From 1d015cf02a1fd46385c03cf3ce8958dbea705dd3 Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Mon, 23 Feb 2009 07:14:02 +0000 Subject: sh: shared register saving code for sh3/sh4/sh4a This patch reworks the sh3/sh4/sh4a register saving code in the following ways: - break out prepare_stack_save_dsp() from handle_exception() - break out save_regs() from handle_exception() - the register saving order is unchanged - align new functions to fit in cache lines - separate exception code from interrupt code - keep main code flow in a single cache line per exception vector - use bsr/rts for regular functions (save pr first) - keep data in one shared cache line (exception_data) - document the functions - tie in the hp6xx code Signed-off-by: Magnus Damm Signed-off-by: Paul Mundt --- arch/sh/kernel/cpu/sh3/entry.S | 273 ++++++++++++++++++++++------------------- 1 file changed, 147 insertions(+), 126 deletions(-) (limited to 'arch/sh/kernel/cpu/sh3/entry.S') diff --git a/arch/sh/kernel/cpu/sh3/entry.S b/arch/sh/kernel/cpu/sh3/entry.S index b4106d0c68e..f3db143e70b 100644 --- a/arch/sh/kernel/cpu/sh3/entry.S +++ b/arch/sh/kernel/cpu/sh3/entry.S @@ -16,6 +16,7 @@ #include #include #include +#include ! NOTE: ! GNU as (as of 2.9.1) changes bf/s into bt/s and bra, when the address @@ -294,7 +295,7 @@ skip_restore: mov #0xf0, k1 extu.b k1, k1 not k1, k1 - and k1, k2 ! Mask orignal SR value + and k1, k2 ! Mask original SR value ! mov k3, k0 ! Calculate IMASK-bits shlr2 k0 @@ -335,82 +336,54 @@ skip_restore: .balign 4096,0,4096 ENTRY(vbr_base) .long 0 +! +! 0x100: General exception vector ! .balign 256,0,256 general_exception: - mov.l 1f, k2 - mov.l 2f, k3 -#ifdef CONFIG_CPU_SUBTYPE_SHX3 - mov.l @k2, k2 +#ifndef CONFIG_CPU_SUBTYPE_SHX3 + bra handle_exception + sts pr, k3 ! save original pr value in k3 +#else + mov.l 1f, k4 + mov.l @k4, k4 ! Is EXPEVT larger than 0x800? mov #0x8, k0 shll8 k0 - cmp/hs k0, k2 + cmp/hs k0, k4 bf 0f ! then add 0x580 (k2 is 0xd80 or 0xda0) mov #0x58, k0 shll2 k0 shll2 k0 - add k0, k2 + add k0, k4 0: - bra handle_exception + ! Setup stack and save DSP context (k0 contains original r15 on return) + bsr prepare_stack_save_dsp nop -#else - bra handle_exception - mov.l @k2, k2 -#endif - .align 2 -1: .long EXPEVT -2: .long ret_from_exception -! -! - .balign 1024,0,1024 -tlb_miss: - mov.l 1f, k2 - mov.l 4f, k3 - bra handle_exception - mov.l @k2, k2 -! - .balign 512,0,512 -interrupt: - mov.l 3f, k3 -#if defined(CONFIG_KGDB) - mov.l 2f, k2 - ! Debounce (filter nested NMI) - mov.l @k2, k0 - mov.l 5f, k1 - cmp/eq k1, k0 - bf 0f - mov.l 6f, k1 - tas.b @k1 - bt 0f - rte + ! Save registers / Switch to bank 0 + bsr save_regs ! needs original pr value in k3 + mov.l k4, k2 ! keep vector in k2 + + bra handle_exception_special nop - .align 2 -2: .long INTEVT -5: .long NMI_VEC -6: .long in_nmi -0: -#endif /* defined(CONFIG_KGDB) */ - bra handle_exception - mov #-1, k2 ! interrupt exception marker .align 2 1: .long EXPEVT -3: .long ret_from_irq -4: .long ret_from_exception +#endif -! -! - .align 2 -ENTRY(handle_exception) - ! Using k0, k1 for scratch registers (r0_bank1, r1_bank), - ! save all registers onto stack. - ! +! prepare_stack_save_dsp() +! - roll back gRB +! - switch to kernel stack +! - save DSP +! k0 returns original sp (after roll back) +! k1 trashed +! k2 trashed +prepare_stack_save_dsp: #ifdef CONFIG_GUSA ! Check for roll back gRB (User and Kernel) mov r15, k0 @@ -430,7 +403,7 @@ ENTRY(handle_exception) 2: mov k1, r15 ! SP = r1 1: #endif - + ! Switch to kernel stack if needed stc ssr, k0 ! Is it from kernel space? shll k0 ! Check MD bit (bit30) by shifting it into... shll k0 ! ...the T bit @@ -443,18 +416,17 @@ ENTRY(handle_exception) add current, k1 mov k1, r15 ! change to kernel stack ! -1: mov.l 2f, k1 - ! +1: #ifdef CONFIG_SH_DSP - mov.l r2, @-r15 ! Save r2, we need another reg - stc sr, k4 - mov.l 1f, r2 - tst r2, k4 ! Check if in DSP mode - mov.l @r15+, r2 ! Restore r2 now + ! Save DSP context if needed + stc sr, k1 + mov #0x10, k2 + shll8 k2 ! DSP=1 (0x00001000) + tst k2, k1 ! Check if in DSP mode (passed in k2) bt/s skip_save - mov #0, k4 ! Set marker for no stack frame + mov #0, k1 ! Set marker for no stack frame - mov r2, k4 ! Backup r2 (in k4) for later + mov k2, k1 ! Save has-frame marker ! Save DSP registers on stack stc.l mod, @-r15 @@ -473,35 +445,73 @@ ENTRY(handle_exception) ! as we're not at all interested in supporting ancient toolchains at ! this point. -- PFM. - mov r15, r2 + mov r15, k2 .word 0xf653 ! movs.l a1, @-r2 .word 0xf6f3 ! movs.l a0g, @-r2 .word 0xf6d3 ! movs.l a1g, @-r2 .word 0xf6c3 ! movs.l m0, @-r2 .word 0xf6e3 ! movs.l m1, @-r2 - mov r2, r15 + mov k2, r15 - mov k4, r2 ! Restore r2 - mov.l 1f, k4 ! Force DSP stack frame skip_save: - mov.l k4, @-r15 ! Push DSP mode marker onto stack + mov.l k1, @-r15 ! Push DSP mode marker onto stack #endif - ! Save the user registers on the stack. - mov.l k2, @-r15 ! EXPEVT + rts + nop +! +! 0x400: Instruction and Data TLB miss exception vector +! + .balign 1024,0,1024 +tlb_miss: + sts pr, k3 ! save original pr value in k3 - mov #-1, k4 - mov.l k4, @-r15 ! set TRA (default: -1) - ! +handle_exception: + ! Setup stack and save DSP context (k0 contains original r15 on return) + bsr prepare_stack_save_dsp + nop + + ! Save registers / Switch to bank 0 + mov.l 5f, k2 ! vector register address + bsr save_regs ! needs original pr value in k3 + mov.l @k2, k2 ! read out vector and keep in k2 + +handle_exception_special: + ! Setup return address and jump to exception handler + mov.l 7f, r9 ! fetch return address + stc r2_bank, r0 ! k2 (vector) + mov.l 6f, r10 + shlr2 r0 + shlr r0 + mov.l @(r0, r10), r10 + jmp @r10 + lds r9, pr ! put return address in pr + + .align L1_CACHE_SHIFT + +! save_regs() +! - save vector, default tra, macl, mach, gbr, ssr, pr* and spc on the stack +! - save r15*, r14, r13, r12, r11, r10, r9, r8 on the stack +! - switch bank +! - save r7, r6, r5, r4, r3, r2, r1, r0 on the stack +! k0 contains original stack pointer* +! k1 trashed +! k2 passes vector (EXPEVT) +! k3 passes original pr* +! k4 trashed +! BL=1 on entry, on exit BL=0. + +save_regs: + mov #-1, r1 + mov.l k2, @-r15 ! vector in k2 + mov.l k1, @-r15 ! set