diff options
Diffstat (limited to 'arch/microblaze/kernel/hw_exception_handler.S')
| -rw-r--r-- | arch/microblaze/kernel/hw_exception_handler.S | 746 |
1 files changed, 739 insertions, 7 deletions
diff --git a/arch/microblaze/kernel/hw_exception_handler.S b/arch/microblaze/kernel/hw_exception_handler.S index cf9486d99838..9d591cd74fc2 100644 --- a/arch/microblaze/kernel/hw_exception_handler.S +++ b/arch/microblaze/kernel/hw_exception_handler.S @@ -53,6 +53,12 @@ * - Illegal instruction opcode * - Divide-by-zero * + * - Privileged instruction exception (MMU) + * - Data storage exception (MMU) + * - Instruction storage exception (MMU) + * - Data TLB miss exception (MMU) + * - Instruction TLB miss exception (MMU) + * * Note we disable interrupts during exception handling, otherwise we will * possibly get multiple re-entrancy if interrupt handles themselves cause * exceptions. JW @@ -71,9 +77,24 @@ #include <asm/asm-offsets.h> /* Helpful Macros */ +#ifndef CONFIG_MMU #define EX_HANDLER_STACK_SIZ (4*19) +#endif #define NUM_TO_REG(num) r ## num +#ifdef CONFIG_MMU +/* FIXME you can't change first load of MSR because there is + * hardcoded jump bri 4 */ + #define RESTORE_STATE \ + lwi r3, r1, PT_R3; \ + lwi r4, r1, PT_R4; \ + lwi r5, r1, PT_R5; \ + lwi r6, r1, PT_R6; \ + lwi r11, r1, PT_R11; \ + lwi r31, r1, PT_R31; \ + lwi r1, r0, TOPHYS(r0_ram + 0); +#endif /* CONFIG_MMU */ + #define LWREG_NOP \ bri ex_handler_unhandled; \ nop; @@ -106,6 +127,54 @@ or r3, r0, NUM_TO_REG (regnum); \ bri ex_sw_tail; +#ifdef CONFIG_MMU + #define R3_TO_LWREG_VM_V(regnum) \ + brid ex_lw_end_vm; \ + swi r3, r7, 4 * regnum; + + #define R3_TO_LWREG_VM(regnum) \ + brid ex_lw_end_vm; \ + or NUM_TO_REG (regnum), r0, r3; + + #define SWREG_TO_R3_VM_V(regnum) \ + brid ex_sw_tail_vm; \ + lwi r3, r7, 4 * regnum; + + #define SWREG_TO_R3_VM(regnum) \ + brid ex_sw_tail_vm; \ + or r3, r0, NUM_TO_REG (regnum); + + /* Shift right instruction depending on available configuration */ + #if CONFIG_XILINX_MICROBLAZE0_USE_BARREL > 0 + #define BSRLI(rD, rA, imm) \ + bsrli rD, rA, imm + #elif CONFIG_XILINX_MICROBLAZE0_USE_DIV > 0 + #define BSRLI(rD, rA, imm) \ + ori rD, r0, (1 << imm); \ + idivu rD, rD, rA + #else + #define BSRLI(rD, rA, imm) BSRLI ## imm (rD, rA) + /* Only the used shift constants defined here - add more if needed */ + #define BSRLI2(rD, rA) \ + srl rD, rA; /* << 1 */ \ + srl rD, rD; /* << 2 */ + #define BSRLI10(rD, rA) \ + srl rD, rA; /* << 1 */ \ + srl rD, rD; /* << 2 */ \ + srl rD, rD; /* << 3 */ \ + srl rD, rD; /* << 4 */ \ + srl rD, rD; /* << 5 */ \ + srl rD, rD; /* << 6 */ \ + srl rD, rD; /* << 7 */ \ + srl rD, rD; /* << 8 */ \ + srl rD, rD; /* << 9 */ \ + srl rD, rD /* << 10 */ + #define BSRLI20(rD, rA) \ + BSRLI10(rD, rA); \ + BSRLI10(rD, rD) + #endif +#endif /* CONFIG_MMU */ + .extern other_exception_handler /* Defined in exception.c */ /* @@ -163,34 +232,119 @@ /* wrappers to restore state before coming to entry.S */ +#ifdef CONFIG_MMU +.section .rodata +.align 4 +_MB_HW_ExceptionVectorTable: +/* 0 - Undefined */ + .long TOPHYS(ex_handler_unhandled) +/* 1 - Unaligned data access exception */ + .long TOPHYS(handle_unaligned_ex) +/* 2 - Illegal op-code exception */ + .long TOPHYS(full_exception_trapw) +/* 3 - Instruction bus error exception */ + .long TOPHYS(full_exception_trapw) +/* 4 - Data bus error exception */ + .long TOPHYS(full_exception_trapw) +/* 5 - Divide by zero exception */ + .long TOPHYS(full_exception_trapw) +/* 6 - Floating point unit exception */ + .long TOPHYS(full_exception_trapw) +/* 7 - Privileged instruction exception */ + .long TOPHYS(full_exception_trapw) +/* 8 - 15 - Undefined */ + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) +/* 16 - Data storage exception */ + .long TOPHYS(handle_data_storage_exception) +/* 17 - Instruction storage exception */ + .long TOPHYS(handle_instruction_storage_exception) +/* 18 - Data TLB miss exception */ + .long TOPHYS(handle_data_tlb_miss_exception) +/* 19 - Instruction TLB miss exception */ + .long TOPHYS(handle_instruction_tlb_miss_exception) +/* 20 - 31 - Undefined */ + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) + .long TOPHYS(ex_handler_unhandled) +#endif + .global _hw_exception_handler .section .text .align 4 .ent _hw_exception_handler _hw_exception_handler: +#ifndef CONFIG_MMU addik r1, r1, -(EX_HANDLER_STACK_SIZ); /* Create stack frame */ +#else + swi r1, r0, TOPHYS(r0_ram + 0); /* GET_SP */ + /* Save date to kernel memory. Here is the problem + * when you came from user space */ + ori r1, r0, TOPHYS(r0_ram + 28); +#endif swi r3, r1, PT_R3 swi r4, r1, PT_R4 swi r5, r1, PT_R5 swi r6, r1, PT_R6 - mfs r5, rmsr; - nop - swi r5, r1, 0; - mfs r4, rbtr /* Save BTR before jumping to handler */ - nop +#ifdef CONFIG_MMU + swi r11, r1, PT_R11 + swi r31, r1, PT_R31 + lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)) /* get saved current */ +#endif + mfs r3, resr nop + mfs r4, rear; + nop +#ifndef CONFIG_MMU andi r5, r3, 0x1000; /* Check ESR[DS] */ beqi r5, not_in_delay_slot; /* Branch if ESR[DS] not set */ mfs r17, rbtr; /* ESR[DS] set - return address in BTR */ nop not_in_delay_slot: swi r17, r1, PT_R17 +#endif andi r5, r3, 0x1F; /* Extract ESR[EXC] */ +#ifdef CONFIG_MMU + /* Calculate exception vector offset = r5 << 2 */ + addk r6, r5, r5; /* << 1 */ + addk r6, r6, r6; /* << 2 */ + +/* counting which exception happen */ + lwi r5, r0, 0x200 + TOPHYS(r0_ram) + addi r5, r5, 1 + swi r5, r0, 0x200 + TOPHYS(r0_ram) + lwi r5, r6, 0x200 + TOPHYS(r0_ram) + addi r5, r5, 1 + swi r5, r6, 0x200 + TOPHYS(r0_ram) +/* end */ + /* Load the HW Exception vector */ + lwi r6, r6, TOPHYS(_MB_HW_ExceptionVectorTable) + bra r6 + +full_exception_trapw: + RESTORE_STATE + bri full_exception_trap +#else /* Exceptions enabled here. This will allow nested exceptions */ mfs r6, rmsr; nop @@ -254,6 +408,7 @@ handle_other_ex: /* Handle Other exceptions here */ lwi r18, r1, PT_R18 bri ex_handler_done; /* Complete exception handling */ +#endif /* 0x01 - Unaligned data access exception * This occurs when a word access is not aligned on a word boundary, @@ -265,11 +420,28 @@ handle_other_ex: /* Handle Other exceptions here */ handle_unaligned_ex: /* Working registers already saved: R3, R4, R5, R6 * R3 = ESR - * R4 = BTR + * R4 = EAR */ - mfs r4, rear; +#ifdef CONFIG_MMU + andi r6, r3, 0x1000 /* Check ESR[DS] */ + beqi r6, _no_delayslot /* Branch if ESR[DS] not set */ + mfs r17, rbtr; /* ESR[DS] set - return address in BTR */ nop +_no_delayslot: +#endif + +#ifdef CONFIG_MMU + /* Check if unaligned address is last on a 4k page */ + andi r5, r4, 0xffc + xori r5, r5, 0xffc + bnei r5, _unaligned_ex2 + _unaligned_ex1: + RESTORE_STATE; +/* Another page must be accessed or physical address not in page table */ + bri unaligned_data_trap + _unaligned_ex2: +#endif andi r6, r3, 0x3E0; /* Mask and extract the register operand */ srl r6, r6; /* r6 >> 5 */ srl r6, r6; @@ -278,6 +450,45 @@ handle_unaligned_ex: srl r6, r6; /* Store the register operand in a temporary location */ sbi r6, r0, TOPHYS(ex_reg_op); +#ifdef CONFIG_MMU + /* Get physical address */ + /* If we are faulting a kernel address, we have to use the + * kernel page tables. + */ + ori r5, r0, CONFIG_KERNEL_START + cmpu r5, r4, r5 + bgti r5, _unaligned_ex3 + ori r5, r0, swapper_pg_dir + bri _unaligned_ex4 + + /* Get the PGD for the current thread. */ +_unaligned_ex3: /* user thread */ + addi r5 ,CURRENT_TASK, TOPHYS(0); /* get current task address */ + lwi r5, r5, TASK_THREAD + PGDIR +_unaligned_ex4: + tophys(r5,r5) + BSRLI(r6,r4,20) /* Create L1 (pgdir/pmd) address */ + andi r6, r6, 0xffc +/* Assume pgdir aligned on 4K boundary, no need for "andi r5,r5,0xfffff003" */ + or r5, r5, r6 + lwi r6, r5, 0 /* Get L1 entry */ + andi r5, r6, 0xfffff000 /* Extract L2 (pte) base address. */ + beqi r5, _unaligned_ex1 /* Bail if no table */ + + tophys(r5,r5) + BSRLI(r6,r4,10) /* Compute PTE address */ + andi r6, r6, 0xffc + andi r5, r5, 0xfffff003 + or r5, r5, r6 + lwi r5, r5, 0 /* Get Linux PTE */ + + andi r6, r5, _PAGE_PRESENT + beqi r6, _unaligned_ex1 /* Bail if no page */ + + andi r5, r5, 0xfffff000 /* Extract RPN */ + andi r4, r4, 0x00000fff /* Extract offset */ + or r4, r4, r5 /* Create physical address */ +#endif /* CONFIG_MMU */ andi r6, r3, 0x400; /* Extract ESR[S] */ bnei r6, ex_sw; @@ -355,6 +566,7 @@ ex_shw: ex_sw_end: /* Exception handling of store word, ends. */ ex_handler_done: +#ifndef CONFIG_MMU lwi r5, r1, 0 /* RMSR */ mts rmsr, r5 nop @@ -366,13 +578,455 @@ ex_handler_done: rted r17, 0 addik r1, r1, (EX_HANDLER_STACK_SIZ); /* Restore stack frame */ +#else + RESTORE_STATE; + rted r17, 0 + nop +#endif + +#ifdef CONFIG_MMU + /* Exception vector entry code. This code runs with address translation + * turned off (i.e. using physical addresses). */ + + /* Exception vectors. */ + + /* 0x10 - Data Storage Exception + * This happens for just a few reasons. U0 set (but we don't do that), + * or zone protection fault (user violation, write to protected