ID_INTEL_82875_6 */
/* four csrows in dual channel, eight in single channel */
#define I82875P_NR_CSROWS(nr_chans) (8/(nr_chans))
/* Intel 82875p register addresses - device 0 function 0 - DRAM Controller */
#define I82875P_EAP 0x58 /* Error Address Pointer (32b)
*
* 31:12 block address
* 11:0 reserved
*/
#define I82875P_DERRSYN 0x5c /* DRAM Error Syndrome (8b)
*
* 7:0 DRAM ECC Syndrome
*/
#define I82875P_DES 0x5d /* DRAM Error Status (8b)
*
* 7:1 reserved
* 0 Error channel 0/1
*/
#define I82875P_ERRSTS 0xc8 /* Error Status Register (16b)
*
* 15:10 reserved
* 9 non-DRAM lock error (ndlock)
* 8 Sftwr Generated SMI
* 7 ECC UE
* 6 reserved
* 5 MCH detects unimplemented cycle
* 4 AGP access outside GA
* 3 Invalid AGP access
* 2 Invalid GA translation table
* 1 Unsupported AGP command
* 0 ECC CE
*/
#define I82875P_ERRCMD 0xca /* Error Command (16b)
*
* 15:10 reserved
* 9 SERR on non-DRAM lock
* 8 SERR on ECC UE
* 7 SERR on ECC CE
* 6 target abort on high exception
* 5 detect unimplemented cyc
* 4 AGP access outside of GA
* 3 SERR on invalid AGP access
* 2 invalid translation table
* 1 SERR on unsupported AGP command
* 0 reserved
*/
/* Intel 82875p register addresses - device 6 function 0 - DRAM Controller */
#define I82875P_PCICMD6 0x04 /* PCI Command Register (16b)
*
* 15:10 reserved
* 9 fast back-to-back - ro 0
* 8 SERR enable - ro 0
* 7 addr/data stepping - ro 0
* 6 parity err enable - ro 0
* 5 VGA palette snoop - ro 0
* 4 mem wr & invalidate - ro 0
* 3 special cycle - ro 0
* 2 bus master - ro 0
* 1 mem access dev6 - 0(dis),1(en)
* 0 IO access dev3 - 0(dis),1(en)
*/
#define I82875P_BAR6 0x10 /* Mem Delays Base ADDR Reg (32b)
*
* 31:12 mem base addr [31:12]
* 11:4 address mask - ro 0
* 3 prefetchable - ro 0(non),1(pre)
* 2:1 mem type - ro 0
* 0 mem space - ro 0
*/
/* Intel 82875p MMIO register space - device 0 function 0 - MMR space */
#define I82875P_DRB_SHIFT 26 /* 64MiB grain */
#define I82875P_DRB 0x00 /* DRAM Row Boundary (8b x 8)
*
* 7 reserved
* 6:0 64MiB row boundary addr
*/
#define I82875P_DRA 0x10 /* DRAM Row Attribute (4b x 8)
*
* 7 reserved
* 6:4 row attr row 1
* 3 reserved
* 2:0 row attr row 0
*
* 000 = 4KiB
* 001 = 8KiB
* 010 = 16KiB
* 011 = 32KiB
*/
#define I82875P_DRC 0x68 /* DRAM Controller Mode (32b)
*
* 31:30 reserved
* 29 init complete
* 28:23 reserved
* 22:21 nr chan 00=1,01=2
* 20 reserved
* 19:18 Data Integ Mode 00=none,01=ecc
* 17:11 reserved
* 10:8 refresh mode
* 7 reserved
* 6:4 mode select
* 3:2 reserved
* 1:0 DRAM type 01=DDR
*/
enum i82875p_chips {
I82875P = 0,
};
struct i82875p_pvt {
struct pci_dev *ovrfl_pdev;
void __iomem *ovrfl_window;
};
struct i82875p_dev_info {
const char *ctl_name;
};
struct i82875p_error_info {
u16 errsts;
u32 eap;
u8 des;
u8 derrsyn;
u16 errsts2;
};
static const struct i82875p_dev_info i82875p_devs[] = {
[I82875P] = {
.ctl_name = "i82875p"},
};
static struct pci_dev *mci_pdev = NULL; /* init dev: in case that AGP code has
* already registered driver
*/
static int i82875p_registered = 1;
static struct edac_pci_ctl_info *i82875p_pci;
static void i82875p_get_error_info(struct mem_ctl_info *mci,
struct i82875p_error_info *info)
{
struct pci_dev *pdev;
pdev = to_pci_dev(mci->dev);
/*
* This is a mess because there is no atomic way to read all the
* registers at once and the registers can transition from CE being
* overwritten by UE.
