[PATCH V4 07/11] powerpc/powernv: Support EEH reset for VFs
Gavin Shan
gwshan at linux.vnet.ibm.com
Fri May 15 17:12:00 AEST 2015
On Fri, May 15, 2015 at 01:46:22PM +0800, Wei Yang wrote:
>Before VF PE is introduced, there isn't a method to reset an individual PCI
>function. And since skiboot firmware is not aware of the VF, the VF's reset
>should be done in kernel.
>
>This patch introduces a function pnv_eeh_vf_pe_reset() to do the FLR or AF
>FLR to a VF.
>
>Signed-off-by: Wei Yang <weiyang at linux.vnet.ibm.com>
>---
> arch/powerpc/include/asm/eeh.h | 1 +
> arch/powerpc/platforms/powernv/eeh-powernv.c | 123 +++++++++++++++++++++++++-
> 2 files changed, 123 insertions(+), 1 deletion(-)
>
>diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
>index c1fde48..3d64cf3 100644
>--- a/arch/powerpc/include/asm/eeh.h
>+++ b/arch/powerpc/include/asm/eeh.h
>@@ -134,6 +134,7 @@ 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 31344a4..61f1a55 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 +892,117 @@ 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)
Could you change this function to something as below?
static bool pnv_eeh_wait_for_pending(struct pci_dn *pdn, int pos, u16 mask)
>+{
>+ int i;
u32 status;
int i;
You don't need the following "u32 status".
>+
>+ /* 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, int option)
>+{
>+ u32 cap;
>+ struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
>+
It's worthy to check if the device has PCIE cap though this function is
used by VFs who always have PCIE cap. However, it's still used for one
without PCIE cap.
>+ 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));
Please print the function name and simplify the log into following one.
Also, the connection symbol between device and function number would
be ".", not ":".
pr_warn("%s: Pending transaction while issuing FLR to "
"%04x:%02x:%02x.%01x",
__func__, .....);
>+
>+ eeh_ops->read_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, 4, &cap);
>+ if (option == EEH_RESET_DEACTIVATE)
>+ cap &= ~PCI_EXP_DEVCTL_BCR_FLR;
>+ else
>+ cap |= PCI_EXP_DEVCTL_BCR_FLR;
>+ eeh_ops->write_config(pdn, edev->pcie_cap + PCI_EXP_DEVCTL, 4, cap);
>+ msleep(100);
The hold and stablization delay has been standarized in EEH as below:
EEH_PE_RST_HOLD_TIME - After asserting reset
EEH_PE_RST_SETTLE_TIME - After deasserting reset
>+ return 0;
>+}
>+
>+static int pnv_eeh_do_af_flr(struct pci_dn *pdn, int option)
>+{
>+ 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;
>+
>+ /*
>+ * 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));
Same as above.
>+
>+ if (option == EEH_RESET_DEACTIVATE)
>+ eeh_ops->write_config(pdn, edev->af_cap + PCI_AF_CTRL, 1, 0);
>+ else
>+ eeh_ops->write_config(pdn, edev->af_cap + PCI_AF_CTRL, 1,
>+ PCI_AF_CTRL_FLR);
>+ msleep(100);
Same as above.
>+ return 0;
>+}
>+
>+static int pnv_eeh_reset_vf(struct pci_dn *pdn, int option)
>+{
>+ int rc;
>+
>+ might_sleep();
This can be removed safely. This function should be called from
"eehd" kernel thread. So we don't need the check.
>+
>+ rc = pnv_eeh_do_flr(pdn, option);
>+ if (rc != -ENOTTY)
>+ goto done;
>+
>+ rc = pnv_eeh_do_af_flr(pdn, option);
>+ if (rc != -ENOTTY)
>+ goto done;
>+
>+done:
>+ return rc;
>+}
You can avoid using unnecessary tag:
rc = pnv_eeh_do_flr();
if (!rc)
return rc;
rc = pnv_eeh_do_af_flr();
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;
>+
>+ eeh_pe_for_each_dev(pe, edev, tmp) {
>+ pdn = eeh_dev_to_pdn(edev);
>+ ret |= pnv_eeh_reset_vf(pdn, option);
>+ if (ret)
>+ return ret;
>+ }
>+
>+ return ret;
>+}
>+
> void pnv_pci_reset_secondary_bus(struct pci_dev *dev)
> {
> struct pci_controller *hose;
>@@ -966,7 +1078,9 @@ 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 +1220,13 @@ 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 config operations since firmware isn't aware of VFs.
>+ */
>+ if ((edev->physfn) && (edev->pe->state & EEH_PE_RESET))
>+ return false;
>+
> if (edev->pe->state & EEH_PE_CFG_BLOCKED)
> return true;
>
Thanks,
Gavin
More information about the Linuxppc-dev
mailing list