[PATCH 4/5] powerpc/powernv: Cache PHB diag-data

[Gavin Shan <shangw@linux.vnet.ibm.com>]

EEH core tries to recover from fenced PHB or frozen PE. Unfortunately,
the log isn't consistent with the site because enabling IO path for
the frozen PE before collecting log would ruin the site. The patch
solves the problem to cache the PHB diag-data in advance with the
help of additional flag PNV_PHB_FLAG_DIAG to pnv_phb::flags.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/powernv/eeh-ioda.c |   65 ++++++++++++++++++-----------
 arch/powerpc/platforms/powernv/pci.c      |   21 ++++++----
 arch/powerpc/platforms/powernv/pci.h      |    1 +
 3 files changed, 55 insertions(+), 32 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/eeh-ioda.c b/arch/powerpc/platforms/powernv/eeh-ioda.c
index 04b4710..3ed8d22 100644
--- a/arch/powerpc/platforms/powernv/eeh-ioda.c
+++ b/arch/powerpc/platforms/powernv/eeh-ioda.c
@@ -114,6 +114,27 @@ DEFINE_SIMPLE_ATTRIBUTE(ioda_eeh_inbB_dbgfs_ops, ioda_eeh_inbB_dbgfs_get,
 			ioda_eeh_inbB_dbgfs_set, "0x%llx\n");
 #endif /* CONFIG_DEBUG_FS */
 
+static void ioda_eeh_phb_diag(struct pci_controller *hose)
+{
+	struct pnv_phb *phb = hose->private_data;
+	unsigned long flags;
+	long rc;
+
+	spin_lock_irqsave(&phb->lock, flags);
+
+	rc = opal_pci_get_phb_diag_data2(phb->opal_id, phb->diag.blob,
+					 PNV_PCI_DIAG_BUF_SIZE);
+	if (rc == OPAL_SUCCESS) {
+		phb->flags |= PNV_PHB_FLAG_DIAG;
+	} else {
+		pr_warn("%s: Can't get diag-data for PHB#%x (%ld)\n",
+			__func__, hose->global_number, rc);
+		phb->flags &= ~PNV_PHB_FLAG_DIAG;
+	}
+
+	spin_unlock_irqrestore(&phb->lock, flags);
+}
+
 /**
  * ioda_eeh_post_init - Chip dependent post initialization
  * @hose: PCI controller
@@ -272,6 +293,8 @@ static int ioda_eeh_get_state(struct eeh_pe *pe)
 			result |= EEH_STATE_DMA_ACTIVE;
 			result |= EEH_STATE_MMIO_ENABLED;
 			result |= EEH_STATE_DMA_ENABLED;
+		} else {
+			ioda_eeh_phb_diag(hose);
 		}
 
 		return result;
@@ -541,24 +564,13 @@ static int ioda_eeh_reset(struct eeh_pe *pe, int option)
 static int ioda_eeh_get_log(struct eeh_pe *pe, int severity,
 			    char *drv_log, unsigned long len)
 {
-	s64 ret;
+	struct pnv_phb *phb = pe->phb->private_data;
 	unsigned long flags;
-	struct pci_controller *hose = pe->phb;
-	struct pnv_phb *phb = hose->private_data;
 
 	spin_lock_irqsave(&phb->lock, flags);
 
-	ret = opal_pci_get_phb_diag_data2(phb->opal_id,
-			phb->diag.blob, PNV_PCI_DIAG_BUF_SIZE);
-	if (ret) {
-		spin_unlock_irqrestore(&phb->lock, flags);
-		pr_warning("%s: Can't get log for PHB#%x-PE#%x (%lld)\n",
-			   __func__, hose->global_number, pe->addr, ret);
-		return -EIO;
-	}
-
-	/* The PHB diag-data is always indicative */
-	pnv_pci_dump_phb_diag_data(hose, phb->diag.blob);
+	pnv_pci_dump_phb_diag_data(pe->phb, phb->diag.blob);
+	phb->flags &= ~PNV_PHB_FLAG_DIAG;
 
 	spin_unlock_irqrestore(&phb->lock, flags);
 
@@ -646,19 +658,11 @@ static void ioda_eeh_hub_diag(struct pci_controller *hose)
 	}
 }
 
