diff options
Diffstat (limited to 'arch/arm64/kernel/entry.S')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 518 |
1 files changed, 452 insertions, 66 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index e1c59d4008a8..cccd2788e631 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -29,6 +29,8 @@ #include <asm/esr.h> #include <asm/irq.h> #include <asm/memory.h> +#include <asm/mmu.h> +#include <asm/processor.h> #include <asm/ptrace.h> #include <asm/thread_info.h> #include <asm/asm-uaccess.h> @@ -69,8 +71,21 @@ #define BAD_FIQ 2 #define BAD_ERROR 3 - .macro kernel_ventry label + .macro kernel_ventry, el, label, regsize = 64 .align 7 +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 +alternative_if ARM64_UNMAP_KERNEL_AT_EL0 + .if \el == 0 + .if \regsize == 64 + mrs x30, tpidrro_el0 + msr tpidrro_el0, xzr + .else + mov x30, xzr + .endif + .endif +alternative_else_nop_endif +#endif + sub sp, sp, #S_FRAME_SIZE #ifdef CONFIG_VMAP_STACK /* @@ -82,7 +97,7 @@ tbnz x0, #THREAD_SHIFT, 0f sub x0, sp, x0 // x0'' = sp' - x0' = (sp + x0) - sp = x0 sub sp, sp, x0 // sp'' = sp' - x0 = (sp + x0) - x0 = sp - b \label + b el\()\el\()_\label 0: /* @@ -114,7 +129,12 @@ sub sp, sp, x0 mrs x0, tpidrro_el0 #endif - b \label + b el\()\el\()_\label + .endm + + .macro tramp_alias, dst, sym + mov_q \dst, TRAMP_VALIAS + add \dst, \dst, #(\sym - .entry.tramp.text) .endm .macro kernel_entry, el, regsize = 64 @@ -185,7 +205,7 @@ alternative_else_nop_endif .if \el != 0 mrs x21, ttbr0_el1 - tst x21, #0xffff << 48 // Check for the reserved ASID + tst x21, #TTBR_ASID_MASK // Check for the reserved ASID orr x23, x23, #PSR_PAN_BIT // Set the emulated PAN in the saved SPSR b.eq 1f // TTBR0 access already disabled and x23, x23, #~PSR_PAN_BIT // Clear the emulated PAN in the saved SPSR @@ -221,6 +241,8 @@ alternative_else_nop_endif .macro kernel_exit, el .if \el != 0 + disable_daif + /* Restore the task's original addr_limit. */ ldr x20, [sp, #S_ORIG_ADDR_LIMIT] str x20, [tsk, #TSK_TI_ADDR_LIMIT] @@ -246,7 +268,7 @@ alternative_else_nop_endif tbnz x22, #22, 1f // Skip re-enabling TTBR0 access if the PSR_PAN_BIT is set .endif - __uaccess_ttbr0_enable x0 + __uaccess_ttbr0_enable x0, x1 .if \el == 0 /* @@ -255,7 +277,7 @@ alternative_else_nop_endif * Cavium erratum 27456 (broadcast TLBI instructions may cause I-cache * corruption). */ - post_ttbr0_update_workaround + bl post_ttbr_update_workaround .endif 1: .if \el != 0 @@ -267,18 +289,20 @@ alternative_else_nop_endif .if \el == 0 ldr x23, [sp, #S_SP] // load return stack pointer msr sp_el0, x23 + tst x22, #PSR_MODE32_BIT // native task? + b.eq 3f + #ifdef CONFIG_ARM64_ERRATUM_845719 alternative_if ARM64_WORKAROUND_845719 - tbz x22, #4, 1f #ifdef CONFIG_PID_IN_CONTEXTIDR mrs x29, contextidr_el1 msr contextidr_el1, x29 #else msr contextidr_el1, xzr #endif -1: alternative_else_nop_endif #endif +3: .endif msr elr_el1, x21 // set up the return data @@ -300,7 +324,25 @@ alternative_else_nop_endif ldp x28, x29, [sp, #16 * 14] ldr lr, [sp, #S_LR] add sp, sp, #S_FRAME_SIZE // restore sp - eret // return to kernel + /* + * ARCH_HAS_MEMBARRIER_SYNC_CORE rely on eret context synchronization + * when returning from IPI handler, and when returning to user-space. + */ + + .if \el == 0 +alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0 +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 + bne 4f + msr far_el1, x30 + tramp_alias x30, tramp_exit_native + br x30 +4: + tramp_alias x30, tramp_exit_compat + br x30 +#endif + .else + eret + .endif .endm .macro irq_stack_entry @@ -365,31 +407,31 @@ tsk .req x28 // current thread_info .align 11 ENTRY(vectors) - kernel_ventry el1_sync_invalid // Synchronous EL1t - kernel_ventry el1_irq_invalid // IRQ EL1t - kernel_ventry el1_fiq_invalid // FIQ EL1t - kernel_ventry el1_error_invalid // Error EL1t + kernel_ventry 1, sync_invalid // Synchronous EL1t + kernel_ventry 1, irq_invalid // IRQ EL1t + kernel_ventry 1, fiq_invalid // FIQ EL1t + kernel_ventry 1, error_invalid // Error EL1t - kernel_ventry el1_sync // Synchronous EL1h - kernel_ventry el1_irq // IRQ EL1h - kernel_ventry el1_fiq_invalid // FIQ EL1h - kernel_ventry el1_error_invalid // Error EL1h + kernel_ventry 1, sync // Synchronous EL1h + kernel_ventry 1, irq // IRQ EL1h + kernel_ventry 1, fiq_invalid // FIQ EL1h + kernel_ventry 1, error // Error EL1h - kernel_ventry el0_sync // Synchronous 64-bit EL0 - kernel_ventry el0_irq // IRQ 64-bit EL0 - kernel_ventry el0_fiq_invalid // FIQ 64-bit EL0 - kernel_ventry el0_error_invalid // Error 64-bit EL0 + kernel_ventry 0, sync // Synchronous 64-bit EL0 + kernel_ventry 0, irq // IRQ 64-bit EL0 + kernel_ventry 0, fiq_invalid // FIQ 64-bit EL0 + kernel_ventry 0, error // Error 64-bit EL0 #ifdef CONFIG_COMPAT - kernel_ventry el0_sync_compat // Synchronous 32-bit EL0 - kernel_ventry el0_irq_compat // IRQ 32-bit EL0 - kernel_ventry el0_fiq_invalid_compat // FIQ 32-bit EL0 - kernel_ventry el0_error_invalid_compat // Error 32-bit EL0 + kernel_ventry 0, sync_compat, 32 // Synchronous 32-bit EL0 + kernel_ventry 0, irq_compat, 32 // IRQ 32-bit EL0 + kernel_ventry 0, fiq_invalid_compat, 32 // FIQ 32-bit EL0 + kernel_ventry 0, error_compat, 32 // Error 32-bit EL0 #else - kernel_ventry el0_sync_invalid // Synchronous 32-bit EL0 - kernel_ventry el0_irq_invalid // IRQ 32-bit EL0 - kernel_ventry el0_fiq_invalid // FIQ 32-bit EL0 - kernel_ventry el0_error_invalid // Error 32-bit EL0 + kernel_ventry 0, sync_invalid, 32 // Synchronous 32-bit EL0 + kernel_ventry 0, irq_invalid, 32 // IRQ 32-bit EL0 + kernel_ventry 0, fiq_invalid, 32 // FIQ 32-bit EL0 + kernel_ventry 0, error_invalid, 32 // Error 32-bit EL0 #endif END(vectors) @@ -453,10 +495,6 @@ ENDPROC(el0_error_invalid) el0_fiq_invalid_compat: inv_entry 0, BAD_FIQ, 32 ENDPROC(el0_fiq_invalid_compat) - -el0_error_invalid_compat: - inv_entry 0, BAD_ERROR, 32 -ENDPROC(el0_error_invalid_compat) #endif el1_sync_invalid: @@ -508,24 +546,18 @@ el1_da: * Data abort handling */ mrs x3, far_el1 - enable_dbg - // re-enable interrupts if they were enabled in the aborted context - tbnz x23, #7, 1f // PSR_I_BIT - enable_irq -1: + inherit_daif pstate=x23, tmp=x2 clear_address_tag x0, x3 mov x2, sp // struct pt_regs bl do_mem_abort - // disable interrupts before pulling preserved data off the stack - disable_irq