[PATCH v4 09/21] powerpc/powernv: Use PCI slot reset infrastructure
Gavin Shan
gwshan at linux.vnet.ibm.com
Mon May 11 16:45:47 AEST 2015
On Sat, May 09, 2015 at 11:41:05PM +1000, Alexey Kardashevskiy wrote:
>On 05/01/2015 04:02 PM, Gavin Shan wrote:
>>For PowerNV platform, running on top of skiboot, all PE level reset
>>should be routed to firmware if the bridge of the PE primary bus has
>>device-node property "ibm,reset-by-firmware". Otherwise, the kernel
>>has to issue hot reset on PE's primary bus despite the requested reset
>>types, which is the behaviour before the firmware supports PCI slot
>>reset. So the changes don't depend on the PCI slot reset capability
>>exposed from the firmware.
>>
>>Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
>>---
>> arch/powerpc/include/asm/eeh.h | 1 +
>> arch/powerpc/include/asm/opal.h | 4 +-
>> arch/powerpc/platforms/powernv/eeh-powernv.c | 206 +++++++++++++--------------
>> 3 files changed, 102 insertions(+), 109 deletions(-)
>>
>>diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
>>index c5eb86f..2793d24 100644
>>--- a/arch/powerpc/include/asm/eeh.h
>>+++ b/arch/powerpc/include/asm/eeh.h
>>@@ -190,6 +190,7 @@ enum {
>> #define EEH_RESET_DEACTIVATE 0 /* Deactivate the PE reset */
>> #define EEH_RESET_HOT 1 /* Hot reset */
>> #define EEH_RESET_FUNDAMENTAL 3 /* Fundamental reset */
>>+#define EEH_RESET_COMPLETE 4 /* PHB complete reset */
>> #define EEH_LOG_TEMP 1 /* EEH temporary error log */
>> #define EEH_LOG_PERM 2 /* EEH permanent error log */
>>
>>diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
>>index 042af1a..6d467df 100644
>>--- a/arch/powerpc/include/asm/opal.h
>>+++ b/arch/powerpc/include/asm/opal.h
>>@@ -129,7 +129,7 @@ int64_t opal_pci_map_pe_dma_window(uint64_t phb_id, uint16_t pe_number, uint16_t
>> int64_t opal_pci_map_pe_dma_window_real(uint64_t phb_id, uint16_t pe_number,
>> uint16_t dma_window_number, uint64_t pci_start_addr,
>> uint64_t pci_mem_size);
>>-int64_t opal_pci_reset(uint64_t phb_id, uint8_t reset_scope, uint8_t assert_state);
>>+int64_t opal_pci_reset(uint64_t id, uint8_t reset_scope, uint8_t assert_state);
>>
>> int64_t opal_pci_get_hub_diag_data(uint64_t hub_id, void *diag_buffer,
>> uint64_t diag_buffer_len);
>>@@ -145,7 +145,7 @@ int64_t opal_get_epow_status(__be64 *status);
>> int64_t opal_set_system_attention_led(uint8_t led_action);
>> int64_t opal_pci_next_error(uint64_t phb_id, __be64 *first_frozen_pe,
>> __be16 *pci_error_type, __be16 *severity);
>>-int64_t opal_pci_poll(uint64_t phb_id);
>>+int64_t opal_pci_poll(uint64_t id, uint8_t *val);
>> int64_t opal_return_cpu(void);
>> int64_t opal_check_token(uint64_t token);
>> int64_t opal_reinit_cpus(uint64_t flags);
>>diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
>>index ce738ab..3c01095 100644
>>--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
>>+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
>>@@ -742,12 +742,12 @@ static int pnv_eeh_get_state(struct eeh_pe *pe, int *delay)
>> return ret;
>> }
>>
>>-static s64 pnv_eeh_phb_poll(struct pnv_phb *phb)
>>+static s64 pnv_eeh_poll(uint64_t id)
>> {
>> s64 rc = OPAL_HARDWARE;
>>
>> while (1) {
>>- rc = opal_pci_poll(phb->opal_id);
>>+ rc = opal_pci_poll(id, NULL);
>> if (rc <= 0)
>> break;
>>
>>@@ -763,84 +763,38 @@ static s64 pnv_eeh_phb_poll(struct pnv_phb *phb)
>> int pnv_eeh_phb_reset(struct pci_controller *hose, int option)
>> {
>> struct pnv_phb *phb = hose->private_data;
>>+ uint8_t scope;
>> s64 rc = OPAL_HARDWARE;
>>
>> pr_debug("%s: Reset PHB#%x, option=%d\n",
>> __func__, hose->global_number, option);
>>-
>>- /* Issue PHB complete reset request */
>>- if (option == EEH_RESET_FUNDAMENTAL ||
>>- option == EEH_RESET_HOT)
>>- rc = opal_pci_reset(phb->opal_id,
>>- OPAL_RESET_PHB_COMPLETE,
>>- OPAL_ASSERT_RESET);
>>- else if (option == EEH_RESET_DEACTIVATE)
>>- rc = opal_pci_reset(phb->opal_id,
>>- OPAL_RESET_PHB_COMPLETE,
>>- OPAL_DEASSERT_RESET);
>>- if (rc < 0)
>>- goto out;
>>-
>>- /*
>>- * Poll state of the PHB until the request is done
>>- * successfully. The PHB reset is usually PHB complete
>>- * reset followed by hot reset on root bus. So we also
>>- * need the PCI bus settlement delay.
>>- */
>>- rc = pnv_eeh_phb_poll(phb);
>>- if (option == EEH_RESET_DEACTIVATE) {
>>- if (system_state < SYSTEM_RUNNING)
>>- udelay(1000 * EEH_PE_RST_SETTLE_TIME);
>>- else
>>- msleep(EEH_PE_RST_SETTLE_TIME);
>
>
>These udelay() and msleep() are gone. How come they are not needed anymore?
>Worth commenting in the commit log or remove those in a separate patch.
>
>I just remember you mentioning some missing delays somewhere which caused
>NVIDIA device to issue EEH and I do not want those to disappear :)
>
Yeah, I think you're correct that it's not safe to remove this yet because
the old firmware (without corresponding PCI hotplug changes) doesn't have
the required delays from opal_pci_poll() yet. I'll add this in next revision.
>
>>+ switch (option) {
>>+ case EEH_RESET_HOT:
>>+ scope = OPAL_RESET_PCI_HOT;
>>+ break;
>>+ case EEH_RESET_FUNDAMENTAL:
>>+ scope = OPAL_RESET_PCI_FUNDAMENTAL;
>>+ break;
>>+ case EEH_RESET_COMPLETE:
>>+ scope = OPAL_RESET_PHB_COMPLETE;
>>+ break;
>>+ case EEH_RESET_DEACTIVATE:
>>+ return 0;
>>+ default:
>>+ pr_warn("%s: Unsupported option %d\n",
>>+ __func__, option);
>>+ return -EINVAL;
>> }
>>-out:
>>- if (rc != OPAL_SUCCESS)
>>- return -EIO;
>>
>>- return 0;
>>-}
>>-
>>-static int pnv_eeh_root_reset(struct pci_controller *hose, int option)
>>-{
>>- struct pnv_phb *phb = hose->private_data;
>>- s64 rc = OPAL_HARDWARE;
>>+ /* Issue reset and poll until it's completed */
>>+ rc = opal_pci_reset(phb->opal_id, scope, OPAL_ASSERT_RESET);
>>+ if (rc > 0)
>>+ rc = pnv_eeh_poll(phb->opal_id);
>>
>>- pr_debug("%s: Reset PHB#%x, option=%d\n",
>>- __func__, hose->global_number, option);
>>-
>>- /*
>>- * During the reset deassert time, we needn't care
>>- * the reset scope because the firmware does nothing
>>- * for fundamental or hot reset during deassert phase.