*/
pci_read_config_word(pdev, I82875P_ERRSTS, &info->errsts);
if (!(info->errsts & 0x0081))
return;
pci_read_config_dword(pdev, I82875P_EAP, &info->eap);
pci_read_config_byte(pdev, I82875P_DES, &info->des);
pci_read_config_byte(pdev, I82875P_DERRSYN, &info->derrsyn);
pci_read_config_word(pdev, I82875P_ERRSTS, &info->errsts2);
/*
* If the error is the same then we can for both reads then
* the first set of reads is valid. If there is a change then
* there is a CE no info and the second set of reads is valid
* and should be UE info.
*/
if ((info->errsts ^ info->errsts2) & 0x0081) {
pci_read_config_dword(pdev, I82875P_EAP, &info->eap);
pci_read_config_byte(pdev, I82875P_DES, &info->des);
pci_read_config_byte(pdev, I82875P_DERRSYN, &info->derrsyn);
}
pci_write_bits16(pdev, I82875P_ERRSTS, 0x0081, 0x0081);
}
static int i82875p_process_error_info(struct mem_ctl_info *mci,
struct i82875p_error_info *info,
int handle_errors)
{
int row, multi_chan;
multi_chan = mci->csrows[0].nr_channels - 1;
if (!(info->errsts & 0x0081))
return 0;
if (!handle_errors)
return 1;
if ((info->errsts ^ info->errsts2) & 0x0081) {
edac_mc_handle_ce_no_info(mci, "UE overwrote CE");
info->errsts = info->errsts2;
}
info->eap >>= PAGE_SHIFT;
row = edac_mc_find_csrow_by_page(mci, info->eap);
if (info->errsts & 0x0080)
edac_mc_handle_ue(mci, info->eap, 0, row, "i82875p UE");
else
edac_mc_handle_ce(mci, info->eap, 0, info->derrsyn, row,
multi_chan ? (info->des & 0x1) : 0,
"i82875p CE");
return 1;
}
static void i82875p_check(struct mem_ctl_info *mci)
{
struct i82875p_error_info info;
debugf1("MC%d: %s()\n", mci->mc_idx, __func__);
i82875p_get_error_info(mci, &info);
i82875p_process_error_info(mci, &info, 1);
}
/* Return 0 on success or 1 on failure. */
static int i82875p_setup_overfl_dev(struct pci_dev *pdev,
struct pci_dev **ovrfl_pdev,
void __iomem **ovrfl_window)
{
struct pci_dev *dev;
void __iomem *window;
*ovrfl_pdev = NULL;
*ovrfl_window = NULL;
dev = pci_get_device(PCI_VEND_DEV(INTEL, 82875_6), NULL);
if (dev == NULL) {
/* Intel tells BIOS developers to hide device 6 which
* configures the overflow device access containing
* the DRBs - this is where we expose device 6.
* http://www.x86-secret.com/articles/tweak/pat/patsecrets-2.htm
*/
pci_write_bits8(pdev, 0xf4, 0x2, 0x2);
dev = pci_scan_single_device(pdev->bus, PCI_DEVFN(6, 0));
if (dev == NULL)
return 1;
pci_bus_add_device(dev);
}
*ovrfl_pdev = dev;
if (pci_enable_device(dev)) {
i82875p_printk(KERN_ERR, "%s(): Failed to enable overflow "
"device\n", __func__);
return 1;
}
if (pci_request_regions(dev, pci_name(dev))) {
#ifdef CORRECT_BIOS
goto fail0;
#endif
}
/* cache is irrelevant for PCI bus reads/writes */
window = ioremap_nocache(pci_resource_start(dev, 0),
pci_resource_len(dev, 0));
if (window == NULL) {
i82875p_printk(KERN_ERR, "%s(): Failed to ioremap bar6\n",
__func__);
goto fail1;
}
*ovrfl_window = window;
return 0;
fail1:
pci_release_regions(dev);
#ifdef CORRECT_BIOS
fail0:
pci_disable_device(dev);
#endif
/* NOTE: the ovrfl proc entry and pci_dev are intentionally left */
return 1;
}
/* Return 1 if dual channel mode is active. Else return 0. */
static inline int dual_channel_active(u32 drc)
{
return (drc >> 21) & 0x1;
}
static void i82875p_init_csrows(struct mem_ctl_info *mci,
struct pci_dev *pdev,
void __iomem * ovrfl_window, u32 drc)
{
struct csrow_info *csrow;
unsigned long last_cumul_size;
u8 value;
u32 drc_ddim; /* DRAM Data Integrity Mode 0=none,2=edac */
u32 cumul_size;
int index;
drc_ddim = (drc >> 18) & 0x1;
last_cumul_size = 0;
/* The dram row boundary (DRB) reg values are boundary address
* for each DRAM row with a granularity of 32 or 64MB (single/dual
* channel operation). DRB regs are cumulative; therefore DRB7 will
* contain the total memory contained in all eight rows.
*/
for (index = 0; index < mci->nr_csrows; index++) {
csrow = &mci->csrows[index];
value = readb(ovrfl_window + I82875P_DRB + index);
cumul_size = value << (I82875P_DRB_SHIFT - PAGE_SHIFT);
debugf3("%s(): (%d) cumul_size 0x%x\n", __func__, index,
cumul_size);
if (cumul_size == last_cumul_size)
continue; /* not populated */
csrow->first_page = last_cumul_size;
csrow->last_page = cumul_size - 1;
csrow->nr_pages = cumul_size - last_cumul_size;
last_cumul_size = cumul_size;
csrow->grain = 1 << 12; /* I82875P_EAP has 4KiB reolution */
csrow->mtype = MEM_DDR;
csrow->dtype = DEV_UNKNOWN;
csrow->edac_mode = drc_ddim ? EDAC_SECDED : EDAC_NONE;
}
}
static int i82875p_probe1(struct pci_dev *pdev, int dev_idx)
{
int rc = -ENODEV;
struct mem_ctl_info *mci;
struct i82875p_pvt *pvt;
struct pci_dev *ovrfl_pdev;
void __iomem *ovrfl_window;
u32 drc;
u32 nr_chans;
struct i82875p_error_info discard;
debugf0("%s()\n", __func__);
ovrfl_pdev = pci_get_device(PCI_VEND_DEV(INTEL, 82875_6), NULL);
if (i82875p_setup_overfl_dev(pdev, &ovrfl_pdev, &ovrfl_window))
return -ENODEV;
drc = readl(ovrfl_window + I82875P_DRC);
nr_chans = dual_channel_active(drc) + 1;
mci = edac_mc_alloc(sizeof(*pvt), I82875P_NR_CSROWS(nr_chans),
nr_chans);
if (!mci) {
rc = -ENOMEM;
goto fail0;
}
debugf3("%s(): init mci\n", __func__);
mci->dev = &pdev->dev;
mci->mtype_cap = MEM_FLAG_DDR;
mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED;
mci->edac_cap = EDAC_FLAG_UNKNOWN;
mci->mod_name = EDAC_MOD_STR;
mci->mod_ver = I82875P_REVISION;
mci->ctl_name = i82875p_devs[dev_idx].ctl_name;
mci->dev_name = pci_name(pdev);
mci->edac_check = i82875p_check;
mci->ctl_page_to_phys = NULL;
debugf3("%s(): init pvt\n", __func__);
pvt = (struct i82875p_pvt *)mci->pvt_info;
pvt->ovrfl_pdev = ovrfl_pdev;
pvt->ovrfl_window = ovrfl_window;
i82875p_init_csrows(mci, pdev, ovrfl_window, drc);
i82875p_get_error_info(mci, &discard); /* clear counters */
/* Here we assume that we will never see multiple instances of this
* type of memory controller. The ID is therefore hardcoded to 0.
