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Diffstat (limited to 'arch/sh64/kernel/entry.S')
| -rw-r--r-- | arch/sh64/kernel/entry.S | 2103 |
1 files changed, 2103 insertions, 0 deletions
diff --git a/arch/sh64/kernel/entry.S b/arch/sh64/kernel/entry.S new file mode 100644 index 00000000000..2e2cfe20b42 --- /dev/null +++ b/arch/sh64/kernel/entry.S @@ -0,0 +1,2103 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * arch/sh64/kernel/entry.S + * + * Copyright (C) 2000, 2001 Paolo Alberelli + * Copyright (C) 2004, 2005 Paul Mundt + * Copyright (C) 2003, 2004 Richard Curnow + * + */ + +#include <linux/config.h> +#include <linux/errno.h> +#include <linux/sys.h> + +#include <asm/processor.h> +#include <asm/registers.h> +#include <asm/unistd.h> +#include <asm/thread_info.h> +#include <asm/asm-offsets.h> + +/* + * SR fields. + */ +#define SR_ASID_MASK 0x00ff0000 +#define SR_FD_MASK 0x00008000 +#define SR_SS 0x08000000 +#define SR_BL 0x10000000 +#define SR_MD 0x40000000 + +/* + * Event code. + */ +#define EVENT_INTERRUPT 0 +#define EVENT_FAULT_TLB 1 +#define EVENT_FAULT_NOT_TLB 2 +#define EVENT_DEBUG 3 + +/* EXPEVT values */ +#define RESET_CAUSE 0x20 +#define DEBUGSS_CAUSE 0x980 + +/* + * Frame layout. Quad index. + */ +#define FRAME_T(x) FRAME_TBASE+(x*8) +#define FRAME_R(x) FRAME_RBASE+(x*8) +#define FRAME_S(x) FRAME_SBASE+(x*8) +#define FSPC 0 +#define FSSR 1 +#define FSYSCALL_ID 2 + +/* Arrange the save frame to be a multiple of 32 bytes long */ +#define FRAME_SBASE 0 +#define FRAME_RBASE (FRAME_SBASE+(3*8)) /* SYSCALL_ID - SSR - SPC */ +#define FRAME_TBASE (FRAME_RBASE+(63*8)) /* r0 - r62 */ +#define FRAME_PBASE (FRAME_TBASE+(8*8)) /* tr0 -tr7 */ +#define FRAME_SIZE (FRAME_PBASE+(2*8)) /* pad0-pad1 */ + +#define FP_FRAME_SIZE FP_FRAME_BASE+(33*8) /* dr0 - dr31 + fpscr */ +#define FP_FRAME_BASE 0 + +#define SAVED_R2 0*8 +#define SAVED_R3 1*8 +#define SAVED_R4 2*8 +#define SAVED_R5 3*8 +#define SAVED_R18 4*8 +#define SAVED_R6 5*8 +#define SAVED_TR0 6*8 + +/* These are the registers saved in the TLB path that aren't saved in the first + level of the normal one. */ +#define TLB_SAVED_R25 7*8 +#define TLB_SAVED_TR1 8*8 +#define TLB_SAVED_TR2 9*8 +#define TLB_SAVED_TR3 10*8 +#define TLB_SAVED_TR4 11*8 +/* Save R0/R1 : PT-migrating compiler currently dishounours -ffixed-r0 and -ffixed-r1 causing + breakage otherwise. */ +#define TLB_SAVED_R0 12*8 +#define TLB_SAVED_R1 13*8 + +#define CLI() \ + getcon SR, r6; \ + ori r6, 0xf0, r6; \ + putcon r6, SR; + +#define STI() \ + getcon SR, r6; \ + andi r6, ~0xf0, r6; \ + putcon r6, SR; + +#ifdef CONFIG_PREEMPT +# define preempt_stop() CLI() +#else +# define preempt_stop() +# define resume_kernel restore_all +#endif + + .section .data, "aw" + +#define FAST_TLBMISS_STACK_CACHELINES 4 +#define FAST_TLBMISS_STACK_QUADWORDS (4*FAST_TLBMISS_STACK_CACHELINES) + +/* Register back-up area for all exceptions */ + .balign 32 + /* Allow for 16 quadwords to be pushed by fast tlbmiss handling + * register saves etc. */ + .fill FAST_TLBMISS_STACK_QUADWORDS, 8, 0x0 +/* This is 32 byte aligned by construction */ +/* Register back-up area for all exceptions */ +reg_save_area: + .quad 0 + .quad 0 + .quad 0 + .quad 0 + + .quad 0 + .quad 0 + .quad 0 + .quad 0 + + .quad 0 + .quad 0 + .quad 0 + .quad 0 + + .quad 0 + .quad 0 + +/* Save area for RESVEC exceptions. We cannot use reg_save_area because of + * reentrancy. Note this area may be accessed via physical address. + * Align so this fits a whole single cache line, for ease of purging. + */ + .balign 32,0,32 +resvec_save_area: + .quad 0 + .quad 0 + .quad 0 + .quad 0 + .quad 0 + .balign 32,0,32 + +/* Jump table of 3rd level handlers */ +trap_jtable: + .long do_exception_error /* 0x000 */ + .long do_exception_error /* 0x020 */ + .long tlb_miss_load /* 0x040 */ + .long tlb_miss_store /* 0x060 */ + ! ARTIFICIAL pseudo-EXPEVT setting + .long do_debug_interrupt /* 0x080 */ + .long tlb_miss_load /* 0x0A0 */ + .long tlb_miss_store /* 0x0C0 */ + .long do_address_error_load /* 0x0E0 */ + .long do_address_error_store /* 0x100 */ +#ifdef CONFIG_SH_FPU + .long do_fpu_error /* 0x120 */ +#else + .long do_exception_error /* 0x120 */ +#endif + .long do_exception_error /* 0x140 */ + .long system_call /* 0x160 */ + .long do_reserved_inst /* 0x180 */ + .long do_illegal_slot_inst /* 0x1A0 */ + .long do_NMI /* 0x1C0 */ + .long do_exception_error /* 0x1E0 */ + .rept 15 + .long do_IRQ /* 0x200 - 0x3C0 */ + .endr + .long do_exception_error /* 0x3E0 */ + .rept 32 + .long do_IRQ /* 0x400 - 0x7E0 */ + .endr + .long fpu_error_or_IRQA /* 0x800 */ + .long fpu_error_or_IRQB /* 0x820 */ + .long do_IRQ /* 0x840 */ + .long do_IRQ /* 0x860 */ + .rept 6 + .long do_exception_error /* 0x880 - 0x920 */ + .endr + .long do_software_break_point /* 0x940 */ + .long do_exception_error /* 0x960 */ + .long do_single_step /* 0x980 */ + + .rept 3 + .long do_exception_error /* 0x9A0 - 0x9E0 */ + .endr + .long do_IRQ /* 0xA00 */ + .long do_IRQ /* 0xA20 */ + .long itlb_miss_or_IRQ /* 0xA40 */ + .long do_IRQ /* 0xA60 */ + .long do_IRQ /* 0xA80 */ + .long itlb_miss_or_IRQ /* 0xAA0 */ + .long do_exception_error /* 0xAC0 */ + .long do_address_error_exec /* 0xAE0 */ + .rept 8 + .long do_exception_error /* 0xB00 - 0xBE0 */ + .endr + .rept 18 + .long do_IRQ /* 0xC00 - 0xE20 */ + .endr + + .section .text64, "ax" + +/* + * --- Exception/Interrupt/Event Handling Section + */ + +/* + * VBR and RESVEC blocks. + * + * First level handler for VBR-based exceptions. + * + * To avoid waste of space, align to the maximum text block size. + * This is assumed to be at most 128 bytes or 32 instructions. + * DO NOT EXCEED 32 instructions on the first level handlers ! + * + * Also note that RESVEC is contained within the VBR block + * where the room left (1KB - TEXT_SIZE) allows placing + * the RESVEC block (at most 512B + TEXT_SIZE). + * + * So first (and only) level handler for RESVEC-based exceptions. + * + * Where the fault/interrupt is handled (not_a_tlb_miss, tlb_miss + * and interrupt) we are a lot tight with register space until + * saving onto the stack frame, which is done in handle_exception(). + * + */ + +#define TEXT_SIZE 128 +#define BLOCK_SIZE 1664 /* Dynamic check, 13*128 */ + + .balign TEXT_SIZE +LVBR_block: + .space 256, 0 /* Power-on class handler, */ + /* not required here */ +not_a_tlb_miss: + synco /* TAKum03020 (but probably a good idea anyway.) */ + /* Save original stack pointer into KCR1 */ + putcon SP, KCR1 + + /* Save other original registers into reg_save_area */ + movi reg_save_area, SP + st.q SP, SAVED_R2, r2 + st.q SP, SAVED_R3, r3 + st.q SP, SAVED_R4, r4 + st.q SP, SAVED_R5, r5 + st.q SP, SAVED_R6, r6 + st.q SP, SAVED_R18, r18 + gettr tr0, r3 + st.q SP, SAVED_TR0, r3 + + /* Set args for Non-debug, Not a TLB miss class handler */ + getcon EXPEVT, r2 + movi ret_from_exception, r3 + ori r3, 1, r3 + movi EVENT_FAULT_NOT_TLB, r4 + or SP, ZERO, r5 + getcon KCR1, SP + pta handle_exception, tr0 + blink tr0, ZERO + + .balign 256 + ! VBR+0x200 + nop + .balign 256 + ! VBR+0x300 + nop + .balign 256 + /* + * Instead of the natural .balign 1024 place RESVEC here + * respecting the final 1KB alignment. + */ + .balign TEXT_SIZE + /* + * Instead of '.space 1024-TEXT_SIZE' place the RESVEC + * block making sure the final alignment is correct. + */ +tlb_miss: + synco /* TAKum03020 (but probably a good idea anyway.) */ + putcon SP, KCR1 + movi reg_save_area, SP + /* SP is guaranteed 32-byte aligned. */ + st.q SP, TLB_SAVED_R0 , r0 + st.q SP, TLB_SAVED_R1 , r1 + st.q SP, SAVED_R2 , r2 + st.q SP, SAVED_R3 , r3 + st.q SP, SAVED_R4 , r4 + st.q SP, SAVED_R5 , r5 + st.q SP, SAVED_R6 , r6 + st.q SP, SAVED_R18, r18 + + /* Save R25 for safety; as/ld may want to use it to achieve the call to + * the code in mm/tlbmiss.c */ + st.q SP, TLB_SAVED_R25, r25 + gettr tr0, r2 + gettr tr1, r3 + gettr tr2, r4 + gettr tr3, r5 + gettr tr4, r18 + st.q SP, SAVED_TR0 , r2 + st.q SP, TLB_SAVED_TR1 , r3 + st.q SP, TLB_SAVED_TR2 , r4 + st.q SP, TLB_SAVED_TR3 , r5 + st.q SP, TLB_SAVED_TR4 , r18 + + pt do_fast_page_fault, tr0 + getcon SSR, r2 + getcon EXPEVT, r3 + getcon TEA, r4 + shlri r2, 30, r2 + andi r2, 1, r2 /* r2 = SSR.MD */ + blink tr0, LINK + + pt fixup_to_invoke_general_handler, tr1 + + /* If the fast path handler fixed the fault, just drop through quickly + to the restore code right away to return to the excepting context. + */ + beqi/u r2, 0, tr1 + +fast_tlb_miss_restore: + ld.q SP, SAVED_TR0, r2 + ld.q SP, TLB_SAVED_TR1, r3 + ld.q SP, TLB_SAVED_TR2, r4 + + ld.q SP, TLB_SAVED_TR3, r5 + ld.q SP, TLB_SAVED_TR4, r18 + + ptabs r2, tr0 + ptabs r3, tr1 + ptabs r4, tr2 + ptabs r5, tr3 + ptabs r18, tr4 + + ld.q SP, TLB_SAVED_R0, r0 + ld.q SP, TLB_SAVED_R1, r1 + ld.q SP, SAVED_R2, r2 + ld.q SP, SAVED_R3, r3 + ld.q SP, SAVED_R4, r4 + ld.q SP, SAVED_R5, r5 + ld.q SP, SAVED_R6, r6 + ld.q SP, SAVED_R18, r18 + ld.q SP, TLB_SAVED_R25, r25 + + getcon KCR1, SP + rte + nop /* for safety, in case the code is run on sh5-101 cut1.x */ + +fixup_to_invoke_general_handler: + + /* OK, new method. Restore stuff that's not expected to get saved into + the 'first-level' reg save area, then just fall through to setting + up the registers and calling the second-level handler. */ + + /* 2nd level expects r2,3,4,5,6,18,tr0 to be saved. So we must restore + r25,tr1-4 and save r6 to get into the right state. */ + + ld.q SP, TLB_SAVED_TR1, r3 + ld.q SP, TLB_SAVED_TR2, r4 + ld.q SP, TLB_SAVED_TR3, r5 + ld.q SP, TLB_SAVED_TR4, r18 + ld.q SP, TLB_SAVED_R25, r25 + + ld.q SP, TLB_SAVED_R0, r0 + ld.q SP, TLB_SAVED_R1, r1 + + ptabs/u r3, tr1 + ptabs/u r4, tr2 + ptabs/u r5, tr3 + ptabs/u r18, tr4 + + /* Set args for Non-debug, TLB miss class handler */ + getcon EXPEVT, r2 + movi ret_from_exception, r3 + ori r3, 1, r3 + movi EVENT_FAULT_TLB, r4 + or SP, ZERO, r5 + getcon KCR1, SP + pta handle_exception, tr0 + blink tr0, ZERO + +/* NB TAKE GREAT CARE HERE TO ENSURE THAT THE INTERRUPT CODE + DOES END UP AT VBR+0x600 */ + nop + nop + nop + nop + nop + nop + + .balign 256 + /* VBR + 0x600 */ + +interrupt: + synco /* TAKum03020 (but probably a good idea anyway.) */ + /* Save original stack pointer into KCR1 */ + putcon SP, KCR1 + + /* Save other original registers into reg_save_area */ + movi reg_save_area, SP + st.q SP, SAVED_R2, r2 + st.q SP, SAVED_R3, r3 + st.q SP, SAVED_R4, r4 + st.q SP, SAVED_R5, r5 + st.q SP, SAVED_R6, r6 + st.q SP, SAVED_R18, r18 + gettr tr0, r3 + st.q SP, SAVED_TR0, r3 + + /* Set args for interrupt class handler */ + getcon INTEVT, r2 + movi ret_from_irq, r3 + ori r3, 1, r3 + movi EVENT_INTERRUPT, r4 + or SP, ZERO, r5 + getcon KCR1, SP + pta handle_exception, tr0 + blink tr0, ZERO + .balign TEXT_SIZE /* let's waste the bare minimum */ + +LVBR_block_end: /* Marker. Used for total checking */ + + .balign 256 +LRESVEC_block: + /* Panic handler. Called with MMU off. Possible causes/actions: + * - Reset: Jump to program start. + * - Single Step: Turn off Single Step & return. + * - Others: Call panic handler, passing PC as arg. + * (this may need to be extended...) + */ +reset_or_panic: + synco /* TAKum03020 (but probably a good idea anyway.) */ + putcon SP, DCR + /* First save r0-1 and tr0, as we need to use these */ + movi resvec_save_area-CONFIG_CACHED_MEMORY_OFFSET, SP + st.q SP, 0, r0 + st.q SP, 8, r1 + gettr tr0, r0 + st.q SP, 32, r0 + + /* Check cause */ + getcon EXPEVT, r0 + movi RESET_CAUSE, r1 + sub r1, r0, r1 /* r1=0 if reset */ + movi _stext-CONFIG_CACHED_MEMORY_OFFSET, r0 + ori r0, 1, r0 + ptabs r0, tr0 + beqi r1, 0, tr0 /* Jump to start address if reset */ + + getcon EXPEVT, r0 + movi DEBUGSS_CAUSE, r1 + sub r1, r0, r1 /* r1=0 if single step */ + pta single_step_panic, tr0 + beqi r1, 0, tr0 /* jump if single step */ + + /* Now jump to where we save the registers. */ + movi panic_stash_regs-CONFIG_CACHED_MEMORY_OFFSET, r1 + ptabs r1, tr0 + blink tr0, r63 + +single_step_panic: + /* We are in a handler with Single Step set. We need to resume the + * handler, by turning on MMU & turning off Single Step. */ + getcon SSR, r0 + movi SR_MMU, r1 + or r0, r1, r0 + movi ~SR_SS, r1 + and r0, r1, r0 + putcon r0, SSR + /* Restore EXPEVT, as the rte won't do this */ + getcon PEXPEVT, r0 + putcon r0, EXPEVT + /* Restore regs */ + ld.q SP, 32, r0 + ptabs r0, tr0 + ld.q SP, 0, r0 + ld.q SP, 8, r1 + getcon DCR, SP + synco + rte + + + .balign 256 +debug_exception: + synco /* TAKum03020 (but probably a good idea anyway.) */ + /* + * Single step/software_break_point first level handler. + * Called with MMU off, so the first thing we do is enable it + * by doing an rte with appropriate SSR. + */ + putcon SP, DCR + /* Save SSR & SPC, together with R0 & R1, as we need to use 2 regs. */ + movi resvec_save_area-CONFIG_CACHED_MEMORY_OFFSET, SP + + /* With the MMU off, we are bypassing the cache, so purge any + * data that will be made stale by the following stores. + */ + ocbp