[PATCH v5 5/5] powerpc/powernv/eeh: Map generic EEH error types to OPAL

[Narayana Murty N <nnmlinux@linux.ibm.com>]

eeh_pe_inject_err() is called with generic EEH error types defined in
the VFIO/EEH userspace ABI (EEH_ERR_TYPE_32, EEH_ERR_TYPE_64).  The
PowerNV backend previously compared these generic values directly against
OPAL firmware constants (OPAL_ERR_INJECT_TYPE_IOA_BUS_ERR and
OPAL_ERR_INJECT_TYPE_IOA_BUS_ERR64).

This is fragile: it relies on the generic EEH ABI values being
numerically identical to OPAL-specific values, and would silently
misbehave if they ever diverged.

Add an explicit mapping in pnv_eeh_err_inject() that translates:
  EEH_ERR_TYPE_32 -> OPAL_ERR_INJECT_TYPE_IOA_BUS_ERR
  EEH_ERR_TYPE_64 -> OPAL_ERR_INJECT_TYPE_IOA_BUS_ERR64

Return -ERANGE for unsupported error types, preserving the behavior
of the original code.  Decouples the VFIO/EEH interface from OPAL
implementation details.

No change to existing userspace ABI or PowerNV behavior.

Signed-off-by: Narayana Murty N <nnmlinux@linux.ibm.com>
---
 arch/powerpc/platforms/powernv/eeh-powernv.c | 22 +++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index db3370d1673c..01dae760cecb 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
@@ -1167,12 +1167,24 @@ static int pnv_eeh_err_inject(struct eeh_pe *pe, int type, int func,
 {
 	struct pci_controller *hose = pe->phb;
 	struct pnv_phb *phb = hose->private_data;
+	int opal_err_type;
 	s64 rc;
 
-	if (type != OPAL_ERR_INJECT_TYPE_IOA_BUS_ERR &&
-	    type != OPAL_ERR_INJECT_TYPE_IOA_BUS_ERR64) {
-		pr_warn("%s: Invalid error type %d\n",
-			__func__, type);
+	/*
+	 * eeh_pe_inject_err() receives generic EEH error types from the
+	 * VFIO/EEH userspace ABI.  The PowerNV backend must not rely on
+	 * these generic values being numerically identical to OPAL firmware
+	 * values.  Translate to OPAL-specific types before calling firmware.
+	 */
+	switch (type) {
+	case EEH_ERR_TYPE_32:
+		opal_err_type = OPAL_ERR_INJECT_TYPE_IOA_BUS_ERR;
+		break;
+	case EEH_ERR_TYPE_64:
+		opal_err_type = OPAL_ERR_INJECT_TYPE_IOA_BUS_ERR64;
+		break;
+	default:
+		pr_warn("%s: Invalid error type %d\n", __func__, type);
 		return -ERANGE;
 	}
 
@@ -1192,7 +1204,7 @@ static int pnv_eeh_err_inject(struct eeh_pe *pe, int type, int func,
 
 	/* Do error injection */
 	rc = opal_pci_err_inject(phb->opal_id, pe->addr,
-				 type, func, addr, mask);
+				 opal_err_type, func, addr, mask);
 	if (rc != OPAL_SUCCESS) {
 		pr_warn("%s: Failure %lld injecting error "
 			"%d-%d to PHB#%x-PE#%x\n",
-- 
2.54.0