public inbox for kvmarm@lists.cs.columbia.edu
 help / color / mirror / Atom feed
From: James Morse <james.morse@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Julien Thierry <julien.thierry@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	wangxiongfeng2@huawei.com, kvmarm@lists.cs.columbia.edu
Subject: [RESEND PATCH v4 7/9] arm64: entry.S convert el0_sync
Date: Thu,  2 Nov 2017 12:12:40 +0000	[thread overview]
Message-ID: <20171102121242.8925-8-james.morse@arm.com> (raw)
In-Reply-To: <20171102121242.8925-1-james.morse@arm.com>

el0_sync also unmasks exceptions on a case-by-case basis, debug exceptions
are enabled, unless this was a debug exception. Irqs are unmasked for
some exception types but not for others.

el0_dbg should run with everything masked to prevent us taking a debug
exception from do_debug_exception. For the other cases we can unmask
everything. This changes the behaviour of fpsimd_{acc,exc} and el0_inv
which previously ran with irqs masked.

This patch removed the last user of enable_dbg_and_irq, remove it.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/include/asm/assembler.h |  9 ---------
 arch/arm64/kernel/entry.S          | 24 ++++++++++--------------
 2 files changed, 10 insertions(+), 23 deletions(-)

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index abb5abd61ddb..c2a37e2f733c 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -96,15 +96,6 @@
 9990:
 	.endm
 
-/*
- * Enable both debug exceptions and interrupts. This is likely to be
- * faster than two daifclr operations, since writes to this register
- * are self-synchronising.
- */
-	.macro	enable_dbg_and_irq
-	msr	daifclr, #(8 | 2)
-	.endm
-
 /*
  * SMP data memory barrier
  */
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index bd54115972a4..f7dfe5d2b1fb 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -670,8 +670,7 @@ el0_da:
 	 * Data abort handling
 	 */
 	mrs	x26, far_el1
-	// enable interrupts before calling the main handler
-	enable_dbg_and_irq
+	enable_daif
 	ct_user_exit
 	clear_address_tag x0, x26
 	mov	x1, x25
@@ -683,8 +682,7 @@ el0_ia:
 	 * Instruction abort handling
 	 */
 	mrs	x26, far_el1
-	// enable interrupts before calling the main handler
-	enable_dbg_and_irq
+	enable_daif
 	ct_user_exit
 	mov	x0, x26
 	mov	x1, x25
@@ -695,7 +693,7 @@ el0_fpsimd_acc:
 	/*
 	 * Floating Point or Advanced SIMD access
 	 */
-	enable_dbg
+	enable_daif
 	ct_user_exit
 	mov	x0, x25
 	mov	x1, sp
@@ -705,7 +703,7 @@ el0_fpsimd_exc:
 	/*
 	 * Floating Point or Advanced SIMD exception
 	 */
-	enable_dbg
+	enable_daif
 	ct_user_exit
 	mov	x0, x25
 	mov	x1, sp
@@ -716,8 +714,7 @@ el0_sp_pc:
 	 * Stack or PC alignment exception handling
 	 */
 	mrs	x26, far_el1
-	// enable interrupts before calling the main handler
-	enable_dbg_and_irq
+	enable_daif
 	ct_user_exit
 	mov	x0, x26
 	mov	x1, x25
@@ -728,8 +725,7 @@ el0_undef:
 	/*
 	 * Undefined instruction
 	 */
-	// enable interrupts before calling the main handler
-	enable_dbg_and_irq
+	enable_daif
 	ct_user_exit
 	mov	x0, sp
 	bl	do_undefinstr
@@ -738,7 +734,7 @@ el0_sys:
 	/*
 	 * System instructions, for trapped cache maintenance instructions
 	 */
-	enable_dbg_and_irq
+	enable_daif
 	ct_user_exit
 	mov	x0, x25
 	mov	x1, sp
@@ -753,11 +749,11 @@ el0_dbg:
 	mov	x1, x25
 	mov	x2, sp
 	bl	do_debug_exception
-	enable_dbg
+	enable_daif
 	ct_user_exit
 	b	ret_to_user
 el0_inv:
-	enable_dbg
+	enable_daif
 	ct_user_exit
 	mov	x0, sp
 	mov	x1, #BAD_SYNC
@@ -836,7 +832,7 @@ el0_svc:
 	mov	wsc_nr, #__NR_syscalls
 el0_svc_naked:					// compat entry point
 	stp	x0, xscno, [sp, #S_ORIG_X0]	// save the original x0 and syscall number
-	enable_dbg_and_irq
+	enable_daif
 	ct_user_exit 1
 
 	ldr	x16, [tsk, #TSK_TI_FLAGS]	// check for syscall hooks
-- 
2.15.0.rc2

  parent reply	other threads:[~2017-11-02 12:13 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-02 12:12 [RESEND PATCH v4 0/9] SError rework (- RAS & IESB for firmware first support) James Morse
2017-11-02 12:12 ` [RESEND PATCH v4 1/9] arm64: explicitly mask all exceptions James Morse
2017-11-02 12:12 ` [RESEND PATCH v4 2/9] arm64: introduce an order for exceptions James Morse
2017-11-02 12:12 ` [RESEND PATCH v4 3/9] arm64: Move the async/fiq helpers to explicitly set process context flags James Morse
2017-11-02 12:12 ` [RESEND PATCH v4 4/9] arm64: Mask all exceptions during kernel_exit James Morse
2017-11-02 12:12 ` [RESEND PATCH v4 5/9] arm64: entry.S: Remove disable_dbg James Morse
2017-11-02 12:12 ` [RESEND PATCH v4 6/9] arm64: entry.S: convert el1_sync James Morse
2017-11-02 12:12 ` James Morse [this message]
2017-11-02 12:12 ` [RESEND PATCH v4 8/9] arm64: entry.S: convert elX_irq James Morse
2017-11-02 12:12 ` [RESEND PATCH v4 9/9] arm64: entry.S: move SError handling into a C function for future expansion James Morse

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=20171102121242.8925-8-james.morse@arm.com \
    --to=james.morse@arm.com \
    --cc=catalin.marinas@arm.com \
    --cc=julien.thierry@arm.com \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=wangxiongfeng2@huawei.com \
    --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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox