#include <asm/entry-macro-multi.S>
/*
- * Interrupt handling. Preserves r7, r8, r9
+ * Interrupt handling.
*/
.macro irq_handler
#ifdef CONFIG_MULTI_IRQ_HANDLER
- ldr r5, =handle_arch_irq
+ ldr r1, =handle_arch_irq
mov r0, sp
- ldr r5, [r5]
+ ldr r1, [r1]
adr lr, BSYM(9997f)
- teq r5, #0
- movne pc, r5
+ teq r1, #0
+ movne pc, r1
#endif
arch_irq_handler_default
9997:
.endm
+ .macro pabt_helper
+ @ PABORT handler takes pt_regs in r2, fault address in r4 and psr in r5
+#ifdef MULTI_PABORT
+ ldr ip, .LCprocfns
+ mov lr, pc
+ ldr pc, [ip, #PROCESSOR_PABT_FUNC]
+#else
+ bl CPU_PABORT_HANDLER
+#endif
+ .endm
+
+ .macro dabt_helper
+
+ @
+ @ Call the processor-specific abort handler:
+ @
+ @ r2 - pt_regs
+ @ r4 - aborted context pc
+ @ r5 - aborted context psr
+ @
+ @ The abort handler must return the aborted address in r0, and
+ @ the fault status register in r1. r9 must be preserved.
+ @
+#ifdef MULTI_DABORT
+ ldr ip, .LCprocfns
+ mov lr, pc
+ ldr pc, [ip, #PROCESSOR_DABT_FUNC]
+#else
+ bl CPU_DABORT_HANDLER
+#endif
+ .endm
+
#ifdef CONFIG_KPROBES
.section .kprobes.text,"ax",%progbits
#else
SPFIX( subeq sp, sp, #4 )
stmia sp, {r1 - r12}
- ldmia r0, {r1 - r3}
- add r5, sp, #S_SP - 4 @ here for interlock avoidance
- mov r4, #-1 @ "" "" "" ""
- add r0, sp, #(S_FRAME_SIZE + \stack_hole - 4)
- SPFIX( addeq r0, r0, #4 )
- str r1, [sp, #-4]! @ save the "real" r0 copied
+ 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 r1, lr
+ mov r3, lr
@
@ We are now ready to fill in the remaining blanks on the stack:
@
- @ r0 - sp_svc
- @ r1 - lr_svc
- @ r2 - lr_<exception>, already fixed up for correct return/restart
- @ r3 - spsr_<exception>
- @ r4 - orig_r0 (see pt_regs definition in ptrace.h)
+ @ 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 r5, {r0 - r4}
+ stmia r7, {r2 - r6}
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+ bl trace_hardirqs_off
+#endif
.endm
.align 5
__dabt_svc:
svc_entry
-
- @
- @ get ready to re-enable interrupts if appropriate
- @
- mrs r9, cpsr
- tst r3, #PSR_I_BIT
- biceq r9, r9, #PSR_I_BIT
-
- @
- @ Call the processor-specific abort handler:
- @
- @ r2 - aborted context pc
- @ r3 - aborted context cpsr
- @
- @ The abort handler must return the aborted address in r0, and
- @ the fault status register in r1. r9 must be preserved.
- @
-#ifdef MULTI_DABORT
- ldr r4, .LCprocfns
- mov lr, pc
- ldr pc, [r4, #PROCESSOR_DABT_FUNC]
-#else
- bl CPU_DABORT_HANDLER
-#endif
-
- @
- @ set desired IRQ state, then call main handler
- @
- debug_entry r1
- msr cpsr_c, r9
mov r2, sp
- bl do_DataAbort
+ dabt_helper
@
@ IRQs off again before pulling preserved data off the stack
@
disable_irq_notrace
- @
- @ restore SPSR and restart the instruction
- @
- ldr r2, [sp, #S_PSR]
- svc_exit r2 @ return from exception
+#ifdef CONFIG_TRACE_IRQFLAGS
+ tst r5, #PSR_I_BIT
+ bleq trace_hardirqs_on
+ tst r5, #PSR_I_BIT
+ blne trace_hardirqs_off
+#endif
+ svc_exit r5 @ return from exception
UNWIND(.fnend )
ENDPROC(__dabt_svc)
.align 5
__irq_svc:
svc_entry
+ irq_handler
-#ifdef CONFIG_TRACE_IRQFLAGS
- bl trace_hardirqs_off
-#endif
#ifdef CONFIG_PREEMPT
get_thread_info tsk
ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
- add r7, r8, #1 @ increment it
- str r7, [tsk, #TI_PREEMPT]
-#endif
-
- irq_handler
-#ifdef CONFIG_PREEMPT
- str r8, [tsk, #TI_PREEMPT] @ restore preempt count
ldr r0, [tsk, #TI_FLAGS] @ get flags
teq r8, #0 @ if preempt count != 0
movne r0, #0 @ force flags to 0
tst r0, #_TIF_NEED_RESCHED
blne svc_preempt
#endif
- ldr r4, [sp, #S_PSR] @ irqs are already disabled
+
#ifdef CONFIG_TRACE_IRQFLAGS
- tst r4, #PSR_I_BIT
- bleq trace_hardirqs_on
+ @ The parent context IRQs must have been enabled to get here in
+ @ the first place, so there's no point checking the PSR I bit.
+ bl trace_hardirqs_on
#endif
- svc_exit r4 @ return from exception
+ svc_exit r5 @ return from exception
UNWIND(.fnend )
ENDPROC(__irq_svc)
#else
svc_entry
#endif
-
@
@ call emulation code, which returns using r9 if it has emulated
@ the instruction, or the more conventional lr if we are to treat
@ r0 - instruction
@
#ifndef CONFIG_THUMB2_KERNEL
- ldr r0, [r2, #-4]
+ ldr r0, [r4, #-4]
#else
- ldrh r0, [r2, #-2] @ Thumb instruction at LR - 2
+ ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2
and r9, r0, #0xf800
cmp r9, #0xe800 @ 32-bit instruction if xx >= 0
- ldrhhs r9, [r2] @ bottom 16 bits
+ ldrhhs r9, [r4] @ bottom 16 bits
orrhs r0, r9, r0, lsl #16
#endif
adr r9, BSYM(1f)
+ mov r2, r4
bl call_fpe
mov r0, sp @ struct pt_regs *regs
@
@ restore SPSR and restart the instruction
@
- ldr r2, [sp, #S_PSR] @ Get SVC cpsr
- svc_exit r2 @ return from exception
+ ldr r5, [sp, #S_PSR] @ Get SVC cpsr
+#ifdef CONFIG_TRACE_IRQFLAGS
+ tst r5, #PSR_I_BIT
+ bleq trace_hardirqs_on
+ tst r5, #PSR_I_BIT
+ blne trace_hardirqs_off
+#endif
+ svc_exit r5 @ return from exception
UNWIND(.fnend )
ENDPROC(__und_svc)
.align 5
__pabt_svc:
svc_entry
-
- @
- @ re-enable interrupts if appropriate
- @
- mrs r9, cpsr
- tst r3, #PSR_I_BIT
- biceq r9, r9, #PSR_I_BIT
-
- mov r0, r2 @ pass address of aborted instruction.
-#ifdef MULTI_PABORT
- ldr r4, .LCprocfns
- mov lr, pc
- ldr pc, [r4, #PROCESSOR_PABT_FUNC]
-#else
- bl CPU_PABORT_HANDLER
-#endif
- debug_entry r1
- msr cpsr_c, r9 @ Maybe enable interrupts
mov r2, sp @ regs
- bl do_PrefetchAbort @ call abort handler
+ pabt_helper
@
@ IRQs off again before pulling preserved data off the stack
@
disable_irq_notrace
- @
- @ restore SPSR and restart the instruction
- @
- ldr r2, [sp, #S_PSR]
- svc_exit r2 @ return from exception
+#ifdef CONFIG_TRACE_IRQFLAGS
+ tst r5, #PSR_I_BIT
+ bleq trace_hardirqs_on
+ tst r5, #PSR_I_BIT
+ blne trace_hardirqs_off
+#endif
+ svc_exit r5 @ return from exception
UNWIND(.fnend )
ENDPROC(__pabt_svc)
ARM( stmib sp, {r1 - r12} )
THUMB( stmia sp, {r0 - r12} )
- ldmia r0, {r1 - r3}
+ ldmia r0, {r3 - r5}
add r0, sp, #S_PC @ here for interlock avoidance
- mov r4, #-1 @ "" "" "" ""
+ mov r6, #-1 @ "" "" "" ""
- str r1, [sp] @ save the "real" r0 copied
+ 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:
@
- @ r2 - lr_<exception>, already fixed up for correct return/restart
- @ r3 - spsr_<exception>
- @ r4 - orig_r0 (see pt_regs definition in ptrace.h)
+ @ 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, {r2 - r4}
+ stmia r0, {r4 - r6}
ARM( stmdb r0, {sp, lr}^ )
THUMB( store_user_sp_lr r0, r1, S_SP - S_PC )
@ Clear FP to mark the first stack frame
@
zero_fp
+
+#ifdef CONFIG_IRQSOFF_TRACER
+ bl trace_hardirqs_off
+#endif
.endm
.macro kuser_cmpxchg_check
-#if __LINUX_ARM_ARCH__ < 6 && !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
+#if !defined(CONFIG_CPU_32v6K) && !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
#ifndef CONFIG_MMU
#warning "NPTL on non MMU needs fixing"
#else
@ 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 r2, #TASK_SIZE
- blhs kuser_cmpxchg_fixup
+ cmp r4, #TASK_SIZE
+ blhs kuser_cmpxchg64_fixup
#endif
#endif
.endm
__dabt_usr:
usr_entry
kuser_cmpxchg_check
-
- @
- @ Call the processor-specific abort handler:
- @
- @ r2 - aborted context pc
- @ r3 - aborted context cpsr
- @
- @ The abort handler must return the aborted address in r0, and
- @ the fault status register in r1.
