diff options
Diffstat (limited to 'arch/arm/kernel/entry-armv.S')
| -rw-r--r-- | arch/arm/kernel/entry-armv.S | 272 |
1 files changed, 149 insertions, 123 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 4eb36155dc93..39a6c1b0b9a3 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -24,48 +24,91 @@ #include "entry-header.S" /* + * Interrupt handling. Preserves r7, r8, r9 + */ + .macro irq_handler +1: get_irqnr_and_base r0, r6, r5, lr + movne r1, sp + @ + @ routine called with r0 = irq number, r1 = struct pt_regs * + @ + adrne lr, 1b + bne asm_do_IRQ + +#ifdef CONFIG_SMP + /* + * XXX + * + * this macro assumes that irqstat (r6) and base (r5) are + * preserved from get_irqnr_and_base above + */ + test_for_ipi r0, r6, r5, lr + movne r0, sp + adrne lr, 1b + bne do_IPI +#endif + + .endm + +/* * Invalid mode handlers */ - .macro inv_entry, sym, reason - sub sp, sp, #S_FRAME_SIZE @ Allocate frame size in one go - stmia sp, {r0 - lr} @ Save XXX r0 - lr - ldr r4, .LC\sym + .macro inv_entry, reason + sub sp, sp, #S_FRAME_SIZE + stmib sp, {r1 - lr} mov r1, #\reason .endm __pabt_invalid: - inv_entry abt, BAD_PREFETCH - b 1f + inv_entry BAD_PREFETCH + b common_invalid __dabt_invalid: - inv_entry abt, BAD_DATA - b 1f + inv_entry BAD_DATA + b common_invalid __irq_invalid: - inv_entry irq, BAD_IRQ - b 1f + inv_entry BAD_IRQ + b common_invalid __und_invalid: - inv_entry und, BAD_UNDEFINSTR + inv_entry BAD_UNDEFINSTR + + @ + @ XXX fall through to common_invalid + @ + +@ +@ common_invalid - generic code for failed exception (re-entrant version of handlers) +@ +common_invalid: + zero_fp + + ldmia r0, {r4 - r6} + add r0, sp, #S_PC @ here for interlock avoidance + mov r7, #-1 @ "" "" "" "" + str r4, [sp] @ save preserved r0 + stmia r0, {r5 - r7} @ lr_<exception>, + @ cpsr_<exception>, "old_r0" -1: zero_fp - ldmia r4, {r5 - r7} @ Get XXX pc, cpsr, old_r0 - add r4, sp, #S_PC - stmia r4, {r5 - r7} @ Save XXX pc, cpsr, old_r0 mov r0, sp - and r2, r6, #31 @ int mode + and r2, r6, #0x1f b bad_mode /* * SVC mode handlers */ - .macro svc_entry, sym + .macro svc_entry sub sp, sp, #S_FRAME_SIZE - stmia sp, {r0 - r12} @ save r0 - r12 - ldr r2, .LC\sym - add r0, sp, #S_FRAME_SIZE - ldmia r2, {r2 - r4} @ get pc, cpsr - add r5, sp, #S_SP + stmib sp, {r1 - r12} + + ldmia r0, {r1 - r3} + add r5, sp, #S_SP @ here for interlock avoidance + mov r4, #-1 @ "" "" "" "" + add r0, sp, #S_FRAME_SIZE @ "" "" "" "" + str r1, [sp] @ save the "real" r0 copied + @ from the exception stack + mov r1, lr @ @@ -82,7 +125,7 @@ __und_invalid: .align 5 __dabt_svc: - svc_entry abt + svc_entry @ @ get ready to re-enable interrupts if appropriate @@ -129,28 +172,24 @@ __dabt_svc: .align 5 __irq_svc: - svc_entry irq + svc_entry + #ifdef CONFIG_PREEMPT - get_thread_info r8 - ldr r9, [r8, #TI_PREEMPT] @ get preempt count - add r7, r9, #1 @ increment it - str r7, [r8, #TI_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 -1: get_irqnr_and_base r0, r6, r5, lr - movne r1, sp - @ - @ routine called with r0 = irq number, r1 = struct pt_regs * - @ - adrne lr, 1b - bne asm_do_IRQ + + irq_handler #ifdef CONFIG_PREEMPT - ldr r0, [r8, #TI_FLAGS] @ get flags + ldr r0, [tsk, #TI_FLAGS] @ get flags tst r0, #_TIF_NEED_RESCHED blne svc_preempt preempt_return: - ldr r0, [r8, #TI_PREEMPT] @ read preempt value + ldr r0, [tsk, #TI_PREEMPT] @ read preempt value + str r8, [tsk, #TI_PREEMPT] @ restore preempt