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 <gws...@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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