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android_kernel_xiaomi_sm8350/arch/powerpc/platforms/pseries/eeh.c
Linas Vepstas c9b65a7da6 [POWERPC] EEH: Be careful when identifying "empty" slots. 
If an "empty" slot is failing, make sure its a permanent failure;
else process the error normally.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-12-03 13:56:26 +11:00

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36 KiB
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/*
* eeh.c
* Copyright IBM Corporation 2001, 2005, 2006
* Copyright Dave Engebretsen & Todd Inglett 2001
* Copyright Linas Vepstas 2005, 2006
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* 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
*
* Please address comments and feedback to Linas Vepstas <linas@austin.ibm.com>
*/
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/rbtree.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>
#include <asm/eeh.h>
#include <asm/eeh_event.h>
#include <asm/io.h>
#include <asm/machdep.h>
#include <asm/ppc-pci.h>
#include <asm/rtas.h>
#undef DEBUG
/** Overview:
* EEH, or "Extended Error Handling" is a PCI bridge technology for
* dealing with PCI bus errors that can't be dealt with within the
* usual PCI framework, except by check-stopping the CPU. Systems
* that are designed for high-availability/reliability cannot afford
* to crash due to a "mere" PCI error, thus the need for EEH.
* An EEH-capable bridge operates by converting a detected error
* into a "slot freeze", taking the PCI adapter off-line, making
* the slot behave, from the OS'es point of view, as if the slot
* were "empty": all reads return 0xff's and all writes are silently
* ignored. EEH slot isolation events can be triggered by parity
* errors on the address or data busses (e.g. during posted writes),
* which in turn might be caused by low voltage on the bus, dust,
* vibration, humidity, radioactivity or plain-old failed hardware.
*
* Note, however, that one of the leading causes of EEH slot
* freeze events are buggy device drivers, buggy device microcode,
* or buggy device hardware. This is because any attempt by the
* device to bus-master data to a memory address that is not
* assigned to the device will trigger a slot freeze. (The idea
* is to prevent devices-gone-wild from corrupting system memory).
* Buggy hardware/drivers will have a miserable time co-existing
* with EEH.
*
* Ideally, a PCI device driver, when suspecting that an isolation
* event has occured (e.g. by reading 0xff's), will then ask EEH
* whether this is the case, and then take appropriate steps to
* reset the PCI slot, the PCI device, and then resume operations.
* However, until that day, the checking is done here, with the
* eeh_check_failure() routine embedded in the MMIO macros. If
* the slot is found to be isolated, an "EEH Event" is synthesized
* and sent out for processing.
*/
/* If a device driver keeps reading an MMIO register in an interrupt
* handler after a slot isolation event has occurred, we assume it
* is broken and panic. This sets the threshold for how many read
* attempts we allow before panicking.
*/
#define EEH_MAX_FAILS 2100000
/* Time to wait for a PCI slot to report status, in milliseconds */
#define PCI_BUS_RESET_WAIT_MSEC (60*1000)
/* RTAS tokens */
static int ibm_set_eeh_option;
static int ibm_set_slot_reset;
static int ibm_read_slot_reset_state;
static int ibm_read_slot_reset_state2;
static int ibm_slot_error_detail;
static int ibm_get_config_addr_info;
static int ibm_get_config_addr_info2;
static int ibm_configure_bridge;
int eeh_subsystem_enabled;
EXPORT_SYMBOL(eeh_subsystem_enabled);
/* Lock to avoid races due to multiple reports of an error */
static DEFINE_SPINLOCK(confirm_error_lock);
/* Buffer for reporting slot-error-detail rtas calls. Its here
* in BSS, and not dynamically alloced, so that it ends up in
* RMO where RTAS can access it.
*/
static unsigned char slot_errbuf[RTAS_ERROR_LOG_MAX];
static DEFINE_SPINLOCK(slot_errbuf_lock);
static int eeh_error_buf_size;
/* Buffer for reporting pci register dumps. Its here in BSS, and
* not dynamically alloced, so that it ends up in RMO where RTAS
* can access it.
*/
#define EEH_PCI_REGS_LOG_LEN 4096
static unsigned char pci_regs_buf[EEH_PCI_REGS_LOG_LEN];
/* System monitoring statistics */
static unsigned long no_device;
static unsigned long no_dn;
static unsigned long no_cfg_addr;
static unsigned long ignored_check;
static unsigned long total_mmio_ffs;
static unsigned long false_positives;
static unsigned long slot_resets;
#define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE)
/* --------------------------------------------------------------- */
/* Below lies the EEH event infrastructure */
static void rtas_slot_error_detail(struct pci_dn *pdn, int severity,
char *driver_log, size_t loglen)
{
int config_addr;
unsigned long flags;
int rc;
/* Log the error with the rtas logger */
spin_lock_irqsave(&slot_errbuf_lock, flags);
memset(slot_errbuf, 0, eeh_error_buf_size);
/* Use PE configuration address, if present */
config_addr = pdn->eeh_config_addr;
if (pdn->eeh_pe_config_addr)
config_addr = pdn->eeh_pe_config_addr;
rc = rtas_call(ibm_slot_error_detail,
8, 1, NULL, config_addr,
BUID_HI(pdn->phb->buid),
BUID_LO(pdn->phb->buid),
virt_to_phys(driver_log), loglen,
virt_to_phys(slot_errbuf),
eeh_error_buf_size,
severity);
if (rc == 0)
log_error(slot_errbuf, ERR_TYPE_RTAS_LOG, 0);
spin_unlock_irqrestore(&slot_errbuf_lock, flags);
}
/**
* gather_pci_data - copy assorted PCI config space registers to buff
* @pdn: device to report data for
* @buf: point to buffer in which to log
* @len: amount of room in buffer
*
* This routine captures assorted PCI configuration space data,
* and puts them into a buffer for RTAS error logging.
