diff options
Diffstat (limited to 'arch/xtensa/kernel/entry.S')
| -rw-r--r-- | arch/xtensa/kernel/entry.S | 115 |
1 files changed, 47 insertions, 68 deletions
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 3f3de283d707..ab025c1f6e23 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -91,9 +91,9 @@ * a0: trashed, original value saved on stack (PT_AREG0) * a1: a1 * a2: new stack pointer, original value in depc - * a3: dispatch table + * a3: a3 * depc: a2, original value saved on stack (PT_DEPC) - * excsave1: a3 + * excsave1: dispatch table * * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception @@ -109,9 +109,8 @@ ENTRY(user_exception) - /* Save a2, a3, and depc, restore excsave_1 and set SP. */ + /* Save a1, a2, a3, and set SP. */ - xsr a3, excsave1 rsr a0, depc s32i a1, a2, PT_AREG1 s32i a0, a2, PT_AREG2 @@ -237,9 +236,9 @@ ENDPROC(user_exception) * a0: trashed, original value saved on stack (PT_AREG0) * a1: a1 * a2: new stack pointer, original in DEPC - * a3: dispatch table + * a3: a3 * depc: a2, original value saved on stack (PT_DEPC) - * excsave_1: a3 + * excsave_1: dispatch table * * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception @@ -255,9 +254,8 @@ ENDPROC(user_exception) ENTRY(kernel_exception) - /* Save a0, a2, a3, DEPC and set SP. */ + /* Save a1, a2, a3, and set SP. */ - xsr a3, excsave1 # restore a3, excsave_1 rsr a0, depc # get a2 s32i a1, a2, PT_AREG1 s32i a0, a2, PT_AREG2 @@ -408,7 +406,7 @@ common_exception: * exception handler and call the exception handler. */ - movi a4, exc_table + rsr a4, excsave1 mov a6, a1 # pass stack frame mov a7, a0 # pass EXCCAUSE addx4 a4, a0, a4 @@ -832,9 +830,9 @@ ENDPROC(unrecoverable_exception) * a0: trashed, original value saved on stack (PT_AREG0) * a1: a1 * a2: new stack pointer, original in DEPC - * a3: dispatch table + * a3: a3 * depc: a2, original value saved on stack (PT_DEPC) - * excsave_1: a3 + * excsave_1: dispatch table * * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception @@ -857,18 +855,16 @@ ENTRY(fast_alloca) rsr a0, depc # get a2 s32i a4, a2, PT_AREG4 # save a4 and + s32i a3, a2, PT_AREG3 s32i a0, a2, PT_AREG2 # a2 to stack /* Exit critical section. */ movi a0, 0 + rsr a3, excsave1 s32i a0, a3, EXC_TABLE_FIXUP - /* Restore a3, excsave_1 */ - - xsr a3, excsave1 # make sure excsave_1 is valid for dbl. rsr a4, epc1 # get exception address - s32i a3, a2, PT_AREG3 # save a3 to stack #ifdef ALLOCA_EXCEPTION_IN_IRAM #error iram not supported @@ -1007,9 +1003,9 @@ ENDPROC(fast_alloca) * a0: trashed, original value saved on stack (PT_AREG0) * a1: a1 * a2: new stack pointer, original in DEPC - * a3: dispatch table + * a3: a3 * depc: a2, original value saved on stack (PT_DEPC) - * excsave_1: a3 + * excsave_1: dispatch table */ ENTRY(fast_syscall_kernel) @@ -1056,7 +1052,6 @@ ENTRY(fast_syscall_unrecoverable) l32i a0, a2, PT_AREG0 # restore a0 xsr a2, depc # restore a2, depc - rsr a3, excsave1 wsr a0, excsave1 movi a0, unrecoverable_exception @@ -1078,10 +1073,10 @@ ENDPROC(fast_syscall_unrecoverable) * a0: a2 (syscall-nr), original value saved on stack (PT_AREG0) * a1: a1 * a2: new stack pointer, original in a0 and DEPC - * a3: dispatch table, original in excsave_1 + * a3: a3 * a4..a15: unchanged * depc: a2, original