[PATCH] powerpc/powernv: Update firmware archaeology around OPAL_HANDLE_HMI

Stewart Smith stewart at linux.ibm.com
Fri May 24 15:09:56 AEST 2019


The first machines to ship with OPAL firmware all got firmware updates
that have the new call, but just in case someone is foolish enough to
believe the first 4 months of firmware is the best, we keep this code
around.

Comment is updated to not refer to late 2014 as recent or the future.

Signed-off-by: Stewart Smith <stewart at linux.ibm.com>
---
 arch/powerpc/platforms/powernv/opal.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index f2b063b027f0..89b6ddc3ed38 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -206,16 +206,18 @@ static int __init opal_register_exception_handlers(void)
 	glue = 0x7000;
 
 	/*
-	 * Check if we are running on newer firmware that exports
-	 * OPAL_HANDLE_HMI token. If yes, then don't ask OPAL to patch
-	 * the HMI interrupt and we catch it directly in Linux.
+	 * Only ancient OPAL firmware requires this.
+	 * Specifically, firmware from FW810.00 (released June 2014)
+	 * through FW810.20 (Released October 2014).
 	 *
-	 * For older firmware (i.e currently released POWER8 System Firmware
-	 * as of today <= SV810_087), we fallback to old behavior and let OPAL
-	 * patch the HMI vector and handle it inside OPAL firmware.
+	 * Check if we are running on newer (post Oct 2014) firmware that
+	 * exports the OPAL_HANDLE_HMI token. If yes, then don't ask OPAL to
+	 * patch the HMI interrupt and we catch it directly in Linux.
 	 *
-	 * For newer firmware (in development/yet to be released) we will
-	 * start catching/handling HMI directly in Linux.
+	 * For older firmware (i.e < FW810.20), we fallback to old behavior and
+	 * let OPAL patch the HMI vector and handle it inside OPAL firmware.
+	 *
+	 * For newer firmware we catch/handle the HMI directly in Linux.
 	 */
 	if (!opal_check_token(OPAL_HANDLE_HMI)) {
 		pr_info("Old firmware detected, OPAL handles HMIs.\n");
@@ -225,6 +227,11 @@ static int __init opal_register_exception_handlers(void)
 		glue += 128;
 	}
 
+	/*
+	 * Only applicable to ancient firmware, all modern
+	 * (post March 2015/skiboot 5.0) firmware will just return
+	 * OPAL_UNSUPPORTED.
+	 */
 	opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue);
 #endif
 
-- 
2.21.0



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