*/
static size_t gather_pci_data(struct pci_dn *pdn, char * buf, size_t len)
{
struct device_node *dn;
struct pci_dev *dev = pdn->pcidev;
u32 cfg;
int cap, i;
int n = 0;
n += scnprintf(buf+n, len-n, "%s\n", pdn->node->full_name);
printk(KERN_WARNING "EEH: of node=%s\n", pdn->node->full_name);
rtas_read_config(pdn, PCI_VENDOR_ID, 4, &cfg);
n += scnprintf(buf+n, len-n, "dev/vend:%08x\n", cfg);
printk(KERN_WARNING "EEH: PCI device/vendor: %08x\n", cfg);
rtas_read_config(pdn, PCI_COMMAND, 4, &cfg);
n += scnprintf(buf+n, len-n, "cmd/stat:%x\n", cfg);
printk(KERN_WARNING "EEH: PCI cmd/status register: %08x\n", cfg);
if (!dev) {
printk(KERN_WARNING "EEH: no PCI device for this of node\n");
return n;
}
/* Gather bridge-specific registers */
if (dev->class >> 16 == PCI_BASE_CLASS_BRIDGE) {
rtas_read_config(pdn, PCI_SEC_STATUS, 2, &cfg);
n += scnprintf(buf+n, len-n, "sec stat:%x\n", cfg);
printk(KERN_WARNING "EEH: Bridge secondary status: %04x\n", cfg);
rtas_read_config(pdn, PCI_BRIDGE_CONTROL, 2, &cfg);
n += scnprintf(buf+n, len-n, "brdg ctl:%x\n", cfg);
printk(KERN_WARNING "EEH: Bridge control: %04x\n", cfg);
}
/* Dump out the PCI-X command and status regs */
cap = pci_find_capability(dev, PCI_CAP_ID_PCIX);
if (cap) {
rtas_read_config(pdn, cap, 4, &cfg);
n += scnprintf(buf+n, len-n, "pcix-cmd:%x\n", cfg);
printk(KERN_WARNING "EEH: PCI-X cmd: %08x\n", cfg);
rtas_read_config(pdn, cap+4, 4, &cfg);
n += scnprintf(buf+n, len-n, "pcix-stat:%x\n", cfg);
printk(KERN_WARNING "EEH: PCI-X status: %08x\n", cfg);
}
/* If PCI-E capable, dump PCI-E cap 10, and the AER */
cap = pci_find_capability(dev, PCI_CAP_ID_EXP);
if (cap) {
n += scnprintf(buf+n, len-n, "pci-e cap10:\n");
printk(KERN_WARNING
"EEH: PCI-E capabilities and status follow:\n");
for (i=0; i<=8; i++) {
rtas_read_config(pdn, cap+4*i, 4, &cfg);
n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg);
printk(KERN_WARNING "EEH: PCI-E %02x: %08x\n", i, cfg);
}
cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
if (cap) {
n += scnprintf(buf+n, len-n, "pci-e AER:\n");
printk(KERN_WARNING
"EEH: PCI-E AER capability register set follows:\n");
for (i=0; i<14; i++) {
rtas_read_config(pdn, cap+4*i, 4, &cfg);
n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg);
printk(KERN_WARNING "EEH: PCI-E AER %02x: %08x\n", i, cfg);
}
}
}
/* Gather status on devices under the bridge */
if (dev->class >> 16 == PCI_BASE_CLASS_BRIDGE) {
dn = pdn->node->child;
while (dn) {
pdn = PCI_DN(dn);
if (pdn)
n += gather_pci_data(pdn, buf+n, len-n);
dn = dn->sibling;
}
}
return n;
}
void eeh_slot_error_detail(struct pci_dn *pdn, int severity)
{
size_t loglen = 0;
pci_regs_buf[0] = 0;
rtas_pci_enable(pdn, EEH_THAW_MMIO);
loglen = gather_pci_data(pdn, pci_regs_buf, EEH_PCI_REGS_LOG_LEN);
rtas_slot_error_detail(pdn, severity, pci_regs_buf, loglen);
}
/**
* read_slot_reset_state - Read the reset state of a device node's slot
* @dn: device node to read
* @rets: array to return results in
*/
static int read_slot_reset_state(struct pci_dn *pdn, int rets[])
{
int token, outputs;
int config_addr;
if (ibm_read_slot_reset_state2 != RTAS_UNKNOWN_SERVICE) {
token = ibm_read_slot_reset_state2;
outputs = 4;
} else {
token = ibm_read_slot_reset_state;
rets[2] = 0; /* fake PE Unavailable info */
outputs = 3;
}
/* Use PE configuration address, if present */
config_addr = pdn->eeh_config_addr;
if (pdn->eeh_pe_config_addr)
config_addr = pdn->eeh_pe_config_addr;
return rtas_call(token, 3, outputs, rets, config_addr,
BUID_HI(pdn->phb->buid), BUID_LO(pdn->phb->buid));
}
/**
* eeh_wait_for_slot_status - returns error status of slot
* @pdn pci device node
* @max_wait_msecs maximum number to millisecs to wait
*
* Return negative value if a permanent error, else return
* Partition Endpoint (PE) status value.
