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powerpc/pseries: PCIE PHB reset

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Several device drivers hit EEH(Extended Error handling) when
triggering kdump on Pseries PowerVM. This patch implemented a reset of
the PHBs in pci general code when triggering kdump. PHB reset stop all
PCI transactions from normal kernel. We have tested the patch in
several enviroments:
  - direct slot adapters
  - adapters under the switch
  - a VF adapter in PowerVM
  - a VF adapter/adapter in KVM guest.

Signed-off-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
[mpe: Fix broken whitespace, subject & SOB formatting]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1594651173-32166-1-git-send-email-wenxiong@linux.vnet.ibm.com
This commit is contained in:
Wen Xiong 2020-07-13 09:39:33 -05:00 committed by Michael Ellerman
parent 2384b36f91
commit 5a090f7c36
1 changed files with 169 additions and 63 deletions
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232
arch/powerpc/platforms/pseries/eeh_pseries.c
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@ -24,6 +24,7 @@
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/crash_dump.h>
#include <asm/eeh.h>
#include <asm/eeh_event.h>
@ -80,6 +81,152 @@ void pseries_pcibios_bus_add_device(struct pci_dev *pdev)
eeh_probe_device(pdev);
}
/**
* pseries_eeh_get_config_addr - Retrieve config address
*
* Retrieve the assocated config address. Actually, there're 2 RTAS
* function calls dedicated for the purpose. We need implement
* it through the new function and then the old one. Besides,
* you should make sure the config address is figured out from
* FDT node before calling the function.
*
* It's notable that zero'ed return value means invalid PE config
* address.
*/
static int pseries_eeh_get_config_addr(struct pci_controller *phb, int config_addr)
{
int ret = 0;
int rets[3];
if (ibm_get_config_addr_info2 != RTAS_UNKNOWN_SERVICE) {
/*
* First of all, we need to make sure there has one PE
* associated with the device. Otherwise, PE address is
* meaningless.
*/
ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
config_addr, BUID_HI(phb->buid),
BUID_LO(phb->buid), 1);
if (ret || (rets[0] == 0))
return 0;
/* Retrieve the associated PE config address */
ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets,
config_addr, BUID_HI(phb->buid),
BUID_LO(phb->buid), 0);
if (ret) {
pr_warn("%s: Failed to get address for PHB#%x-PE#%x\n",
__func__, phb->global_number, config_addr);
return 0;
}
return rets[0];
}
if (ibm_get_config_addr_info != RTAS_UNKNOWN_SERVICE) {
ret = rtas_call(ibm_get_config_addr_info, 4, 2, rets,
config_addr, BUID_HI(phb->buid),
BUID_LO(phb->buid), 0);
if (ret) {
pr_warn("%s: Failed to get address for PHB#%x-PE#%x\n",
__func__, phb->global_number, config_addr);
return 0;
}
return rets[0];
}
return ret;
}
/**
* pseries_eeh_phb_reset - Reset the specified PHB
* @phb: PCI controller
* @config_adddr: the associated config address
* @option: reset option
*
* Reset the specified PHB/PE
*/
static int pseries_eeh_phb_reset(struct pci_controller *phb, int config_addr, int option)
{
int ret;
/* Reset PE through RTAS call */
ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
config_addr, BUID_HI(phb->buid),
BUID_LO(phb->buid), option);
/* If fundamental-reset not supported, try hot-reset */
if (option == EEH_RESET_FUNDAMENTAL &&
ret == -8) {
option = EEH_RESET_HOT;
ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
config_addr, BUID_HI(phb->buid),
BUID_LO(phb->buid), option);
}
/* We need reset hold or settlement delay */
if (option == EEH_RESET_FUNDAMENTAL ||
option == EEH_RESET_HOT)
msleep(EEH_PE_RST_HOLD_TIME);
else
msleep(EEH_PE_RST_SETTLE_TIME);
return ret;
}
/**
* pseries_eeh_phb_configure_bridge - Configure PCI bridges in the indicated PE
* @phb: PCI controller
* @config_adddr: the associated config address
*
* The function will be called to reconfigure the bridges included
* in the specified PE so that the mulfunctional PE would be recovered
* again.