page). + * If this is just an update of modified status, we do that quickly + * and exit. Otherwise, we call heavyweight functions to do the work. + */ + handle_data_storage_exception: + /* Working registers already saved: R3, R4, R5, R6 + * R3 = ESR + */ + mfs r11, rpid + nop + bri 4 + mfs r3, rear /* Get faulting address */ + nop + /* If we are faulting a kernel address, we have to use the + * kernel page tables. + */ + ori r4, r0, CONFIG_KERNEL_START + cmpu r4, r3, r4 + bgti r4, ex3 + /* First, check if it was a zone fault (which means a user + * tried to access a kernel or read-protected page - always + * a SEGV). All other faults here must be stores, so no + * need to check ESR_S as well. */ + mfs r4, resr + nop + andi r4, r4, 0x800 /* ESR_Z - zone protection */ + bnei r4, ex2 + + ori r4, r0, swapper_pg_dir + mts rpid, r0 /* TLB will have 0 TID */ + nop + bri ex4 + + /* Get the PGD for the current thread. */ + ex3: + /* First, check if it was a zone fault (which means a user + * tried to access a kernel or read-protected page - always + * a SEGV). All other faults here must be stores, so no + * need to check ESR_S as well. */ + mfs r4, resr + nop + andi r4, r4, 0x800 /* ESR_Z */ + bnei r4, ex2 + /* get current task address */ + addi r4 ,CURRENT_TASK, TOPHYS(0); + lwi r4, r4, TASK_THREAD+PGDIR + ex4: + tophys(r4,r4) + BSRLI(r5,r3,20) /* Create L1 (pgdir/pmd) address */ + andi r5, r5, 0xffc +/* Assume pgdir aligned on 4K boundary, no need for "andi r4,r4,0xfffff003" */ + or r4, r4, r5 + lwi r4, r4, 0 /* Get L1 entry */ + andi r5, r4, 0xfffff000 /* Extract L2 (pte) base address */ + beqi r5, ex2 /* Bail if no table */ + + tophys(r5,r5) + BSRLI(r6,r3,10) /* Compute PTE address */ + andi r6, r6, 0xffc + andi r5, r5, 0xfffff003 + or r5, r5, r6 + lwi r4, r5, 0 /* Get Linux PTE */ + + andi r6, r4, _PAGE_RW /* Is it writeable? */ + beqi r6, ex2 /* Bail if not */ + + /* Update 'changed' */ + ori r4, r4, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE + swi r4, r5, 0 /* Update Linux page table */ + + /* Most of the Linux PTE is ready to load into the TLB LO. + * We set ZSEL, where only the LS-bit determines user access. + * We set execute, because we don't have the granularity to + * properly set this at the page level (Linux problem). + * If shared is set, we cause a zero PID->TID load. + * Many of these bits are software only. Bits we don't set + * here we (properly should) assume have the appropriate value. + */ + andni r4, r4, 0x0ce2 /* Make sure 20, 21 are zero */ + ori r4, r4, _PAGE_HWEXEC /* make it executable */ + + /* find the TLB index that caused the fault. It has to be here*/ + mts rtlbsx, r3 + nop + mfs r5, rtlbx /* DEBUG: TBD */ + nop + mts rtlblo, r4 /* Load TLB LO */ + nop + /* Will sync shadow TLBs */ + + /* Done...restore registers and get out of here. */ + mts rpid, r11 + nop + bri 4 + + RESTORE_STATE; + rted r17, 0 + nop + ex2: + /* The bailout. Restore registers to pre-exception conditions + * and call the heavyweights