*
* If @max_wait_msecs is positive, then this routine will
* sleep until a valid status can be obtained, or until
* the max allowed wait time is exceeded, in which case
* a -2 is returned.
*/
int
eeh_wait_for_slot_status(struct pci_dn *pdn, int max_wait_msecs)
{
int rc;
int rets[3];
int mwait;
while (1) {
rc = read_slot_reset_state(pdn, rets);
if (rc) return rc;
if (rets[1] == 0) return -1; /* EEH is not supported */
if (rets[0] != 5) return rets[0]; /* return actual status */
if (rets[2] == 0) return -1; /* permanently unavailable */
if (max_wait_msecs <= 0) break;
mwait = rets[2];
if (mwait <= 0) {
printk (KERN_WARNING
"EEH: Firmware returned bad wait value=%d\n", mwait);
mwait = 1000;
} else if (mwait > 300*1000) {
printk (KERN_WARNING
"EEH: Firmware is taking too long, time=%d\n", mwait);
mwait = 300*1000;
}
max_wait_msecs -= mwait;
msleep (mwait);
}
printk(KERN_WARNING "EEH: Timed out waiting for slot status\n");
return -2;
}
/**
* eeh_token_to_phys - convert EEH address token to phys address
* @token i/o token, should be address in the form 0xA....
*/
static inline unsigned long eeh_token_to_phys(unsigned long token)
{
pte_t *ptep;
unsigned long pa;
ptep = find_linux_pte(init_mm.pgd, token);
if (!ptep)
return token;
pa = pte_pfn(*ptep) << PAGE_SHIFT;
return pa | (token & (PAGE_SIZE-1));
}
/**
* Return the "partitionable endpoint" (pe) under which this device lies
*/
struct device_node * find_device_pe(struct device_node *dn)
{
while ((dn->parent) && PCI_DN(dn->parent) &&
(PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) {
dn = dn->parent;
}
return dn;
}
/** Mark all devices that are peers of this device as failed.
* Mark the device driver too, so that it can see the failure
* immediately; this is critical, since some drivers poll
* status registers in interrupts ... If a driver is polling,
* and the slot is frozen, then the driver can deadlock in
* an interrupt context, which is bad.
*/
static void __eeh_mark_slot (struct device_node *dn, int mode_flag)
{
while (dn) {
if (PCI_DN(dn)) {
/* Mark the pci device driver too */
struct pci_dev *dev = PCI_DN(dn)->pcidev;
PCI_DN(dn)->eeh_mode |= mode_flag;
if (dev && dev->driver)
dev->error_state = pci_channel_io_frozen;
if (dn->child)
__eeh_mark_slot (dn->child, mode_flag);
}
dn = dn->sibling;
}
}
void eeh_mark_slot (struct device_node *dn, int mode_flag)
{
struct pci_dev *dev;
dn = find_device_pe (dn);
/* Back up one, since config addrs might be shared */
if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent))
dn = dn->parent;
PCI_DN(dn)->eeh_mode |= mode_flag;
/* Mark the pci device too */
dev = PCI_DN(dn)->pcidev;
if (dev)
dev->error_state = pci_channel_io_frozen;
__eeh_mark_slot (dn->child, mode_flag);
}
static void __eeh_clear_slot (struct device_node *dn, int mode_flag)
{
while (dn) {
if (PCI_DN(dn)) {
PCI_DN(dn)->eeh_mode &= ~mode_flag;
PCI_DN(dn)->eeh_check_count = 0;
if (dn->child)
__eeh_clear_slot (dn->child, mode_flag);
}
dn = dn->sibling;
}
}
void eeh_clear_slot (struct device_node *dn, int mode_flag)
{
unsigned long flags;
spin_lock_irqsave(&confirm_error_lock, flags);
dn = find_device_pe (dn);
/* Back up one, since config addrs might be shared */
if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent))
dn = dn->parent;
PCI_DN(dn)->eeh_mode &= ~mode_flag;
PCI_DN(dn)->eeh_check_count = 0;
__eeh_clear_slot (dn->child, mode_flag);
spin_unlock_irqrestore(&confirm_error_lock, flags);
}
/**
* eeh_dn_check_failure - check if all 1's data is due to EEH slot freeze
* @dn device node
* @dev pci device, if known
*
* Check for an EEH failure for the given device node. Call this
* routine if the result of a read was all 0xff's and you want to
* find out if this is due to an EEH slot freeze. This routine
* will query firmware for the EEH status.
