All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: akpm@linux-foundation.org, ard.biesheuvel@linaro.org,
	catalin.marinas@arm.com, james.morse@arm.com,
	keescook@chromium.org, linux-kernel@vger.kernel.org,
	lorenzo.pieralisi@arm.com, luto@kernel.org, mark.rutland@arm.com,
	suzuki.poulose@arm.com, takahiro.akashi@linaro.org,
	will.deacon@arm.com, kernel-hardening@lists.openwall.com
Subject: [RFC PATCH 5/8] arm64: assembler: introduce ldr_this_cpu
Date: Thu, 15 Sep 2016 14:49:06 +0100	[thread overview]
Message-ID: <1473947349-14521-6-git-send-email-mark.rutland@arm.com> (raw)
In-Reply-To: <1473947349-14521-1-git-send-email-mark.rutland@arm.com>

Shortly we will want to load a percpu variable in the return from
userspace path. We can save an instruction by folding the addition of
the percpu offset into the load instruction, and this patch adds a new
helper to do so.

At the same time, we clean up this_cpu_ptr for consistency. As with
{adr,ldr,str}_l, we change the template to take the destination register
first, and name this dst. Secondly, we rename the macro to adr_this_cpu,
following the scheme of adr_l, and matching the newly added
ldr_this_cpu.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/assembler.h | 19 +++++++++++++++----
 arch/arm64/kernel/entry.S          |  2 +-
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index d5025c6..265fd81 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -193,14 +193,25 @@ lr	.req	x30		// link register
 	.endm
 
 	/*
+	 * @dst: Result of per_cpu(sym, smp_processor_id())
 	 * @sym: The name of the per-cpu variable
-	 * @reg: Result of per_cpu(sym, smp_processor_id())
 	 * @tmp: scratch register
 	 */
-	.macro this_cpu_ptr, sym, reg, tmp
-	adr_l	\reg, \sym
+	.macro adr_this_cpu, dst, sym, tmp
+	adr_l	\dst, \sym
 	mrs	\tmp, tpidr_el1
-	add	\reg, \reg, \tmp
+	add	\dst, \dst, \tmp
+	.endm
+
+	/*
+	 * @dst: Result of READ_ONCE(per_cpu(sym, smp_processor_id()))
+	 * @sym: The name of the per-cpu variable
+	 * @tmp: scratch register
+	 */
+	.macro ldr_this_cpu dst, sym, tmp
+	adr_l	\dst, \sym
+	mrs	\tmp, tpidr_el1
+	ldr	\dst, [\dst, \tmp]
 	.endm
 
 /*
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 441420c..52b4241 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -206,7 +206,7 @@ alternative_endif
 	cmp	x25, tsk
 	b.ne	9998f
 
-	this_cpu_ptr irq_stack, x25, x26
+	adr_this_cpu x25, irq_stack, x26
 	mov	x26, #IRQ_STACK_START_SP
 	add	x26, x25, x26
 
-- 
1.9.1

WARNING: multiple messages have this Message-ID (diff)
From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 5/8] arm64: assembler: introduce ldr_this_cpu
Date: Thu, 15 Sep 2016 14:49:06 +0100	[thread overview]
Message-ID: <1473947349-14521-6-git-send-email-mark.rutland@arm.com> (raw)
In-Reply-To: <1473947349-14521-1-git-send-email-mark.rutland@arm.com>

Shortly we will want to load a percpu variable in the return from
userspace path. We can save an instruction by folding the addition of
the percpu offset into the load instruction, and this patch adds a new
helper to do so.

At the same time, we clean up this_cpu_ptr for consistency. As with
{adr,ldr,str}_l, we change the template to take the destination register
first, and name this dst. Secondly, we rename the macro to adr_this_cpu,
following the scheme of adr_l, and matching the newly added
ldr_this_cpu.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/assembler.h | 19 +++++++++++++++----
 arch/arm64/kernel/entry.S          |  2 +-
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index d5025c6..265fd81 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -193,14 +193,25 @@ lr	.req	x30		// link register
 	.endm
 
