opal: Deprecate reading the PHB status

The OPAL_PCI_EEH_FREEZE_STATUS call takes a bunch of parameters, one of
them is @phb_status. It is defined as __be64* and always NULL in
the current Linux upstream but if anyone ever decides to read that status,
then the PHB3's handler will assume it is struct OpalIoPhb3ErrorData*
(which is a lot bigger than 8 bytes) and zero it causing the stack
corruption; p7ioc-phb has the same issue.

This removes @phb_status from all eeh_freeze_status() hooks and moves
the error message from PHB4 to the affected OPAL handlers.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-By: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>

9 files changed, 24 insertions, 34 deletions

diff --git a/core/pci-opal.c b/core/pci-opal.c
index a4d6eeed..d7abb15b 100644
--- a/core/pci-opal.c
+++ b/core/pci-opal.c
@@ -111,8 +111,13 @@ static int64_t opal_pci_eeh_freeze_status(uint64_t phb_id, uint64_t pe_number,
 	if (!phb->ops->eeh_freeze_status)
 		return OPAL_UNSUPPORTED;
 	phb_lock(phb);
+
+	if (phb_status)
+		prlog(PR_ERR, "PHB#%04llx: %s: deprecated PHB status\n",
+				phb_id, __func__);
+
 	rc = phb->ops->eeh_freeze_status(phb, pe_number, freeze_state,
-					 pci_error_type, NULL, phb_status);
+					 pci_error_type, NULL);
 	phb_unlock(phb);
 
 	return rc;
@@ -961,8 +966,13 @@ static int64_t opal_pci_eeh_freeze_status2(uint64_t phb_id, uint64_t pe_number,
 	if (!phb->ops->eeh_freeze_status)
 		return OPAL_UNSUPPORTED;
 	phb_lock(phb);
+
+	if (phb_status)
+		prlog(PR_ERR, "PHB#%04llx: %s: deprecated PHB status\n",
+				phb_id, __func__);
+
 	rc = phb->ops->eeh_freeze_status(phb, pe_number, freeze_state,
-					 pci_error_type, severity, phb_status);
+					 pci_error_type, severity);
 	phb_unlock(phb);
 
 	return rc;
diff --git a/core/pci.c b/core/pci.c
index 14654d41..454b5010 100644
--- a/core/pci.c
+++ b/core/pci.c
@@ -337,7 +337,7 @@ static void pci_check_clear_freeze(struct phb *phb)
 
 	/* Retrieve the frozen state */
 	rc = phb->ops->eeh_freeze_status(phb, pe_number, &freeze_state,
-					 &pci_error_type, &sev, NULL);
+					 &pci_error_type, &sev);
 	if (rc)
 		return;
 	if (freeze_state == OPAL_EEH_STOPPED_NOT_FROZEN)
diff --git a/hw/npu.c b/hw/npu.c
index fcc19417..2c3f19e5 100644
--- a/hw/npu.c
+++ b/hw/npu.c
@@ -882,8 +882,7 @@ static int64_t npu_freeze_status(struct phb *phb,
 				     uint64_t pe_number __unused,
 				     uint8_t *freeze_state,
 				     uint16_t *pci_error_type __unused,
-				     uint16_t *severity __unused,
-				     uint64_t *phb_status __unused)
+				     uint16_t *severity __unused)
 {
 	/* FIXME: When it's called by skiboot PCI config accessor,
 	 * the PE number is fixed to 0, which is incorrect. We need
diff --git a/hw/npu2.c b/hw/npu2.c
index f034490b..0a7b1573 100644
--- a/hw/npu2.c
+++ b/hw/npu2.c
@@ -1274,8 +1274,7 @@ int64_t npu2_freeze_status(struct phb *phb __unused,
 			   uint64_t pe_number __unused,
 			   uint8_t *freeze_state,
 			   uint16_t *pci_error_type,
-			   uint16_t *severity,
-			   uint64_t *phb_status __unused)
+			   uint16_t *severity)
 {
 	/*
 	 * FIXME: When it's called by skiboot PCI config accessor,
diff --git a/hw/p7ioc-phb.c b/hw/p7ioc-phb.c
index 33de10ad..47f4f3c9 100644
--- a/hw/p7ioc-phb.c
+++ b/hw/p7ioc-phb.c
@@ -284,8 +284,7 @@ static void p7ioc_eeh_read_phb_status(struct p7ioc_phb *p,
 static int64_t p7ioc_eeh_freeze_status(struct phb *phb, uint64_t pe_number,
 				       uint8_t *freeze_state,
 				       uint16_t *pci_error_type,
-				       uint16_t *severity,
-				       uint64_t *phb_status)
+				       uint16_t *severity)
 {
 	struct p7ioc_phb *p = phb_to_p7ioc_phb(phb);
 	uint64_t peev_bit = PPC_BIT(pe_number & 0x3f);
@@ -301,7 +300,7 @@ static int64_t p7ioc_eeh_freeze_status(struct phb *phb, uint64_t pe_number,
 		*pci_error_type = OPAL_EEH_PHB_ERROR;
 		if (severity)
 			*severity = OPAL_EEH_SEV_PHB_DEAD;
-		goto bail;
+		return OPAL_SUCCESS;
 	}
 