to help us out. */ + mts rpid, r11 + nop + bri 4 + RESTORE_STATE; + bri page_fault_data_trap + + + /* 0x11 - Instruction Storage Exception + * This is caused by a fetch from non-execute or guarded pages. */ + handle_instruction_storage_exception: + /* Working registers already saved: R3, R4, R5, R6 + * R3 = ESR + */ + + mfs r3, rear /* Get faulting address */ + nop + RESTORE_STATE; + bri page_fault_instr_trap + + /* 0x12 - Data TLB Miss Exception + * As the name implies, translation is not in the MMU, so search the + * page tables and fix it. The only purpose of this function is to + * load TLB entries from the page table if they exist. + */ + handle_data_tlb_miss_exception: + /* Working registers already saved: R3, R4, R5, R6 + * R3 = ESR + */ + mfs r11, rpid + nop + bri 4 + mfs r3, rear /* Get faulting address */ + nop + + /* If we are faulting a kernel address, we have to use the + * kernel page tables. */ + ori r4, r0, CONFIG_KERNEL_START + cmpu r4, r3, r4 + bgti r4, ex5 + ori r4, r0, swapper_pg_dir + mts rpid, r0 /* TLB will have 0 TID */ + nop + bri ex6 + /* Get the PGD for the current thread. */ + ex5: + /* get current task address */ + addi r4 ,CURRENT_TASK, TOPHYS(0); + lwi r4, r4, TASK_THREAD+PGDIR + ex6: + tophys(r4,r4) + BSRLI(r5,r3,20) /* Create L1 (pgdir/pmd) address */ + andi r5, r5, 0xffc +/* Assume pgdir aligned on 4K boundary, no need for "andi r4,r4,0xfffff003" */ + or r4, r4, r5 + lwi r4, r4, 0 /* Get L1 entry */ + andi r5, r4, 0xfffff000 /* Extract L2 (pte) base address */ + beqi r5, ex7 /* Bail if no table */ + + tophys(r5,r5) + BSRLI(r6,r3,10) /* Compute PTE address */ + andi r6, r6, 0xffc + andi r5, r5, 0xfffff003 + or r5, r5, r6 + lwi r4, r5, 0 /* Get Linux PTE */ + + andi r6, r4, _PAGE_PRESENT + beqi r6, ex7 + + ori r4, r4, _PAGE_ACCESSED + swi r4, r5, 0 + + /* Most of the Linux PTE is ready to load into the TLB LO. + * We set ZSEL, where only the LS-bit determines user access. + * We set execute, because we don't have the granularity to + * properly set this at the page level (Linux problem). + * If shared is set, we cause a zero PID->TID load. + * Many of these bits are software only. Bits we don't set + * here we (properly should) assume have the appropriate value. + */ + andni r4, r4, 0x0ce2 /* Make sure 20, 21 are zero */ + + bri finish_tlb_load + ex7: + /* The bailout. Restore registers to pre-exception conditions + * and call the heavyweights to help us out. + */ + mts rpid, r11 + nop + bri 4 + RESTORE_STATE; + bri page_fault_data_trap + + /* 0x13 - Instruction TLB Miss Exception + * Nearly the same as above, except we get our information from + * different registers and bailout to a different point. + */ + handle_instruction_tlb_miss_exception: + /* Working registers already saved: R3, R4, R5, R6 + * R3 = ESR + */ + mfs r11, rpid + nop + bri 4 + mfs r3, rear /* Get faulting address */ + nop + + /* If we are faulting a kernel address, we have to use the + * kernel page tables. + */ + ori r4, r0, CONFIG_KERNEL_START + cmpu r4, r3, r4 + bgti r4, ex8 + ori r4, r0, swapper_pg_dir + mts rpid, r0 /* TLB will have 0 TID */ + nop + bri ex9 + + /* Get the PGD for the current thread. */ + ex8: + /* get current task address */ + addi r4 ,CURRENT_TASK, TOPHYS(0); + lwi r4, r4, TASK_THREAD+PGDIR + ex9: + tophys(r4,r4) + BSRLI(r5,r3,20) /* Create L1 (pgdir/pmd) address */ + andi r5, r5, 0xffc +/* Assume pgdir aligned on 4K boundary, no need for "andi r4,r4,0xfffff003" */ + or r4, r4, r5 + lwi r4, r4, 0 /* Get L1 entry */ + andi r5, r4, 0xfffff000 /* Extract L2 (pte) base address */ + beqi r5, ex10 /* Bail if no table */ + + tophys(r5,r5) + BSRLI(r6,r3,10) /* Compute PTE address */ + andi r6, r6, 0xffc + andi r5, r5, 0xfffff003 + or r5, r5, r6 + lwi r4, r5, 0 /* Get Linux PTE */ + + andi r6, r4, _PAGE_PRESENT + beqi r6, ex7 + + ori r4, r4, _PAGE_ACCESSED + swi r4, r5, 0 + + /* Most of the Linux PTE is ready to load into the TLB LO. + * We set ZSEL, where only the LS-bit determines user access. + * We set execute, because we don't have the granularity to + * properly set this at the page level (Linux problem). + * If shared is set, we cause a zero PID->TID load. + * Many of these bits are software only. Bits we don't set + * here we (properly should) assume have the appropriate value. + */ + andni r4, r4, 0x0ce2 /* Make sure 20, 21 are zero */ + + bri finish_tlb_load + ex10: + /* The bailout. Restore registers to pre-exception conditions + * and call the heavyweights to help us out. + */ + mts rpid, r11 + nop + bri 4 + RESTORE_STATE; + bri page_fault_instr_trap + +/* Both the instruction and data TLB miss get to this point to load the TLB. + * r3 - EA of fault + * r4 - TLB LO (info from Linux PTE) + * r5, r6 - available to use + * PID - loaded with proper value when we get here + * Upon exit, we reload everything and RFI. + * A common place to load the TLB. + */ + tlb_index: + .long 1 /* MS: storing last used tlb index */ + finish_tlb_load: + /* MS: load the last used TLB index. */ + lwi r5, r0, TOPHYS(tlb_index) + addik r5, r5, 1 /* MS: inc tlb_index -> use next one */ + +/* MS: FIXME this is potential fault, because this is mask not count */ + andi r5, r5, (MICROBLAZE_TLB_SIZE-1) + ori r6, r0, 1 + cmp r31, r5, r6 + blti r31, sem + addik r5, r6, 1 + sem: + /* MS: save back current TLB index */ + swi r5, r0, TOPHYS(tlb_index) + + ori r4, r4, _PAGE_HWEXEC /* make it executable */ + mts rtlbx, r5 /* MS: save current TLB */ + nop + mts rtlblo, r4 /* MS: save to TLB LO */ + nop + + /* Create EPN. This is the faulting address plus a static + * set of bits. These are size, valid, E, U0, and ensure + * bits 20 and 21 are zero. + */ + andi r3, r3, 0xfffff000 + ori r3, r3, 0x0c0 + mts rtlbhi, r3 /* Load TLB HI */ + nop + + /* Done...restore registers and get out of here. */ + ex12: + mts rpid, r11 + nop + bri 4 + RESTORE_STATE; + rted r17, 0 + nop + + /* extern void giveup_fpu(struct task_struct *prev) + * + * The MicroBlaze processor may have an FPU, so this should