From: Nathan Lynch <nathanl@linux.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linuxppc-dev@lists.ozlabs.org,
Tyrel Datwyler <tyreld@linux.ibm.com>,
Scott Cheloha <cheloha@linux.ibm.com>,
Andrew Donnellan <ajd@linux.ibm.com>,
Nick Child <nnac123@linux.ibm.com>,
Laurent Dufour <ldufour@linux.ibm.com>,
Nathan Lynch <nathanl@linux.ibm.com>
Subject: [PATCH 1/8] powerpc/rtas: ensure 8-byte alignment for struct rtas_args
Date: Mon, 06 Mar 2023 15:33:40 -0600 [thread overview]
Message-ID: <20230220-rtas-queue-for-6-4-v1-1-010e4416f13f@linux.ibm.com> (raw)
In-Reply-To: <20230220-rtas-queue-for-6-4-v1-0-010e4416f13f@linux.ibm.com>
CHRP and PAPR agree: "In order to make an RTAS call, the operating
system must construct an argument call buffer aligned on an eight byte
boundary in physically contiguous real memory [...]." (7.2.7 Calling
Mechanism and Conventions).
struct rtas_args is the type used for this argument call buffer. The
unarchitected 'rets' member happens to produce 8-byte alignment for
the struct on 64-bit targets in practice. But without an alignment
directive the structure will have only 4-byte alignment on 32-bit
targets:
$ nm b/{before,after}/chrp32/vmlinux | grep rtas_args
c096881c b rtas_args
c0968820 b rtas_args
Add an alignment directive to the struct rtas_args declaration so all
instances have the alignment required by the specs. rtas-types.h no
longer refers to any spinlock types, so drop the spinlock_types.h
inclusion while we're here.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
---
arch/powerpc/include/asm/rtas-types.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/rtas-types.h b/arch/powerpc/include/asm/rtas-types.h
index f2ad4a96cbc5..861145c8a021 100644
--- a/arch/powerpc/include/asm/rtas-types.h
+++ b/arch/powerpc/include/asm/rtas-types.h
@@ -2,7 +2,8 @@
#ifndef _ASM_POWERPC_RTAS_TYPES_H
#define _ASM_POWERPC_RTAS_TYPES_H
-#include <linux/spinlock_types.h>
+#include <linux/compiler_attributes.h>
+#include <linux/sizes.h>
typedef __be32 rtas_arg_t;
@@ -12,7 +13,7 @@ struct rtas_args {
__be32 nret;
rtas_arg_t args[16];
rtas_arg_t *rets; /* Pointer to return values in args[]. */
-};
+} __aligned(SZ_8);
struct rtas_t {
unsigned long entry; /* physical address pointer */
--
2.39.1
WARNING: multiple messages have this Message-ID (diff)
From: Nathan Lynch via B4 Relay <devnull+nathanl.linux.ibm.com@kernel.org>
To: Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Nathan Lynch <nathanl@linux.ibm.com>,
Tyrel Datwyler <tyreld@linux.ibm.com>,
Nick Child <nnac123@linux.ibm.com>,
Andrew Donnellan <ajd@linux.ibm.com>,
Scott Cheloha <cheloha@linux.ibm.com>,
Laurent Dufour <ldufour@linux.ibm.com>,
linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 1/8] powerpc/rtas: ensure 8-byte alignment for struct rtas_args
Date: Mon, 06 Mar 2023 15:33:40 -0600 [thread overview]
Message-ID: <20230220-rtas-queue-for-6-4-v1-1-010e4416f13f@linux.ibm.com> (raw)
In-Reply-To: <20230220-rtas-queue-for-6-4-v1-0-010e4416f13f@linux.ibm.com>
From: Nathan Lynch <nathanl@linux.ibm.com>
CHRP and PAPR agree: "In order to make an RTAS call, the operating
system must construct an argument call buffer aligned on an eight byte
boundary in physically contiguous real memory [...]." (7.2.7 Calling
Mechanism and Conventions).