>>- */
>>- if (option == EEH_RESET_FUNDAMENTAL)
>>- rc = opal_pci_reset(phb->opal_id,
>>- OPAL_RESET_PCI_FUNDAMENTAL,
>>- OPAL_ASSERT_RESET);
>>- else if (option == EEH_RESET_HOT)
>>- rc = opal_pci_reset(phb->opal_id,
>>- OPAL_RESET_PCI_HOT,
>>- OPAL_ASSERT_RESET);
>>- else if (option == EEH_RESET_DEACTIVATE)
>>- rc = opal_pci_reset(phb->opal_id,
>>- OPAL_RESET_PCI_HOT,
>>- OPAL_DEASSERT_RESET);
>>- if (rc < 0)
>>- goto out;
>>-
>>- /* Poll state of the PHB until the request is done */
>>- rc = pnv_eeh_phb_poll(phb);
>>- if (option == EEH_RESET_DEACTIVATE)
>>- msleep(EEH_PE_RST_SETTLE_TIME);
>>-out:
>>- if (rc != OPAL_SUCCESS)
>>- return -EIO;
>>-
>>- return 0;
>>+ return (rc == OPAL_SUCCESS) ? 0 : -EIO;
>> }
>>
>>-static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option)
>>+static int __pnv_eeh_bridge_reset(struct pci_dev *dev, int option)
>> {
>> struct pci_dn *pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
>> struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
>>@@ -891,14 +845,57 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option)
>> return 0;
>> }
>>
>>+static int pnv_eeh_bridge_reset(struct pci_dev *dev, int option)
>>+{
>>+ struct pci_controller *hose;
>>+ struct pnv_phb *phb;
>>+ struct device_node *dn = dev ? pci_device_to_OF_node(dev) : NULL;
>>+ uint64_t id = (0x1ul << 60);
>>+ uint8_t scope;
>>+ s64 rc;
>
>
>int64_t for @rc?
>
>
Yes.
>>+
>>+ /*
>>+ * If the firmware can't handle it, we will issue hot reset
>>+ * on the secondary bus despite the requested reset type
>>+ */
>>+ if (!dn || !of_get_property(dn, "ibm,reset-by-firmware", NULL))
>>+ return __pnv_eeh_bridge_reset(dev, option);
>>+
>>+ /* The firmware can handle the request */
>>+ switch (option) {
>>+ case EEH_RESET_HOT:
>>+ scope = OPAL_RESET_PCI_HOT;
>>+ break;
>>+ case EEH_RESET_FUNDAMENTAL:
>>+ scope = OPAL_RESET_PCI_FUNDAMENTAL;
>>+ break;
>>+ case EEH_RESET_DEACTIVATE:
>>+ return 0;
>>+ case EEH_RESET_COMPLETE:
>>+ default:
>>+ pr_warn("%s: Unsupported option %d on device %s\n",
>>+ __func__, option, pci_name(dev));
>>+ return -EINVAL;
>>+ }
>
>
>This is the same switch as earlier in this patch (slightly different order).
>Move it and opal_pci_reset() into a helper and call it pnv_opal_pci_reset()?
>
>
It sounds a good idea. I'll do accordingly.
>>+
>>+ hose = pci_bus_to_host(dev->bus);
>>+ phb = hose->private_data;
>
>Previously you would initialize @hose and @phb where you declared those but
>not here. If you did the same thing as before, the patch could have been
>smaller and easier to read.
>
Sure.
>>+ id |= (dev->bus->number << 24) | (dev->devfn << 16) | phb->opal_id;
>>+ rc = opal_pci_reset(id, scope, OPAL_ASSERT_RESET);
>>+ if (rc > 0)
>>+ rc = pnv_eeh_poll(id);
>>+
>>+ return (rc == OPAL_SUCCESS) ? 0 : -EIO;
>>+}
>>+
>> void pnv_pci_reset_secondary_bus(struct pci_dev *dev)
>> {
>> struct pci_controller *hose;
>>
>> if (pci_is_root_bus(dev->bus)) {
>> hose = pci_bus_to_host(dev->bus);
>>- pnv_eeh_root_reset(hose, EEH_RESET_HOT);
>>- pnv_eeh_root_reset(hose, EEH_RESET_DEACTIVATE);
>>+ pnv_eeh_phb_reset(hose, EEH_RESET_HOT);
>>+ pnv_eeh_phb_reset(hose, EEH_RESET_DEACTIVATE);
>> } else {
>> pnv_eeh_bridge_reset(dev, EEH_RESET_HOT);
>> pnv_eeh_bridge_reset(dev, EEH_RESET_DEACTIVATE);
>>@@ -920,8 +917,9 @@ void pnv_pci_reset_secondary_bus(struct pci_dev *dev)
>> static int pnv_eeh_reset(struct eeh_pe *pe, int option)
>> {
>> struct pci_controller *hose = pe->phb;
>>+ struct pnv_phb *phb;
>> struct pci_bus *bus;
>>- int ret;
>>+ s64 rc;
>>
>> /*
>> * For PHB reset, we always have complete reset. For those PEs whose
>>@@ -937,43 +935,37 @@ static int pnv_eeh_reset(struct eeh_pe *pe, int option)
>> * reset. The side effect is that EEH core has to clear the frozen
>> * state explicitly after BAR restore.
