eeh_pe_reset and eeh_reset_pe are two different functions in the same
file which do mostly the same thing. Not only is this confusing, but
potentially causes disrepancies in functionality, notably eeh_reset_pe
as it does not check return values for failure.
Refactor this into the following:
- eeh_pe_reset(): stays as is, performs a single operation, exported
- eeh_pe_reset_full(): new, full reset process that calls eeh_pe_reset()
- eeh_reset_pe(): removed and replaced by eeh_pe_reset_full()
- eeh_reset_pe_once(): removed
Signed-off-by: Russell Currey <rus...@russell.cc>
---
I'm not sure if this should go to stable. Apparently it fixes some bug by
checking returns, but I don't fully understand what the problem was or how
severe it is. Andrew (on CC) should know more.
Also the diff for this looks awful, much easier to read when applied
---
arch/powerpc/include/asm/ppc-pci.h | 2 +-
arch/powerpc/kernel/eeh.c | 82 +++++++++++++++++---------------------
arch/powerpc/kernel/eeh_driver.c | 4 +-
3 files changed, 40 insertions(+), 48 deletions(-)
diff --git a/arch/powerpc/include/asm/ppc-pci.h
b/arch/powerpc/include/asm/ppc-pci.h
index 0f73de0..7262880 100644
--- a/arch/powerpc/include/asm/ppc-pci.h
+++ b/arch/powerpc/include/asm/ppc-pci.h
@@ -53,7 +53,7 @@ void eeh_addr_cache_rmv_dev(struct pci_dev *dev);
struct eeh_dev *eeh_addr_cache_get_dev(unsigned long addr);
void eeh_slot_error_detail(struct eeh_pe *pe, int severity);
int eeh_pci_enable(struct eeh_pe *pe, int function);
-int eeh_reset_pe(struct eeh_pe *);
+int eeh_pe_reset_full(struct eeh_pe *pe);
void eeh_save_bars(struct eeh_dev *edev);
int rtas_write_config(struct pci_dn *, int where, int size, u32 val);
int rtas_read_config(struct pci_dn *, int where, int size, u32 *val);
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index f257316..ad743d3 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -808,76 +808,67 @@ static void *eeh_set_dev_freset(void *data, void *flag)
}
/**
- * eeh_reset_pe_once - Assert the pci #RST line for 1/4 second
+ * eeh_pe_reset_full - Complete a full reset process on the indicated PE
* @pe: EEH PE
*
- * Assert the PCI #RST line for 1/4 second.
+ * This function executes a full reset procedure on a PE, including setting
+ * the appropriate flags, performing a fundamental or hot reset, and then
+ * deactivating the reset status. It is designed to be used within the EEH
+ * subsystem, as opposed to eeh_pe_reset which is exported to drivers and
+ * only performs a single operation at a time.
+ *
+ * This function will attempt to reset a PE three times before failing.
*/
-static void eeh_reset_pe_once(struct eeh_pe *pe)
+int eeh_pe_reset_full(struct eeh_pe *pe)
{
+ int active_flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);
+ int reset_state = (EEH_PE_RESET | EEH_PE_CFG_BLOCKED);
+ int type = EEH_RESET_HOT;
unsigned int freset = 0;
+ int i, state, ret;
- /* Determine type of EEH reset required for
- * Partitionable Endpoint, a hot-reset (1)
- * or a fundamental reset (3).
- * A fundamental reset required by any device under
- * Partitionable Endpoint trumps hot-reset.
+ /*
+ * Determine the type of reset to perform - hot or fundamental.
+ * Hot reset is the default operation, unless any device under the
+ * PE requires a fundamental reset.
*/
eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset);
if (freset)
- eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL);
- else
- eeh_ops->reset(pe, EEH_RESET_HOT);
-
- eeh_ops->reset(pe, EEH_RESET_DEACTIVATE);
-}
-
-/**
- * eeh_reset_pe - Reset the indicated PE
- * @pe: EEH PE
- *
- * This routine should be called to reset indicated device, including
- * PE. A PE might include multiple PCI devices and sometimes PCI bridges
- * might be involved as well.
- */
-int eeh_reset_pe(struct eeh_pe *pe)
-{
- int flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);
- int i, state, ret;
+ type = EEH_RESET_FUNDAMENTAL;
- /* Mark as reset and block config space */
- eeh_pe_state_mark(pe, EEH_PE_RESET | EEH_PE_CFG_BLOCKED);
+ /* Mark the PE as in reset state and block config space accesses */
+ eeh_pe_state_mark(pe, reset_state);
- /* Take three shots at resetting the bus */
+ /* Make three attempts at resetting the bus */
for (i = 0; i < 3; i++) {
- eeh_reset_pe_once(pe);
+ ret = eeh_pe_reset(pe, type);
+ if (ret)
+ break;
- /*
- * EEH_PE_ISOLATED is expected to be removed after
- * BAR restore.
- */
+ ret = eeh_pe_reset(pe, EEH_RESET_DEACTIVATE);
+ if (ret)
+ break;
+
+ /* Wait until the PE is in a functioning state */
state = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
- if ((state & flags) == flags) {
- ret = 0;
- goto out;
- }
+ if ((state & active_flags) == active_flags)
+ break;
if (state < 0) {
- pr_warn("%s: Unrecoverable slot failure on
PHB#%d-PE#%x",
+ pr_warn("%s: Unrecoverable slot failure on
PHB#%x-PE#%d",
__func__, pe->phb->global_number, pe->addr);
ret = -ENOTRECOVERABLE;
- goto out;
+ break;
}
- /* We might run out of credits */
+ /* Set error in case this is our last attempt */
ret = -EIO;
- pr_warn("%s: Failure %d resetting PHB#%x-PE#%x\n (%d)\n",
+ pr_warn("%s: Failure %d resetting PHB#%x-PE#%d\n (%d)\n",
__func__, state, pe->phb->global_number, pe->addr, (i +
1));
}
-out:
- eeh_pe_state_clear(pe, EEH_PE_RESET | EEH_PE_CFG_BLOCKED);
+ eeh_pe_state_clear(pe, reset_state);
return ret;
}
@@ -1601,6 +1592,7 @@ static int eeh_pe_reenable_devices(struct eeh_pe *pe)
return eeh_unfreeze_pe(pe, true);
}
+
/**
* eeh_pe_reset - Issue PE reset according to specified type
* @pe: EEH PE
diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index a62be72..bb653f6 100644
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -588,7 +588,7 @@ int eeh_pe_reset_and_recover(struct eeh_pe *pe)
eeh_pe_dev_traverse(pe, eeh_dev_save_state, NULL);
/* Issue reset */
- ret = eeh_reset_pe(pe);
+ ret = eeh_pe_reset_full(pe);
if (ret) {
eeh_pe_state_clear(pe, EEH_PE_RECOVERING);
return ret;
@@ -659,7 +659,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct
pci_bus *bus,
* config accesses. So we prefer to block them. However, controlled
* PCI config accesses initiated from EEH itself are allowed.
*/
- rc = eeh_reset_pe(pe);
+ rc = eeh_pe_reset_full(pe);
if (rc)
return rc;
--
2.10.2
