On Mon, May 04, 2015 at 03:07:36PM +0800, Wei Yang wrote:
>Before VF PE introduced, there isn't a method to reset an individual pci
             ^                                                        ^^^
             is                                                       PCI

>function. And since FW is not aware of the VF, the VF's reset should be
                     ^^
                    skiboot firmware

>done in kernel.
>
>This patch introduce a pnv_eeh_vf_pe_reset() to do the flr or af_flr to a
            ^^^^^^^^^  ^                                ^^^    ^^^^^^
            introduces function                         FLR    AF FLR
>VF.
>
>Signed-off-by: Wei Yang <weiy...@linux.vnet.ibm.com>
>---
> arch/powerpc/include/asm/eeh.h               |    1 +
> arch/powerpc/platforms/powernv/eeh-powernv.c |  111 +++++++++++++++++++++++++-
> 2 files changed, 111 insertions(+), 1 deletion(-)
>
>diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
>index 2067de4..78c8bec 100644
>--- a/arch/powerpc/include/asm/eeh.h
>+++ b/arch/powerpc/include/asm/eeh.h
>@@ -135,6 +135,7 @@ struct eeh_dev {
>       int pcix_cap;                   /* Saved PCIx capability        */
>       int pcie_cap;                   /* Saved PCIe capability        */
>       int aer_cap;                    /* Saved AER capability         */
>+      int af_cap;                     /* Saved AF capability          */
>       struct eeh_pe *pe;              /* Associated PE                */
>       struct list_head list;          /* Form link list in the PE     */
>       struct pci_controller *phb;     /* Associated PHB               */
>diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c 
>b/arch/powerpc/platforms/powernv/eeh-powernv.c
>index 5447481..1ad322f 100644
>--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
>+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
>@@ -402,6 +402,7 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
>       edev->pcix_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_PCIX);
>       edev->pcie_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_EXP);
>       edev->aer_cap  = pnv_eeh_find_ecap(pdn, PCI_EXT_CAP_ID_ERR);
>+      edev->af_cap   = pnv_eeh_find_cap(pdn, PCI_CAP_ID_AF);
>       if ((edev->class_code >> 8) == PCI_CLASS_BRIDGE_PCI) {
>               edev->mode |= EEH_DEV_BRIDGE;
>               if (edev->pcie_cap) {
>@@ -891,6 +892,105 @@ static int pnv_eeh_bridge_reset(struct pci_dev *dev, int 
>option)
>       return 0;
> }
>
>+static int pnv_pci_wait_for_pending(struct pci_dn *pdn, int pos, u16 mask)
>+{
>+      int i;
>+
>+      /* Wait for Transaction Pending bit clean */
>+      for (i = 0; i < 4; i++) {
>+              u32 status;
>+              if (i)
>+                      msleep((1 << (i - 1)) * 100);
>+
>+              eeh_ops->read_config(pdn, pos, 2, &status);
>+              if (!(status & mask))
>+                      return 1;
>+      }
>+
>+      return 0;
>+}
>+
>+static int pnv_eeh_do_flr(struct pci_dn *pdn)
>+{
>+      u32 cap;
>+      struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
>+
>+      eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCAP, 4, &cap);
>+      if (!(cap & PCI_EXP_DEVCAP_FLR))
>+              return -ENOTTY;
>+
>+      if (!pnv_pci_wait_for_pending(pdn, edev->pcie_cap + PCI_EXP_DEVSTA, 
>PCI_EXP_DEVSTA_TRPND))
>+              pr_err("%04x:%02x:%02x:%01x timed out waiting for pending 
>transaction; performing function level reset anyway\n",
>+                      edev->phb->global_number, pdn->busno,
>+                      PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
>+

It's breaking the limitation that each line has 80 columns to maximal degree.

>+      eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, 4, &cap);
>+      cap |= PCI_EXP_DEVCTL_BCR_FLR;
>+      eeh_ops->write_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, 4, cap);
>+      msleep(100);
>+      return 0;
>+}
>+
>+static int pnv_eeh_do_af_flr(struct pci_dn *pdn)
>+{
>+      u32 cap;
>+      struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
>+
>+      if (!edev->af_cap)
>+              return -ENOTTY;
>+
>+      eeh_ops->read_config(pdn, edev->af_cap + PCI_AF_CAP, 1, &cap);
>+      if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
>+              return -ENOTTY;

Why not cache af_cap is it really support reset during probe time? With
that, you don't have the check.

>+
>+      /*
>+       * Wait for Transaction Pending bit to clear.  A word-aligned test
>+       * is used, so we use the conrol offset rather than status and shift
>+       * the test bit to match.
>+       */
>+      if (!pnv_pci_wait_for_pending(pdn, edev->af_cap + PCI_AF_CTRL,
>+                               PCI_AF_STATUS_TP << 8))
>+              pr_err("%04x:%02x:%02x:%01x timed out waiting for pending 
>transaction; performing AF function level reset anyway\n",
>+                      edev->phb->global_number, pdn->busno,
>+                      PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
>+

It's breaking the limitation that each line has 80 columns.

>+      eeh_ops->write_config(pdn, edev->af_cap + PCI_AF_CTRL, 1, 
>PCI_AF_CTRL_FLR);
>+      msleep(100);
>+      return 0;
>+}
>+

Can you merge the above two functions to one (pnv_eeh_do_vf_reset())? 

>+static int pnv_eeh_reset_vf(struct pci_dn *pdn)
>+{
>+      int rc;
>+
>+      might_sleep();
>+
>+      rc = pnv_eeh_do_flr(pdn);
>+      if (rc != -ENOTTY)
>+              goto done;
>+
>+      rc = pnv_eeh_do_af_flr(pdn);
>+      if (rc != -ENOTTY)
>+              goto done;
>+
>+done:
>+      return rc;
>+}
>+
>+static int pnv_eeh_vf_pe_reset(struct eeh_pe *pe, int option)
>+{
>+      struct eeh_dev *edev, *tmp;
>+      struct pci_dn *pdn;
>+      int ret = 0;
>+

Why you ignore "option" here? In that case, the PE will be resetted
for twice at asserting/deasserting time.

>+      eeh_pe_for_each_dev(pe, edev, tmp) {
>+              pdn = eeh_dev_to_pdn(edev);
>+              ret |= pnv_eeh_reset_vf(pdn);

When hitting error from reset on one VF, you don't need proceed, no?

>+      }
>+
>+      return ret;
>+}
>+
> void pnv_pci_reset_secondary_bus(struct pci_dev *dev)
> {
>       struct pci_controller *hose;
>@@ -966,7 +1066,9 @@ static int pnv_eeh_reset(struct eeh_pe *pe, int option)
>               }
>
>               bus = eeh_pe_bus_get(pe);
>-              if (pci_is_root_bus(bus) ||
>+              if (pe->type & EEH_PE_VF)
>+                      ret = pnv_eeh_vf_pe_reset(pe, option);
>+              else if (pci_is_root_bus(bus) ||
>                       pci_is_root_bus(bus->parent))
>                       ret = pnv_eeh_root_reset(hose, option);
>               else
>@@ -1106,6 +1208,13 @@ static inline bool pnv_eeh_cfg_blocked(struct pci_dn 
>*pdn)
>       if (!edev || !edev->pe)
>               return false;
>
>+      /*
>+       * For VF's reset operation, we need to rely on the kernel to
>+       * do those pci read/write, since FW isn't aware of VFs.
              ^^^^^^^^^^^^^^^^^^^^

              PCI config operations since firmware isn't aware of VFs.

>+       */
>+      if ((edev->mode & EEH_DEV_VF) && (edev->pe->state & EEH_PE_RESET))
>+              return true;
>+

Hrm, did you test the code? The PCI config is blocked when issuing reset
to VF PE. "false" should be returned here, isn't it?

>       if (edev->pe->state & EEH_PE_CFG_BLOCKED)
>               return true;
>

Thanks,
Gavin

_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Reply via email to