*
* Returns 0 if there has not been an EEH error; otherwise returns
* a non-zero value and queues up a slot isolation event notification.
*
* It is safe to call this routine in an interrupt context.
*/
int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
{
int ret;
int rets[3];
unsigned long flags;
struct pci_dn *pdn;
int rc = 0;
total_mmio_ffs++;
if (!eeh_subsystem_enabled)
return 0;
if (!dn) {
no_dn++;
return 0;
}
dn = find_device_pe(dn);
pdn = PCI_DN(dn);
/* Access to IO BARs might get this far and still not want checking. */
if (!(pdn->eeh_mode & EEH_MODE_SUPPORTED) ||
pdn->eeh_mode & EEH_MODE_NOCHECK) {
ignored_check++;
#ifdef DEBUG
printk ("EEH:ignored check (%x) for %s %s\n",
pdn->eeh_mode, pci_name (dev), dn->full_name);
#endif
return 0;
}
if (!pdn->eeh_config_addr && !pdn->eeh_pe_config_addr) {
no_cfg_addr++;
return 0;
}
/* If we already have a pending isolation event for this
* slot, we know it's bad already, we don't need to check.
* Do this checking under a lock; as multiple PCI devices
* in one slot might report errors simultaneously, and we
* only want one error recovery routine running.
*/
spin_lock_irqsave(&confirm_error_lock, flags);
rc = 1;
if (pdn->eeh_mode & EEH_MODE_ISOLATED) {
pdn->eeh_check_count ++;
if (pdn->eeh_check_count >= EEH_MAX_FAILS) {
printk (KERN_ERR "EEH: Device driver ignored %d bad reads, panicing\n",
pdn->eeh_check_count);
dump_stack();
msleep(5000);
/* re-read the slot reset state */
if (read_slot_reset_state(pdn, rets) != 0)
rets[0] = -1; /* reset state unknown */
/* If we are here, then we hit an infinite loop. Stop. */
panic("EEH: MMIO halt (%d) on device:%s\n", rets[0], pci_name(dev));
}
goto dn_unlock;
}
/*
* Now test for an EEH failure. This is VERY expensive.
* Note that the eeh_config_addr may be a parent device
* in the case of a device behind a bridge, or it may be
* function zero of a multi-function device.
* In any case they must share a common PHB.
*/
ret = read_slot_reset_state(pdn, rets);
/* If the call to firmware failed, punt */
if (ret != 0) {
printk(KERN_WARNING "EEH: read_slot_reset_state() failed; rc=%d dn=%s\n",
ret, dn->full_name);
false_positives++;
pdn->eeh_false_positives ++;
rc = 0;
goto dn_unlock;
}
/* Note that config-io to empty slots may fail;
* they are empty when they don't have children. */
if ((rets[0] == 5) && (rets[2] == 0) && (dn->child == NULL)) {
false_positives++;
pdn->eeh_false_positives ++;
rc = 0;
goto dn_unlock;
}
/* If EEH is not supported on this device, punt. */
if (rets[1] != 1) {
printk(KERN_WARNING "EEH: event on unsupported device, rc=%d dn=%s\n",
ret, dn->full_name);
false_positives++;
pdn->eeh_false_positives ++;
rc = 0;
goto dn_unlock;
}
/* If not the kind of error we know about, punt. */
if (rets[0] != 1 && rets[0] != 2 && rets[0] != 4 && rets[0] != 5) {
false_positives++;
pdn->eeh_false_positives ++;
rc = 0;
goto dn_unlock;
}
slot_resets++;
/* Avoid repeated reports of this failure, including problems
* with other functions on this device, and functions under
* bridges. */
eeh_mark_slot (dn, EEH_MODE_ISOLATED);
spin_unlock_irqrestore(&confirm_error_lock, flags);
eeh_send_failure_event (dn, dev);
/* Most EEH events are due to device driver bugs. Having
* a stack trace will help the device-driver authors figure
* out what happened. So print that out. */
dump_stack();
return 1;
dn_unlock:
spin_unlock_irqrestore(&confirm_error_lock, flags);
return rc;
}
EXPORT_SYMBOL_GPL(eeh_dn_check_failure);
/**
* eeh_check_failure - check if all 1's data is due to EEH slot freeze
* @token i/o token, should be address in the form 0xA....
* @val value, should be all 1's (XXX why do we need this arg??)
*
* Check for an EEH failure at the given token address. Call this
* routine if the result of a read was all 0xff's and you want to
* find out if this is due to an EEH slot freeze event. This routine
* will query firmware for the EEH status.
*
* Note this routine is safe to call in an interrupt context.