struct rtas_args is the type used for this argument call buffer. The
unarchitected 'rets' member happens to produce 8-byte alignment for
the struct on 64-bit targets in practice. But without an alignment
directive the structure will have only 4-byte alignment on 32-bit
targets:
$ nm b/{before,after}/chrp32/vmlinux | grep rtas_args
c096881c b rtas_args
c0968820 b rtas_args
Add an alignment directive to the struct rtas_args declaration so all
instances have the alignment required by the specs. rtas-types.h no
longer refers to any spinlock types, so drop the spinlock_types.h
inclusion while we're here.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
---
arch/powerpc/include/asm/rtas-types.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/rtas-types.h b/arch/powerpc/include/asm/rtas-types.h
index f2ad4a96cbc5..861145c8a021 100644
--- a/arch/powerpc/include/asm/rtas-types.h
+++ b/arch/powerpc/include/asm/rtas-types.h
@@ -2,7 +2,8 @@
#ifndef _ASM_POWERPC_RTAS_TYPES_H
#define _ASM_POWERPC_RTAS_TYPES_H
-#include <linux/spinlock_types.h>
+#include <linux/compiler_attributes.h>
+#include <linux/sizes.h>
typedef __be32 rtas_arg_t;
@@ -12,7 +13,7 @@ struct rtas_args {
__be32 nret;
rtas_arg_t args[16];
rtas_arg_t *rets; /* Pointer to return values in args[]. */
-};
+} __aligned(SZ_8);
struct rtas_t {
unsigned long entry; /* physical address pointer */
--
2.39.1
next prev parent reply other threads:[~2023-03-06 21:33 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-06 21:33 [PATCH 0/8] RTAS changes for 6.4 Nathan Lynch via B4 Relay
2023-03-06 21:33 ` Nathan Lynch
2023-03-06 21:33 ` Nathan Lynch [this message]
2023-03-06 21:33 ` [PATCH 1/8] powerpc/rtas: ensure 8-byte alignment for struct rtas_args Nathan Lynch via B4 Relay
2023-03-23 4:00 ` Andrew Donnellan
2023-03-06 21:33 ` [PATCH 2/8] powerpc/rtas: use memmove for potentially overlapping buffer copy Nathan Lynch
2023-03-06 21:33 ` Nathan Lynch via B4 Relay
2023-03-23 4:09 ` Andrew Donnellan
2023-03-06 21:33 ` [PATCH 3/8] powerpc/rtas: rtas_call_unlocked() kerneldoc Nathan Lynch via B4 Relay
2023-03-06 21:33 ` Nathan Lynch
2023-03-23 4:15 ` Andrew Donnellan
2023-03-06 21:33 ` [PATCH 4/8] powerpc/rtas: fix miswording in rtas_function kerneldoc Nathan Lynch via B4 Relay
2023-03-06 21:33 ` Nathan Lynch
2023-03-23 0:17 ` Andrew Donnellan
2023-03-06 21:33 ` [PATCH 5/8] powerpc/rtas: rename va_rtas_call_unlocked() to va_rtas_call() Nathan Lynch
2023-03-06 21:33 ` Nathan Lynch via B4 Relay
2023-03-23 4:17 ` Andrew Donnellan
2023-03-23 16:11 ` Nathan Lynch
2023-03-29 12:24 ` Michael Ellerman
2023-03-06 21:33 ` [PATCH 6/8] powerpc/rtas: lockdep annotations Nathan Lynch
2023-03-06 21:33 ` Nathan Lynch via B4 Relay
2023-03-23 6:01 ` Andrew Donnellan
2023-03-06 21:33 ` [PATCH 7/8] powerpc/rtas: warn on unsafe argument to rtas_call_unlocked() Nathan Lynch via B4 Relay
2023-03-06 21:33 ` Nathan Lynch
2023-03-23 4:25 ` Andrew Donnellan
2023-03-23 12:17 ` Nathan Lynch
2023-03-24 0:56 ` Nathan Lynch
2023-03-29 12:20 ` Michael Ellerman
2023-03-29 16:23 ` Nathan Lynch
2023-03-06 21:33 ` [PATCH 8/8] powerpc/rtas: consume retry statuses in sys_rtas() Nathan Lynch via B4 Relay
2023-03-06 21:33 ` Nathan Lynch
2023-03-23 6:26 ` Andrew Donnellan
2023-03-23 19:39 ` Nathan Lynch
2023-03-23 9:44 ` Michael Ellerman
2023-03-23 13:40 ` Nathan Lynch
2024-01-25 15:55 ` Christophe Leroy
2024-01-25 16:33 ` Nathan Lynch
2024-01-25 16:46 ` Christophe Leroy
2024-01-25 17:23 ` Nathan Lynch
2023-04-06 1:09 ` (subset) [PATCH 0/8] RTAS changes for 6.4 Michael Ellerman
2023-04-26 12:12 ` Michael Ellerman
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