SP, 0 + synco + + st.q SP, 0, r0 + st.q SP, 8, r1 + getcon SPC, r0 + st.q SP, 16, r0 + getcon SSR, r0 + st.q SP, 24, r0 + + /* Enable MMU, block exceptions, set priv mode, disable single step */ + movi SR_MMU | SR_BL | SR_MD, r1 + or r0, r1, r0 + movi ~SR_SS, r1 + and r0, r1, r0 + putcon r0, SSR + /* Force control to debug_exception_2 when rte is executed */ + movi debug_exeception_2, r0 + ori r0, 1, r0 /* force SHmedia, just in case */ + putcon r0, SPC + getcon DCR, SP + synco + rte +debug_exeception_2: + /* Restore saved regs */ + putcon SP, KCR1 + movi resvec_save_area, SP + ld.q SP, 24, r0 + putcon r0, SSR + ld.q SP, 16, r0 + putcon r0, SPC + ld.q SP, 0, r0 + ld.q SP, 8, r1 + + /* Save other original registers into reg_save_area */ + movi reg_save_area, SP + st.q SP, SAVED_R2, r2 + st.q SP, SAVED_R3, r3 + st.q SP, SAVED_R4, r4 + st.q SP, SAVED_R5, r5 + st.q SP, SAVED_R6, r6 + st.q SP, SAVED_R18, r18 + gettr tr0, r3 + st.q SP, SAVED_TR0, r3 + + /* Set args for debug class handler */ + getcon EXPEVT, r2 + movi ret_from_exception, r3 + ori r3, 1, r3 + movi EVENT_DEBUG, r4 + or SP, ZERO, r5 + getcon KCR1, SP + pta handle_exception, tr0 + blink tr0, ZERO + + .balign 256 +debug_interrupt: + /* !!! WE COME HERE IN REAL MODE !!! */ + /* Hook-up debug interrupt to allow various debugging options to be + * hooked into its handler. */ + /* Save original stack pointer into KCR1 */ + synco + putcon SP, KCR1 + movi resvec_save_area-CONFIG_CACHED_MEMORY_OFFSET, SP + ocbp SP, 0 + ocbp SP, 32 + synco + + /* Save other original registers into reg_save_area thru real addresses */ + st.q SP, SAVED_R2, r2 + st.q SP, SAVED_R3, r3 + st.q SP, SAVED_R4, r4 + st.q SP, SAVED_R5, r5 + st.q SP, SAVED_R6, r6 + st.q SP, SAVED_R18, r18 + gettr tr0, r3 + st.q SP, SAVED_TR0, r3 + + /* move (spc,ssr)->(pspc,pssr). The rte will shift + them back again, so that they look like the originals + as far as the real handler code is concerned. */ + getcon spc, r6 + putcon r6, pspc + getcon ssr, r6 + putcon r6, pssr + + ! construct useful SR for handle_exception + movi 3, r6 + shlli r6, 30, r6 + getcon sr, r18 + or r18, r6, r6 + putcon r6, ssr + + ! SSR is now the current SR with the MD and MMU bits set + ! i.e. the rte will switch back to priv mode and put + ! the mmu back on + + ! construct spc + movi handle_exception, r18 + ori r18, 1, r18 ! for safety (do we need this?) + putcon r18, spc + + /* Set args for Non-debug, Not a TLB miss class handler */ + + ! EXPEVT==0x80 is unused, so 'steal' this value to put the + ! debug interrupt handler in the vectoring table + movi 0x80, r2 + movi ret_from_exception, r3 + ori r3, 1, r3 + movi EVENT_FAULT_NOT_TLB, r4 + + or SP, ZERO, r5 + movi CONFIG_CACHED_MEMORY_OFFSET, r6 + add r6, r5, r5 + getcon KCR1, SP + + synco ! for safety + rte ! -> handle_exception, switch back to priv mode again + +LRESVEC_block_end: /* Marker. Unused. */ + + .balign TEXT_SIZE + +/* + * Second level handler for VBR-based exceptions. Pre-handler. + * In common to all stack-frame sensitive handlers. + * + * Inputs: + * (KCR0) Current [current task union] + * (KCR1) Original SP + * (r2) INTEVT/EXPEVT + * (r3) appropriate return address + * (r4) Event (0 = interrupt, 1 = TLB miss fault, 2 = Not TLB miss fault, 3=debug) + * (r5) Pointer to reg_save_area + * (SP) Original SP + * + * Available registers: + * (r6) + * (r18) + * (tr0) + * + */ +handle_exception: + /* Common 2nd level handler. */ + + /* First thing we need an appropriate stack pointer */ + getcon SSR, r6 + shlri r6, 30, r6 + andi r6, 1, r6 + pta stack_ok, tr0 + bne r6, ZERO, tr0 /* Original stack pointer is fine */ + + /* Set stack pointer for user fault */ + getcon KCR0, SP + movi THREAD_SIZE, r6 /* Point to the end */ + add SP, r6, SP + +stack_ok: + +/* DEBUG : check for underflow/overflow of the kernel stack */ + pta no_underflow, tr0 + getcon KCR0, r6 + movi 1024, r18 + add r6, r18, r6 + bge SP, r6, tr0 ! ? below 1k from bottom of stack : danger zone + +/* Just panic to cause a crash. */ +bad_sp: + ld.b r63, 0, r6 + nop + +no_underflow: + pta bad_sp, tr0 + getcon kcr0, r6 + movi THREAD_SIZE, r18 + add r18, r6, r6 + bgt SP, r6, tr0 ! sp above the stack + + /* Make some room for the BASIC frame. */ + movi -(FRAME_SIZE), r6 + add SP, r6, SP + +/* Could do this with no stalling if we had another spare register, but the + code below will be OK. */ + ld.q r5, SAVED_R2, r6 + ld.q r5, SAVED_R3, r18 + st.q SP, FRAME_R(2), r6 + ld.q r5, SAVED_R4, r6 + st.q SP, FRAME_R(3), r18 + ld.q r5, SAVED_R5, r18 + st.q SP, FRAME_R(4), r6 + ld.q r5, SAVED_R6, r6 + st.q SP, FRAME_R(5), r18 + ld.q r5, SAVED_R18, r18 + st.q SP, FRAME_R(6), r6 + ld.q r5, SAVED_TR0, r6 + st.q SP, FRAME_R(18), r18 + st.q SP, FRAME_T(0), r6 + + /* Keep old SP around */ + getcon KCR1, r6 + + /* Save the rest of the general purpose registers */ + st.q SP, FRAME_R(0), r0 + st.q SP, FRAME_R(1), r1 + st.q SP, FRAME_R(7), r7 + st.q SP, FRAME_R(8), r8 + st.q SP, FRAME_R(9), r9 + st.q SP, FRAME_R(10), r10 + st.q SP, FRAME_R(11), r11 + st.q SP, FRAME_R(12), r12 + st.q SP, FRAME_R(13), r13 + st.q SP, FRAME_R(14), r14 + + /* SP is somewhere else */ + st.q SP, FRAME_R(15), r6 + + st.q SP, FRAME_R(16), r16 + st.q SP, FRAME_R(17), r17 + /* r18 is saved earlier. */ + st.q SP, FRAME_R(19), r19 + st.q SP, FRAME_R(20), r20 + st.q SP, FRAME_R(21), r21 + st.q SP, FRAME_R(22), r22 + st.q SP, FRAME_R(23), r23 + st.q SP, FRAME_R(24), r24 + st.q SP, FRAME_R(25), r25 + st.q SP, FRAME_R(26), r26 + st.q SP, FRAME_R(27), r27 + st.q SP, FRAME_R(28), r28 + st.q SP, FRAME_R(29), r29 + st.q SP, FRAME_R(30), r30 + st.q SP, FRAME_R(31), r31 + st.q SP, FRAME_R(32), r32 + st.q SP, FRAME_R(33), r33 + st.q SP, FRAME_R(34), r34 + st.q SP, FRAME_R(35), r35 + st.q SP, FRAME_R(36), r36 + st.q SP, FRAME_R(37), r37 + st.q SP, FRAME_R(38), r38 + st.q SP, FRAME_R(39), r39 + st.q SP, FRAME_R(40), r40 + st.q SP, FRAME_R(41), r41 + st.q SP, FRAME_R(42), r42 + st.q SP, FRAME_R(43), r43 + st.q SP, FRAME_R(44), r44 + st.q SP, FRAME_R(45), r45 + st.q SP, FRAME_R(46), r46 + st.q SP, FRAME_R(47), r47 + st.q SP, FRAME_R(48), r48 + st.q SP, FRAME_R(49), r49 + st.q SP, FRAME_R(50), r50 + st.q SP, FRAME_R(51), r51 + st.q SP, FRAME_R(52), r52 + st.q SP, FRAME_R(53), r53 + st.q SP, FRAME_R(54), r54 + st.q SP, FRAME_R(55), r55 + st.q SP, FRAME_R(56), r56 + st.q SP, FRAME_R(57), r57 + st.q SP, FRAME_R(58), r58 + st.q SP, FRAME_R(59), r59 + st.q SP, FRAME_R(60), r60 + st.q SP, FRAME_R(61), r61 + st.q SP, FRAME_R(62), r62 + + /* + * Save the S* registers. + */ + getcon SSR, r61 + st.q SP, FRAME_S(FSSR), r61 + getcon SPC, r62 + st.q SP, FRAME_S(FSPC), r62 + movi -1, r62 /* Reset syscall_nr */ + st.q SP, FRAME_S(FSYSCALL_ID), r62 + + /* Save the rest of the target registers */ + gettr tr1, r6 + st.q SP, FRAME_T(1), r6 + gettr tr2, r6 + st.q SP, FRAME_T(2), r6 + gettr tr3, r6 + st.q SP, FRAME_T(3), r6 + gettr tr4, r6 + st.q SP, FRAME_T(4), r6 + gettr tr5, r6 + st.q SP, FRAME_T(5), r6 + gettr tr6, r6 + st.q SP, FRAME_T(6), r6 + gettr tr7, r6 + st.q SP, FRAME_T(7), r6 + + ! setup FP so that unwinder can wind back through nested kernel mode + ! exceptions + add SP, ZERO, r14 + +#ifdef CONFIG_POOR_MANS_STRACE + /* We've pushed all the registers now, so only r2-r4 hold anything + * useful. Move them into callee save registers */ + or r2, ZERO, r28 + or r3, ZERO, r29 + or r4, ZERO, r30 + + /* Preserve r2 as the event code */ + movi evt_debug, r3 + ori r3, 1, r3 + ptabs r3, tr0 + + or SP, ZERO, r6 + getcon TRA, r5 + blink tr0, LINK + + or r28, ZERO, r2 + or r29, ZERO, r3 + or r30, ZERO, r4 +#endif + + /* For syscall and debug race condition, get TRA now */ + getcon TRA, r5 + + /* We are in a safe position to turn SR.BL off, but set IMASK=0xf + * Also set FD, to catch FPU usage in the kernel. + * + * benedict.gaster@superh.com 29/07/2002 + * + * On all SH5-101 revisions it is unsafe to raise the IMASK and at the + * same time change BL from 1->0, as any pending interrupt of a level + * higher than he previous value of IMASK will leak through and be + * taken unexpectedly. + * + * To avoid this we raise the IMASK and then issue another PUTCON to + * enable interrupts. + */ + getcon SR, r6 + movi SR_IMASK | SR_FD, r7 + or r6, r7, r6 + putcon r6, SR + movi SR_UNBLOCK_EXC, r7 + and r6, r7, r6 + putcon r6, SR + + + /* Now call the appropriate 3rd level handler */ + or r3, ZERO, LINK + movi trap_jtable, r3 + shlri r2, 3, r2 + ldx.l r2, r3, r3 + shlri r2, 2, r2 + ptabs r3, tr0 + or SP, ZERO, r3 + blink tr0, ZERO + +/* + * Second level handler for VBR-based exceptions. Post-handlers. + * + * Post-handlers for interrupts (ret_from_irq), exceptions + * (ret_from_exception) and common reentrance doors (restore_all + * to get back to the original context, ret_from_syscall loop to + * check kernel exiting). + * + * ret_with_reschedule and work_notifysig are an inner lables of + * the ret_from_syscall loop. + * + * In common to all stack-frame sensitive handlers. + * + * Inputs: + * (SP) struct pt_regs *, original register's frame pointer (basic) + * + */ + .global ret_from_irq +ret_from_irq: +#ifdef CONFIG_POOR_MANS_STRACE + pta evt_debug_ret_from_irq, tr0 + ori SP, 0, r2 + blink tr0, LINK +#endif + ld.q SP, FRAME_S(FSSR), r6 + shlri r6, 30, r6 + andi r6, 1, r6 + pta resume_kernel, tr0 + bne r6, ZERO, tr0 /* no further checks */ + STI() + pta ret_with_reschedule, tr0 + blink tr0, ZERO /* Do not check softirqs */ + + .global ret_from_exception +ret_from_exception: + preempt_stop() + +#ifdef CONFIG_POOR_MANS_STRACE + pta evt_debug_ret_from_exc, tr0 + ori SP, 0, r2 + blink tr0, LINK +#endif + + ld.q SP, FRAME_S(FSSR), r6 + shlri r6, 30, r6 + andi r6, 1, r6 + pta resume_kernel, tr0 + bne r6, ZERO, tr0 /* no further checks */ + + /* Check softirqs */ + +#ifdef CONFIG_PREEMPT + pta ret_from_syscall, tr0 + blink tr0, ZERO + +resume_kernel: + pta restore_all, tr0 + + getcon KCR0, r6 + ld.l r6, TI_PRE_COUNT, r7 + beq/u r7, ZERO, tr0 + +need_resched: + ld.l r6, TI_FLAGS, r7 + movi (1 << TIF_NEED_RESCHED), r8 + and r8, r7, r8 + bne r8, ZERO, tr0 + + getcon SR, r7 + andi r7, 0xf0, r7 + bne r7, ZERO, tr0 + + movi ((PREEMPT_ACTIVE >> 16) & 65535), r8 + shori (PREEMPT_ACTIVE & 65535), r8 + st.l r6, TI_PRE_COUNT, r8 + + STI() + movi schedule, r7 + ori r7, 1, r7 + ptabs r7, tr1 + blink tr1, LINK + + st.l r6, TI_PRE_COUNT, ZERO + CLI() + + pta need_resched, tr1 + blink tr1, ZERO +#endif + + .global ret_from_syscall +ret_from_syscall: + +ret_with_reschedule: + getcon KCR0, r6 ! r6 contains current_thread_info + ld.l r6, TI_FLAGS, r7 ! r7 contains current_thread_info->flags + + ! FIXME:!!! + ! no handling of TIF_SYSCALL_TRACE yet!! + + movi (1 << TIF_NEED_RESCHED), r8 + and r8, r7, r8 + pta work_resched, tr0 + bne r8, ZERO, tr0 + + pta restore_all, tr1 + + movi (1 << TIF_SIGPENDING), r8 + and r8, r7, r8 + pta work_notifysig, tr0 + bne r8, ZERO, tr0 + + blink tr1, ZERO + +work_resched: + pta ret_from_syscall, tr0 + gettr tr0, LINK + movi schedule, r6 + ptabs r6, tr0 + blink tr0, ZERO /* Call schedule(), return on top */ + +work_notifysig: + gettr tr1, LINK + + movi do_signal, r6 + ptabs r6, tr0 + or SP, ZERO, r2 + or ZERO, ZERO, r3 + blink tr0, LINK /* Call do_signal(regs, 0), return here */ + +restore_all: + /* Do prefetches */ + + ld.q SP, FRAME_T(0), r6 + ld.q SP, FRAME_T(1), r7 + ld.q SP, FRAME_T(2), r8 + ld.q SP, FRAME_T(3), r9 + ptabs r6, tr0 + ptabs r7, tr1 + ptabs r8, tr2 + ptabs r9, tr3 + ld.q SP, FRAME_T(4), r6 + ld.q SP, FRAME_T(5), r7 + ld.q SP, FRAME_T(6), r8 + ld.q SP, FRAME_T(7), r9 + ptabs r6, tr4 + ptabs r7, tr5 + ptabs r8, tr6 + ptabs r9, tr7 + + ld.q SP, FRAME_R(0), r0 + ld.q SP, FRAME_R(1), r1 + ld.q SP, FRAME_R(2), r2 + ld.q SP, FRAME_R(3), r3 + ld.q SP, FRAME_R(4), r4 + ld.q SP, FRAME_R(5), r5 + ld.q SP, FRAME_R(6), r6 + ld.q SP, FRAME_R(7), r7 + ld.q SP, FRAME_R(8), r8 + ld.q SP, FRAME_R(9), r9 + ld.q SP, FRAME_R(10), r10 + ld.q SP, FRAME_R(11), r11 + ld.q SP, FRAME_R(12), r12 + ld.q SP, FRAME_R(13), r13 + ld.q SP, FRAME_R(14), r14 + + ld.q SP, FRAME_R(16), r16 + ld.q SP, FRAME_R(17), r17 + ld.q SP, FRAME_R(18), r18 + ld.q SP, FRAME_R(19), r19 + ld.q SP, FRAME_R(20), r20 + ld.q SP, FRAME_R(21), r21 + ld.q SP, FRAME_R(22), r22 + ld.q SP, FRAME_R(23), r23 + ld.q SP, FRAME_R(24), r24 + ld.q SP, FRAME_R(25), r25 + ld.q SP, FRAME_R(26), r26 + ld.q SP, FRAME_R(27), r27 + ld.q SP, FRAME_R(28), r28 + ld.q SP, FRAME_R(29), r29 + ld.q SP, FRAME_R(30), r30 + ld.q SP, FRAME_R(31), r31 + ld.q SP, FRAME_R(32), r32 + ld.q SP, FRAME_R(33), r33 + ld.q SP, FRAME_R(34), r34 + ld.q SP, FRAME_R(35), r35 + ld.q SP, FRAME_R(36), r36 + ld.q SP, FRAME_R(37), r37 + ld.q SP, FRAME_R(38), r38 + ld.q SP, FRAME_R(39), r39 + ld.q SP, FRAME_R(40), r40 + ld.q SP, FRAME_R(41), r41 + ld.q SP, FRAME_R(42), r42 + ld.q SP, FRAME_R(43), r43 + ld.q SP, FRAME_R(44), r44 + ld.q SP, FRAME_R(45), r45 + ld.q SP, FRAME_R(46), r46 + ld.q SP, FRAME_R(47), r47 + ld.q