*/
unsigned long eeh_check_failure(const volatile void __iomem *token, unsigned long val)
{
unsigned long addr;
struct pci_dev *dev;
struct device_node *dn;
/* Finding the phys addr + pci device; this is pretty quick. */
addr = eeh_token_to_phys((unsigned long __force) token);
dev = pci_get_device_by_addr(addr);
if (!dev) {
no_device++;
return val;
}
dn = pci_device_to_OF_node(dev);
eeh_dn_check_failure (dn, dev);
pci_dev_put(dev);
return val;
}
EXPORT_SYMBOL(eeh_check_failure);
/* ------------------------------------------------------------- */
/* The code below deals with error recovery */
/**
* rtas_pci_enable - enable MMIO or DMA transfers for this slot
* @pdn pci device node
*/
int
rtas_pci_enable(struct pci_dn *pdn, int function)
{
int config_addr;
int rc;
/* Use PE configuration address, if present */
config_addr = pdn->eeh_config_addr;
if (pdn->eeh_pe_config_addr)
config_addr = pdn->eeh_pe_config_addr;
rc = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
config_addr,
BUID_HI(pdn->phb->buid),
BUID_LO(pdn->phb->buid),
function);
if (rc)
printk(KERN_WARNING "EEH: Unexpected state change %d, err=%d dn=%s\n",
function, rc, pdn->node->full_name);
rc = eeh_wait_for_slot_status (pdn, PCI_BUS_RESET_WAIT_MSEC);
if ((rc == 4) && (function == EEH_THAW_MMIO))
return 0;
return rc;
}
/**
* rtas_pci_slot_reset - raises/lowers the pci #RST line
* @pdn pci device node
* @state: 1/0 to raise/lower the #RST
*
* Clear the EEH-frozen condition on a slot. This routine
* asserts the PCI #RST line if the 'state' argument is '1',
* and drops the #RST line if 'state is '0'. This routine is
* safe to call in an interrupt context.
*
*/
static void
rtas_pci_slot_reset(struct pci_dn *pdn, int state)
{
int config_addr;
int rc;
BUG_ON (pdn==NULL);
if (!pdn->phb) {
printk (KERN_WARNING "EEH: in slot reset, device node %s has no phb\n",
pdn->node->full_name);
return;
}
/* Use PE configuration address, if present */
config_addr = pdn->eeh_config_addr;
if (pdn->eeh_pe_config_addr)
config_addr = pdn->eeh_pe_config_addr;
rc = rtas_call(ibm_set_slot_reset,4,1, NULL,
config_addr,
BUID_HI(pdn->phb->buid),
BUID_LO(pdn->phb->buid),
state);
if (rc)
printk (KERN_WARNING "EEH: Unable to reset the failed slot,"
" (%d) #RST=%d dn=%s\n",
rc, state, pdn->node->full_name);
}
/**
* pcibios_set_pcie_slot_reset - Set PCI-E reset state
* @dev: pci device struct
* @state: reset state to enter
*
* Return value:
* 0 if success
**/
int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
{
struct device_node *dn = pci_device_to_OF_node(dev);
struct pci_dn *pdn = PCI_DN(dn);
switch (state) {
case pcie_deassert_reset:
rtas_pci_slot_reset(pdn, 0);
break;
case pcie_hot_reset:
rtas_pci_slot_reset(pdn, 1);
break;
case pcie_warm_reset:
rtas_pci_slot_reset(pdn, 3);
break;
default:
return -EINVAL;
};
return 0;
}
/**
* rtas_set_slot_reset -- assert the pci #RST line for 1/4 second
* @pdn: pci device node to be reset.
*
* Return 0 if success, else a non-zero value.
*/
static void __rtas_set_slot_reset(struct pci_dn *pdn)
{
rtas_pci_slot_reset (pdn, 1);
/* The PCI bus requires that the reset be held high for at least
* a 100 milliseconds. We wait a bit longer 'just in case'. */
#define PCI_BUS_RST_HOLD_TIME_MSEC 250
msleep (PCI_BUS_RST_HOLD_TIME_MSEC);
/* We might get hit with another EEH freeze as soon as the
* pci slot reset line is dropped. Make sure we don't miss
* these, and clear the flag now. */
eeh_clear_slot (pdn->node, EEH_MODE_ISOLATED);
rtas_pci_slot_reset (pdn, 0);
/* After a PCI slot has been reset, the PCI Express spec requires
* a 1.5 second idle time for the bus to stabilize, before starting
* up traffic. */
#define PCI_BUS_SETTLE_TIME_MSEC 1800
msleep (PCI_BUS_SETTLE_TIME_MSEC);
}
int rtas_set_slot_reset(struct pci_dn *pdn)
{
int i, rc;
/* Take three shots at resetting the bus */
for (i=0; i<3; i++) {
__rtas_set_slot_reset(pdn);
rc = eeh_wait_for_slot_status(pdn, PCI_BUS_RESET_WAIT_MSEC);
if (rc == 0)
return 0;
if (rc < 0) {
printk(KERN_ERR "EEH: unrecoverable slot failure %s\n",
pdn->node->full_name);
return -1;
}
printk(KERN_ERR "EEH: bus reset %d failed on slot %s, rc=%d\n",
i+1, pdn->node->full_name, rc);
}
return -1;
}
/* ------------------------------------------------------- */
/** Save and restore of PCI BARs
*
* Although firmware will set up BARs during boot, it doesn't
* set up device BAR's after a device reset, although it will,
* if requested, set up bridge configuration. Thus, we need to
* configure the PCI devices ourselves.
