From ed3768db588291ddb5dc794daed12cc751373566 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Fri, 25 Oct 2019 17:42:13 +0100 Subject: arm64: entry: convert el1_sync to C This patch converts the EL1 sync entry assembly logic to C code. Doing this will allow us to make changes in a slightly more readable way. A case in point is supporting kernel-first RAS. do_sea() should be called on the CPU that took the fault. Largely the assembly code is converted to C in a relatively straightforward manner. Since all sync sites share a common asm entry point, the ASM_BUG() instances are no longer required for effective backtraces back to assembly, and we don't need similar BUG() entries. The ESR_ELx.EC codes for all (supported) debug exceptions are now checked in the el1_sync_handler's switch statement, which renders the check in el1_dbg redundant. This both simplifies the el1_dbg handler, and makes the EL1 exception handling more robust to currently-unallocated ESR_ELx.EC encodings. Signed-off-by: Mark Rutland [split out of a bigger series, added nokprobes, moved prototypes] Signed-off-by: James Morse Reviewed-by: Mark Rutland Cc: Julien Thierry Signed-off-by: Catalin Marinas --- arch/arm64/kernel/entry.S | 69 +---------------------------------------------- 1 file changed, 1 insertion(+), 68 deletions(-) (limited to 'arch/arm64/kernel/entry.S') diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index e304fe04b098..5d7f42eb0e89 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -578,76 +578,9 @@ ENDPROC(el1_error_invalid) .align 6 el1_sync: kernel_entry 1 - mrs x1, esr_el1 // read the syndrome register - lsr x24, x1, #ESR_ELx_EC_SHIFT // exception class - cmp x24, #ESR_ELx_EC_DABT_CUR // data abort in EL1 - b.eq el1_da - cmp x24, #ESR_ELx_EC_IABT_CUR // instruction abort in EL1 - b.eq el1_ia - cmp x24, #ESR_ELx_EC_SYS64 // configurable trap - b.eq el1_undef - cmp x24, #ESR_ELx_EC_PC_ALIGN // pc alignment exception - b.eq el1_pc - cmp x24, #ESR_ELx_EC_UNKNOWN // unknown exception in EL1 - b.eq el1_undef - cmp x24, #ESR_ELx_EC_BREAKPT_CUR // debug exception in EL1 - b.ge el1_dbg - b el1_inv - -el1_ia: - /* - * Fall through to the Data abort case - */ -el1_da: - /* - * Data abort handling - */ - mrs x3, far_el1 - inherit_daif pstate=x23, tmp=x2 - clear_address_tag x0, x3 - mov x2, sp // struct pt_regs - bl do_mem_abort - - kernel_exit 1 -el1_pc: - /* - * PC alignment exception handling. We don't handle SP alignment faults, - * since we will have hit a recursive exception when trying to push the - * initial pt_regs. - */ - mrs x0, far_el1 - inherit_daif pstate=x23, tmp=x2 - mov x2, sp - bl do_sp_pc_abort - ASM_BUG() -el1_undef: - /* - * Undefined instruction - */ - inherit_daif pstate=x23, tmp=x2 mov x0, sp - bl do_undefinstr - kernel_exit 1 -el1_dbg: - /* - * Debug exception handling - */ - cmp x24, #ESR_ELx_EC_BRK64 // if BRK64 - cinc x24, x24, eq // set bit '0' - tbz x24, #0, el1_inv // EL1 only - gic_prio_kentry_setup tmp=x3 - mrs x0, far_el1 - mov x2, sp // struct pt_regs - bl do_debug_exception + bl el1_sync_handler kernel_exit 1 -el1_inv: - // TODO: add support for undefined instructions in kernel mode - inherit_daif pstate=x23, tmp=x2 - mov x0, sp - mov x2, x1 - mov x1, #BAD_SYNC - bl bad_mode - ASM_BUG() ENDPROC(el1_sync) .align 6 -- cgit v1.2.3