 	/* Check fence */
@@ -311,7 +310,7 @@ static int64_t p7ioc_eeh_freeze_status(struct phb *phb, uint64_t pe_number,
 		*pci_error_type = OPAL_EEH_PHB_ERROR;
 		if (severity)
 			*severity = OPAL_EEH_SEV_PHB_FENCED;
-		goto bail;
+		return OPAL_SUCCESS;
 	}
 
 	/* Check the PEEV */
@@ -345,10 +344,6 @@ static int64_t p7ioc_eeh_freeze_status(struct phb *phb, uint64_t pe_number,
 	else
 		*pci_error_type = OPAL_EEH_PE_DMA_ERROR;
 
- bail:
-	if (phb_status)
-		p7ioc_eeh_read_phb_status(p, (struct OpalIoP7IOCPhbErrorData *)
-					  phb_status);
 	return OPAL_SUCCESS;
 }
 
diff --git a/hw/phb3.c b/hw/phb3.c
index 46897c0c..30e406fc 100644
--- a/hw/phb3.c
+++ b/hw/phb3.c
@@ -2718,8 +2718,7 @@ static struct pci_slot *phb3_slot_create(struct phb *phb)
 static int64_t phb3_eeh_freeze_status(struct phb *phb, uint64_t pe_number,
 				      uint8_t *freeze_state,
 				      uint16_t *pci_error_type,
-				      uint16_t *severity,
-				      uint64_t *phb_status)
+				      uint16_t *severity)
 {
 	struct phb3 *p = phb_to_phb3(phb);
 	uint64_t peev_bit = PPC_BIT(pe_number & 0x3f);
@@ -2744,7 +2743,7 @@ static int64_t phb3_eeh_freeze_status(struct phb *phb, uint64_t pe_number,
 		*pci_error_type = OPAL_EEH_PHB_ERROR;
 		if (severity)
 			*severity = OPAL_EEH_SEV_PHB_FENCED;
-		goto bail;
+		return OPAL_SUCCESS;
 	}
 
 	/* Check the PEEV */
@@ -2770,11 +2769,6 @@ static int64_t phb3_eeh_freeze_status(struct phb *phb, uint64_t pe_number,
 	if (pestb & IODA2_PESTB_DMA_STOPPED)
 		*freeze_state |= OPAL_EEH_STOPPED_DMA_FREEZE;
 
-bail:
-	if (phb_status)
-		phb3_read_phb_status(p,
-			(struct OpalIoPhb3ErrorData *)phb_status);
-
 	return OPAL_SUCCESS;
 }
 
diff --git a/hw/phb4.c b/hw/phb4.c
index 48969fa1..f832620e 100644
--- a/hw/phb4.c
+++ b/hw/phb4.c
@@ -3398,8 +3398,7 @@ static bool phb4_freeze_escalate(uint64_t pesta)
 static int64_t phb4_eeh_freeze_status(struct phb *phb, uint64_t pe_number,
 				      uint8_t *freeze_state,
 				      uint16_t *pci_error_type,
-				      uint16_t *severity,
-				      uint64_t *phb_status)
+				      uint16_t *severity)
 {
 	struct phb4 *p = phb_to_phb4(phb);
 	uint64_t peev_bit = PPC_BIT(pe_number & 0x3f);
@@ -3424,7 +3423,7 @@ static int64_t phb4_eeh_freeze_status(struct phb *phb, uint64_t pe_number,
 		*pci_error_type = OPAL_EEH_PHB_ERROR;
 		if (severity)
 			*severity = OPAL_EEH_SEV_PHB_FENCED;
-		goto bail;
+		return OPAL_SUCCESS;
 	}
 
 	/* Check the PEEV */
@@ -3458,10 +3457,6 @@ static int64_t phb4_eeh_freeze_status(struct phb *phb, uint64_t pe_number,
 	if (pestb & IODA3_PESTB_DMA_STOPPED)
 		*freeze_state |= OPAL_EEH_STOPPED_DMA_FREEZE;
 
-bail:
-	if (phb_status)
-		PHBERR(p, "%s: deprecated PHB status\n", __func__);
-
 	return OPAL_SUCCESS;
 }
 
diff --git a/include/npu2.h b/include/npu2.h
index f51a6a2a..0e79e0e0 100644
--- a/include/npu2.h
+++ b/include/npu2.h
@@ -225,6 +225,5 @@ int64_t npu2_freeze_status(struct phb *phb __unused,
 			   uint64_t pe_number __unused,
 			   uint8_t *freeze_state,
 			   uint16_t *pci_error_type __unused,
-			   uint16_t *severity __unused,
-			   uint64_t *phb_status __unused);
+			   uint16_t *severity __unused);
 #endif /* __NPU2_H */
diff --git a/include/pci.h b/include/pci.h
index 05165614..b49641ca 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -260,8 +260,7 @@ struct phb_ops {
 	int64_t (*eeh_freeze_status)(struct phb *phb, uint64_t pe_number,
 				     uint8_t *freeze_state,
 				     uint16_t *pci_error_type,
-				     uint16_t *severity,
-				     uint64_t *phb_status);
+				     uint16_t *severity);
 	int64_t (*eeh_freeze_clear)(struct phb *phb, uint64_t pe_number,
 				    uint64_t eeh_action_token);
 	int64_t (*eeh_freeze_set)(struct phb *phb, uint64_t pe_number,