value saved on stack (PT_DEPC) - * excsave_1: a3 + * excsave_1: dispatch table * * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception @@ -1114,8 +1109,6 @@ ENDPROC(fast_syscall_unrecoverable) ENTRY(fast_syscall_xtensa) - xsr a3, excsave1 # restore a3, excsave1 - s32i a7, a2, PT_AREG7 # we need an additional register movi a7, 4 # sizeof(unsigned int) access_ok a3, a7, a0, a2, .Leac # a0: scratch reg, a2: sp @@ -1178,9 +1171,9 @@ ENDPROC(fast_syscall_xtensa) * a0: trashed, original value saved on stack (PT_AREG0) * a1: a1 * a2: new stack pointer, original in DEPC - * a3: dispatch table + * a3: a3 * depc: a2, original value saved on stack (PT_DEPC) - * excsave_1: a3 + * excsave_1: dispatch table * * Note: We assume the stack pointer is EXC_TABLE_KSTK in the fixup handler. */ @@ -1189,15 +1182,16 @@ ENTRY(fast_syscall_spill_registers) /* Register a FIXUP handler (pass current wb as a parameter) */ + xsr a3, excsave1 movi a0, fast_syscall_spill_registers_fixup s32i a0, a3, EXC_TABLE_FIXUP rsr a0, windowbase s32i a0, a3, EXC_TABLE_PARAM + xsr a3, excsave1 # restore a3 and excsave_1 - /* Save a3 and SAR on stack. */ + /* Save a3, a4 and SAR on stack. */ rsr a0, sar - xsr a3, excsave1 # restore a3 and excsave_1 s32i a3, a2, PT_AREG3 s32i a4, a2, PT_AREG4 s32i a0, a2, PT_AREG5 # store SAR to PT_AREG5 @@ -1251,14 +1245,14 @@ fast_syscall_spill_registers_fixup: * in WS, so that the exception handlers save them to the task stack. */ - rsr a3, excsave1 # get spill-mask + xsr a3, excsave1 # get spill-mask slli a2, a3, 1 # shift left by one slli a3, a2, 32-WSBITS src a2, a2, a3 # a1 = xxwww1yyxxxwww1yy...... wsr a2, windowstart # set corrected windowstart - movi a3, exc_table + rsr a3, excsave1 l32i a2, a3, EXC_TABLE_DOUBLE_SAVE # restore a2 l32i a3, a3, EXC_TABLE_PARAM # original WB (in user task) @@ -1295,7 +1289,7 @@ fast_syscall_spill_registers_fixup: /* Jump to the exception handler. */ - movi a3, exc_table + rsr a3, excsave1 rsr a0, exccause addx4 a0, a0, a3 # find entry in table l32i a0, a0, EXC_TABLE_FAST_USER # load handler @@ -1312,6 +1306,7 @@ fast_syscall_spill_registers_fixup_return: xsr a3, excsave1 movi a2, fast_syscall_spill_registers_fixup s32i a2, a3, EXC_TABLE_FIXUP + s32i a0, a3, EXC_TABLE_DOUBLE_SAVE rsr a2, windowbase s32i a2, a3, EXC_TABLE_PARAM l32i a2, a3, EXC_TABLE_KSTK @@ -1323,11 +1318,6 @@ fast_syscall_spill_registers_fixup_return: wsr a3, windowbase rsync - /* Restore a3 and return. */ - - movi a3, exc_table - xsr a3, excsave1 - rfde @@ -1514,9 +1504,8 @@ ENTRY(_spill_registers) movi a0, 0 - movi a3, exc_table + rsr a3, excsave1 l32i a1, a3, EXC_TABLE_KSTK - wsr a3, excsave1 movi a4, (1 << PS_WOE_BIT) | LOCKLEVEL wsr a4, ps @@ -1560,9 +1549,9 @@ ENDPROC(fast_second_level_miss_double_kernel) * a0: trashed, original value saved on stack (PT_AREG0) * a1: a1 * a2: new stack pointer, original in DEPC - * a3: dispatch table + * a3: a3 * depc: a2, original value saved on stack (PT_DEPC) - * excsave_1: a3 + * excsave_1: dispatch table * * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception @@ -1570,9 +1559,10 @@ ENDPROC(fast_second_level_miss_double_kernel) ENTRY(fast_second_level_miss) - /* Save a1. Note: we don't expect a double exception. */ + /* Save a1 and a3. Note: we don't expect