SP, FRAME_R(48), r48 + ld.q SP, FRAME_R(49), r49 + ld.q SP, FRAME_R(50), r50 + ld.q SP, FRAME_R(51), r51 + ld.q SP, FRAME_R(52), r52 + ld.q SP, FRAME_R(53), r53 + ld.q SP, FRAME_R(54), r54 + ld.q SP, FRAME_R(55), r55 + ld.q SP, FRAME_R(56), r56 + ld.q SP, FRAME_R(57), r57 + ld.q SP, FRAME_R(58), r58 + + getcon SR, r59 + movi SR_BLOCK_EXC, r60 + or r59, r60, r59 + putcon r59, SR /* SR.BL = 1, keep nesting out */ + ld.q SP, FRAME_S(FSSR), r61 + ld.q SP, FRAME_S(FSPC), r62 + movi SR_ASID_MASK, r60 + and r59, r60, r59 + andc r61, r60, r61 /* Clear out older ASID */ + or r59, r61, r61 /* Retain current ASID */ + putcon r61, SSR + putcon r62, SPC + + /* Ignore FSYSCALL_ID */ + + ld.q SP, FRAME_R(59), r59 + ld.q SP, FRAME_R(60), r60 + ld.q SP, FRAME_R(61), r61 + ld.q SP, FRAME_R(62), r62 + + /* Last touch */ + ld.q SP, FRAME_R(15), SP + rte + nop + +/* + * Third level handlers for VBR-based exceptions. Adapting args to + * and/or deflecting to fourth level handlers. + * + * Fourth level handlers interface. + * Most are C-coded handlers directly pointed by the trap_jtable. + * (Third = Fourth level) + * Inputs: + * (r2) fault/interrupt code, entry number (e.g. NMI = 14, + * IRL0-3 (0000) = 16, RTLBMISS = 2, SYSCALL = 11, etc ...) + * (r3) struct pt_regs *, original register's frame pointer + * (r4) Event (0 = interrupt, 1 = TLB miss fault, 2 = Not TLB miss fault) + * (r5) TRA control register (for syscall/debug benefit only) + * (LINK) return address + * (SP) = r3 + * + * Kernel TLB fault handlers will get a slightly different interface. + * (r2) struct pt_regs *, original register's frame pointer + * (r3) writeaccess, whether it's a store fault as opposed to load fault + * (r4) execaccess, whether it's a ITLB fault as opposed to DTLB fault + * (r5) Effective Address of fault + * (LINK) return address + * (SP) = r2 + * + * fpu_error_or_IRQ? is a helper to deflect to the right cause. + * + */ +tlb_miss_load: + or SP, ZERO, r2 + or ZERO, ZERO, r3 /* Read */ + or ZERO, ZERO, r4 /* Data */ + getcon TEA, r5 + pta call_do_page_fault, tr0 + beq ZERO, ZERO, tr0 + +tlb_miss_store: + or SP, ZERO, r2 + movi 1, r3 /* Write */ + or ZERO, ZERO, r4 /* Data */ + getcon TEA, r5 + pta call_do_page_fault, tr0 + beq ZERO, ZERO, tr0 + +itlb_miss_or_IRQ: + pta its_IRQ, tr0 + beqi/u r4, EVENT_INTERRUPT, tr0 + or SP, ZERO, r2 + or ZERO, ZERO, r3 /* Read */ + movi 1, r4 /* Text */ + getcon TEA, r5 + /* Fall through */ + +call_do_page_fault: + movi do_page_fault, r6 + ptabs r6, tr0 + blink tr0, ZERO + +fpu_error_or_IRQA: + pta its_IRQ, tr0 + beqi/l r4, EVENT_INTERRUPT, tr0 +#ifdef CONFIG_SH_FPU + movi do_fpu_state_restore, r6 +#else + movi do_exception_error, r6 +#endif + ptabs r6, tr0 + blink tr0, ZERO + +fpu_error_or_IRQB: + pta its_IRQ, tr0 + beqi/l r4, EVENT_INTERRUPT, tr0 +#ifdef CONFIG_SH_FPU + movi do_fpu_state_restore, r6 +#else + movi do_exception_error, r6 +#endif + ptabs r6, tr0 + blink tr0, ZERO + +its_IRQ: + movi do_IRQ, r6 + ptabs r6, tr0 + blink tr0, ZERO + +/* + * system_call/unknown_trap third level handler: + * + * Inputs: + * (r2) fault/interrupt code, entry number (TRAP = 11) + * (r3) struct pt_regs *, original register's frame pointer + * (r4) Not used. Event (0=interrupt, 1=TLB miss fault, 2=Not TLB miss fault) + * (r5) TRA Control Reg (0x00xyzzzz: x=1 SYSCALL, y = #args, z=nr) + * (SP) = r3 + * (LINK) return address: ret_from_exception + * (*r3) Syscall parms: SC#, arg0, arg1, ..., arg5 in order (Saved r2/r7) + * + * Outputs: + * (*r3) Syscall reply (Saved r2) + * (LINK) In case of syscall only it can be scrapped. + * Common second level post handler will be ret_from_syscall. + * Common (non-trace) exit point to that is syscall_ret (saving + * result to r2). Common bad exit point is syscall_bad (returning + * ENOSYS then saved to r2). + * + */ + +unknown_trap: + /* Unknown Trap or User Trace */ + movi do_unknown_trapa, r6 + ptabs r6, tr0 + ld.q r3, FRAME_R(9), r2 /* r2 = #arg << 16 | syscall # */ + andi r2, 0x1ff, r2 /* r2 = syscall # */ + blink tr0, LINK + + pta syscall_ret, tr0 + blink tr0, ZERO + + /* New syscall implementation*/ +system_call: + pta unknown_trap, tr0 + or r5, ZERO, r4 /* TRA (=r5) -> r4 */ + shlri r4, 20, r4 + bnei r4, 1, tr0 /* unknown_trap if not 0x1yzzzz */ + + /* It's a system call */ + st.q r3, FRAME_S(FSYSCALL_ID), r5 /* ID (0x1yzzzz) -> stack */ + andi r5, 0x1ff, r5 /* syscall # -> r5 */ + + STI() + + pta syscall_allowed, tr0 + movi NR_syscalls - 1, r4 /* Last valid */ + bgeu/l r4, r5, tr0 + +syscall_bad: + /* Return ENOSYS ! */ + movi -(ENOSYS), r2 /* Fall-through */ + + .global syscall_ret +syscall_ret: + st.q SP, FRAME_R(9), r2 /* Expecting SP back to BASIC frame */ + +#ifdef CONFIG_POOR_MANS_STRACE + /* nothing useful in registers at this point */ + + movi evt_debug2, r5 + ori r5, 1, r5 + ptabs r5, tr0 + ld.q SP, FRAME_R(9), r2 + or SP, ZERO, r3 + blink tr0, LINK +#endif + + ld.q SP, FRAME_S(FSPC), r2 + addi r2, 4, r2 /* Move PC, being pre-execution event */ + st.q SP, FRAME_S(FSPC), r2 + pta ret_from_syscall, tr0 + blink tr0, ZERO + + +/* A different return path for ret_from_fork, because we now need + * to call schedule_tail with the later kernels. Because prev is + * loaded into r2 by switch_to() means we can just call it straight away + */ + +.global ret_from_fork +ret_from_fork: + + movi schedule_tail,r5 + ori r5, 1, r5 + ptabs r5, tr0 + blink tr0, LINK + +#ifdef CONFIG_POOR_MANS_STRACE + /* nothing useful in registers at this point */ + + movi evt_debug2, r5 + ori r5, 1, r5 + ptabs r5, tr0 + ld.q SP, FRAME_R(9), r2 + or SP, ZERO, r3 + blink tr0, LINK +#endif + + ld.q SP, FRAME_S(FSPC), r2 + addi r2, 4, r2 /* Move PC, being pre-execution event */ + st.q SP, FRAME_S(FSPC), r2 + pta ret_from_syscall, tr0 + blink tr0, ZERO + + + +syscall_allowed: + /* Use LINK to deflect the exit point, default is syscall_ret */ + pta syscall_ret, tr0 + gettr tr0, LINK + pta syscall_notrace, tr0 + + getcon KCR0, r2 + ld.l r2, TI_FLAGS, r4 + movi (1 << TIF_SYSCALL_TRACE), r6 + and r6, r4, r6 + beq/l r6, ZERO, tr0 + + /* Trace it by calling syscall_trace before and after */ + movi syscall_trace, r4 + ptabs r4, tr0 + blink tr0, LINK + /* Reload syscall number as r5 is trashed by syscall_trace */ + ld.q SP, FRAME_S(FSYSCALL_ID), r5 + andi r5, 0x1ff, r5 + + pta syscall_ret_trace, tr0 + gettr tr0, LINK + +syscall_notrace: + /* Now point to the appropriate 4th level syscall handler */ + movi sys_call_table, r4 + shlli r5, 2, r5 + ldx.l r4, r5, r5 + ptabs r5, tr0 + + /* Prepare original args */ + ld.q SP, FRAME_R(2), r2 + ld.q SP, FRAME_R(3), r3 + ld.q SP, FRAME_R(4), r4 + ld.q SP, FRAME_R(5), r5 + ld.q SP, FRAME_R(6), r6 + ld.q SP, FRAME_R(7), r7 + + /* And now the trick for those syscalls requiring regs * ! */ + or SP, ZERO, r8 + + /* Call it */ + blink tr0, ZERO /* LINK is already properly set */ + +syscall_ret_trace: + /* We get back here only if under trace */ + st.q SP, FRAME_R(9), r2 /* Save return value */ + + movi syscall_trace, LINK + ptabs LINK, tr0 + blink tr0, LINK + + /* This needs to be done after any syscall tracing */ + ld.q SP, FRAME_S(FSPC), r2 + addi r2, 4, r2 /* Move PC, being pre-execution event */ + st.q SP, FRAME_S(FSPC), r2 + + pta ret_from_syscall, tr0 + blink tr0, ZERO /* Resume normal return sequence */ + +/* + * --- Switch to running under a particular ASID and return the previous ASID value + * --- The caller is assumed to have done a cli before calling this. + * + * Input r2 : new ASID + * Output r2 : old ASID + */ + + .global switch_and_save_asid +switch_and_save_asid: + getcon sr, r0 + movi 255, r4 + shlli r4, 16, r4 /* r4 = mask to select ASID */ + and r0, r4, r3 /* r3 = shifted old ASID */ + andi r2, 255, r2 /* mask down new ASID */ + shlli r2, 16, r2 /* align new ASID against SR.ASID */ + andc r0, r4, r0 /* efface old ASID from SR */ + or r0, r2, r0 /* insert the new ASID */ + putcon r0, ssr + movi 1f, r0 + putcon r0, spc + rte + nop +1: + ptabs LINK, tr0 + shlri r3, 16, r2 /* r2 = old ASID */ + blink tr0, r63 + + .global route_to_panic_handler +route_to_panic_handler: + /* Switch to real mode, goto panic_handler, don't return. Useful for + last-chance debugging, e.g. if no output wants to go to the console. + */ + + movi panic_handler - CONFIG_CACHED_MEMORY_OFFSET, r1 + ptabs r1, tr0 + pta 1f, tr1 + gettr tr1, r0 + putcon r0, spc + getcon sr, r0 + movi 1, r1 + shlli r1, 31, r1 + andc r0, r1, r0 + putcon r0, ssr + rte + nop +1: /* Now in real mode */ + blink tr0, r63 + nop + + .global peek_real_address_q +peek_real_address_q: + /* Two args: + r2 : real mode address to peek + r2(out) : result quadword + + This is provided as a cheapskate way of manipulating device + registers for debugging (to avoid the need to onchip_remap the debug + module, and to avoid the need to onchip_remap the watchpoint + controller in a way that identity maps sufficient bits to avoid the + SH5-101 cut2 silicon defect). + + This code is not performance critical + */ + + add.l r2, r63, r2 /* sign extend address */ + getcon sr, r0 /* r0 = saved original SR */ + movi 1, r1 + shlli r1, 28, r1 + or r0, r1, r1 /* r0 with block bit set */ + putcon r1, sr /* now in critical section */ + movi 1, r36 + shlli r36, 31, r36 + andc r1, r36, r1 /* turn sr.mmu off in real mode section */ + + putcon r1, ssr + movi .peek0 - CONFIG_CACHED_MEMORY_OFFSET, r36 /* real mode target address */ + movi 1f, r37 /* virtual mode return addr */ + putcon r36, spc + + synco + rte + nop + +.peek0: /* come here in real mode, don't touch caches!! + still in critical section (sr.bl==1) */ + putcon r0, ssr + putcon r37, spc + /* Here's the actual peek. If the address is bad, all bets are now off + * what will happen (handlers invoked in real-mode = bad news) */ + ld.q r2, 0, r2 + synco + rte /* Back to virtual mode */ + nop + +1: + ptabs LINK, tr0 + blink tr0, r63 + + .global poke_real_address_q +poke_real_address_q: + /* Two args: + r2 : real mode address to poke + r3 : quadword value to write. + + This is provided as a cheapskate way of manipulating device + registers for debugging (to avoid the need to onchip_remap the debug + module, and to avoid the need to onchip_remap the watchpoint + controller in a way that identity maps sufficient bits to avoid the + SH5-101 cut2 silicon defect). + + This code is not performance critical + */ + + add.l r2, r63, r2 /* sign extend address */ + getcon sr, r0 /* r0 = saved original SR */ + movi 1, r1 + shlli r1, 28, r1 + or r0, r1, r1 /* r0 with block bit set */ + putcon r1, sr /* now in critical section */ + movi 1, r36 + shlli r36, 31, r36 + andc r1, r36, r1 /* turn sr.mmu off in real mode section */ + + putcon r1, ssr + movi .poke0-CONFIG_CACHED_MEMORY_OFFSET, r36 /* real mode target address */ + movi 1f, r37 /* virtual mode return addr */ + putcon r36, spc + + synco + rte + nop + +.poke0: /* come here in real mode, don't touch caches!! + still in critical section (sr.bl==1) */ + putcon r0, ssr + putcon r37, spc + /* Here's the actual poke. If the address is bad, all bets are now off + * what will happen (handlers invoked in real-mode = bad news) */ + st.q r2, 0, r3 + synco + rte /* Back to virtual mode */ + nop + +1: + ptabs LINK, tr0 + blink tr0, r63 + +/* + * --- User Access Handling Section + */ + +/* + * User Access support. It all moved to non inlined Assembler + * functions in here. + * + * __kernel_size_t __copy_user(void *__to, const void *__from, + * __kernel_size_t __n) + * + * Inputs: + * (r2) target address + * (r3) source address + * (r4) size in bytes + * + * Ouputs: + * (*r2) target data + * (r2) non-copied bytes + * + * If a fault occurs on the user pointer, bail out early and return the + * number of bytes not copied in r2. + * Strategy : for large blocks, call a real memcpy function which can + * move >1 byte at a time using unaligned ld/st instructions, and can + * manipulate the cache using prefetch + alloco to improve the speed + * further. If a fault occurs in that function, just revert to the + * byte-by-byte approach used for small blocks; this is rare so the + * performance hit for that case does not matter. + * + * For small blocks it's not worth the overhead of setting up and calling + * the memcpy routine; do the copy a byte at a time. + * + */ + .global __copy_user +__copy_user: + pta __copy_user_byte_by_byte, tr1 + movi 16, r0 ! this value is a best guess, should tune it by benchmarking + bge/u r0, r4, tr1 + pta copy_user_memcpy, tr0 + addi SP, -32, SP + /* Save arguments in case we have to fix-up unhandled page fault */ + st.q SP, 0, r2 + st.q SP, 8, r3 + st.q SP, 16, r4 + st.q SP, 24, r35 ! r35 is callee-save + /* Save LINK in a register to reduce RTS time later (otherwise + ld SP,*,LINK;ptabs LINK;trn;blink trn,r63 becomes a critical path) */ + ori LINK, 0, r35 + blink tr0, LINK + + /* Copy completed normally if we get back here */ + ptabs r35, tr0 + ld.q SP, 24, r35 + /* don't