kernel_exit 1 el1_sp_pc: /* * Stack or PC alignment exception handling */ mrs x0, far_el1 - enable_dbg + inherit_daif pstate=x23, tmp=x2 mov x2, sp bl do_sp_pc_abort ASM_BUG() @@ -533,7 +565,7 @@ el1_undef: /* * Undefined instruction */ - enable_dbg + inherit_daif pstate=x23, tmp=x2 mov x0, sp bl do_undefinstr ASM_BUG() @@ -550,7 +582,7 @@ el1_dbg: kernel_exit 1 el1_inv: // TODO: add support for undefined instructions in kernel mode - enable_dbg + inherit_daif pstate=x23, tmp=x2 mov x0, sp mov x2, x1 mov x1, #BAD_SYNC @@ -561,7 +593,7 @@ ENDPROC(el1_sync) .align 6 el1_irq: kernel_entry 1 - enable_dbg + enable_da_f #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_off #endif @@ -607,6 +639,8 @@ el0_sync: b.eq el0_ia cmp x24, #ESR_ELx_EC_FP_ASIMD // FP/ASIMD access b.eq el0_fpsimd_acc + cmp x24, #ESR_ELx_EC_SVE // SVE access + b.eq el0_sve_acc cmp x24, #ESR_ELx_EC_FP_EXC64 // FP/ASIMD exception b.eq el0_fpsimd_exc cmp x24, #ESR_ELx_EC_SYS64 // configurable trap @@ -658,6 +692,7 @@ el0_svc_compat: /* * AArch32 syscall handling */ + ldr x16, [tsk, #TSK_TI_FLAGS] // load thread flags adrp stbl, compat_sys_call_table // load compat syscall table pointer mov wscno, w7 // syscall number in w7 (r7) mov wsc_nr, #__NR_compat_syscalls @@ -667,6 +702,10 @@ el0_svc_compat: el0_irq_compat: kernel_entry 0, 32 b el0_irq_naked + +el0_error_compat: + kernel_entry 0, 32 + b el0_error_naked #endif el0_da: @@ -674,8 +713,7 @@ el0_da: * Data abort handling */ mrs x26, far_el1 - // enable interrupts before calling the main handler - enable_dbg_and_irq + enable_daif ct_user_exit clear_address_tag x0, x26 mov x1, x25 @@ -687,29 +725,41 @@ el0_ia: * Instruction abort handling */ mrs x26, far_el1 - // enable interrupts before calling the main handler - enable_dbg_and_irq + enable_da_f +#ifdef CONFIG_TRACE_IRQFLAGS + bl trace_hardirqs_off +#endif ct_user_exit mov x0, x26 mov x1, x25 mov x2, sp - bl do_mem_abort + bl do_el0_ia_bp_hardening b ret_to_user el0_fpsimd_acc: /* * Floating Point or Advanced SIMD access */ - enable_dbg + enable_daif ct_user_exit mov x0, x25 mov x1, sp bl do_fpsimd_acc b ret_to_user +el0_sve_acc: + /* + * Scalable Vector Extension access + */ + enable_daif + ct_user_exit + mov x0, x25 + mov x1, sp + bl do_sve_acc + b ret_to_user el0_fpsimd_exc: /* - * Floating Point or Advanced SIMD exception + * Floating Point, Advanced SIMD or SVE exception */ - enable_dbg + enable_daif ct_user_exit mov x0, x25 mov x1, sp @@ -720,8 +770,7 @@ el0_sp_pc: * Stack or PC alignment exception handling */ mrs x26, far_el1 - // enable interrupts before calling the main handler - enable_dbg_and_irq + enable_daif ct_user_exit mov x0, x26 mov x1, x25 @@ -732,8 +781,7 @@ el0_undef: /* * Undefined instruction */ - // enable interrupts before calling the main handler - enable_dbg_and_irq + enable_daif ct_user_exit mov x0, sp bl do_undefinstr @@ -742,7 +790,7 @@ el0_sys: /* * System instructions, for trapped cache maintenance instructions */ - enable_dbg_and_irq + enable_daif ct_user_exit mov x0, x25 mov x1, sp @@ -757,11 +805,11 @@ el0_dbg: mov x1, x25 mov x2, sp bl do_debug_exception - enable_dbg + enable_daif ct_user_exit b ret_to_user el0_inv: - enable_dbg + enable_daif ct_user_exit mov x0, sp mov x1, #BAD_SYNC @@ -774,7 +822,7 @@ ENDPROC(el0_sync) el0_irq: kernel_entry 0 el0_irq_naked: - enable_dbg + enable_da_f #ifdef CONFIG_TRACE_IRQFLAGS bl trace_hardirqs_off #endif @@ -788,12 +836,34 @@ el0_irq_naked: b ret_to_user ENDPROC(el0_irq) +el1_error: + kernel_entry 1 + mrs x1, esr_el1 + enable_dbg + mov x0, sp + bl do_serror + kernel_exit 1 +ENDPROC(el1_error) + +el0_error: + kernel_entry 0 +el0_error_naked: + mrs x1, esr_el1 + enable_dbg + mov x0, sp + bl do_serror + enable_daif + ct_user_exit + b ret_to_user +ENDPROC(el0_error) + + /* * This is the fast syscall return path. We do as little as possible here, * and this includes saving x0 back into the kernel stack. */ ret_fast_syscall: - disable_irq // disable interrupts + disable_daif str x0, [sp, #S_X0] // returned x0 ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing and x2, x1, #_TIF_SYSCALL_WORK @@ -803,7 +873,7 @@ ret_fast_syscall: enable_step_tsk x1, x2 kernel_exit 0 ret_fast_syscall_trace: - enable_irq // enable interrupts + enable_daif b __sys_trace_return_skipped // we already saved x0 /* @@ -821,7 +891,7 @@ work_pending: * "slow" syscall return path. */ ret_to_user: - disable_irq // disable interrupts + disable_daif ldr x1, [tsk, #TSK_TI_FLAGS] and x2, x1, #_TIF_WORK_MASK cbnz x2, work_pending @@ -835,16 +905,37 @@ ENDPROC(ret_to_user) */ .align 6 el0_svc: + ldr x16, [tsk, #TSK_TI_FLAGS] // load thread flags adrp stbl, sys_call_table // load syscall table pointer mov wscno, w8 // syscall number in w8 mov wsc_nr, #__NR_syscalls + +#ifdef CONFIG_ARM64_SVE +alternative_if_not ARM64_SVE + b el0_svc_naked +alternative_else_nop_endif + tbz x16, #TIF_SVE, el0_svc_naked // Skip unless TIF_SVE set: + bic x16, x16, #_TIF_SVE // discard SVE state + str x16, [tsk, #TSK_TI_FLAGS] + + /* + * task_fpsimd_load() won't be called to update CPACR_EL1 in + * ret_to_user unless TIF_FOREIGN_FPSTATE is still set, which only + * happens if a context switch or kernel_neon_begin() or context + * modification (sigreturn, ptrace) intervenes. + * So, ensure that CPACR_EL1 is already correct for the fast-path case: + */ + mrs x9, cpacr_el1 + bic x9, x9, #CPACR_EL1_ZEN_EL0EN // disable SVE for el0 + msr cpacr_el1, x9 // synchronised by eret to el0 +#endif + el0_svc_naked: // compat entry point stp x0, xscno, [sp, #S_ORIG_X0] // save the original x0 and syscall number - enable_dbg_and_irq + enable_daif ct_user_exit 1 - ldr x16, [tsk, #TSK_TI_FLAGS] // check for syscall hooks - tst x16, #_TIF_SYSCALL_WORK + tst x16, #_TIF_SYSCALL_WORK // check for syscall hooks b.ne __sys_trace cmp wscno, wsc_nr // check upper syscall limit b.hs ni_sys @@ -895,6 +986,124 @@ __ni_sys_trace: .popsection // .entry.text +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 +/* + * Exception vectors trampoline. + */ + .pushsection ".entry.tramp.text", "ax" + + .macro tramp_map_kernel, tmp + mrs \tmp, ttbr1_el1 + add \tmp, \tmp, #(PAGE_SIZE + RESERVED_TTBR0_SIZE) + bic \tmp, \tmp, #USER_ASID_FLAG + msr ttbr1_el1, \tmp +#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003 +alternative_if