- @
-#ifdef MULTI_DABORT
- ldr r4, .LCprocfns
- mov lr, pc
- ldr pc, [r4, #PROCESSOR_DABT_FUNC]
-#else
- bl CPU_DABORT_HANDLER
-#endif
-
- @
- @ IRQs on, then call the main handler
- @
- debug_entry r1
- enable_irq
mov r2, sp
- adr lr, BSYM(ret_from_exception)
- b do_DataAbort
+ dabt_helper
+ b ret_from_exception
UNWIND(.fnend )
ENDPROC(__dabt_usr)
__irq_usr:
usr_entry
kuser_cmpxchg_check
-
-#ifdef CONFIG_IRQSOFF_TRACER
- bl trace_hardirqs_off
-#endif
-
- get_thread_info tsk
-#ifdef CONFIG_PREEMPT
- ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
- add r7, r8, #1 @ increment it
- str r7, [tsk, #TI_PREEMPT]
-#endif
-
irq_handler
-#ifdef CONFIG_PREEMPT
- ldr r0, [tsk, #TI_PREEMPT]
- str r8, [tsk, #TI_PREEMPT]
- teq r0, r7
- ARM( strne r0, [r0, -r0] )
- THUMB( movne r0, #0 )
- THUMB( strne r0, [r0] )
-#endif
-
+ get_thread_info tsk
mov why, #0
b ret_to_user_from_irq
UNWIND(.fnend )
__und_usr:
usr_entry
+ mov r2, r4
+ mov r3, r5
+
@
@ fall through to the emulation code, which returns using r9 if
@ it has emulated the instruction, or the more conventional lr
.align 5
__pabt_usr:
usr_entry
-
- mov r0, r2 @ pass address of aborted instruction.
-#ifdef MULTI_PABORT
- ldr r4, .LCprocfns
- mov lr, pc
- ldr pc, [r4, #PROCESSOR_PABT_FUNC]
-#else
- bl CPU_PABORT_HANDLER
-#endif
- debug_entry r1
- enable_irq @ Enable interrupts
mov r2, sp @ regs
- bl do_PrefetchAbort @ call abort handler
+ pabt_helper
UNWIND(.fnend )
/* fall through */
/*
/*
* User helpers.
*
- * These are segment of kernel provided user code reachable from user space
- * at a fixed address in kernel memory. This is used to provide user space
- * with some operations which require kernel help because of unimplemented
- * native feature and/or instructions in many ARM CPUs. The idea is for
- * this code to be executed directly in user mode for best efficiency but
- * which is too intimate with the kernel counter part to be left to user
- * libraries. In fact this code might even differ from one CPU to another
- * depending on the available instruction set and restrictions like on
- * SMP systems. In other words, the kernel reserves the right to change
- * this code as needed without warning. Only the entry points and their
- * results are guaranteed to be stable.
- *
* Each segment is 32-byte aligned and will be moved to the top of the high
* vector page. New segments (if ever needed) must be added in front of
* existing ones. This mechanism should be used only for things that are
* really small and justified, and not be abused freely.
*
- * User space is expected to implement those things inline when optimizing
- * for a processor that has the necessary native support, but only if such
- * resulting binaries are already to be incompatible with earlier ARM
- * processors due to the use of unsupported instructions other than what
- * is provided here. In other words don't make binaries unable to run on
- * earlier processors just for the sake of not using these kernel helpers
- * if your compiled code is not going to use the new instructions for other
- * purpose.
+ * See Documentation/arm/kernel_user_helpers.txt for formal definitions.
