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powerpc/pseries/eeh: Handle RTAS delay requests in configure_bridge 

In the "ibm,configure-pe" and "ibm,configure-bridge" RTAS calls, the
spec states that values of 9900-9905 can be returned, indicating that
software should delay for 10^x (where x is the last digit, i.e. 990x)
milliseconds and attempt the call again. Currently, the kernel doesn't
know about this, and respecting it fixes some PCI failures when the
hypervisor is busy.

The delay is capped at 0.2 seconds.

Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Russell Currey <ruscur@russell.cc>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Russell Currey 2016-04-07 16:28:26 +10:00 committed by Michael Ellerman
parent 1a695a905c
commit 871e178e0f
1 changed files with 36 additions and 15 deletions
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51
arch/powerpc/platforms/pseries/eeh_pseries.c
View File

@ -615,29 +615,50 @@ 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;
/* Use new configure-pe function, if supported */
if (ibm_configure_pe != RTAS_UNKNOWN_SERVICE) {
ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
config_addr, BUID_HI(pe->phb->buid),
BUID_LO(pe->phb->buid));
} else if (ibm_configure_bridge != RTAS_UNKNOWN_SERVICE) {
ret = rtas_call(ibm_configure_bridge, 3, 1, NULL,
config_addr, BUID_HI(pe->phb->buid),
BUID_LO(pe->phb->buid));
} else {
return -EFAULT;
while (max_wait > 0) {
/* Use new configure-pe function, if supported */
if (ibm_configure_pe != RTAS_UNKNOWN_SERVICE) {
ret = rtas_call(ibm_configure_pe, 3, 1, NULL,
config_addr, BUID_HI(pe->phb->buid),
BUID_LO(pe->phb->buid));
} else if (ibm_configure_bridge != RTAS_UNKNOWN_SERVICE) {
ret = rtas_call(ibm_configure_bridge, 3, 1, NULL,
config_addr, BUID_HI(pe->phb->buid),
BUID_LO(pe->phb->buid));
} else {
return -EFAULT;
}
if (!ret)
return ret;
/*
* 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);
}
if (ret)
pr_warn("%s: Unable to configure bridge PHB#%d-PE#%x (%d)\n",
__func__, pe->phb->global_number, pe->addr, ret);
pr_warn("%s: Unable to configure bridge PHB#%d-PE#%x (%d)\n",
__func__, pe->phb->global_number, pe->addr, ret);
return ret;
}