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powerpc/eeh: Cleanup eeh_pe_clear_frozen_state()

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The 'clear_sw_state' parameter for eeh_pe_clear_frozen_state() is
redundant because it has no effect (except in the rare case of a
hardware error part way through unfreezing a tree of PEs, where it
would dangerously allow partial de-isolation before returning
failure).

It is passed down to __eeh_pe_clear_frozen_state(), and from there to
eeh_unfreeze_pe(), where it causes EEH_PE_ISOLATED to be removed
from the state of each PE during the traversal.  However, when the
traversal finishes, EEH_PE_ISOLATED is unconditionally removed by a
call to eeh_pe_state_clear() regardless of the parameter's value.

So remove the flag and pass false to eeh_unfreeze_pe() (to avoid the
rare case described above, as it was before the flag was introduced).
Also, perform the recursion directly in the function and eliminate a
bit of boilerplate.

There should be no change in functionality, except as mentioned above.

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Sam Bobroff 2018-11-29 14:16:37 +11:00 committed by Michael Ellerman
parent 26b523356f
commit 3376cb91ed
1 changed files with 13 additions and 27 deletions
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40
arch/powerpc/kernel/eeh_driver.c
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@ -591,34 +591,20 @@ static void *eeh_pe_detach_dev(struct eeh_pe *pe, void *userdata)
* PE reset (for 3 times), we try to clear the frozen state
* for 3 times as well.
*/
static void *__eeh_clear_pe_frozen_state(struct eeh_pe *pe, void *flag)
static int eeh_clear_pe_frozen_state(struct eeh_pe *root)
{
bool clear_sw_state = *(bool *)flag;
int i, rc = 1;
struct eeh_pe *pe;
int i;
for (i = 0; rc && i < 3; i++)
rc = eeh_unfreeze_pe(pe, clear_sw_state);
/* Stop immediately on any errors */
if (rc) {
pr_warn("%s: Failure %d unfreezing PHB#%x-PE#%x\n",
__func__, rc, pe->phb->global_number, pe->addr);
return (void *)pe;
eeh_for_each_pe(root, pe) {
for (i = 0; i < 3; i++)
if (!eeh_unfreeze_pe(pe, false))
break;
if (i >= 3)
return -EIO;
}
return NULL;
}
static int eeh_clear_pe_frozen_state(struct eeh_pe *pe,
bool clear_sw_state)
{
void *rc;
rc = eeh_pe_traverse(pe, __eeh_clear_pe_frozen_state, &clear_sw_state);
if (!rc)
eeh_pe_state_clear(pe, EEH_PE_ISOLATED);
return rc ? -EIO : 0;
eeh_pe_state_clear(root, EEH_PE_ISOLATED);
return 0;
}
int eeh_pe_reset_and_recover(struct eeh_pe *pe)
@ -643,7 +629,7 @@ int eeh_pe_reset_and_recover(struct eeh_pe *pe)
}
/* Unfreeze the PE */
ret = eeh_clear_pe_frozen_state(pe, true);
ret = eeh_clear_pe_frozen_state(pe);
if (ret) {
eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
return ret;
@ -716,7 +702,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus,
eeh_pe_restore_bars(pe);
/* Clear frozen state */
rc = eeh_clear_pe_frozen_state(pe, false);
rc = eeh_clear_pe_frozen_state(pe);
if (rc) {
pci_unlock_rescan_remove();
return rc;