*/
THUMB( .arm )
__kuser_helper_start:
/*
- * Reference prototype:
- *
- * void __kernel_memory_barrier(void)
- *
- * Input:
- *
- * lr = return address
- *
- * Output:
- *
- * none
- *
- * Clobbered:
- *
- * none
- *
- * Definition and user space usage example:
- *
- * typedef void (__kernel_dmb_t)(void);
- * #define __kernel_dmb (*(__kernel_dmb_t *)0xffff0fa0)
- *
- * Apply any needed memory barrier to preserve consistency with data modified
- * manually and __kuser_cmpxchg usage.
- *
- * This could be used as follows:
- *
- * #define __kernel_dmb() \
- * asm volatile ( "mov r0, #0xffff0fff; mov lr, pc; sub pc, r0, #95" \
- * : : : "r0", "lr","cc" )
+ * Due to the length of some sequences, __kuser_cmpxchg64 spans 2 regular
+ * kuser "slots", therefore 0xffff0f80 is not used as a valid entry point.
*/
-__kuser_memory_barrier: @ 0xffff0fa0
+__kuser_cmpxchg64: @ 0xffff0f60
+
+#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
+
+ /*
+ * Poor you. No fast solution possible...
+ * The kernel itself must perform the operation.
+ * A special ghost syscall is used for that (see traps.c).
+ */
+ stmfd sp!, {r7, lr}
+ ldr r7, 1f @ it's 20 bits
+ swi __ARM_NR_cmpxchg64
+ ldmfd sp!, {r7, pc}
+1: .word __ARM_NR_cmpxchg64
+
+#elif defined(CONFIG_CPU_32v6K)
+
+ stmfd sp!, {r4, r5, r6, r7}
+ ldrd r4, r5, [r0] @ load old val
+ ldrd r6, r7, [r1] @ load new val
+ smp_dmb arm
+1: ldrexd r0, r1, [r2] @ load current val
+ eors r3, r0, r4 @ compare with oldval (1)
+ eoreqs r3, r1, r5 @ compare with oldval (2)
+ strexdeq r3, r6, r7, [r2] @ store newval if eq
+ teqeq r3, #1 @ success?
+ beq 1b @ if no then retry
smp_dmb arm
+ rsbs r0, r3, #0 @ set returned val and C flag
+ ldmfd sp!, {r4, r5, r6, r7}
+ bx lr
+
+#elif !defined(CONFIG_SMP)
+
+#ifdef CONFIG_MMU
+
+ /*
+ * The only thing that can break atomicity in this cmpxchg64
+ * implementation is either an IRQ or a data abort exception
+ * causing another process/thread to be scheduled in the middle of
+ * the critical sequence. The same strategy as for cmpxchg is used.
+ */
+ stmfd sp!, {r4, r5, r6, lr}
+ ldmia r0, {r4, r5} @ load old val
+ ldmia r1, {r6, lr} @ load new val
+1: ldmia r2, {r0, r1} @ load current val
+ eors r3, r0, r4 @ compare with oldval (1)
+ eoreqs r3, r1, r5 @ compare with oldval (2)
+2: stmeqia r2, {r6, lr} @ store newval if eq
+ rsbs r0, r3, #0 @ set return val and C flag
+ ldmfd sp!, {r4, r5, r6, pc}
+
+ .text
+kuser_cmpxchg64_fixup:
+ @ Called from kuser_cmpxchg_fixup.
+ @ r4 = address of interrupted insn (must be preserved).
+ @ sp = saved regs. r7 and r8 are clobbered.
+ @ 1b = first critical insn, 2b = last critical insn.
+ @ If r4 >= 1b and r4 <= 2b then saved pc_usr is set to 1b.
+ mov r7, #0xffff0fff
+ sub r7, r7, #(0xffff0fff - (0xffff0f60 + (1b - __kuser_cmpxchg64)))
+ subs r8, r4, r7
+ rsbcss r8, r8, #(2b - 1b)
+ strcs r7, [sp, #S_PC]
+#if __LINUX_ARM_ARCH__ < 6
+ bcc kuser_cmpxchg32_fixup
+#endif
+ mov pc, lr
+ .previous
+
+#else
+#warning "NPTL on non MMU needs fixing"
+ mov r0, #-1
+ adds r0, r0, #0
usr_ret lr
+#endif
+
+#else
+#error "incoherent kernel configuration"
+#endif
+
+ /* pad to next slot */
+ .rept (16 - (. - __kuser_cmpxchg64)/4)
+ .word 0
+ .endr
.align 5
-/*
- * Reference prototype:
- *
- * int __kernel_cmpxchg(int oldval, int newval, int *ptr)
- *
- * Input:
- *
- * r0 = oldval
- * r1 = newval
- * r2 = ptr
- * lr = return address
- *
- * Output:
- *
- * r0 = returned value (zero or non-zero)
- * C flag = set if r0 == 0, clear if r0 != 0
- *
- * Clobbered:
- *
- * r3, ip, flags
- *
- * Definition and user space usage example:
- *
- * typedef int (__kernel_cmpxchg_t)(int oldval, int newval, int *ptr);
- * #define __kernel_cmpxchg (*(__kernel_cmpxchg_t *)0xffff0fc0)
- *
- * Atomically store newval in *ptr if *ptr is equal to oldval for user space.
