From: Narayana Murty N <nnmlinux@linux•ibm.com>
To: mahesh@linux•ibm.com, maddy@linux•ibm.com, mpe@ellerman•id.au,
christophe.leroy@csgroup•eu, gregkh@linuxfoundation•org,
oohall@gmail•com, npiggin@gmail•com
Cc: linuxppc-dev@lists•ozlabs.org, linux-kernel@vger•kernel.org,
tyreld@linux•ibm.com, vaibhav@linux•ibm.com, sbhat@linux•ibm.com,
ganeshgr@linux•ibm.com, sourabhjain@linux•ibm.com,
haren@linux•ibm.com, nnmlinux@linux•ibm.com, thuth@redhat•com
Subject: [PATCH v2 1/5] powerpc/rtas: Handle special return format for RTAS_FN_IBM_OPEN_ERRINJCT
Date: Wed, 27 May 2026 12:54:29 +0530 [thread overview]
Message-ID: <20260527072433.94510-2-nnmlinux@linux.ibm.com> (raw)
In-Reply-To: <20260527072433.94510-1-nnmlinux@linux.ibm.com>
RTAS_FN_IBM_OPEN_ERRINJCT returns results in special format:
rets[0] = session token (output)
rets[1] = status code
rets[2..] = additional outputs (if any)
Unlike standard RTAS calls where:
rets[0] = status code
rets[1..] = outputs
This patch adds special handling for OPEN_ERRINJCT to:
1. Check correct status position (rets[1]) for __fetch_rtas_last_error()
2. Copy all rets[0..nret-1] to outputs[] (including token at rets[0])
3. Return status from rets[1] instead of rets[0]
Reference: OpenPOWER PAPR documentation
https://files.openpower.foundation/s/XFgfMaqLMD5Bcm8
Signed-off-by: Narayana Murty N <nnmlinux@linux•ibm.com>
---
arch/powerpc/kernel/rtas.c | 47 ++++++++++++++++++++++++++++++++------
1 file changed, 40 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 8d81c1e7a8db..a2dd94eed9d0 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -1183,7 +1183,7 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...)
unsigned long flags;
struct rtas_args *args;
char *buff_copy = NULL;
- int ret;
+ int ret = 0;
if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
return -1;
@@ -1213,15 +1213,48 @@ int rtas_call(int token, int nargs, int nret, int *outputs, ...)
va_rtas_call_unlocked(args, token, nargs, nret, list);
va_end(list);
+ /*
+ * Special handling for RTAS_FN_IBM_OPEN_ERRINJCT:
+ * Per PAPR, ibm,open-errinjct has a unique return format:
+ * rets[0] = injection session token (output parameter)
+ * rets[1] = status code
+ *
+ * This differs from standard RTAS calls which return:
+ * rets[0] = status code
+ * rets[1..] = output parameters
+ *
+ * We must extract status from rets[1] (not rets[0]) to correctly
+ * detect errors and trigger __fetch_rtas_last_error() when status == -1.
+ */
/* A -1 return code indicates that the last command couldn't
- be completed due to a hardware error. */
- if (be32_to_cpu(args->rets[0]) == -1)
+ * be completed due to a hardware error.
+ */
+ if (token == rtas_function_token(RTAS_FN_IBM_OPEN_ERRINJCT) && nret > 1)
+ ret = be32_to_cpu(args->rets[1]);
+ else if (nret > 0)
+ ret = be32_to_cpu(args->rets[0]);
+
+ if (ret == -1)
buff_copy = __fetch_rtas_last_error(NULL);
- if (nret > 1 && outputs != NULL)
- for (i = 0; i < nret-1; ++i)
- outputs[i] = be32_to_cpu(args->rets[i + 1]);
- ret = (nret > 0) ? be32_to_cpu(args->rets[0]) : 0;
+ /* Copy all return values to caller's outputs buffer if provided */
+ if (nret > 1 && outputs != NULL) {
+ if (token == rtas_function_token(RTAS_FN_IBM_OPEN_ERRINJCT)) {
+ /* Special case: rets[0]=token, rets[1]=status, rets[2..]=outputs */
+ for (i = 0; i < nret; ++i)
+ outputs[i] = be32_to_cpu(args->rets[i]);
+ } else {
+ /* Normal case: rets[0]=status, rets[1..]=outputs */
+ for (i = 0; i < nret - 1; ++i)
+ outputs[i] = be32_to_cpu(args->rets[i + 1]);
+ }
+ } else {
+ /* Either no outputs to copy (nret <= 1) or caller
+ * didn't provide output buffer ensure ret contains
+ * the status code for standard RTAS calls.
+ */
+ ret = (nret > 0) ? be32_to_cpu(args->rets[0]) : 0;
+ }
lockdep_unpin_lock(&rtas_lock, cookie);
raw_spin_unlock_irqrestore(&rtas_lock, flags);
--
2.54.0
next prev parent reply other threads:[~2026-05-27 7:26 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-27 7:24 [PATCH v2 0/5] powerpc/pseries: Add full RTAS-based error injection support Narayana Murty N
2026-05-27 7:24 ` Narayana Murty N [this message]
2026-06-07 11:19 ` [PATCH v2 1/5] powerpc/rtas: Handle special return format for RTAS_FN_IBM_OPEN_ERRINJCT Sourabh Jain
2026-05-27 7:24 ` [PATCH v2 2/5] powerpc/pseries: Add RTAS error injection buffer infrastructure Narayana Murty N
2026-05-27 7:24 ` [PATCH v2 3/5] powerpc/pseries: Add RTAS error injection validation helpers Narayana Murty N
2026-06-07 12:17 ` Sourabh Jain
2026-05-27 7:24 ` [PATCH v2 4/5] powerpc/pseries: Implement RTAS error injection via pseries_eeh_err_inject Narayana Murty N
2026-06-07 13:35 ` Sourabh Jain
2026-05-27 7:24 ` [PATCH v2 5/5] powerpc/powernv: Map EEH error types to OPAL error injection types Narayana Murty N
2026-06-07 13:46 ` Sourabh Jain
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