a double exception. */ s32i a1, a2, PT_AREG1 + s32i a3, a2, PT_AREG3 /* We need to map the page of PTEs for the user task. Find * the pointer to that page. Also, it's possible for tsk->mm @@ -1594,9 +1584,6 @@ ENTRY(fast_second_level_miss) l32i a0, a1, TASK_MM # tsk->mm beqz a0, 9f - - /* We deliberately destroy a3 that holds the exception table. */ - 8: rsr a3, excvaddr # fault address _PGD_OFFSET(a0, a3, a1) l32i a0, a0, 0 # read pmdval @@ -1647,7 +1634,7 @@ ENTRY(fast_second_level_miss) /* Exit critical section. */ -4: movi a3, exc_table # restore a3 +4: rsr a3, excsave1 movi a0, 0 s32i a0, a3, EXC_TABLE_FIXUP @@ -1655,8 +1642,8 @@ ENTRY(fast_second_level_miss) l32i a0, a2, PT_AREG0 l32i a1, a2, PT_AREG1 + l32i a3, a2, PT_AREG3 l32i a2, a2, PT_DEPC - xsr a3, excsave1 bgeui a2, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f @@ -1743,11 +1730,8 @@ ENTRY(fast_second_level_miss) 2: /* Invalid PGD, default exception handling */ - movi a3, exc_table rsr a1, depc - xsr a3, excsave1 s32i a1, a2, PT_AREG2 - s32i a3, a2, PT_AREG3 mov a1, a2 rsr a2, ps @@ -1767,9 +1751,9 @@ ENDPROC(fast_second_level_miss) * a0: trashed, original value saved on stack (PT_AREG0) * a1: a1 * a2: new stack pointer, original in DEPC - * a3: dispatch table + * a3: a3 * depc: a2, original value saved on stack (PT_DEPC) - * excsave_1: a3 + * excsave_1: dispatch table * * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS: double exception, DEPC * < VALID_DOUBLE_EXCEPTION_ADDRESS: regular exception @@ -1777,17 +1761,17 @@ ENDPROC(fast_second_level_miss) ENTRY(fast_store_prohibited) - /* Save a1 and a4. */ + /* Save a1 and a3. */ s32i a1, a2, PT_AREG1 - s32i a4, a2, PT_AREG4 + s32i a3, a2, PT_AREG3 GET_CURRENT(a1,a2) l32i a0, a1, TASK_MM # tsk->mm beqz a0, 9f 8: rsr a1, excvaddr # fault address - _PGD_OFFSET(a0, a1, a4) + _PGD_OFFSET(a0, a1, a3) l32i a0, a0, 0 beqz a0, 2f @@ -1796,39 +1780,37 @@ ENTRY(fast_store_prohibited) * and is not PAGE_NONE. See pgtable.h for possible PTE layouts. */ - _PTE_OFFSET(a0, a1, a4) - l32i a4, a0, 0 # read pteval + _PTE_OFFSET(a0, a1, a3) + l32i a3, a0, 0 # read pteval movi a1, _PAGE_CA_INVALID - ball a4, a1, 2f - bbci.l a4, _PAGE_WRITABLE_BIT, 2f + ball a3, a1, 2f + bbci.l a3, _PAGE_WRITABLE_BIT, 2f movi a1, _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_HW_WRITE - or a4, a4, a1 + or a3, a3, a1 rsr a1, excvaddr - s32i a4, a0, 0 + s32i a3, a0, 0 /* We need to flush the cache if we have page coloring. */ #if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK dhwb a0, 0 #endif pdtlb a0, a1 - wdtlb a4, a0 + wdtlb a3, a0 /* Exit critical section. */ movi a0, 0 + rsr a3, excsave1 s32i a0, a3, EXC_TABLE_FIXUP /* Restore the working registers, and return. */ - l32i a4, a2, PT_AREG4 + l32i a3, a2, PT_AREG3 l32i a1, a2, PT_AREG1 l32i a0, a2, PT_AREG0 l32i a2, a2, PT_DEPC - /* Restore excsave1 and a3. */ - - xsr a3, excsave1 bgeui a2, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f rsr a2, depc @@ -1845,11 +1827,8 @@ ENTRY(fast_store_prohibited) 2: /* If there was a problem, handle fault in C */ - rsr a4, depc # still holds a2 - xsr a3, excsave1 - s32i a4, a2, PT_AREG2 - s32i a3, a2, PT_AREG3 - l32i a4, a2, PT_AREG4 + rsr a3, depc # still holds a2 + s32i a3, a2, PT_AREG2 mov a1, a2 rsr a2, ps |