count teq r0, r7 - str r9, [r8, #TI_PREEMPT] @ restore preempt count strne r0, [r0, -r0] @ bug() #endif ldr r0, [sp, #S_PSR] @ irqs are already disabled @@ -161,7 +200,7 @@ preempt_return: #ifdef CONFIG_PREEMPT svc_preempt: - teq r9, #0 @ was preempt count = 0 + teq r8, #0 @ was preempt count = 0 ldreq r6, .LCirq_stat movne pc, lr @ no ldr r0, [r6, #4] @ local_irq_count @@ -169,9 +208,9 @@ svc_preempt: adds r0, r0, r1 movne pc, lr mov r7, #0 @ preempt_schedule_irq - str r7, [r8, #TI_PREEMPT] @ expects preempt_count == 0 + str r7, [tsk, #TI_PREEMPT] @ expects preempt_count == 0 1: bl preempt_schedule_irq @ irq en/disable is done inside - ldr r0, [r8, #TI_FLAGS] @ get new tasks TI_FLAGS + ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS tst r0, #_TIF_NEED_RESCHED beq preempt_return @ go again b 1b @@ -179,7 +218,7 @@ svc_preempt: .align 5 __und_svc: - svc_entry und + svc_entry @ @ call emulation code, which returns using r9 if it has emulated @@ -209,7 +248,7 @@ __und_svc: .align 5 __pabt_svc: - svc_entry abt + svc_entry @ @ re-enable interrupts if appropriate @@ -242,12 +281,8 @@ __pabt_svc: ldmia sp, {r0 - pc}^ @ load r0 - pc, cpsr .align 5 -.LCirq: - .word __temp_irq -.LCund: - .word __temp_und -.LCabt: - .word __temp_abt +.LCcralign: + .word cr_alignment #ifdef MULTI_ABORT .LCprocfns: .word processor @@ -262,14 +297,18 @@ __pabt_svc: /* * User mode handlers */ - .macro usr_entry, sym - sub sp, sp, #S_FRAME_SIZE @ Allocate frame size in one go - stmia sp, {r0 - r12} @ save r0 - r12 - ldr r7, .LC\sym - add r5, sp, #S_PC - ldmia r7, {r2 - r4} @ Get USR pc, cpsr - -#if __LINUX_ARM_ARCH__ < 6 + .macro usr_entry + sub sp, sp, #S_FRAME_SIZE + stmib sp, {r1 - r12} + + ldmia r0, {r1 - r3} + add r0, sp, #S_PC @ here for interlock avoidance + mov r4, #-1 @ "" "" "" "" + + str r1, [sp] @ save the "real" r0 copied + @ from the exception stack + +#if __LINUX_ARM_ARCH__ < 6 && !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG) @ make sure our user space atomic helper is aborted cmp r2, #VIRT_OFFSET bichs r3, r3, #PSR_Z_BIT @@ -284,13 +323,13 @@ __pabt_svc: @ @ Also, separately save sp_usr and lr_usr @ - stmia r5, {r2 - r4} - stmdb r5, {sp, lr}^ + stmia r0, {r2 - r4} + stmdb r0, {sp, lr}^ @ @ Enable the alignment trap while in kernel mode @ - alignment_trap r7, r0, __temp_\sym + alignment_trap r0 @ @ Clear FP to mark the first stack frame @@ -300,7 +339,7 @@ __pabt_svc: .align 5 __dabt_usr: - usr_entry abt + usr_entry @ @ Call the processor-specific abort handler: @@ -329,30 +368,23 @@ __dabt_usr: .align 5 __irq_usr: - usr_entry irq + usr_entry + get_thread_info tsk #ifdef CONFIG_PREEMPT - get_thread_info r8 - ldr r9, [r8, #TI_PREEMPT] @ get preempt count - add r7, r9, #1 @ increment it - str r7, [r8, #TI_PREEMPT] + ldr r8, [tsk, #TI_PREEMPT] @ get preempt count + add r7, r8, #1 @ increment it + str r7, [tsk, #TI_PREEMPT] #endif -1: get_irqnr_and_base r0, r6, r5, lr - movne r1, sp - adrne lr, 1b - @ - @ routine called with r0 = irq number, r1 = struct pt_regs * - @ - bne asm_do_IRQ + + irq_handler #ifdef CONFIG_PREEMPT - ldr r0, [r8, #TI_PREEMPT] + ldr r0, [tsk, #TI_PREEMPT] + str r8, [tsk, #TI_PREEMPT] teq r0, r7 - str r9, [r8, #TI_PREEMPT] strne r0, [r0, -r0] - mov tsk, r8 -#else - get_thread_info tsk #endif + mov why, #0 b ret_to_user @@ -360,7 +392,7 @@ __irq_usr: .align 5 __und_usr: - usr_entry und + usr_entry tst r3, #PSR_T_BIT @ Thumb mode? bne fpundefinstr @ ignore FP @@ -476,7 +508,7 @@ fpundefinstr: .align 5 __pabt_usr: - usr_entry abt + usr_entry enable_irq @ Enable interrupts mov r0, r2 @ address (pc) @@ -616,11 +648,17 @@ __kuser_helper_start: __kuser_cmpxchg: @ 0xffff0fc0 -#if __LINUX_ARM_ARCH__ < 6 +#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG) -#ifdef CONFIG_SMP /* sanity check */ -#error "CONFIG_SMP on a machine supporting pre-ARMv6 processors?" -#endif + /* + * Poor you. No fast solution possible... + * The kernel itself must perform the operation. + * A special ghost syscall is used for that (see traps.c). + */ + swi #0x9ffff0 + mov pc, lr + +#elif __LINUX_ARM_ARCH__ < 6 /* * Theory of operation: @@ -735,29 +773,41 @@ __kuser_helper_end: * * Common stub entry macro: * Enter in IRQ mode, spsr = SVC/USR CPSR, lr = SVC/USR PC + * + * 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, sym, correction=0 + .macro vector_stub, name, correction=0 .align 5 vector_\name: - ldr r13, .LCs\sym .if \correction sub lr, lr, #\correction .endif - str lr, [r13] @ save lr_IRQ + + @ + @ Save r0, lr_<exception> (parent PC) and spsr_<exception> + @ (parent CPSR) + @ + stmia sp, {r0, lr} @ save r0, lr mrs lr, spsr - str lr, [r13, #4] @ save spsr_IRQ + str lr, [sp, #8] @ save spsr + @ - @ now branch to the relevant MODE handling routine + @ Prepare for SVC32 mode. IRQs remain disabled. @ - mrs r13, cpsr - bic r13, r13, #MODE_MASK - orr r13, r13, #SVC_MODE - msr spsr_cxsf, r13 @ switch to SVC_32 mode + mrs r0, cpsr + bic r0, r0, #MODE_MASK + orr r0, r0, #SVC_MODE + msr spsr_cxsf, r0 - and lr, lr, #15 + @ + @ the branch table must immediately follow this code + @ + mov r0, sp + and lr, lr, #0x0f ldr lr, [pc, lr, lsl #2] - movs pc, lr @ Changes mode and branches + movs pc, lr @ branch to handler in SVC mode .endm .globl __stubs_start @@ -765,7 +815,7 @@ __stubs_start: /* * Interrupt dispatcher */ - vector_stub irq, irq, 4 + vector_stub irq, 4 .long __irq_usr @ 0 (USR_26 / USR_32) .long __irq_invalid @ 1 (FIQ_26 / FIQ_32) @@ -788,7 +838,7 @@ __stubs_start: * Data abort dispatcher * Enter in ABT mode, spsr = USR CPSR, lr = USR PC */ - vector_stub dabt, abt, 8 + vector_stub dabt, 8 .long __dabt_usr @ 0 (USR_26 / USR_32) .long __dabt_invalid @ 1 (FIQ_26 / FIQ_32) @@ -811,7 +861,7 @@ __stubs_start: * Prefetch abort dispatcher * Enter in ABT mode, spsr = USR CPSR, lr = USR PC */ - vector_stub pabt, abt, 4 + vector_stub pabt, 4 .long __pabt_usr @ 0 (USR_26 / USR_32) .long __pabt_invalid @ 1 (FIQ_26 / FIQ_32) @@ -834,7 +884,7 @@ __stubs_start: * Undef instr entry dispatcher * Enter in UND mode, spsr = SVC/USR CPSR, lr = SVC/USR PC */ - vector_stub und, und + vector_stub und .long __und_usr @ 0 (USR_26 / USR_32) .long __und_invalid @ 1 (FIQ_26 / FIQ_32) @@ -888,13 +938,6 @@ vector_addrexcptn: .LCvswi: .word vector_swi -.LCsirq: - .word __temp_irq -.LCsund: - .word __temp_und -.LCsabt: - .word __temp_abt - .globl __stubs_end __stubs_end: @@ -916,23 +959,6 @@ __vectors_end: .data -/* - * Do not reorder these, and do not insert extra data between... - */ - -__temp_irq: - .word 0 @ saved lr_irq - .word 0 @ saved spsr_irq - .word -1 @ old_r0 -__temp_und: - .word 0 @ Saved lr_und - .word 0 @ Saved spsr_und - .word -1 @ old_r0 -__temp_abt: - .word 0 @ Saved lr_abt - .word 0 @ Saved spsr_abt - .word -1 @ old_r0 - .globl cr_alignment .globl cr_no_alignment cr_alignment: |