-static void ioda_eeh_phb_diag(struct pci_controller *hose)
+static void ioda_eeh_phb_diag_dump(struct pci_controller *hose)
 {
 	struct pnv_phb *phb = hose->private_data;
-	long rc;
-
-	rc = opal_pci_get_phb_diag_data2(phb->opal_id, phb->diag.blob,
-					 PNV_PCI_DIAG_BUF_SIZE);
-	if (rc != OPAL_SUCCESS) {
-		pr_warning("%s: Failed to get diag-data for PHB#%x (%ld)\n",
-			    __func__, hose->global_number, rc);
-		return;
-	}
 
+	ioda_eeh_phb_diag(hose);
 	pnv_pci_dump_phb_diag_data(hose, phb->diag.blob);
 }
 
@@ -778,7 +782,7 @@ static int ioda_eeh_next_error(struct eeh_pe **pe)
 				pr_info("EEH: PHB#%x informative error "
 					"detected\n",
 					hose->global_number);
-				ioda_eeh_phb_diag(hose);
+				ioda_eeh_phb_diag_dump(hose);
 				ret = EEH_NEXT_ERR_NONE;
 			}
 
@@ -809,6 +813,17 @@ static int ioda_eeh_next_error(struct eeh_pe **pe)
 		}
 
 		/*
+		 * EEH core will try recover from fenced PHB or
+		 * frozen PE. In the time for frozen PE, EEH core
+		 * enable IO path for that before collecting logs,
+		 * but it ruins the site. So we have to cache the
+		 * log in advance here.
+		 */
+		if (ret == EEH_NEXT_ERR_FROZEN_PE ||
+		    ret == EEH_NEXT_ERR_FENCED_PHB)
+			ioda_eeh_phb_diag(hose);
+
+		/*
 		 * If we have no errors on the specific PHB or only
 		 * informative error there, we continue poking it.
 		 * Otherwise, we need actions to be taken by upper
diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index 437c37d..67b2254 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -259,11 +259,15 @@ static void pnv_pci_dump_phb3_diag_data(struct pci_controller *hose,
 void pnv_pci_dump_phb_diag_data(struct pci_controller *hose,
 				unsigned char *log_buff)
 {
+	struct pnv_phb *phb = hose->private_data;
 	struct OpalIoPhbErrorCommon *common;
 
 	if (!hose || !log_buff)
 		return;
 
+	if (!(phb->flags & PNV_PHB_FLAG_DIAG))
+		return;
+
 	common = (struct OpalIoPhbErrorCommon *)log_buff;
 	switch (common->ioType) {
 	case OPAL_PHB_ERROR_DATA_TYPE_P7IOC:
@@ -281,13 +285,19 @@ void pnv_pci_dump_phb_diag_data(struct pci_controller *hose,
 static void pnv_pci_handle_eeh_config(struct pnv_phb *phb, u32 pe_no)
 {
 	unsigned long flags, rc;
-	int has_diag;
+	bool has_diag = false;
 
 	spin_lock_irqsave(&phb->lock, flags);
 
-	rc = opal_pci_get_phb_diag_data2(phb->opal_id, phb->diag.blob,
-					 PNV_PCI_DIAG_BUF_SIZE);
-	has_diag = (rc == OPAL_SUCCESS);
+	if (!(phb->flags & PNV_PHB_FLAG_DIAG)) {
+		rc = opal_pci_get_phb_diag_data2(phb->opal_id,
+						 phb->diag.blob,
+						 PNV_PCI_DIAG_BUF_SIZE);
+		if (rc == OPAL_SUCCESS) {
+			phb->flags |= PNV_PHB_FLAG_DIAG;
+			has_diag = true;
+		}
+	}
 
 	rc = opal_pci_eeh_freeze_clear(phb->opal_id, pe_no,
 				       OPAL_EEH_ACTION_CLEAR_FREEZE_ALL);
@@ -303,9 +313,6 @@ static void pnv_pci_handle_eeh_config(struct pnv_phb *phb, u32 pe_no)
 		 */
 		if (has_diag)
 			pnv_pci_dump_phb_diag_data(phb->hose, phb->diag.blob);
-		else
-			pr_warning("PCI %d: No diag data available\n",
-				   phb->hose->global_number);
 	}
 
 	spin_unlock_irqrestore(&phb->lock, flags);
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index adeb3c4..153af9a 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -82,6 +82,7 @@ struct pnv_eeh_ops {
 #endif /* CONFIG_EEH */
 
 #define PNV_PHB_FLAG_EEH	(1 << 0)
+#define PNV_PHB_FLAG_DIAG	(1 << 1)
 
 struct pnv_phb {
 	struct pci_controller	*hose;
-- 
1.7.10.4