From: Daniel Thompson <daniel.thompson@linaro.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Daniel Thompson <daniel.thompson@linaro.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org, patches@linaro.org,
linaro-kernel@lists.linaro.org,
John Stultz <john.stultz@linaro.org>,
Sumit Semwal <sumit.semwal@linaro.org>,
Marc Zyngier <marc.zyngier@arm.com>,
Andrew Thoelke <andrew.thoelke@arm.com>,
Dave Martin <dave.martin@arm.com>
Subject: [RFC PATCH v2 3/7] arm64: alternative: Apply alternatives early in boot process
Date: Mon, 14 Sep 2015 14:26:17 +0100 [thread overview]
Message-ID: <1442237181-17064-4-git-send-email-daniel.thompson@linaro.org> (raw)
In-Reply-To: <1442237181-17064-1-git-send-email-daniel.thompson@linaro.org>
Currently alternatives are applied very late in the boot process (and
a long time after we enable scheduling). Some alternative sequences,
such as those that alter the way CPU context is stored, must be applied
much earlier in the boot sequence.
Introduce apply_alternatives_early() to allow some alternatives to be
applied immediately after we detect the CPU features of the boot CPU.
Currently apply_alternatives_all() is not optimized and will re-patch
code that has already been updated. This is harmless but could be
removed by adding extra flags to the alternatives store.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
---
arch/arm64/include/asm/alternative.h | 1 +
arch/arm64/kernel/alternative.c | 15 +++++++++++++++
arch/arm64/kernel/setup.c | 7 +++++++
3 files changed, 23 insertions(+)
diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h
index d56ec0715157..f9dad1b7c651 100644
--- a/arch/arm64/include/asm/alternative.h
+++ b/arch/arm64/include/asm/alternative.h
@@ -17,6 +17,7 @@ struct alt_instr {
u8 alt_len; /* size of new instruction(s), <= orig_len */
};
+void __init apply_alternatives_early(void);
void __init apply_alternatives_all(void);
void apply_alternatives(void *start, size_t length);
void free_alternatives_memory(void);
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c
index ab9db0e9818c..59989a4bed7c 100644
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@ -117,6 +117,21 @@ static void __apply_alternatives(void *alt_region)
}
/*
+ * This is called very early in the boot process (directly after we run
+ * a feature detect on the boot CPU). No need to worry about other CPUs
+ * here.
+ */
+void apply_alternatives_early(void)
+{
+ struct alt_region region = {
+ .begin = __alt_instructions,
+ .end = __alt_instructions_end,
+ };
+
+ __apply_alternatives(®ion);
+}
+
+/*
* We might be patching the stop_machine state machine, so implement a
* really simple polling protocol here.
*/
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 6bab21f84a9f..0cddc5ff8089 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -211,6 +211,13 @@ static void __init setup_processor(void)
cpuinfo_store_boot_cpu();
/*
+ * We now know enough about the boot CPU to apply the
+ * alternatives that cannot wait until interrupt handling
+ * and/or scheduling is enabled.
+ */
+ apply_alternatives_early();
+
+ /*
* Check for sane CTR_EL0.CWG value.
*/
cwg = cache_type_cwg();
--
2.4.3
WARNING: multiple messages have this Message-ID (diff)
From: daniel.thompson@linaro.org (Daniel Thompson)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH v2 3/7] arm64: alternative: Apply alternatives early in boot process
Date: Mon, 14 Sep 2015 14:26:17 +0100 [thread overview]
Message-ID: <1442237181-17064-4-git-send-email-daniel.thompson@linaro.org> (raw)
In-Reply-To: <1442237181-17064-1-git-send-email-daniel.thompson@linaro.org>
Currently alternatives are applied very late in the boot process (and
a long time after we enable scheduling). Some alternative sequences,
such as those that alter the way CPU context is stored, must be applied
much earlier in the boot sequence.
Introduce apply_alternatives_early() to allow some alternatives to be
applied immediately after we detect the CPU features of the boot CPU.
