[PATCH v7 3/4] ARM: Move some macros from entry-armv to entry-header

From: Daniel Thompson
Date: Mon Jun 30 2014 - 05:01:47 EST


From: Anton Vorontsov <anton.vorontsov@xxxxxxxxxx>

Just move the macros into header file as we would want to use them for
KGDB FIQ entry code.

The following macros were moved:

- svc_entry
- usr_entry
- kuser_cmpxchg_check
- vector_stub

To make kuser_cmpxchg_check actually work across different files, we
also have to make kuser_cmpxchg64_fixup global.

Signed-off-by: Anton Vorontsov <anton.vorontsov@xxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Acked-by: Nicolas Pitre <nico@xxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
arch/arm/kernel/entry-armv.S | 151 +------------------------------------
arch/arm/kernel/entry-header.S | 164 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 165 insertions(+), 150 deletions(-)

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 52a949a..4172cd6 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -140,53 +140,6 @@ ENDPROC(__und_invalid)
* SVC mode handlers
*/

-#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5)
-#define SPFIX(code...) code
-#else
-#define SPFIX(code...)
-#endif
-
- .macro svc_entry, stack_hole=0
- UNWIND(.fnstart )
- UNWIND(.save {r0 - pc} )
- sub sp, sp, #(S_FRAME_SIZE + \stack_hole - 4)
-#ifdef CONFIG_THUMB2_KERNEL
- SPFIX( str r0, [sp] ) @ temporarily saved
- SPFIX( mov r0, sp )
- SPFIX( tst r0, #4 ) @ test original stack alignment
- SPFIX( ldr r0, [sp] ) @ restored
-#else
- SPFIX( tst sp, #4 )
-#endif
- SPFIX( subeq sp, sp, #4 )
- stmia sp, {r1 - r12}
-
- ldmia r0, {r3 - r5}
- add r7, sp, #S_SP - 4 @ here for interlock avoidance
- mov r6, #-1 @ "" "" "" ""
- add r2, sp, #(S_FRAME_SIZE + \stack_hole - 4)
- SPFIX( addeq r2, r2, #4 )
- str r3, [sp, #-4]! @ save the "real" r0 copied
- @ from the exception stack
-
- mov r3, lr
-
- @
- @ We are now ready to fill in the remaining blanks on the stack:
- @
- @ r2 - sp_svc
- @ r3 - lr_svc
- @ r4 - lr_<exception>, already fixed up for correct return/restart
- @ r5 - spsr_<exception>
- @ r6 - orig_r0 (see pt_regs definition in ptrace.h)
- @
- stmia r7, {r2 - r6}
-
-#ifdef CONFIG_TRACE_IRQFLAGS
- bl trace_hardirqs_off
-#endif
- .endm
-
.align 5
__dabt_svc:
svc_entry
@@ -306,73 +259,8 @@ ENDPROC(__pabt_svc)

/*
* User mode handlers
- *
- * EABI note: sp_svc is always 64-bit aligned here, so should S_FRAME_SIZE
*/

-#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5) && (S_FRAME_SIZE & 7)
-#error "sizeof(struct pt_regs) must be a multiple of 8"
-#endif
-
- .macro usr_entry
- UNWIND(.fnstart )
- UNWIND(.cantunwind ) @ don't unwind the user space
- sub sp, sp, #S_FRAME_SIZE
- ARM( stmib sp, {r1 - r12} )
- THUMB( stmia sp, {r0 - r12} )
-
- ldmia r0, {r3 - r5}
- add r0, sp, #S_PC @ here for interlock avoidance
- mov r6, #-1 @ "" "" "" ""
-
- str r3, [sp] @ save the "real" r0 copied
- @ from the exception stack
-
- @
- @ We are now ready to fill in the remaining blanks on the stack:
- @
- @ r4 - lr_<exception>, already fixed up for correct return/restart
- @ r5 - spsr_<exception>
- @ r6 - orig_r0 (see pt_regs definition in ptrace.h)
- @
- @ Also, separately save sp_usr and lr_usr
- @
- stmia r0, {r4 - r6}
- ARM( stmdb r0, {sp, lr}^ )
- THUMB( store_user_sp_lr r0, r1, S_SP - S_PC )
-
- @
- @ Enable the alignment trap while in kernel mode
- @
- alignment_trap r0, .LCcralign
-
- @
- @ Clear FP to mark the first stack frame
- @
- zero_fp
-
-#ifdef CONFIG_IRQSOFF_TRACER
- bl trace_hardirqs_off
-#endif
- ct_user_exit save = 0
- .endm
-
- .macro kuser_cmpxchg_check
-#if !defined(CONFIG_CPU_32v6K) && defined(CONFIG_KUSER_HELPERS) && \
- !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
-#ifndef CONFIG_MMU
-#warning "NPTL on non MMU needs fixing"
-#else
- @ Make sure our user space atomic helper is restarted
- @ if it was interrupted in a critical region. Here we
- @ perform a quick test inline since it should be false
- @ 99.9999% of the time. The rest is done out of line.
- cmp r4, #TASK_SIZE
- blhs kuser_cmpxchg64_fixup
-#endif
-#endif
- .endm
-
.align 5
__dabt_usr:
usr_entry
@@ -823,6 +711,7 @@ __kuser_cmpxchg64: @ 0xffff0f60
ldmfd sp!, {r4, r5, r6, pc}