*/
/**
* __restore_bars - Restore the Base Address Registers
* @pdn: pci device node
*
* Loads the PCI configuration space base address registers,
* the expansion ROM base address, the latency timer, and etc.
* from the saved values in the device node.
*/
static inline void __restore_bars (struct pci_dn *pdn)
{
int i;
if (NULL==pdn->phb) return;
for (i=4; i<10; i++) {
rtas_write_config(pdn, i*4, 4, pdn->config_space[i]);
}
/* 12 == Expansion ROM Address */
rtas_write_config(pdn, 12*4, 4, pdn->config_space[12]);
#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF))
#define SAVED_BYTE(OFF) (((u8 *)(pdn->config_space))[BYTE_SWAP(OFF)])
rtas_write_config (pdn, PCI_CACHE_LINE_SIZE, 1,
SAVED_BYTE(PCI_CACHE_LINE_SIZE));
rtas_write_config (pdn, PCI_LATENCY_TIMER, 1,
SAVED_BYTE(PCI_LATENCY_TIMER));
/* max latency, min grant, interrupt pin and line */
rtas_write_config(pdn, 15*4, 4, pdn->config_space[15]);
}
/**
* eeh_restore_bars - restore the PCI config space info
*
* This routine performs a recursive walk to the children
* of this device as well.
*/
void eeh_restore_bars(struct pci_dn *pdn)
{
struct device_node *dn;
if (!pdn)
return;
if ((pdn->eeh_mode & EEH_MODE_SUPPORTED) && !IS_BRIDGE(pdn->class_code))
__restore_bars (pdn);
dn = pdn->node->child;
while (dn) {
eeh_restore_bars (PCI_DN(dn));
dn = dn->sibling;
}
}
/**
* eeh_save_bars - save device bars
*
* Save the values of the device bars. Unlike the restore
* routine, this routine is *not* recursive. This is because
* PCI devices are added individuallly; but, for the restore,
* an entire slot is reset at a time.
*/
static void eeh_save_bars(struct pci_dn *pdn)
{
int i;
if (!pdn )
return;
for (i = 0; i < 16; i++)
rtas_read_config(pdn, i * 4, 4, &pdn->config_space[i]);
}
void
rtas_configure_bridge(struct pci_dn *pdn)
{
int config_addr;
int rc;
/* Use PE configuration address, if present */
config_addr = pdn->eeh_config_addr;
if (pdn->eeh_pe_config_addr)
config_addr = pdn->eeh_pe_config_addr;
rc = rtas_call(ibm_configure_bridge,3,1, NULL,
config_addr,
BUID_HI(pdn->phb->buid),
BUID_LO(pdn->phb->buid));
if (rc) {
printk (KERN_WARNING "EEH: Unable to configure device bridge (%d) for %s\n",
rc, pdn->node->full_name);
}
}
/* ------------------------------------------------------------- */
/* The code below deals with enabling EEH for devices during the
* early boot sequence. EEH must be enabled before any PCI probing
* can be done.
*/
#define EEH_ENABLE 1
struct eeh_early_enable_info {
unsigned int buid_hi;
unsigned int buid_lo;
};
static int get_pe_addr (int config_addr,
struct eeh_early_enable_info *info)
{
unsigned int rets[3];
int ret;
/* Use latest config-addr token on power6 */
if (ibm_get_config_addr_info2 != RTAS_UNKNOWN_SERVICE) {
/* Make sure we have a PE in hand */
ret = rtas_call (ibm_get_config_addr_info2, 4, 2, rets,
config_addr, info->buid_hi, info->buid_lo, 1);
if (ret || (rets[0]==0))
return 0;
ret = rtas_call (ibm_get_config_addr_info2, 4, 2, rets,
config_addr, info->buid_hi, info->buid_lo, 0);
if (ret)
return 0;
return rets[0];
}
/* Use older config-addr token on power5 */
if (ibm_get_config_addr_info != RTAS_UNKNOWN_SERVICE) {
ret = rtas_call (ibm_get_config_addr_info, 4, 2, rets,
config_addr, info->buid_hi, info->buid_lo, 0);
if (ret)
return 0;
return rets[0];
}
return 0;
}
/* Enable eeh for the given device node. */
static void *early_enable_eeh(struct device_node *dn, void *data)
{
unsigned int rets[3];
struct eeh_early_enable_info *info = data;
int ret;
const char *status = of_get_property(dn, "status", NULL);
const u32 *class_code = of_get_property(dn, "class-code", NULL);
const u32 *vendor_id = of_get_property(dn, "vendor-id", NULL);
const u32 *device_id = of_get_property(dn, "device-id", NULL);
const u32 *regs;
int enable;
struct pci_dn *pdn = PCI_DN(dn);
pdn->class_code = 0;
pdn->eeh_mode = 0;
pdn->eeh_check_count = 0;
pdn->eeh_freeze_count = 0;
pdn->eeh_false_positives = 0;
if (status && strncmp(status, "ok", 2) != 0)
return NULL; /* ignore devices with bad status */
/* Ignore bad nodes. */
if (!class_code || !vendor_id || !device_id)
return NULL;
/* There is nothing to check on PCI to ISA bridges */
if (dn->type && !strcmp(dn->type, "isa")) {