ARM64_WORKAROUND_QCOM_FALKOR_E1003 + /* ASID already in \tmp[63:48] */ + movk \tmp, #:abs_g2_nc:(TRAMP_VALIAS >> 12) + movk \tmp, #:abs_g1_nc:(TRAMP_VALIAS >> 12) + /* 2MB boundary containing the vectors, so we nobble the walk cache */ + movk \tmp, #:abs_g0_nc:((TRAMP_VALIAS & ~(SZ_2M - 1)) >> 12) + isb + tlbi vae1, \tmp + dsb nsh +alternative_else_nop_endif +#endif /* CONFIG_QCOM_FALKOR_ERRATUM_1003 */ + .endm + + .macro tramp_unmap_kernel, tmp + mrs \tmp, ttbr1_el1 + sub \tmp, \tmp, #(PAGE_SIZE + RESERVED_TTBR0_SIZE) + orr \tmp, \tmp, #USER_ASID_FLAG + msr ttbr1_el1, \tmp + /* + * We avoid running the post_ttbr_update_workaround here because the + * user and kernel ASIDs don't have conflicting mappings, so any + * "blessing" as described in: + * + * http://lkml.kernel.org/r/56BB848A.6060603@caviumnetworks.com + * + * will not hurt correctness. Whilst this may partially defeat the + * point of using split ASIDs in the first place, it avoids + * the hit of invalidating the entire I-cache on every return to + * userspace. + */ + .endm + + .macro tramp_ventry, regsize = 64 + .align 7 +1: + .if \regsize == 64 + msr tpidrro_el0, x30 // Restored in kernel_ventry + .endif + /* + * Defend against branch aliasing attacks by pushing a dummy + * entry onto the return stack and using a RET instruction to + * enter the full-fat kernel vectors. + */ + bl 2f + b . +2: + tramp_map_kernel x30 +#ifdef CONFIG_RANDOMIZE_BASE + adr x30, tramp_vectors + PAGE_SIZE +alternative_insn isb, nop, ARM64_WORKAROUND_QCOM_FALKOR_E1003 + ldr x30, [x30] +#else + ldr x30, =vectors +#endif + prfm plil1strm, [x30, #(1b - tramp_vectors)] + msr vbar_el1, x30 + add x30, x30, #(1b - tramp_vectors) + isb + ret + .endm + + .macro tramp_exit, regsize = 64 + adr x30, tramp_vectors + msr vbar_el1, x30 + tramp_unmap_kernel x30 + .if \regsize == 64 + mrs x30, far_el1 + .endif + eret + .endm + + .align 11 +ENTRY(tramp_vectors) + .space 0x400 + + tramp_ventry + tramp_ventry + tramp_ventry + tramp_ventry + + tramp_ventry 32 + tramp_ventry 32 + tramp_ventry 32 + tramp_ventry 32 +END(tramp_vectors) + +ENTRY(tramp_exit_native) + tramp_exit +END(tramp_exit_native) + +ENTRY(tramp_exit_compat) + tramp_exit 32 +END(tramp_exit_compat) + + .ltorg + .popsection // .entry.tramp.text +#ifdef CONFIG_RANDOMIZE_BASE + .pushsection ".rodata", "a" + .align PAGE_SHIFT + .globl __entry_tramp_data_start +__entry_tramp_data_start: + .quad vectors + .popsection // .rodata +#endif /* CONFIG_RANDOMIZE_BASE */ +#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ + /* * Special system call wrappers. */ @@ -948,3 +1157,180 @@ ENTRY(ret_from_fork) b ret_to_user ENDPROC(ret_from_fork) NOKPROBE(ret_from_fork) + +#ifdef CONFIG_ARM_SDE_INTERFACE + +#include <asm/sdei.h> +#include <uapi/linux/arm_sdei.h> + +.macro sdei_handler_exit exit_mode + /* On success, this call never returns... */ + cmp \exit_mode, #SDEI_EXIT_SMC + b.ne 99f + smc #0 + b . +99: hvc #0 + b . +.endm + +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 +/* + * The regular SDEI entry point may have been unmapped along with the rest of + * the kernel. This trampoline restores the kernel mapping