>> */
>>- if (pe->type & EEH_PE_PHB) {
>>- ret = pnv_eeh_phb_reset(hose, option);
>>- } else {
>>- struct pnv_phb *phb;
>>- s64 rc;
>>+ if (pe->type & EEH_PE_PHB)
>
>I would keep "{" in the line above ....
>
>>+ return pnv_eeh_phb_reset(hose, EEH_RESET_COMPLETE);
>
>...put "} else {" here...
>
>and the chunk below would become 1) very small 2) very trivial... And then
>you could make a trivial patch which would do scope removal but without
>functional changes. Or vice versa.
>
I intended to remove nested if(). If you really want me to change the code
according to your comments, I'll do. Otherwise, I prefer to keep it as
of being.
>>
>>- /*
>>- * The frozen PE might be caused by PAPR error injection
>>- * registers, which are expected to be cleared after hitting
>>- * frozen PE as stated in the hardware spec. Unfortunately,
>>- * that's not true on P7IOC. So we have to clear it manually
>>- * to avoid recursive EEH errors during recovery.
>>- */
>>- phb = hose->private_data;
>>- if (phb->model == PNV_PHB_MODEL_P7IOC &&
>>- (option == EEH_RESET_HOT ||
>>- option == EEH_RESET_FUNDAMENTAL)) {
>>- rc = opal_pci_reset(phb->opal_id,
>>- OPAL_RESET_PHB_ERROR,
>>- OPAL_ASSERT_RESET);
>>- if (rc != OPAL_SUCCESS) {
>>- pr_warn("%s: Failure %lld clearing "
>>- "error injection registers\n",
>>- __func__, rc);
>>- return -EIO;
>>- }
>>+ /*
>>+ * The frozen PE might be caused by PAPR error injection
>>+ * registers, which are expected to be cleared after hitting
>>+ * frozen PE as stated in the hardware spec. Unfortunately,
>>+ * that's not true on P7IOC. So we have to clear it manually
>>+ * to avoid recursive EEH errors during recovery.
>>+ */
>>+ phb = hose->private_data;
>>+ if (phb->model == PNV_PHB_MODEL_P7IOC &&
>>+ (option == EEH_RESET_HOT ||
>>+ option == EEH_RESET_FUNDAMENTAL)) {
>>+ rc = opal_pci_reset(phb->opal_id,
>>+ OPAL_RESET_PHB_ERROR,
>>+ OPAL_ASSERT_RESET);
>>+ if (rc != OPAL_SUCCESS) {
>>+ pr_warn("%s: Failure %lld clearing error "
>>+ "injection registers on PHB#%d\n",
>>+ __func__, rc, hose->global_number);
>>+ return -EIO;
>> }
>>-
>>- bus = eeh_pe_bus_get(pe);
>>- if (pci_is_root_bus(bus) ||
>>- pci_is_root_bus(bus->parent))
>>- ret = pnv_eeh_root_reset(hose, option);
>>- else
>>- ret = pnv_eeh_bridge_reset(bus->self, option);
>> }
>>
>>- return ret;
>>+ /* Route the reset request to PHB or upstream bridge */
>>+ bus = eeh_pe_bus_get(pe);
>>+ if (pci_is_root_bus(bus))
>>+ return pnv_eeh_phb_reset(hose, option);
>>+
>>+ return pnv_eeh_bridge_reset(bus->self, option);
>> }
>>
>> /**
>>
Thanks,
Gavin
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