restore r2-r4, pointless */ + /* set result=r2 to zero as the copy must have succeeded. */ + or r63, r63, r2 + addi SP, 32, SP + blink tr0, r63 ! RTS + + .global __copy_user_fixup +__copy_user_fixup: + /* Restore stack frame */ + ori r35, 0, LINK + ld.q SP, 24, r35 + ld.q SP, 16, r4 + ld.q SP, 8, r3 + ld.q SP, 0, r2 + addi SP, 32, SP + /* Fall through to original code, in the 'same' state we entered with */ + +/* The slow byte-by-byte method is used if the fast copy traps due to a bad + user address. In that rare case, the speed drop can be tolerated. */ +__copy_user_byte_by_byte: + pta ___copy_user_exit, tr1 + pta ___copy_user1, tr0 + beq/u r4, r63, tr1 /* early exit for zero length copy */ + sub r2, r3, r0 + addi r0, -1, r0 + +___copy_user1: + ld.b r3, 0, r5 /* Fault address 1 */ + + /* Could rewrite this to use just 1 add, but the second comes 'free' + due to load latency */ + addi r3, 1, r3 + addi r4, -1, r4 /* No real fixup required */ +___copy_user2: + stx.b r3, r0, r5 /* Fault address 2 */ + bne r4, ZERO, tr0 + +___copy_user_exit: + or r4, ZERO, r2 + ptabs LINK, tr0 + blink tr0, ZERO + +/* + * __kernel_size_t __clear_user(void *addr, __kernel_size_t size) + * + * Inputs: + * (r2) target address + * (r3) size in bytes + * + * Ouputs: + * (*r2) zero-ed target data + * (r2) non-zero-ed bytes + */ + .global __clear_user +__clear_user: + pta ___clear_user_exit, tr1 + pta ___clear_user1, tr0 + beq/u r3, r63, tr1 + +___clear_user1: + st.b r2, 0, ZERO /* Fault address */ + addi r2, 1, r2 + addi r3, -1, r3 /* No real fixup required */ + bne r3, ZERO, tr0 + +___clear_user_exit: + or r3, ZERO, r2 + ptabs LINK, tr0 + blink tr0, ZERO + + +/* + * int __strncpy_from_user(unsigned long __dest, unsigned long __src, + * int __count) + * + * Inputs: + * (r2) target address + * (r3) source address + * (r4) maximum size in bytes + * + * Ouputs: + * (*r2) copied data + * (r2) -EFAULT (in case of faulting) + * copied data (otherwise) + */ + .global __strncpy_from_user +__strncpy_from_user: + pta ___strncpy_from_user1, tr0 + pta ___strncpy_from_user_done, tr1 + or r4, ZERO, r5 /* r5 = original count */ + beq/u r4, r63, tr1 /* early exit if r4==0 */ + movi -(EFAULT), r6 /* r6 = reply, no real fixup */ + or ZERO, ZERO, r7 /* r7 = data, clear top byte of data */ + +___strncpy_from_user1: + ld.b r3, 0, r7 /* Fault address: only in reading */ + st.b r2, 0, r7 + addi r2, 1, r2 + addi r3, 1, r3 + beq/u ZERO, r7, tr1 + addi r4, -1, r4 /* return real number of copied bytes */ + bne/l ZERO, r4, tr0 + +___strncpy_from_user_done: + sub r5, r4, r6 /* If done, return copied */ + +___strncpy_from_user_exit: + or r6, ZERO, r2 + ptabs LINK, tr0 + blink tr0, ZERO + +/* + * extern long __strnlen_user(const char *__s, long __n) + * + * Inputs: + * (r2) source address + * (r3) source size in bytes + * + * Ouputs: + * (r2) -EFAULT (in case of faulting) + * string length (otherwise) + */ + .global __strnlen_user +__strnlen_user: + pta ___strnlen_user_set_reply, tr0 + pta ___strnlen_user1, tr1 + or ZERO, ZERO, r5 /* r5 = counter */ + movi -(EFAULT), r6 /* r6 = reply, no real fixup */ + or ZERO, ZERO, r7 /* r7 = data, clear top byte of data */ + beq r3, ZERO, tr0 + +___strnlen_user1: + ldx.b r2, r5, r7 /* Fault address: only in reading */ + addi r3, -1, r3 /* No real fixup */ + addi r5, 1, r5 + beq r3, ZERO, tr0 + bne r7, ZERO, tr1 +! The line below used to be active. This meant led to a junk byte lying between each pair +! of entries in the argv & envp structures in memory. Whilst the program saw the right data +! via the argv and envp arguments to main, it meant the 'flat' representation visible through +! /proc/$pid/cmdline was corrupt, causing trouble with ps, for example. +! addi r5, 1, r5 /* Include '\0' */ + +___strnlen_user_set_reply: + or r5, ZERO, r6 /* If done, return counter */ + +___strnlen_user_exit: + or r6, ZERO, r2 + ptabs LINK, tr0 + blink tr0, ZERO + +/* + * extern long __get_user_asm_?(void *val, long addr) + * + * Inputs: + * (r2) dest address + * (r3) source address (in User Space) + * + * Ouputs: + * (r2) -EFAULT (faulting) + * 0 (not faulting) + */ + .global __get_user_asm_b +__get_user_asm_b: + or r2, ZERO, r4 + movi -(EFAULT), r2 /* r2 = reply, no real fixup */ + +___get_user_asm_b1: + ld.b r3, 0, r5 /* r5 = data */ + st.b r4, 0, r5 + or ZERO, ZERO, r2 + +___get_user_asm_b_exit: + ptabs LINK, tr0 + blink tr0, ZERO + + + .global __get_user_asm_w +__get_user_asm_w: + or r2, ZERO, r4 + movi -(EFAULT), r2 /* r2 = reply, no real fixup */ + +___get_user_asm_w1: + ld.w r3, 0, r5 /* r5 = data */ + st.w r4, 0, r5 + or ZERO, ZERO, r2 + +___get_user_asm_w_exit: + ptabs LINK, tr0 + blink tr0, ZERO + + + .global __get_user_asm_l +__get_user_asm_l: + or r2, ZERO, r4 + movi -(EFAULT), r2 /* r2 = reply, no real fixup */ + +___get_user_asm_l1: + ld.l r3, 0, r5 /* r5 = data */ + st.l r4, 0, r5 + or ZERO, ZERO, r2 + +___get_user_asm_l_exit: + ptabs LINK, tr0 + blink tr0, ZERO + + + .global __get_user_asm_q +__get_user_asm_q: + or r2, ZERO, r4 + movi -(EFAULT), r2 /* r2 = reply, no real fixup */ + +___get_user_asm_q1: + ld.q r3, 0, r5 /* r5 = data */ + st.q r4, 0, r5 + or ZERO, ZERO, r2 + +___get_user_asm_q_exit: + ptabs LINK, tr0 + blink tr0, ZERO + +/* + * extern long __put_user_asm_?(void *pval, long addr) + * + * Inputs: + * (r2) kernel pointer to value + * (r3) dest address (in User Space) + * + * Ouputs: + * (r2) -EFAULT (faulting) + * 0 (not faulting) + */ + .global __put_user_asm_b +__put_user_asm_b: + ld.b r2, 0, r4 /* r4 = data */ + movi -(EFAULT), r2 /* r2 = reply, no real fixup */ + +___put_user_asm_b1: + st.b r3, 0, r4 + or ZERO, ZERO, r2 + +___put_user_asm_b_exit: + ptabs LINK, tr0 + blink tr0, ZERO + + + .global __put_user_asm_w +__put_user_asm_w: + ld.w r2, 0, r4 /* r4 = data */ + movi -(EFAULT), r2 /* r2 = reply, no real fixup */ + +___put_user_asm_w1: + st.w r3, 0, r4 + or ZERO, ZERO, r2 + +___put_user_asm_w_exit: + ptabs LINK, tr0 + blink tr0, ZERO + + + .global __put_user_asm_l +__put_user_asm_l: + ld.l r2, 0, r4 /* r4 = data */ + movi -(EFAULT), r2 /* r2 = reply, no real fixup */ + +___put_user_asm_l1: + st.l r3, 0, r4 + or ZERO, ZERO, r2 + +___put_user_asm_l_exit: + ptabs LINK, tr0 + blink tr0, ZERO + + + .global __put_user_asm_q +__put_user_asm_q: + ld.q r2, 0, r4 /* r4 = data */ + movi -(EFAULT), r2 /* r2 = reply, no real fixup */ + +___put_user_asm_q1: + st.q r3, 0, r4 + or ZERO, ZERO, r2 + +___put_user_asm_q_exit: + ptabs