not just + * return: TBD. + */ + .globl giveup_fpu; + .align 4; + giveup_fpu: + bralid r15,0 /* TBD */ + nop + + /* At present, this routine just hangs. - extern void abort(void) */ + .globl abort; + .align 4; + abort: + br r0 + + .globl set_context; + .align 4; + set_context: + mts rpid, r5 /* Shadow TLBs are automatically */ + nop + bri 4 /* flushed by changing PID */ + rtsd r15,8 + nop + +#endif .end _hw_exception_handler +#ifdef CONFIG_MMU +/* Unaligned data access exception last on a 4k page for MMU. + * When this is called, we are in virtual mode with exceptions enabled + * and registers 1-13,15,17,18 saved. + * + * R3 = ESR + * R4 = EAR + * R7 = pointer to saved registers (struct pt_regs *regs) + * + * This handler perform the access, and returns via ret_from_exc. + */ +.global _unaligned_data_exception +.ent _unaligned_data_exception +_unaligned_data_exception: + andi r8, r3, 0x3E0; /* Mask and extract the register operand */ + BSRLI(r8,r8,2); /* r8 >> 2 = register operand * 8 */ + andi r6, r3, 0x400; /* Extract ESR[S] */ + bneid r6, ex_sw_vm; + andi r6, r3, 0x800; /* Extract ESR[W] - delay slot */ +ex_lw_vm: + beqid r6, ex_lhw_vm; + lbui r5, r4, 0; /* Exception address in r4 - delay slot */ +/* Load a word, byte-by-byte from destination address and save it in tmp space*/ + la r6, r0, ex_tmp_data_loc_0; + sbi r5, r6, 0; + lbui r5, r4, 1; + sbi r5, r6, 1; + lbui r5, r4, 2; + sbi r5, r6, 2; + lbui r5, r4, 3; + sbi r5, r6, 3; + brid ex_lw_tail_vm; +/* Get the destination register value into r3 - delay slot */ + lwi r3, r6, 0; +ex_lhw_vm: + /* Load a half-word, byte-by-byte from destination address and + * save it in tmp space */ + la r6, r0, ex_tmp_data_loc_0; + sbi r5, r6, 0; + lbui r5, r4, 1; + sbi r5, r6, 1; + lhui r3, r6, 0; /* Get the destination register value into r3 */ +ex_lw_tail_vm: + /* Form load_word jump table offset (lw_table_vm + (8 * regnum)) */ + addik r5, r8, lw_table_vm; + bra r5; +ex_lw_end_vm: /* Exception handling of load word, ends */ + brai ret_from_exc; +ex_sw_vm: +/* Form store_word jump table offset (sw_table_vm + (8 * regnum)) */ + addik r5, r8, sw_table_vm; + bra r5; +ex_sw_tail_vm: + la r5, r0, ex_tmp_data_loc_0; + beqid r6, ex_shw_vm; + swi r3, r5, 0; /* Get the word - delay slot */ + /* Store the word, byte-by-byte into destination address */ + lbui r3, r5, 0; + sbi r3, r4, 0; + lbui r3, r5, 1; + sbi r3, r4, 1; + lbui r3, r5, 2; + sbi r3, r4, 2; + lbui r3, r5, 3; + brid ret_from_exc; + sbi r3, r4, 3; /* Delay slot */ +ex_shw_vm: + /* Store the lower half-word, byte-by-byte into destination address */ + lbui r3, r5, 2; + sbi r3, r4, 0; + lbui r3, r5, 3; + brid ret_from_exc; + sbi r3, r4, 1; /* Delay slot */ +ex_sw_end_vm: /* Exception handling of store word, ends. */ +.end _unaligned_data_exception +#endif /* CONFIG_MMU */ + ex_handler_unhandled: /* FIXME add handle function for unhandled exception - dump register */ bri 0 +/* + * hw_exception_handler Jump Table + * - Contains code snippets for each