powerpc/eeh: I/O chip EEH state retrieval

The patch adds I/O chip backend to retrieve the state for the
indicated PE. While the PE state is temperarily unavailable,
the upper layer (powernv platform) should return default delay
(1 second).

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 98 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/powernv/eeh-ioda.c b/arch/powerpc/platforms/powernv/eeh-ioda.c
index 744eb9e39be2..a76870b6a184 100644
--- a/arch/powerpc/platforms/powernv/eeh-ioda.c
+++ b/arch/powerpc/platforms/powernv/eeh-ioda.c
@@ -116,10 +116,107 @@ static int ioda_eeh_set_option(struct eeh_pe *pe, int option)
         return ret;
 }
 
+/**
+ * ioda_eeh_get_state - Retrieve the state of PE
+ * @pe: EEH PE
+ *
+ * The PE's state should be retrieved from the PEEV, PEST
+ * IODA tables. Since the OPAL has exported the function
+ * to do it, it'd better to use that.
+ */
+static int ioda_eeh_get_state(struct eeh_pe *pe)
+{
+        s64 ret = 0;
+        u8 fstate;
+        u16 pcierr;
+        u32 pe_no;
+        int result;
+        struct pci_controller *hose = pe->phb;
+        struct pnv_phb *phb = hose->private_data;
+
+        /*
+         * Sanity check on PE address. The PHB PE address should
+         * be zero.
+         */
+        if (pe->addr < 0 || pe->addr >= phb->ioda.total_pe) {
+                pr_err("%s: PE address %x out of range [0, %x] "
+                       "on PHB#%x\n",
+                       __func__, pe->addr, phb->ioda.total_pe,
+                       hose->global_number);
+                return EEH_STATE_NOT_SUPPORT;
+        }
+
+        /* Retrieve PE status through OPAL */
+        pe_no = pe->addr;
+        ret = opal_pci_eeh_freeze_status(phb->opal_id, pe_no,
+                        &fstate, &pcierr, NULL);
+        if (ret) {
+                pr_err("%s: Failed to get EEH status on "
+                       "PHB#%x-PE#%x\n, err=%lld\n",
+                       __func__, hose->global_number, pe_no, ret);
+                return EEH_STATE_NOT_SUPPORT;
+        }
+
+        /* Check PHB status */
+        if (pe->type & EEH_PE_PHB) {
+                result = 0;
+                result &= ~EEH_STATE_RESET_ACTIVE;
+
+                if (pcierr != OPAL_EEH_PHB_ERROR) {
+                        result |= EEH_STATE_MMIO_ACTIVE;
+                        result |= EEH_STATE_DMA_ACTIVE;
+                        result |= EEH_STATE_MMIO_ENABLED;
+                        result |= EEH_STATE_DMA_ENABLED;
+                }
+
+                return result;
+        }
+
+        /* Parse result out */
+        result = 0;
+        switch (fstate) {
+        case OPAL_EEH_STOPPED_NOT_FROZEN:
+                result &= ~EEH_STATE_RESET_ACTIVE;
+                result |= EEH_STATE_MMIO_ACTIVE;
+                result |= EEH_STATE_DMA_ACTIVE;
+                result |= EEH_STATE_MMIO_ENABLED;
+                result |= EEH_STATE_DMA_ENABLED;
+                break;
+        case OPAL_EEH_STOPPED_MMIO_FREEZE:
+                result &= ~EEH_STATE_RESET_ACTIVE;
+                result |= EEH_STATE_DMA_ACTIVE;
+                result |= EEH_STATE_DMA_ENABLED;
+                break;
+        case OPAL_EEH_STOPPED_DMA_FREEZE:
+                result &= ~EEH_STATE_RESET_ACTIVE;
+                result |= EEH_STATE_MMIO_ACTIVE;
+                result |= EEH_STATE_MMIO_ENABLED;
+                break;
+        case OPAL_EEH_STOPPED_MMIO_DMA_FREEZE:
+                result &= ~EEH_STATE_RESET_ACTIVE;
+                break;
+        case OPAL_EEH_STOPPED_RESET:
+                result |= EEH_STATE_RESET_ACTIVE;
+                break;
+        case OPAL_EEH_STOPPED_TEMP_UNAVAIL:
+                result |= EEH_STATE_UNAVAILABLE;
+                break;
+        case OPAL_EEH_STOPPED_PERM_UNAVAIL:
+                result |= EEH_STATE_NOT_SUPPORT;
+                break;
+        default:
+                pr_warning("%s: Unexpected EEH status 0x%x "
+                           "on PHB#%x-PE#%x\n",
+                           __func__, fstate, hose->global_number, pe_no);
+        }
+
+        return result;
+}
+
 struct pnv_eeh_ops ioda_eeh_ops = {
         .post_init              = ioda_eeh_post_init,
         .set_option             = ioda_eeh_set_option,
-        .get_state              = NULL,
+        .get_state              = ioda_eeh_get_state,
         .reset                  = NULL,
         .get_log                = NULL,
         .configure_bridge       = NULL,