*/
if (edac_mc_add_mc(mci, 0)) {
debugf3("%s(): failed edac_mc_add_mc()\n", __func__);
goto fail1;
}
/* allocating generic PCI control info */
i82875p_pci = edac_pci_create_generic_ctl(&pdev->dev, EDAC_MOD_STR);
if (!i82875p_pci) {
printk(KERN_WARNING
"%s(): Unable to create PCI control\n",
__func__);
printk(KERN_WARNING
"%s(): PCI error report via EDAC not setup\n",
__func__);
}
/* get this far and it's successful */
debugf3("%s(): success\n", __func__);
return 0;
fail1:
edac_mc_free(mci);
fail0:
iounmap(ovrfl_window);
pci_release_regions(ovrfl_pdev);
pci_disable_device(ovrfl_pdev);
/* NOTE: the ovrfl proc entry and pci_dev are intentionally left */
return rc;
}
/* returns count (>= 0), or negative on error */
static int __devinit i82875p_init_one(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
int rc;
debugf0("%s()\n", __func__);
i82875p_printk(KERN_INFO, "i82875p init one\n");
if (pci_enable_device(pdev) < 0)
return -EIO;
rc = i82875p_probe1(pdev, ent->driver_data);
if (mci_pdev == NULL)
mci_pdev = pci_dev_get(pdev);
return rc;
}
static void __devexit i82875p_remove_one(struct pci_dev *pdev)
{
struct mem_ctl_info *mci;
struct i82875p_pvt *pvt = NULL;
debugf0("%s()\n", __func__);
if (i82875p_pci)
edac_pci_release_generic_ctl(i82875p_pci);
if ((mci = edac_mc_del_mc(&pdev->dev)) == NULL)
return;
pvt = (struct i82875p_pvt *)mci->pvt_info;
if (pvt->ovrfl_window)
iounmap(pvt->ovrfl_window);
if (pvt->ovrfl_pdev) {
#ifdef CORRECT_BIOS
pci_release_regions(pvt->ovrfl_pdev);
#endif /*CORRECT_BIOS */
pci_disable_device(pvt->ovrfl_pdev);
pci_dev_put(pvt->ovrfl_pdev);
}
edac_mc_free(mci);
}
static const struct pci_device_id i82875p_pci_tbl[] __devinitdata = {
{
PCI_VEND_DEV(INTEL, 82875_0), PCI_ANY_ID, PCI_ANY_ID, 0, 0,
I82875P},
{
0,
} /* 0 terminated list. */
};
MODULE_DEVICE_TABLE(pci, i82875p_pci_tbl);
static struct pci_driver i82875p_driver = {
.name = EDAC_MOD_STR,
.probe = i82875p_init_one,
.remove = __devexit_p(i82875p_remove_one),
.id_table = i82875p_pci_tbl,
};
static int __init i82875p_init(void)
{
int pci_rc;
debugf3("%s()\n", __func__);
pci_rc = pci_register_driver(&i82875p_driver);
if (pci_rc < 0)
goto fail0;
if (mci_pdev == NULL) {
mci_pdev = pci_get_device(PCI_VENDOR_ID_INTEL,
PCI_DEVICE_ID_INTEL_82875_0, NULL);
if (!mci_pdev) {
debugf0("875p pci_get_device fail\n");
pci_rc = -ENODEV;
goto fail1;
}
pci_rc = i82875p_init_one(mci_pdev, i82875p_pci_tbl);
if (pci_rc < 0) {
debugf0("875p init fail\n");
pci_rc = -ENODEV;
goto fail1;
}
}
return 0;
fail1:
pci_unregister_driver(&i82875p_driver);
fail0:
if (mci_pdev != NULL)
pci_dev_put(mci_pdev);
return pci_rc;
}
static void __exit i82875p_exit(void)
{
debugf3("%s()\n", __func__);
pci_unregister_driver(&i82875p_driver);
if (!i82875p_registered) {
i82875p_remove_one(mci_pdev);
pci_dev_put(mci_pdev);
}
}
module_init(i82875p_init);
module_exit(i82875p_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Linux Networx (http://lnxi.com) Thayne Harbaugh");
MODULE_DESCRIPTION("MC support for Intel 82875 memory hub controllers");