TRA (default: -1) sts.l macl, @-r15 sts.l mach, @-r15 stc.l gbr, @-r15 stc.l ssr, @-r15 - sts.l pr, @-r15 + mov.l k3, @-r15 ! original pr in k3 stc.l spc, @-r15 - ! - lds k3, pr ! Set the return address to pr - ! - mov.l k0, @-r15 ! save orignal stack + + mov.l k0, @-r15 ! original stack pointer in k0 mov.l r14, @-r15 mov.l r13, @-r15 mov.l r12, @-r15 @@ -509,13 +519,15 @@ skip_save: mov.l r10, @-r15 mov.l r9, @-r15 mov.l r8, @-r15 - ! - stc sr, r8 ! Back to normal register bank, and - or k1, r8 ! Block all interrupts - mov.l 3f, k1 - and k1, r8 ! ... - ldc r8, sr ! ...changed here. - ! + + mov.l 0f, k3 ! SR bits to set in k3 + mov.l 1f, k4 ! SR bits to clear in k4 + + stc sr, r8 + or k3, r8 + and k4, r8 + ldc r8, sr + mov.l r7, @-r15 mov.l r6, @-r15 mov.l r5, @-r15 @@ -523,52 +535,61 @@ skip_save: mov.l r3, @-r15 mov.l r2, @-r15 mov.l r1, @-r15 - mov.l r0, @-r15 - - /* - * This gets a bit tricky.. in the INTEVT case we don't want to use - * the VBR offset as a destination in the jump call table, since all - * of the destinations are the same. In this case, (interrupt) sets - * a marker in r2 (now r2_bank since SR.RB changed), which we check - * to determine the exception type. For all other exceptions, we - * forcibly read EXPEVT from memory and fix up the jump address, in - * the interrupt exception case we jump to do_IRQ() and defer the - * INTEVT read until there. As a bonus, we can also clean up the SR.RB - * checks that do_IRQ() was doing.. - */ - stc r2_bank, r8 - cmp/pz r8 - bf interrupt_exception - shlr2 r8 - shlr r8 - mov.l 4f, r9 - add r8, r9 - mov.l @r9, r9 - jmp @r9 - nop rts - nop + mov.l r0, @-r15 +! +! 0x600: Interrupt / NMI vector +! + .balign 512,0,512 +ENTRY(handle_interrupt) +#if defined(CONFIG_KGDB) + mov.l 2f, k2 + ! Debounce (filter nested NMI) + mov.l @k2, k0 + mov.l 9f, k1 + cmp/eq k1, k0 + bf 11f + mov.l 10f, k1 + tas.b @k1 + bt 11f + rte + nop .align 2 -1: .long 0x00001000 ! DSP=1 -2: .long 0x000080f0 ! FD=1, IMASK=15 -3: .long 0xcfffffff ! RB=0, BL=0 -4: .long exception_handling_table +9: .long NMI_VEC +10: .long in_nmi +11: +#endif /* defined(CONFIG_KGDB) */ + sts pr, k3 ! save original pr value in k3 -interrupt_exception: - mov.l 1f, r9 - mov.l 2f, r4 - mov.l @r4, r4 - jmp @r9 - mov r15, r5 - rts + ! Setup stack and save DSP context (k0 contains original r15 on return) + bsr prepare_stack_save_dsp nop - .align 2 -1: .long do_IRQ -2: .long INTEVT + ! Save registers / Switch to bank 0 + bsr save_regs ! needs original pr value in k3 + mov #-1, k2 ! default vector kept in k2 + + ! Setup return address and jump to do_IRQ + mov.l 4f, r9 ! fetch return address + lds r9, pr ! put return address in pr + mov.l 2f, r4 + mov.l 3f, r9 + mov.l @r4, r4 ! pass INTEVT vector as arg0 + jmp @r9 + mov r15, r5 ! pass saved registers as arg1 - .align 2 ENTRY(exception_none) rts nop + + .align L1_CACHE_SHIFT +exception_data: +0: .long 0x000080f0 ! FD=1, IMASK=15 +1: .long 0xcfffffff ! RB=0, BL=0 +2: .long INTEVT +3: .long do_IRQ +4: .long ret_from_irq +5: .long EXPEVT +6: .long exception_handling_table +7: .long ret_from_exception -- cgit v1.2.3