 	/*
+	 * @dst: Result of per_cpu(sym, smp_processor_id())
 	 * @sym: The name of the per-cpu variable
-	 * @reg: Result of per_cpu(sym, smp_processor_id())
 	 * @tmp: scratch register
 	 */
-	.macro this_cpu_ptr, sym, reg, tmp
-	adr_l	\reg, \sym
+	.macro adr_this_cpu, dst, sym, tmp
+	adr_l	\dst, \sym
 	mrs	\tmp, tpidr_el1
-	add	\reg, \reg, \tmp
+	add	\dst, \dst, \tmp
+	.endm
+
+	/*
+	 * @dst: Result of READ_ONCE(per_cpu(sym, smp_processor_id()))
+	 * @sym: The name of the per-cpu variable
+	 * @tmp: scratch register
+	 */
+	.macro ldr_this_cpu dst, sym, tmp
+	adr_l	\dst, \sym
+	mrs	\tmp, tpidr_el1
+	ldr	\dst, [\dst, \tmp]
 	.endm
 
 /*
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 441420c..52b4241 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -206,7 +206,7 @@ alternative_endif
 	cmp	x25, tsk
 	b.ne	9998f
 
-	this_cpu_ptr irq_stack, x25, x26
+	adr_this_cpu x25, irq_stack, x26
 	mov	x26, #IRQ_STACK_START_SP
 	add	x26, x25, x26
 
-- 
1.9.1

WARNING: multiple messages have this Message-ID (diff)
From: Mark Rutland <mark.rutland@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: akpm@linux-foundation.org, ard.biesheuvel@linaro.org,
	catalin.marinas@arm.com, james.morse@arm.com,
	keescook@chromium.org, linux-kernel@vger.kernel.org,
	lorenzo.pieralisi@arm.com, luto@kernel.org, mark.rutland@arm.com,
	suzuki.poulose@arm.com, takahiro.akashi@linaro.org,
	will.deacon@arm.com, kernel-hardening@lists.openwall.com
Subject: [kernel-hardening] [RFC PATCH 5/8] arm64: assembler: introduce ldr_this_cpu
Date: Thu, 15 Sep 2016 14:49:06 +0100	[thread overview]
Message-ID: <1473947349-14521-6-git-send-email-mark.rutland@arm.com> (raw)
In-Reply-To: <1473947349-14521-1-git-send-email-mark.rutland@arm.com>

Shortly we will want to load a percpu variable in the return from
userspace path. We can save an instruction by folding the addition of
the percpu offset into the load instruction, and this patch adds a new
helper to do so.

At the same time, we clean up this_cpu_ptr for consistency. As with
{adr,ldr,str}_l, we change the template to take the destination register
first, and name this dst. Secondly, we rename the macro to adr_this_cpu,
following the scheme of adr_l, and matching the newly added
ldr_this_cpu.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/include/asm/assembler.h | 19 +++++++++++++++----
 arch/arm64/kernel/entry.S          |  2 +-
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index d5025c6..265fd81 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -193,14 +193,25 @@ lr	.req	x30		// link register
 	.endm
 
 	/*
+	 * @dst: Result of per_cpu(sym, smp_processor_id())
 	 * @sym: The name of the per-cpu variable
-	 * @reg: Result of per_cpu(sym, smp_processor_id())
 	 * @tmp: scratch register
 	 */
-	.macro this_cpu_ptr, sym, reg, tmp
-	adr_l	\reg, \sym
+	.macro adr_this_cpu, dst, sym, tmp
+	adr_l	\dst, \sym
 	mrs	\tmp, tpidr_el1
-	add	\reg, \reg, \tmp
+	add	\dst, \dst, \tmp
+	.endm
+
+	/*
+	 * @dst: Result of READ_ONCE(per_cpu(sym, smp_processor_id()))
+	 * @sym: The name of the per-cpu variable
+	 * @tmp: scratch register
+	 */
+	.macro ldr_this_cpu dst, sym, tmp
+	adr_l	\dst, \sym
+	mrs	\tmp, tpidr_el1
+	ldr	\dst, [\dst, \tmp]
 	.endm
 
 /*
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 441420c..52b4241 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -206,7 +206,7 @@ alternative_endif
 	cmp	x25, tsk
 	b.ne	9998f
 
-	this_cpu_ptr irq_stack, x25, x26
+	adr_this_cpu x25, irq_stack, x26
 	mov	x26, #IRQ_STACK_START_SP
 	add	x26, x25, x26
 