.text
+ .global kuser_cmpxchg64_fixup
kuser_cmpxchg64_fixup:
@ Called from kuser_cmpxchg_fixup.
@ r4 = address of interrupted insn (must be preserved).
@@ -964,44 +853,6 @@ __kuser_helper_end:
* SP points to a minimal amount of processor-private memory, the address
* of which is copied into r0 for the mode specific abort handler.
*/
- .macro vector_stub, name, mode, correction=0
- .align 5
-
-vector_\name:
- .if \correction
- sub lr, lr, #\correction
- .endif
-
- @
- @ Save r0, lr_<exception> (parent PC) and spsr_<exception>
- @ (parent CPSR)
- @
- stmia sp, {r0, lr} @ save r0, lr
- mrs lr, spsr
- str lr, [sp, #8] @ save spsr
-
- @
- @ Prepare for SVC32 mode. IRQs remain disabled.
- @
- mrs r0, cpsr
- eor r0, r0, #(\mode ^ SVC_MODE | PSR_ISETSTATE)
- msr spsr_cxsf, r0
-
- @
- @ the branch table must immediately follow this code
- @
- and lr, lr, #0x0f
- THUMB( adr r0, 1f )
- THUMB( ldr lr, [r0, lr, lsl #2] )
- mov r0, sp
- ARM( ldr lr, [pc, lr, lsl #2] )
- movs pc, lr @ branch to handler in SVC mode
-ENDPROC(vector_\name)
-
- .align 2
- @ handler addresses follow this label
-1:
- .endm

