From dcbf1cc282cc1dbcffd596b8feb476cda2f2d5fe Mon Sep 17 00:00:00 2001
From: Miroslav Franc <mfranc@suse.cz>
Date: May 24 2023 15:54:19 +0000
Subject: s390/qdio: fix do_sqbs() inline assembly constraint (git-fixes

bsc#1211693).

---

diff --git a/patches.suse/s390-qdio-fix-do_sqbs-inline-assembly-constraint.patch b/patches.suse/s390-qdio-fix-do_sqbs-inline-assembly-constraint.patch
new file mode 100644
index 0000000..5ad8cbf
--- /dev/null
+++ b/patches.suse/s390-qdio-fix-do_sqbs-inline-assembly-constraint.patch
@@ -0,0 +1,62 @@
+From: Heiko Carstens <hca@linux.ibm.com>
+Date: Thu, 11 May 2023 17:04:41 +0200
+Subject: s390/qdio: fix do_sqbs() inline assembly constraint
+Git-commit: 2862a2fdfae875888e3c1c3634e3422e01d98147
+Patch-mainline: v6.4-rc3
+References: git-fixes bsc#1211693
+
+Use "a" constraint instead of "d" constraint to pass the state parameter to
+the do_sqbs() inline assembly. This prevents that general purpose register
+zero is used for the state parameter.
+
+If the compiler would select general purpose register zero this would be
+problematic for the used instruction in rsy format: the register used for
+the state parameter is a base register. If the base register is general
+purpose register zero the contents of the register are unexpectedly ignored
+when the instruction is executed.
+
+This only applies to z/VM guests using QIOASSIST with dedicated (pass through)
+QDIO-based devices such as FCP [zfcp driver] as well as real OSA or
+HiperSockets [qeth driver].
+
+A possible symptom for this case using zfcp is the following repeating kernel
+message pattern:
+
+zfcp <devbusid>: A QDIO problem occurred
+zfcp <devbusid>: A QDIO problem occurred
+zfcp <devbusid>: qdio: ZFCP on SC <sc> using AI:1 QEBSM:1 PRI:1 TDD:1 SIGA: W
+zfcp <devbusid>: A QDIO problem occurred
+zfcp <devbusid>: A QDIO problem occurred
+
+Each of the qdio problem message can be accompanied by the following entries
+for the affected subchannel <sc> in
+/sys/kernel/debug/s390dbf/qdio_error/hex_ascii for zfcp or qeth:
+
+<sc> ccq: 69....
+<sc> SQBS ERROR.
+
+Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
+Cc: Steffen Maier <maier@linux.ibm.com>
+Fixes: 8129ee164267 ("[PATCH] s390: qdio V=V pass-through")
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
+Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
+Acked-by: Miroslav Franc <mfranc@suse.cz>
+---
+ drivers/s390/cio/qdio.h | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/drivers/s390/cio/qdio.h b/drivers/s390/cio/qdio.h
+index 5ea6249d8180..641f0dbb65a9 100644
+--- a/drivers/s390/cio/qdio.h
++++ b/drivers/s390/cio/qdio.h
+@@ -95,7 +95,7 @@ static inline int do_sqbs(u64 token, unsigned char state, int queue,
+ 		"	lgr	1,%[token]\n"
+ 		"	.insn	rsy,0xeb000000008a,%[qs],%[ccq],0(%[state])"
+ 		: [ccq] "+&d" (_ccq), [qs] "+&d" (_queuestart)
+-		: [state] "d" ((unsigned long)state), [token] "d" (token)
++		: [state] "a" ((unsigned long)state), [token] "d" (token)
+ 		: "memory", "cc", "1");
+ 	*count = _ccq & 0xff;
+ 	*start = _queuestart & 0xff;
+
diff --git a/series.conf b/series.conf
index 2065458..799a828 100644
--- a/series.conf
+++ b/series.conf
@@ -20085,6 +20085,7 @@
 	patches.suse/ALSA-hda-Fix-Oops-by-9.1-surround-channel-names.patch
 	patches.suse/ALSA-cs46xx-mark-snd_cs46xx_download_image-as-static.patch
 	patches.suse/ALSA-hda-Add-NVIDIA-codec-IDs-a3-through-a7-to-patch.patch
+	patches.suse/s390-qdio-fix-do_sqbs-inline-assembly-constraint.patch
 	patches.suse/Documentation-filesystems-sharedsubtree-add-section-.patch
 	patches.suse/Documentation-filesystems-ramfs-rootfs-initramfs-use.patch
 	patches.suse/drm-exynos-fix-g2d_open-close-helper-function-defini.patch