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>
Cc: "Nathan Lynch" <nathanl@linux.ibm.com>,
tyreld@linux.ibm.com, gcwilson@linux.ibm.com,
"Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>,
"Michal Suchánek" <msuchanek@suse.de>,
linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v6 07/13] powerpc/rtas: Serialize firmware activation sequences
Date: Tue, 12 Dec 2023 11:01:54 -0600 [thread overview]
Message-ID: <20231212-papr-sys_rtas-vs-lockdown-v6-7-e9eafd0c8c6c@linux.ibm.com> (raw)
In-Reply-To: <20231212-papr-sys_rtas-vs-lockdown-v6-0-e9eafd0c8c6c@linux.ibm.com>
From: Nathan Lynch <nathanl@linux.ibm.com>
Use rtas_ibm_activate_firmware_lock to prevent interleaving call
sequences of the ibm,activate-firmware RTAS function, which typically
requires multiple calls to complete the update. While the spec does
not specifically prohibit interleaved sequences, there's almost
certainly no advantage to allowing them.
Reviewed-by: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
---
arch/powerpc/kernel/rtas.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 4d28983e8b1d..72f6b5a402dd 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -1734,10 +1734,14 @@ void rtas_activate_firmware(void)
return;
}
+ mutex_lock(&rtas_ibm_activate_firmware_lock);
+
do {
fwrc = rtas_call(token, 0, 1, NULL);
} while (rtas_busy_delay(fwrc));
+ mutex_unlock(&rtas_ibm_activate_firmware_lock);
+
if (fwrc)
pr_err("ibm,activate-firmware failed (%i)\n", fwrc);
}
--
2.41.0
next prev parent reply other threads:[~2023-12-12 17:03 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-12 17:01 [PATCH v6 00/13] powerpc/pseries: New character devices for system parameters and VPD Nathan Lynch via B4 Relay
2023-12-12 17:01 ` [PATCH v6 01/13] powerpc/rtas: Avoid warning on invalid token argument to sys_rtas() Nathan Lynch via B4 Relay
2023-12-12 17:01 ` [PATCH v6 02/13] powerpc/rtas: Add for_each_rtas_function() iterator Nathan Lynch via B4 Relay
2023-12-12 17:01 ` [PATCH v6 03/13] powerpc/rtas: Fall back to linear search on failed token->function lookup Nathan Lynch via B4 Relay
2023-12-12 17:01 ` [PATCH v6 04/13] powerpc/rtas: Add function return status constants Nathan Lynch via B4 Relay
2023-12-12 17:01 ` [PATCH v6 05/13] powerpc/rtas: Move token validation from block_rtas_call() to sys_rtas() Nathan Lynch via B4 Relay
2023-12-12 17:01 ` [PATCH v6 06/13] powerpc/rtas: Facilitate high-level call sequences Nathan Lynch via B4 Relay
2023-12-12 17:01 ` Nathan Lynch via B4 Relay [this message]
2023-12-12 17:01 ` [PATCH v6 08/13] powerpc/rtas: Warn if per-function lock isn't held Nathan Lynch via B4 Relay
2023-12-12 17:01 ` [PATCH v6 09/13] powerpc/pseries: Add papr-vpd character driver for VPD retrieval Nathan Lynch via B4 Relay
2023-12-12 17:01 ` [PATCH v6 10/13] powerpc/pseries/papr-sysparm: Validate buffer object lengths Nathan Lynch via B4 Relay
2023-12-12 17:01 ` [PATCH v6 11/13] powerpc/pseries/papr-sysparm: Expose character device to user space Nathan Lynch via B4 Relay
2023-12-12 17:01 ` [PATCH v6 12/13] powerpc/selftests: Add test for papr-vpd Nathan Lynch via B4 Relay
2023-12-12 17:02 ` [PATCH v6 13/13] powerpc/selftests: Add test for papr-sysparm Nathan Lynch via B4 Relay
2023-12-21 10:38 ` [PATCH v6 00/13] powerpc/pseries: New character devices for system parameters and VPD Michael Ellerman
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