.section .stubs, "ax", %progbits
__stubs_start:
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 5d702f8..eb2c426 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -356,3 +356,167 @@ scno .req r7 @ syscall number
tbl .req r8 @ syscall table pointer
why .req r8 @ Linux syscall (!= 0)
tsk .req r9 @ current thread_info
+
+/*
+ * SVC mode handler macros
+ */
+
+#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5)
+#define SPFIX(code...) code
+#else
+#define SPFIX(code...)
+#endif
+
+ .macro svc_entry, stack_hole=0
+ UNWIND(.fnstart )
+ UNWIND(.save {r0 - pc} )
+ sub sp, sp, #(S_FRAME_SIZE + \stack_hole - 4)
+#ifdef CONFIG_THUMB2_KERNEL
+ SPFIX( str r0, [sp] ) @ temporarily saved
+ SPFIX( mov r0, sp )
+ SPFIX( tst r0, #4 ) @ test original stack alignment
+ SPFIX( ldr r0, [sp] ) @ restored
+#else
+ SPFIX( tst sp, #4 )
+#endif
+ SPFIX( subeq sp, sp, #4 )
+ stmia sp, {r1 - r12}
+
+ ldmia r0, {r3 - r5}
+ add r7, sp, #S_SP - 4 @ here for interlock avoidance
+ mov r6, #-1 @ "" "" "" ""
+ add r2, sp, #(S_FRAME_SIZE + \stack_hole - 4)
+ SPFIX( addeq r2, r2, #4 )
+ str r3, [sp, #-4]! @ save the "real" r0 copied
+ @ from the exception stack
+
+ mov r3, lr
+
+ @
+ @ We are now ready to fill in the remaining blanks on the stack:
+ @
+ @ r2 - sp_svc
+ @ r3 - lr_svc
+ @ r4 - lr_<exception>, already fixed up for correct return/restart
+ @ r5 - spsr_<exception>
+ @ r6 - orig_r0 (see pt_regs definition in ptrace.h)
+ @
+ stmia r7, {r2 - r6}
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+ bl trace_hardirqs_off
+#endif
+ .endm
+
+/*
+ * User mode handler macros
+ *
+ * EABI note: sp_svc is always 64-bit aligned here, so should S_FRAME_SIZE
+ */
+
+#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5) && (S_FRAME_SIZE & 7)
+#error "sizeof(struct pt_regs) must be a multiple of 8"
+#endif
+
+ .macro usr_entry
+ UNWIND(.fnstart )
+ UNWIND(.cantunwind ) @ don't unwind the user space
+ sub sp, sp, #S_FRAME_SIZE
+ ARM( stmib sp, {r1 - r12} )
+ THUMB( stmia sp, {r0 - r12} )
+
+ ldmia r0, {r3 - r5}
+ add r0, sp, #S_PC @ here for interlock avoidance
+ mov r6, #-1 @ "" "" "" ""
+
+ str r3, [sp] @ save the "real" r0 copied
+ @ from the exception stack
+
+ @
+ @ We are now ready to fill in the remaining blanks on the stack:
+ @
+ @ r4 - lr_<exception>, already fixed up for correct return/restart
+ @ r5 - spsr_<exception>
+ @ r6 - orig_r0 (see pt_regs definition in ptrace.h)
+ @
+ @ Also, separately save sp_usr and lr_usr
+ @
+ stmia r0, {r4 - r6}
+ ARM( stmdb r0, {sp, lr}^ )
+ THUMB( store_user_sp_lr r0, r1, S_SP - S_PC )
+
+ @
+ @ Enable the alignment trap while in kernel mode
+ @
+ alignment_trap r0, .LCcralign
+
+ @
+ @ Clear FP to mark the first stack frame
+ @
+ zero_fp
+
+#ifdef CONFIG_IRQSOFF_TRACER
+ bl trace_hardirqs_off
+#endif
+ ct_user_exit save = 0
+ .endm
+
+ .macro kuser_cmpxchg_check
+#if !defined(CONFIG_CPU_32v6K) && defined(CONFIG_KUSER_HELPERS) && \
+ !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
+#ifndef CONFIG_MMU
+#warning "NPTL on non MMU needs fixing"
+#else
+ @ Make sure our user space atomic helper is restarted
+ @ if it was interrupted in a critical region. Here we
+ @ perform a quick test inline since it should be false
+ @ 99.9999% of the time. The rest is done out of line.
+ cmp r4, #TASK_SIZE
+ blhs kuser_cmpxchg64_fixup
+#endif
+#endif
+ .endm
+
+/*
+ * Vector stubs macro.
+ */
+ .macro vector_stub, name, mode, correction=0
+ .align 5
+
+vector_\name:
+ .if \correction
+ sub lr, lr, #\correction
+ .endif
+
+ @
+ @ Save r0, lr_<exception> (parent PC) and spsr_<exception>
+ @ (parent CPSR)
+ @
+ stmia sp, {r0, lr} @ save r0, lr
+ mrs lr, spsr
+ str lr, [sp, #8] @ save spsr
+
+ @
+ @ Prepare for SVC32 mode. IRQs remain disabled.
+ @
+ mrs r0, cpsr
+ eor r0, r0, #(\mode ^ SVC_MODE | PSR_ISETSTATE)
+ msr spsr_cxsf, r0
+
+ @
+ @ the branch table must immediately follow this code
+ @
+ and lr, lr, #0x0f
+ THUMB( adr r0, 1f )
+ THUMB( ldr lr, [r0, lr, lsl #2] )
+ mov r0, sp
+ ARM( ldr lr, [pc, lr, lsl #2] )
+ movs pc, lr @ branch to handler in SVC mode
+ENDPROC(vector_\name)
+
+ .align 2
+ @ handler addresses follow this label
+1:
+ .endm
+
+
--
1.9.3

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