Currently apply_alternatives_all() is not optimized and will re-patch
code that has already been updated. This is harmless but could be
removed by adding extra flags to the alternatives store.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
---
arch/arm64/include/asm/alternative.h | 1 +
arch/arm64/kernel/alternative.c | 15 +++++++++++++++
arch/arm64/kernel/setup.c | 7 +++++++
3 files changed, 23 insertions(+)
diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h
index d56ec0715157..f9dad1b7c651 100644
--- a/arch/arm64/include/asm/alternative.h
+++ b/arch/arm64/include/asm/alternative.h
@@ -17,6 +17,7 @@ struct alt_instr {
u8 alt_len; /* size of new instruction(s), <= orig_len */
};
+void __init apply_alternatives_early(void);
void __init apply_alternatives_all(void);
void apply_alternatives(void *start, size_t length);
void free_alternatives_memory(void);
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c
index ab9db0e9818c..59989a4bed7c 100644
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@ -117,6 +117,21 @@ static void __apply_alternatives(void *alt_region)
}
/*
+ * This is called very early in the boot process (directly after we run
+ * a feature detect on the boot CPU). No need to worry about other CPUs
+ * here.
+ */
+void apply_alternatives_early(void)
+{
+ struct alt_region region = {
+ .begin = __alt_instructions,
+ .end = __alt_instructions_end,
+ };
+
+ __apply_alternatives(®ion);
+}
+
+/*
* We might be patching the stop_machine state machine, so implement a
* really simple polling protocol here.
*/
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 6bab21f84a9f..0cddc5ff8089 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -211,6 +211,13 @@ static void __init setup_processor(void)
cpuinfo_store_boot_cpu();
/*
+ * We now know enough about the boot CPU to apply the
+ * alternatives that cannot wait until interrupt handling
+ * and/or scheduling is enabled.
+ */
+ apply_alternatives_early();
+
+ /*
* Check for sane CTR_EL0.CWG value.
*/
cwg = cache_type_cwg();
--
2.4.3
next prev parent reply other threads:[~2015-09-14 13:27 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-14 13:26 [RFC PATCH v2 0/7] Pseudo-NMI for arm64 using ICC_PMR_EL1 (GICv3) Daniel Thompson
2015-09-14 13:26 ` Daniel Thompson
2015-09-14 13:26 ` [RFC PATCH v2 1/7] irqchip: gic-v3: Reset BPR during initialization Daniel Thompson
2015-09-14 13:26 ` Daniel Thompson
2015-09-14 13:26 ` [RFC PATCH v2 2/7] arm64: Add support for on-demand backtrace of other CPUs Daniel Thompson
2015-09-14 13:26 ` Daniel Thompson
2015-09-14 13:26 ` Daniel Thompson [this message]
2015-09-14 13:26 ` [RFC PATCH v2 3/7] arm64: alternative: Apply alternatives early in boot process Daniel Thompson
2015-09-16 13:05 ` Will Deacon
2015-09-16 13:05 ` Will Deacon
2015-09-16 15:51 ` Daniel Thompson
2015-09-16 15:51 ` Daniel Thompson
2015-09-16 16:24 ` Will Deacon
2015-09-16 16:24 ` Will Deacon
2015-09-17 13:25 ` Daniel Thompson
2015-09-17 13:25 ` Daniel Thompson
2015-09-17 14:01 ` Will Deacon
2015-09-17 14:01 ` Will Deacon
2015-09-17 15:28 ` Daniel Thompson
2015-09-17 15:28 ` Daniel Thompson
2015-09-17 15:43 ` Will Deacon
2015-09-17 15:43 ` Will Deacon
2015-09-14 13:26 ` [RFC PATCH v2 4/7] arm64: irqflags: Reorder the fiq & async macros Daniel Thompson
2015-09-14 13:26 ` Daniel Thompson
2015-09-14 13:26 ` [RFC PATCH v2 5/7] arm64: irqflags: Use ICC sysregs to implement IRQ masking Daniel Thompson
2015-09-14 13:26 ` Daniel Thompson
2015-09-14 13:26 ` [RFC PATCH v2 6/7] arm64: Implement IPI_CPU_BACKTRACE using pseudo-NMIs Daniel Thompson
2015-09-14 13:26 ` Daniel Thompson
2015-09-14 13:26 ` [RFC PATCH v2 7/7] arm64: irqflags: Automatically identify I bit mis-management Daniel Thompson
2015-09-14 13:26 ` Daniel Thompson
2015-09-18 5:11 ` [RFC PATCH v2 0/7] Pseudo-NMI for arm64 using ICC_PMR_EL1 (GICv3) Jon Masters
2015-09-18 5:11 ` Jon Masters
2015-09-18 11:23 ` Daniel Thompson
2015-09-18 11:23 ` Daniel Thompson
2015-09-22 18:08 ` 答复: " Dingtianhong
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