From: Larry Bassel <larry.bassel@linaro.org>
To: catalin.marinas@arm.com, will.deacon@arm.com
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linaro-kernel@lists.linaro.org, khilman@linaro.org,
Larry Bassel <larry.bassel@linaro.org>
Subject: [PATCH 1/3] arm64: adjust el0_sync so that a function can be called
Date: Sun, 27 Apr 2014 12:44:12 -0700 [thread overview]
Message-ID: <1398627854-9617-2-git-send-email-larry.bassel@linaro.org> (raw)
In-Reply-To: <1398627854-9617-1-git-send-email-larry.bassel@linaro.org>
To implement the context tracker properly on arm64,
a function call needs to be made after debugging and
interrupts are turned on, but before the lr is changed
to point to ret_from_exception(). If the function call
is made after the lr is changed the function will not
return to the correct place. For similar reasons, defer
the setting of x0 so that it doesn't need to be saved
around the function call.
Signed-off-by: Larry Bassel <larry.bassel@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
---
arch/arm64/kernel/entry.S | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 39ac630..eda7755 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -349,11 +349,11 @@ el0_sync:
lsr x24, x25, #ESR_EL1_EC_SHIFT // exception class
cmp x24, #ESR_EL1_EC_SVC64 // SVC in 64-bit state
b.eq el0_svc
- adr lr, ret_from_exception
cmp x24, #ESR_EL1_EC_DABT_EL0 // data abort in EL0
b.eq el0_da
cmp x24, #ESR_EL1_EC_IABT_EL0 // instruction abort in EL0
b.eq el0_ia
+ adr lr, ret_from_exception
cmp x24, #ESR_EL1_EC_FP_ASIMD // FP/ASIMD access
b.eq el0_fpsimd_acc
cmp x24, #ESR_EL1_EC_FP_EXC64 // FP/ASIMD exception
@@ -378,11 +378,11 @@ el0_sync_compat:
lsr x24, x25, #ESR_EL1_EC_SHIFT // exception class
cmp x24, #ESR_EL1_EC_SVC32 // SVC in 32-bit state
b.eq el0_svc_compat
- adr lr, ret_from_exception
cmp x24, #ESR_EL1_EC_DABT_EL0 // data abort in EL0
b.eq el0_da
cmp x24, #ESR_EL1_EC_IABT_EL0 // instruction abort in EL0
b.eq el0_ia
+ adr lr, ret_from_exception
cmp x24, #ESR_EL1_EC_FP_ASIMD // FP/ASIMD access
b.eq el0_fpsimd_acc
cmp x24, #ESR_EL1_EC_FP_EXC32 // FP/ASIMD exception
@@ -421,28 +421,30 @@ el0_da:
/*
* Data abort handling
*/
- mrs x0, far_el1
- bic x0, x0, #(0xff << 56)
disable_step x1
isb
enable_dbg
// enable interrupts before calling the main handler
enable_irq
+ mrs x0, far_el1
+ bic x0, x0, #(0xff << 56)
mov x1, x25
mov x2, sp
+ adr lr, ret_from_exception
b do_mem_abort
el0_ia:
/*
* Instruction abort handling
*/
- mrs x0, far_el1
disable_step x1
isb
enable_dbg
// enable interrupts before calling the main handler
enable_irq
+ mrs x0, far_el1
orr x1, x25, #1 << 24 // use reserved ISS bit for instruction aborts
mov x2, sp
+ adr lr, ret_from_exception
b do_mem_abort
el0_fpsimd_acc:
/*
--
1.8.3.2
next prev parent reply other threads:[~2014-04-27 19:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-27 19:44 [PATCH 0/3] context tracker support for arm64 Larry Bassel
2014-04-27 19:44 ` Larry Bassel [this message]
2014-04-29 9:42 ` [PATCH 1/3] arm64: adjust el0_sync so that a function can be called Catalin Marinas
2014-05-05 22:44 ` Kevin Hilman
2014-04-27 19:44 ` [PATCH 2/3] arm64: add support for context tracking Larry Bassel
2014-04-27 19:44 ` [PATCH 3/3] arm64: enable " Larry Bassel
2014-04-29 9:43 ` Catalin Marinas
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