-- 
1.9.1

  parent reply	other threads:[~2016-09-15 13:50 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-15 13:49 [RFC PATCH 0/8] arm64: move thread_info off of the task stack Mark Rutland
2016-09-15 13:49 ` [kernel-hardening] " Mark Rutland
2016-09-15 13:49 ` Mark Rutland
2016-09-15 13:49 ` [RFC PATCH 1/8] thread_info: include <current.h> for THREAD_INFO_IN_TASK Mark Rutland
2016-09-15 13:49   ` [kernel-hardening] " Mark Rutland
2016-09-15 13:49   ` Mark Rutland
2016-09-15 13:49 ` [RFC PATCH 2/8] thread_info: allow custom in-task thread_info Mark Rutland
2016-09-15 13:49   ` [kernel-hardening] " Mark Rutland
2016-09-15 13:49   ` Mark Rutland
2016-09-15 18:37   ` Andy Lutomirski
2016-09-15 18:37     ` [kernel-hardening] " Andy Lutomirski
2016-09-15 18:37     ` Andy Lutomirski
2016-09-16 10:33     ` Mark Rutland
2016-09-16 10:33       ` [kernel-hardening] " Mark Rutland
2016-09-16 10:33       ` Mark Rutland
2016-09-16 15:11       ` Andy Lutomirski
2016-09-16 15:11         ` [kernel-hardening] " Andy Lutomirski
2016-09-16 15:11         ` Andy Lutomirski
2016-09-19 10:44         ` Mark Rutland
2016-09-19 10:44           ` [kernel-hardening] " Mark Rutland
2016-09-19 10:44           ` Mark Rutland
2016-09-21 10:28         ` Mark Rutland
2016-09-21 10:28           ` [kernel-hardening] " Mark Rutland
2016-09-21 10:28           ` Mark Rutland
2016-09-22 22:23           ` Andy Lutomirski
2016-09-22 22:23             ` [kernel-hardening] " Andy Lutomirski
2016-09-22 22:23             ` Andy Lutomirski
2016-09-23 17:31             ` Mark Rutland
2016-09-23 17:31               ` [kernel-hardening] " Mark Rutland
2016-09-23 17:31               ` Mark Rutland
2016-09-15 13:49 ` [RFC PATCH 3/8] arm64: thread_info remove stale items Mark Rutland
2016-09-15 13:49   ` [kernel-hardening] " Mark Rutland
2016-09-15 13:49   ` Mark Rutland
2016-09-15 13:49 ` [RFC PATCH 4/8] arm64: asm-offsets: remove unused definitions Mark Rutland
2016-09-15 13:49   ` [kernel-hardening] " Mark Rutland
2016-09-15 13:49   ` Mark Rutland
2016-09-15 13:49 ` Mark Rutland [this message]
2016-09-15 13:49   ` [kernel-hardening] [RFC PATCH 5/8] arm64: assembler: introduce ldr_this_cpu Mark Rutland
2016-09-15 13:49   ` Mark Rutland
2016-09-15 13:49 ` [RFC PATCH 6/8] arm64: traps: use task_struct instead of thread_info Mark Rutland
2016-09-15 13:49   ` [kernel-hardening] " Mark Rutland
2016-09-15 13:49   ` Mark Rutland
2016-09-15 13:49 ` [RFC PATCH 7/8] arm64: move sp_el0 and tpidr_el1 into cpu_suspend_ctx Mark Rutland
2016-09-15 13:49   ` [kernel-hardening] " Mark Rutland
2016-09-15 13:49   ` Mark Rutland
2016-09-15 13:49 ` [RFC PATCH 8/8] arm64: split thread_info from task stack Mark Rutland
2016-09-15 13:49   ` [kernel-hardening] " Mark Rutland
2016-09-15 13:49   ` Mark Rutland
2016-09-21  1:26 ` [RFC PATCH 0/8] arm64: move thread_info off of the " Laura Abbott
2016-09-21  1:26   ` [kernel-hardening] " Laura Abbott
2016-09-21  1:26   ` Laura Abbott
2016-09-21 10:31   ` Mark Rutland
2016-09-21 10:31     ` [kernel-hardening] " Mark Rutland
2016-09-21 10:31     ` Mark Rutland

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1473947349-14521-6-git-send-email-mark.rutland@arm.com \
    --to=mark.rutland@arm.com \
    --cc=akpm@linux-foundation.org \
    --cc=ard.biesheuvel@linaro.org \
    --cc=catalin.marinas@arm.com \
    --cc=james.morse@arm.com \
    --cc=keescook@chromium.org \
    --cc=kernel-hardening@lists.openwall.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lorenzo.pieralisi@arm.com \
    --cc=luto@kernel.org \
    --cc=suzuki.poulose@arm.com \
    --cc=takahiro.akashi@linaro.org \
    --cc=will.deacon@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.