- * Return zero if *ptr was changed or non-zero if no exchange happened.
- * The C flag is also set if *ptr was changed to allow for assembly
- * optimization in the calling code.
- *
- * Notes:
- *
- * - This routine already includes memory barriers as needed.
- *
- * For example, a user space atomic_add implementation could look like this:
- *
- * #define atomic_add(ptr, val) \
- * ({ register unsigned int *__ptr asm("r2") = (ptr); \
- * register unsigned int __result asm("r1"); \
- * asm volatile ( \
- * "1: @ atomic_add\n\t" \
- * "ldr r0, [r2]\n\t" \
- * "mov r3, #0xffff0fff\n\t" \
- * "add lr, pc, #4\n\t" \
- * "add r1, r0, %2\n\t" \
- * "add pc, r3, #(0xffff0fc0 - 0xffff0fff)\n\t" \
- * "bcc 1b" \
- * : "=&r" (__result) \
- * : "r" (__ptr), "rIL" (val) \
- * : "r0","r3","ip","lr","cc","memory" ); \
- * __result; })
- */
+__kuser_memory_barrier: @ 0xffff0fa0
+ smp_dmb arm
+ usr_ret lr
+
+ .align 5
__kuser_cmpxchg: @ 0xffff0fc0
usr_ret lr
.text
-kuser_cmpxchg_fixup:
+kuser_cmpxchg32_fixup:
@ Called from kuser_cmpxchg_check macro.
- @ r2 = address of interrupted insn (must be preserved).
+ @ r4 = address of interrupted insn (must be preserved).
@ sp = saved regs. r7 and r8 are clobbered.
@ 1b = first critical insn, 2b = last critical insn.
- @ If r2 >= 1b and r2 <= 2b then saved pc_usr is set to 1b.
+ @ If r4 >= 1b and r4 <= 2b then saved pc_usr is set to 1b.
mov r7, #0xffff0fff
sub r7, r7, #(0xffff0fff - (0xffff0fc0 + (1b - __kuser_cmpxchg)))
- subs r8, r2, r7
+ subs r8, r4, r7
rsbcss r8, r8, #(2b - 1b)
strcs r7, [sp, #S_PC]
mov pc, lr
.align 5
-/*
- * Reference prototype:
- *
- * int __kernel_get_tls(void)
- *
- * Input:
- *
- * lr = return address
- *
- * Output:
- *
- * r0 = TLS value
- *
- * Clobbered:
- *
- * none
- *
- * Definition and user space usage example:
- *
- * typedef int (__kernel_get_tls_t)(void);
- * #define __kernel_get_tls (*(__kernel_get_tls_t *)0xffff0fe0)
- *
- * Get the TLS value as previously set via the __ARM_NR_set_tls syscall.
- *
- * This could be used as follows:
- *
- * #define __kernel_get_tls() \
- * ({ register unsigned int __val asm("r0"); \
- * asm( "mov r0, #0xffff0fff; mov lr, pc; sub pc, r0, #31" \
- * : "=r" (__val) : : "lr","cc" ); \
- * __val; })
- */
-
__kuser_get_tls: @ 0xffff0fe0
ldr r0, [pc, #(16 - 8)] @ read TLS, set in kuser_get_tls_init
usr_ret lr
.word 0 @ 0xffff0ff0 software TLS value, then
.endr @ pad up to __kuser_helper_version
-/*
- * Reference declaration:
- *
- * extern unsigned int __kernel_helper_version;
- *
- * Definition and user space usage example:
- *
- * #define __kernel_helper_version (*(unsigned int *)0xffff0ffc)
- *
- * User space may read this to determine the curent number of helpers
- * available.
- */
-
__kuser_helper_version: @ 0xffff0ffc
.word ((__kuser_helper_end - __kuser_helper_start) >> 5)
git.openpandora.org / pandora-kernel.git / blobdiff