*/
static int pseries_eeh_phb_configure_bridge(struct pci_controller *phb, int config_addr)
{
int ret;
/* Waiting 0.2s maximum before skipping configuration */
int max_wait = 200;
while (max_wait > 0) {
ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
config_addr, BUID_HI(phb->buid),
BUID_LO(phb->buid));
if (!ret)
return ret;
if (ret < 0)
break;
/*
* If RTAS returns a delay value that's above 100ms, cut it
* down to 100ms in case firmware made a mistake. For more
* on how these delay values work see rtas_busy_delay_time
*/
if (ret > RTAS_EXTENDED_DELAY_MIN+2 &&
ret <= RTAS_EXTENDED_DELAY_MAX)
ret = RTAS_EXTENDED_DELAY_MIN+2;
max_wait -= rtas_busy_delay_time(ret);
if (max_wait < 0)
break;
rtas_busy_delay(ret);
}
pr_warn("%s: Unable to configure bridge PHB#%x-PE#%x (%d)\n",
__func__, phb->global_number, config_addr, ret);
/* PAPR defines -3 as "Parameter Error" for this function: */
if (ret == -3)
return -EINVAL;
else
return -EIO;
}
/*
* Buffer for reporting slot-error-detail rtas calls. Its here
* in BSS, and not dynamically alloced, so that it ends up in
@ -96,6 +243,10 @@ static int eeh_error_buf_size;
*/
static int pseries_eeh_init(void)
{
struct pci_controller *phb;
struct pci_dn *pdn;
int addr, config_addr;
/* figure out EEH RTAS function call tokens */
ibm_set_eeh_option = rtas_token("ibm,set-eeh-option");
ibm_set_slot_reset = rtas_token("ibm,set-slot-reset");
@ -148,6 +299,22 @@ static int pseries_eeh_init(void)
/* Set EEH machine dependent code */
ppc_md.pcibios_bus_add_device = pseries_pcibios_bus_add_device;
if (is_kdump_kernel() || reset_devices) {
pr_info("Issue PHB reset ...\n");
list_for_each_entry(phb, &hose_list, list_node) {
pdn = list_first_entry(&PCI_DN(phb->dn)->child_list, struct pci_dn, list);
addr = (pdn->busno << 16) | (pdn->devfn << 8);
config_addr = pseries_eeh_get_config_addr(phb, addr);
/* invalid PE config addr */
if (config_addr == 0)
continue;
pseries_eeh_phb_reset(phb, config_addr, EEH_RESET_FUNDAMENTAL);
pseries_eeh_phb_reset(phb, config_addr, EEH_RESET_DEACTIVATE);
pseries_eeh_phb_configure_bridge(phb, config_addr);
}
}
return 0;
}
@ -569,35 +736,13 @@ static int pseries_eeh_get_state(struct eeh_pe *pe, int *delay)
static int pseries_eeh_reset(struct eeh_pe *pe, int option)
{
int config_addr;
int ret;
/* Figure out PE address */
config_addr = pe->config_addr;
if (pe->addr)
config_addr = pe->addr;
/* Reset PE through RTAS call */
ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
config_addr, BUID_HI(pe->phb->buid),
BUID_LO(pe->phb->buid), option);
/* If fundamental-reset not supported, try hot-reset */
if (option == EEH_RESET_FUNDAMENTAL &&
ret == -8) {
option = EEH_RESET_HOT;
ret = rtas_call(ibm_set_slot_reset, 4, 1, NULL,
config_addr, BUID_HI(pe->phb->buid),
BUID_LO(pe->phb->buid), option);
}
/* We need reset hold or settlement delay */
if (option == EEH_RESET_FUNDAMENTAL ||
option == EEH_RESET_HOT)
msleep(EEH_PE_RST_HOLD_TIME);
else
msleep(EEH_PE_RST_SETTLE_TIME);
return ret;
return pseries_eeh_phb_reset(pe->phb, config_addr, option);
}
/**
@ -641,56 +786,17 @@ static int pseries_eeh_get_log(struct eeh_pe *pe, int severity, char *drv_log, u
* pseries_eeh_configure_bridge - Configure PCI bridges in the indicated PE
* @pe: EEH PE
*
* The function will be called to reconfigure the bridges included
* in the specified PE so that the mulfunctional PE would be recovered
* again.
*/
static int pseries_eeh_configure_bridge(struct eeh_pe *pe)
{
int config_addr;
int ret;
/* Waiting 0.2s maximum before skipping configuration */
int max_wait = 200;
/* Figure out the PE address */
config_addr = pe->config_addr;
if (pe->addr)
config_addr = pe->addr;
while (max_wait > 0) {
ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
config_addr, BUID_HI(pe->phb->buid),
BUID_LO(pe->phb->buid));
if (!ret)
return ret;
if (ret < 0)
break;
/*
* If RTAS returns a delay value that's above 100ms, cut it
* down to 100ms in case firmware made a mistake. For more
* on how these delay values work see rtas_busy_delay_time
*/
if (ret > RTAS_EXTENDED_DELAY_MIN+2 &&
ret <= RTAS_EXTENDED_DELAY_MAX)
ret = RTAS_EXTENDED_DELAY_MIN+2;
max_wait -= rtas_busy_delay_time(ret);
if (max_wait < 0)
break;
rtas_busy_delay(ret);
}
pr_warn("%s: Unable to configure bridge PHB#%x-PE#%x (%d)\n",
__func__, pe->phb->global_number, pe->addr, ret);
/* PAPR defines -3 as "Parameter Error" for this function: */
if (ret == -3)
return -EINVAL;
else
return -EIO;
return pseries_eeh_phb_configure_bridge(pe->phb, config_addr);
}
/**