diff options
Diffstat (limited to 'arch/microblaze/kernel/hw_exception_handler.S')
| -rw-r--r-- | arch/microblaze/kernel/hw_exception_handler.S | 109 |
1 files changed, 46 insertions, 63 deletions
diff --git a/arch/microblaze/kernel/hw_exception_handler.S b/arch/microblaze/kernel/hw_exception_handler.S index 9d591cd74fc2..3288c9737671 100644 --- a/arch/microblaze/kernel/hw_exception_handler.S +++ b/arch/microblaze/kernel/hw_exception_handler.S @@ -74,6 +74,7 @@ #include <asm/mmu.h> #include <asm/pgtable.h> +#include <asm/signal.h> #include <asm/asm-offsets.h> /* Helpful Macros */ @@ -428,19 +429,9 @@ handle_unaligned_ex: 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: + /* jump to high level unaligned handler */ + RESTORE_STATE; + bri unaligned_data_trap #endif andi r6, r3, 0x3E0; /* Mask and extract the register operand */ srl r6, r6; /* r6 >> 5 */ @@ -450,45 +441,6 @@ _no_delayslot: 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; @@ -959,15 +911,15 @@ _unaligned_data_exception: 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 */ +load1: 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; +load2: lbui r5, r4, 1; sbi r5, r6, 1; - lbui r5, r4, 2; +load3: lbui r5, r4, 2; sbi r5, r6, 2; - lbui r5, r4, 3; +load4: lbui r5, r4, 3; sbi r5, r6, 3; brid ex_lw_tail_vm; /* Get the destination register value into r3 - delay slot */ @@ -977,7 +929,7 @@ ex_lhw_vm: * save it in tmp space */ la r6, r0, ex_tmp_data_loc_0; sbi r5, r6, 0; - lbui r5, r4, 1; +load5: lbui r5, r4, 1; sbi r5, r6, 1; lhui r3, r6, 0; /* Get the destination register value into r3 */ ex_lw_tail_vm: @@ -996,22 +948,53 @@ ex_sw_tail_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; +store1: sbi r3, r4, 0; lbui r3, r5, 1; - sbi r3, r4, 1; +store2: sbi r3, r4, 1; lbui r3, r5, 2; - sbi r3, r4, 2; +store3: sbi r3, r4, 2; lbui r3, r5, 3; brid ret_from_exc; - sbi r3, r4, 3; /* Delay slot */ +store4: 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; +store5: sbi r3, r4, 0; lbui r3, r5, 3; brid ret_from_exc; - sbi r3, r4, 1; /* Delay slot */ +store6: sbi r3, r4, 1; /* Delay slot */ ex_sw_end_vm: /* Exception handling of store word, ends. */ + +/* We have to prevent cases that get/put_user macros get unaligned pointer + * to bad page area. We have to find out which origin instruction caused it + * and called fixup for that origin instruction not instruction in unaligned + * handler */ +ex_unaligned_fixup: + ori r5, r7, 0 /* setup pointer to pt_regs */ + lwi r6, r7, PT_PC; /* faulting address is one instruction above */ + addik r6, r6, -4 /* for finding proper fixup */ + swi r6, r7, PT_PC; /* a save back it to PT_PC */ + addik r7, r0, SIGSEGV + /* call bad_page_fault for finding aligned fixup, fixup address is saved + * in PT_PC which is used as return address from exception */ + la r15, r0, ret_from_exc-8 /* setup return address */ + brid bad_page_fault + nop + +/* We prevent all load/store because it could failed any attempt to access */ +.section __ex_table,"a"; + .word load1,ex_unaligned_fixup; + .word load2,ex_unaligned_fixup; + .word load3,ex_unaligned_fixup; + .word load4,ex_unaligned_fixup; + .word load5,ex_unaligned_fixup; + .word store1,ex_unaligned_fixup; + .word store2,ex_unaligned_fixup; + .word store3,ex_unaligned_fixup; + .word store4,ex_unaligned_fixup; + .word store5,ex_unaligned_fixup; + .word store6,ex_unaligned_fixup; +.previous; .end _unaligned_data_exception #endif /* CONFIG_MMU */ |