pdn->eeh_mode |= EEH_MODE_NOCHECK;
return NULL;
}
pdn->class_code = *class_code;
/* Ok... see if this device supports EEH. Some do, some don't,
* and the only way to find out is to check each and every one. */
regs = of_get_property(dn, "reg", NULL);
if (regs) {
/* First register entry is addr (00BBSS00) */
/* Try to enable eeh */
ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL,
regs[0], info->buid_hi, info->buid_lo,
EEH_ENABLE);
enable = 0;
if (ret == 0) {
pdn->eeh_config_addr = regs[0];
/* If the newer, better, ibm,get-config-addr-info is supported,
* then use that instead. */
pdn->eeh_pe_config_addr = get_pe_addr(pdn->eeh_config_addr, info);
/* Some older systems (Power4) allow the
* ibm,set-eeh-option call to succeed even on nodes
* where EEH is not supported. Verify support
* explicitly. */
ret = read_slot_reset_state(pdn, rets);
if ((ret == 0) && (rets[1] == 1))
enable = 1;
}
if (enable) {
eeh_subsystem_enabled = 1;
pdn->eeh_mode |= EEH_MODE_SUPPORTED;
#ifdef DEBUG
printk(KERN_DEBUG "EEH: %s: eeh enabled, config=%x pe_config=%x\n",
dn->full_name, pdn->eeh_config_addr, pdn->eeh_pe_config_addr);
#endif
} else {
/* This device doesn't support EEH, but it may have an
* EEH parent, in which case we mark it as supported. */
if (dn->parent && PCI_DN(dn->parent)
&& (PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) {
/* Parent supports EEH. */
pdn->eeh_mode |= EEH_MODE_SUPPORTED;
pdn->eeh_config_addr = PCI_DN(dn->parent)->eeh_config_addr;
return NULL;
}
}
} else {
printk(KERN_WARNING "EEH: %s: unable to get reg property.\n",
dn->full_name);
}
eeh_save_bars(pdn);
return NULL;
}
/*
* Initialize EEH by trying to enable it for all of the adapters in the system.
* As a side effect we can determine here if eeh is supported at all.
* Note that we leave EEH on so failed config cycles won't cause a machine
* check. If a user turns off EEH for a particular adapter they are really
* telling Linux to ignore errors. Some hardware (e.g. POWER5) won't
* grant access to a slot if EEH isn't enabled, and so we always enable
* EEH for all slots/all devices.
*
* The eeh-force-off option disables EEH checking globally, for all slots.
* Even if force-off is set, the EEH hardware is still enabled, so that
* newer systems can boot.
*/
void __init eeh_init(void)
{
struct device_node *phb, *np;
struct eeh_early_enable_info info;
spin_lock_init(&confirm_error_lock);
spin_lock_init(&slot_errbuf_lock);
np = of_find_node_by_path("/rtas");
if (np == NULL)
return;
ibm_set_eeh_option = rtas_token("ibm,set-eeh-option");
ibm_set_slot_reset = rtas_token("ibm,set-slot-reset");
ibm_read_slot_reset_state2 = rtas_token("ibm,read-slot-reset-state2");
ibm_read_slot_reset_state = rtas_token("ibm,read-slot-reset-state");
ibm_slot_error_detail = rtas_token("ibm,slot-error-detail");
ibm_get_config_addr_info = rtas_token("ibm,get-config-addr-info");
ibm_get_config_addr_info2 = rtas_token("ibm,get-config-addr-info2");
ibm_configure_bridge = rtas_token ("ibm,configure-bridge");
if (ibm_set_eeh_option == RTAS_UNKNOWN_SERVICE)
return;
eeh_error_buf_size = rtas_token("rtas-error-log-max");
if (eeh_error_buf_size == RTAS_UNKNOWN_SERVICE) {
eeh_error_buf_size = 1024;
}
if (eeh_error_buf_size > RTAS_ERROR_LOG_MAX) {
printk(KERN_WARNING "EEH: rtas-error-log-max is bigger than allocated "
"buffer ! (%d vs %d)", eeh_error_buf_size, RTAS_ERROR_LOG_MAX);
eeh_error_buf_size = RTAS_ERROR_LOG_MAX;
}
/* Enable EEH for all adapters. Note that eeh requires buid's */
for (phb = of_find_node_by_name(NULL, "pci"); phb;
phb = of_find_node_by_name(phb, "pci")) {
unsigned long buid;
buid = get_phb_buid(phb);
if (buid == 0 || PCI_DN(phb) == NULL)
continue;
info.buid_lo = BUID_LO(buid);
info.buid_hi = BUID_HI(buid);
traverse_pci_devices(phb, early_enable_eeh, &info);
}
if (eeh_subsystem_enabled)
printk(KERN_INFO "EEH: PCI Enhanced I/O Error Handling Enabled\n");
else
printk(KERN_WARNING "EEH: No capable adapters found\n");
}
/**
* eeh_add_device_early - enable EEH for the indicated device_node
* @dn: device node for which to set up EEH
*
* This routine must be used to perform EEH initialization for PCI
* devices that were added after system boot (e.g. hotplug, dlpar).