LINK, tr0 + blink tr0, ZERO + +panic_stash_regs: + /* The idea is : when we get an unhandled panic, we dump the registers + to a known memory location, the just sit in a tight loop. + This allows the human to look at the memory region through the GDB + session (assuming the debug module's SHwy initiator isn't locked up + or anything), to hopefully analyze the cause of the panic. */ + + /* On entry, former r15 (SP) is in DCR + former r0 is at resvec_saved_area + 0 + former r1 is at resvec_saved_area + 8 + former tr0 is at resvec_saved_area + 32 + DCR is the only register whose value is lost altogether. + */ + + movi 0xffffffff80000000, r0 ! phy of dump area + ld.q SP, 0x000, r1 ! former r0 + st.q r0, 0x000, r1 + ld.q SP, 0x008, r1 ! former r1 + st.q r0, 0x008, r1 + st.q r0, 0x010, r2 + st.q r0, 0x018, r3 + st.q r0, 0x020, r4 + st.q r0, 0x028, r5 + st.q r0, 0x030, r6 + st.q r0, 0x038, r7 + st.q r0, 0x040, r8 + st.q r0, 0x048, r9 + st.q r0, 0x050, r10 + st.q r0, 0x058, r11 + st.q r0, 0x060, r12 + st.q r0, 0x068, r13 + st.q r0, 0x070, r14 + getcon dcr, r14 + st.q r0, 0x078, r14 + st.q r0, 0x080, r16 + st.q r0, 0x088, r17 + st.q r0, 0x090, r18 + st.q r0, 0x098, r19 + st.q r0, 0x0a0, r20 + st.q r0, 0x0a8, r21 + st.q r0, 0x0b0, r22 + st.q r0, 0x0b8, r23 + st.q r0, 0x0c0, r24 + st.q r0, 0x0c8, r25 + st.q r0, 0x0d0, r26 + st.q r0, 0x0d8, r27 + st.q r0, 0x0e0, r28 + st.q r0, 0x0e8, r29 + st.q r0, 0x0f0, r30 + st.q r0, 0x0f8, r31 + st.q r0, 0x100, r32 + st.q r0, 0x108, r33 + st.q r0, 0x110, r34 + st.q r0, 0x118, r35 + st.q r0, 0x120, r36 + st.q r0, 0x128, r37 + st.q r0, 0x130, r38 + st.q r0, 0x138, r39 + st.q r0, 0x140, r40 + st.q r0, 0x148, r41 + st.q r0, 0x150, r42 + st.q r0, 0x158, r43 + st.q r0, 0x160, r44 + st.q r0, 0x168, r45 + st.q r0, 0x170, r46 + st.q r0, 0x178, r47 + st.q r0, 0x180, r48 + st.q r0, 0x188, r49 + st.q r0, 0x190, r50 + st.q r0, 0x198, r51 + st.q r0, 0x1a0, r52 + st.q r0, 0x1a8, r53 + st.q r0, 0x1b0, r54 + st.q r0, 0x1b8, r55 + st.q r0, 0x1c0, r56 + st.q r0, 0x1c8, r57 + st.q r0, 0x1d0, r58 + st.q r0, 0x1d8, r59 + st.q r0, 0x1e0, r60 + st.q r0, 0x1e8, r61 + st.q r0, 0x1f0, r62 + st.q r0, 0x1f8, r63 ! bogus, but for consistency's sake... + + ld.q SP, 0x020, r1 ! former tr0 + st.q r0, 0x200, r1 + gettr tr1, r1 + st.q r0, 0x208, r1 + gettr tr2, r1 + st.q r0, 0x210, r1 + gettr tr3, r1 + st.q r0, 0x218, r1 + gettr tr4, r1 + st.q r0, 0x220, r1 + gettr tr5, r1 + st.q r0, 0x228, r1 + gettr tr6, r1 + st.q r0, 0x230, r1 + gettr tr7, r1 + st.q r0, 0x238, r1 + + getcon sr, r1 + getcon ssr, r2 + getcon pssr, r3 + getcon spc, r4 + getcon pspc, r5 + getcon intevt, r6 + getcon expevt, r7 + getcon pexpevt, r8 + getcon tra, r9 + getcon tea, r10 + getcon kcr0, r11 + getcon kcr1, r12 + getcon vbr, r13 + getcon resvec, r14 + + st.q r0, 0x240, r1 + st.q r0, 0x248, r2 + st.q r0, 0x250, r3 + st.q r0, 0x258, r4 + st.q r0, 0x260, r5 + st.q r0, 0x268, r6 + st.q r0, 0x270, r7 + st.q r0, 0x278, r8 + st.q r0, 0x280, r9 + st.q r0, 0x288, r10 + st.q r0, 0x290, r11 + st.q r0, 0x298, r12 + st.q r0, 0x2a0, r13 + st.q r0, 0x2a8, r14 + + getcon SPC,r2 + getcon SSR,r3 + getcon EXPEVT,r4 + /* Prepare to jump to C - physical address */ + movi panic_handler-CONFIG_CACHED_MEMORY_OFFSET, r1 + ori r1, 1, r1 + ptabs r1, tr0 + getcon DCR, SP + blink tr0, ZERO + nop + nop + nop + nop + + + + +/* + * --- Signal Handling Section + */ + +/* + * extern long long _sa_default_rt_restorer + * extern long long _sa_default_restorer + * + * or, better, + * + * extern void _sa_default_rt_restorer(void) + * extern void _sa_default_restorer(void) + * + * Code prototypes to do a sys_rt_sigreturn() or sys_sysreturn() + * from user space. Copied into user space by signal management. + * Both must be quad aligned and 2 quad long (4 instructions). + * + */ + .balign 8 + .global sa_default_rt_restorer +sa_default_rt_restorer: + movi 0x10, r9 + shori __NR_rt_sigreturn, r9 + trapa r9 + nop + + .balign 8 + .global sa_default_restorer +sa_default_restorer: + movi 0x10, r9 + shori __NR_sigreturn, r9 + trapa r9 + nop + +/* + * --- __ex_table Section + */ + +/* + * User Access Exception Table. + */ + .section __ex_table, "a" + + .global asm_uaccess_start /* Just a marker */ +asm_uaccess_start: + + .long ___copy_user1, ___copy_user_exit + .long ___copy_user2, ___copy_user_exit + .long ___clear_user1, ___clear_user_exit + .long ___strncpy_from_user1, ___strncpy_from_user_exit + .long ___strnlen_user1, ___strnlen_user_exit + .long ___get_user_asm_b1, ___get_user_asm_b_exit + .long ___get_user_asm_w1, ___get_user_asm_w_exit + .long ___get_user_asm_l1, ___get_user_asm_l_exit + .long ___get_user_asm_q1, ___get_user_asm_q_exit + .long ___put_user_asm_b1, ___put_user_asm_b_exit + .long ___put_user_asm_w1, ___put_user_asm_w_exit + .long ___put_user_asm_l1, ___put_user_asm_l_exit + .long ___put_user_asm_q1, ___put_user_asm_q_exit + + .global asm_uaccess_end /* Just a marker */ +asm_uaccess_end: + + + + +/* + * --- .text.init Section + */ + + .section .text.init, "ax" + +/* + * void trap_init (void) + * + */ + .global trap_init +trap_init: + addi SP, -24, SP /* Room to save r28/r29/r30 */ + st.q SP, 0, r28 + st.q SP, 8, r29 + st.q SP, 16, r30 + + /* Set VBR and RESVEC */ + movi LVBR_block, r19 + andi r19, -4, r19 /* reset MMUOFF + reserved */ + /* For RESVEC exceptions we force the MMU off, which means we need the + physical address. */ + movi LRESVEC_block-CONFIG_CACHED_MEMORY_OFFSET, r20 + andi r20, -4, r20 /* reset reserved */ + ori r20, 1, r20 /* set MMUOFF */ + putcon r19, VBR + putcon r20, RESVEC + + /* Sanity check */ + movi LVBR_block_end, r21 + andi r21, -4, r21 + movi BLOCK_SIZE, r29 /* r29 = expected size */ + or r19, ZERO, r30 + add r19, r29, r19 + + /* + * Ugly, but better loop forever now than crash afterwards. + * We should print a message, but if we touch LVBR or + * LRESVEC blocks we should not be surprised if we get stuck + * in trap_init(). + */ + pta trap_init_loop, tr1 + gettr tr1, r28 /* r28 = trap_init_loop */ + sub r21, r30, r30 /* r30 = actual size */ + + /* + * VBR/RESVEC handlers overlap by being bigger than + * allowed. Very bad. Just loop forever. + * (r28) panic/loop address + * (r29) expected size + * (r30) actual size + */ +trap_init_loop: + bne r19, r21, tr1 + + /* Now that exception vectors are set up reset SR.BL */ + getcon SR, r22 + movi SR_UNBLOCK_EXC, r23 + and r22, r23, r22 + putcon r22, SR + + addi SP, 24, SP + ptabs LINK, tr0 + blink tr0, ZERO + |