register that caused the unalign exception + * - Hence exception handler is NOT self-modifying + * - Separate table for load exceptions and store exceptions. + * - Each table is of size: (8 * 32) = 256 bytes + */ + .section .text .align 4 lw_table: @@ -407,7 +1061,11 @@ lw_r27: R3_TO_LWREG (27); lw_r28: R3_TO_LWREG (28); lw_r29: R3_TO_LWREG (29); lw_r30: R3_TO_LWREG (30); +#ifdef CONFIG_MMU +lw_r31: R3_TO_LWREG_V (31); +#else lw_r31: R3_TO_LWREG (31); +#endif sw_table: sw_r0: SWREG_TO_R3 (0); @@ -441,7 +1099,81 @@ sw_r27: SWREG_TO_R3 (27); sw_r28: SWREG_TO_R3 (28); sw_r29: SWREG_TO_R3 (29); sw_r30: SWREG_TO_R3 (30); +#ifdef CONFIG_MMU +sw_r31: SWREG_TO_R3_V (31); +#else sw_r31: SWREG_TO_R3 (31); +#endif + +#ifdef CONFIG_MMU +lw_table_vm: +lw_r0_vm: R3_TO_LWREG_VM (0); +lw_r1_vm: R3_TO_LWREG_VM_V (1); +lw_r2_vm: R3_TO_LWREG_VM_V (2); +lw_r3_vm: R3_TO_LWREG_VM_V (3); +lw_r4_vm: R3_TO_LWREG_VM_V (4); +lw_r5_vm: R3_TO_LWREG_VM_V (5); +lw_r6_vm: R3_TO_LWREG_VM_V (6); +lw_r7_vm: R3_TO_LWREG_VM_V (7); +lw_r8_vm: R3_TO_LWREG_VM_V (8); +lw_r9_vm: R3_TO_LWREG_VM_V (9); +lw_r10_vm: R3_TO_LWREG_VM_V (10); +lw_r11_vm: R3_TO_LWREG_VM_V (11); +lw_r12_vm: R3_TO_LWREG_VM_V (12); +lw_r13_vm: R3_TO_LWREG_VM_V (13); +lw_r14_vm: R3_TO_LWREG_VM (14); +lw_r15_vm: R3_TO_LWREG_VM_V (15); +lw_r16_vm: R3_TO_LWREG_VM (16); +lw_r17_vm: R3_TO_LWREG_VM_V (17); +lw_r18_vm: R3_TO_LWREG_VM_V (18); +lw_r19_vm: R3_TO_LWREG_VM (19); +lw_r20_vm: R3_TO_LWREG_VM (20); +lw_r21_vm: R3_TO_LWREG_VM (21); +lw_r22_vm: R3_TO_LWREG_VM (22); +lw_r23_vm: R3_TO_LWREG_VM (23); +lw_r24_vm: R3_TO_LWREG_VM (24); +lw_r25_vm: R3_TO_LWREG_VM (25); +lw_r26_vm: R3_TO_LWREG_VM (26); +lw_r27_vm: R3_TO_LWREG_VM (27); +lw_r28_vm: R3_TO_LWREG_VM (28); +lw_r29_vm: R3_TO_LWREG_VM (29); +lw_r30_vm: R3_TO_LWREG_VM (30); +lw_r31_vm: R3_TO_LWREG_VM_V (31); + +sw_table_vm: +sw_r0_vm: SWREG_TO_R3_VM (0); +sw_r1_vm: SWREG_TO_R3_VM_V (1); +sw_r2_vm: SWREG_TO_R3_VM_V (2); +sw_r3_vm: SWREG_TO_R3_VM_V (3); +sw_r4_vm: SWREG_TO_R3_VM_V (4); +sw_r5_vm: SWREG_TO_R3_VM_V (5); +sw_r6_vm: SWREG_TO_R3_VM_V (6); +sw_r7_vm: SWREG_TO_R3_VM_V (7); +sw_r8_vm: SWREG_TO_R3_VM_V (8); +sw_r9_vm: SWREG_TO_R3_VM_V (9); +sw_r10_vm: SWREG_TO_R3_VM_V (10); +sw_r11_vm: SWREG_TO_R3_VM_V (11); +sw_r12_vm: SWREG_TO_R3_VM_V (12); +sw_r13_vm: SWREG_TO_R3_VM_V (13); +sw_r14_vm: SWREG_TO_R3_VM (14); +sw_r15_vm: SWREG_TO_R3_VM_V (15); +sw_r16_vm: SWREG_TO_R3_VM (16); +sw_r17_vm: SWREG_TO_R3_VM_V (17); +sw_r18_vm: SWREG_TO_R3_VM_V (18); +sw_r19_vm: SWREG_TO_R3_VM (19); +sw_r20_vm: SWREG_TO_R3_VM (20); +sw_r21_vm: SWREG_TO_R3_VM (21); +sw_r22_vm: SWREG_TO_R3_VM (22); +sw_r23_vm: SWREG_TO_R3_VM (23); +sw_r24_vm: SWREG_TO_R3_VM (24); +sw_r25_vm: SWREG_TO_R3_VM (25); +sw_r26_vm: SWREG_TO_R3_VM (26); +sw_r27_vm: SWREG_TO_R3_VM (27); +sw_r28_vm: SWREG_TO_R3_VM (28); +sw_r29_vm: SWREG_TO_R3_VM (29); +sw_r30_vm: SWREG_TO_R3_VM (30); +sw_r31_vm: SWREG_TO_R3_VM_V (31); +#endif /* CONFIG_MMU */ /* Temporary data structures used in the handler */ .section .data |