* This routine must be called before any i/o is performed to the
* adapter (inluding any config-space i/o).
* Whether this actually enables EEH or not for this device depends
* on the CEC architecture, type of the device, on earlier boot
* command-line arguments & etc.
*/
static void eeh_add_device_early(struct device_node *dn)
{
struct pci_controller *phb;
struct eeh_early_enable_info info;
if (!dn || !PCI_DN(dn))
return;
phb = PCI_DN(dn)->phb;
/* USB Bus children of PCI devices will not have BUID's */
if (NULL == phb || 0 == phb->buid)
return;
info.buid_hi = BUID_HI(phb->buid);
info.buid_lo = BUID_LO(phb->buid);
early_enable_eeh(dn, &info);
}
void eeh_add_device_tree_early(struct device_node *dn)
{
struct device_node *sib;
for (sib = dn->child; sib; sib = sib->sibling)
eeh_add_device_tree_early(sib);
eeh_add_device_early(dn);
}
EXPORT_SYMBOL_GPL(eeh_add_device_tree_early);
/**
* eeh_add_device_late - perform EEH initialization for the indicated pci device
* @dev: pci device for which to set up EEH
*
* This routine must be used to complete EEH initialization for PCI
* devices that were added after system boot (e.g. hotplug, dlpar).
*/
static void eeh_add_device_late(struct pci_dev *dev)
{
struct device_node *dn;
struct pci_dn *pdn;
if (!dev || !eeh_subsystem_enabled)
return;
#ifdef DEBUG
printk(KERN_DEBUG "EEH: adding device %s\n", pci_name(dev));
#endif
pci_dev_get (dev);
dn = pci_device_to_OF_node(dev);
pdn = PCI_DN(dn);
pdn->pcidev = dev;
pci_addr_cache_insert_device(dev);
eeh_sysfs_add_device(dev);
}
void eeh_add_device_tree_late(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
eeh_add_device_late(dev);
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
struct pci_bus *subbus = dev->subordinate;
if (subbus)
eeh_add_device_tree_late(subbus);
}
}
}
EXPORT_SYMBOL_GPL(eeh_add_device_tree_late);
/**
* eeh_remove_device - undo EEH setup for the indicated pci device
* @dev: pci device to be removed
*
* This routine should be called when a device is removed from
* a running system (e.g. by hotplug or dlpar). It unregisters
* the PCI device from the EEH subsystem. I/O errors affecting
* this device will no longer be detected after this call; thus,
* i/o errors affecting this slot may leave this device unusable.
*/
static void eeh_remove_device(struct pci_dev *dev)
{
struct device_node *dn;
if (!dev || !eeh_subsystem_enabled)
return;
/* Unregister the device with the EEH/PCI address search system */
#ifdef DEBUG
printk(KERN_DEBUG "EEH: remove device %s\n", pci_name(dev));
#endif
pci_addr_cache_remove_device(dev);
eeh_sysfs_remove_device(dev);
dn = pci_device_to_OF_node(dev);
if (PCI_DN(dn)->pcidev) {
PCI_DN(dn)->pcidev = NULL;
pci_dev_put (dev);
}
}
void eeh_remove_bus_device(struct pci_dev *dev)
{
struct pci_bus *bus = dev->subordinate;
struct pci_dev *child, *tmp;
eeh_remove_device(dev);
if (bus && dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
list_for_each_entry_safe(child, tmp, &bus->devices, bus_list)
eeh_remove_bus_device(child);
}
}
EXPORT_SYMBOL_GPL(eeh_remove_bus_device);
static int proc_eeh_show(struct seq_file *m, void *v)
{
if (0 == eeh_subsystem_enabled) {
seq_printf(m, "EEH Subsystem is globally disabled\n");
seq_printf(m, "eeh_total_mmio_ffs=%ld\n", total_mmio_ffs);
} else {
seq_printf(m, "EEH Subsystem is enabled\n");
seq_printf(m,
"no device=%ld\n"
"no device node=%ld\n"
"no config address=%ld\n"
"check not wanted=%ld\n"
"eeh_total_mmio_ffs=%ld\n"
"eeh_false_positives=%ld\n"
"eeh_slot_resets=%ld\n",
no_device, no_dn, no_cfg_addr,
ignored_check, total_mmio_ffs,
false_positives,
slot_resets);
}
return 0;
}
static int proc_eeh_open(struct inode *inode, struct file *file)
{
return single_open(file, proc_eeh_show, NULL);
}
static const struct file_operations proc_eeh_operations = {
.open = proc_eeh_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init eeh_init_proc(void)
{
struct proc_dir_entry *e;
if (machine_is(pseries)) {
e = create_proc_entry("ppc64/eeh", 0, NULL);
if (e)
e->proc_fops = &proc_eeh_operations;
}
return 0;
}
__initcall(eeh_init_proc);
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