to make the x1 memory + * argument accessible. + * + * This clobbers x4, __sdei_handler() will restore this from firmware's + * copy. + */ +.ltorg +.pushsection ".entry.tramp.text", "ax" +ENTRY(__sdei_asm_entry_trampoline) + mrs x4, ttbr1_el1 + tbz x4, #USER_ASID_BIT, 1f + + tramp_map_kernel tmp=x4 + isb + mov x4, xzr + + /* + * Use reg->interrupted_regs.addr_limit to remember whether to unmap + * the kernel on exit. + */ +1: str x4, [x1, #(SDEI_EVENT_INTREGS + S_ORIG_ADDR_LIMIT)] + +#ifdef CONFIG_RANDOMIZE_BASE + adr x4, tramp_vectors + PAGE_SIZE + add x4, x4, #:lo12:__sdei_asm_trampoline_next_handler + ldr x4, [x4] +#else + ldr x4, =__sdei_asm_handler +#endif + br x4 +ENDPROC(__sdei_asm_entry_trampoline) +NOKPROBE(__sdei_asm_entry_trampoline) + +/* + * Make the exit call and restore the original ttbr1_el1 + * + * x0 & x1: setup for the exit API call + * x2: exit_mode + * x4: struct sdei_registered_event argument from registration time. + */ +ENTRY(__sdei_asm_exit_trampoline) + ldr x4, [x4, #(SDEI_EVENT_INTREGS + S_ORIG_ADDR_LIMIT)] + cbnz x4, 1f + + tramp_unmap_kernel tmp=x4 + +1: sdei_handler_exit exit_mode=x2 +ENDPROC(__sdei_asm_exit_trampoline) +NOKPROBE(__sdei_asm_exit_trampoline) + .ltorg +.popsection // .entry.tramp.text +#ifdef CONFIG_RANDOMIZE_BASE +.pushsection ".rodata", "a" +__sdei_asm_trampoline_next_handler: + .quad __sdei_asm_handler +.popsection // .rodata +#endif /* CONFIG_RANDOMIZE_BASE */ +#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ + +/* + * Software Delegated Exception entry point. + * + * x0: Event number + * x1: struct sdei_registered_event argument from registration time. + * x2: interrupted PC + * x3: interrupted PSTATE + * x4: maybe clobbered by the trampoline + * + * Firmware has preserved x0->x17 for us, we must save/restore the rest to + * follow SMC-CC. We save (or retrieve) all the registers as the handler may + * want them. + */ +ENTRY(__sdei_asm_handler) + stp x2, x3, [x1, #SDEI_EVENT_INTREGS + S_PC] + stp x4, x5, [x1, #SDEI_EVENT_INTREGS + 16 * 2] + stp x6, x7, [x1, #SDEI_EVENT_INTREGS + 16 * 3] + stp x8, x9, [x1, #SDEI_EVENT_INTREGS + 16 * 4] + stp x10, x11, [x1, #SDEI_EVENT_INTREGS + 16 * 5] + stp x12, x13, [x1, #SDEI_EVENT_INTREGS + 16 * 6] + stp x14, x15, [x1, #SDEI_EVENT_INTREGS + 16 * 7] + stp x16, x17, [x1, #SDEI_EVENT_INTREGS + 16 * 8] + stp x18, x19, [x1, #SDEI_EVENT_INTREGS + 16 * 9] + stp x20, x21, [x1, #SDEI_EVENT_INTREGS + 16 * 10] + stp x22, x23, [x1, #SDEI_EVENT_INTREGS + 16 * 11] + stp x24, x25, [x1, #SDEI_EVENT_INTREGS + 16 * 12] + stp x26, x27, [x1, #SDEI_EVENT_INTREGS + 16 * 13] + stp x28, x29, [x1, #SDEI_EVENT_INTREGS + 16 * 14] + mov x4, sp + stp lr, x4, [x1, #SDEI_EVENT_INTREGS + S_LR] + + mov x19, x1 + +#ifdef CONFIG_VMAP_STACK + /* + * entry.S may have been using sp as a scratch register, find whether + * this is a normal or critical event and switch to the appropriate + * stack for this CPU. + */ + ldrb w4, [x19, #SDEI_EVENT_PRIORITY] + cbnz w4, 1f + ldr_this_cpu dst=x5, sym=sdei_stack_normal_ptr, tmp=x6 + b 2f +1: ldr_this_cpu dst=x5, sym=sdei_stack_critical_ptr, tmp=x6 +2: mov x6, #SDEI_STACK_SIZE + add x5, x5, x6 + mov sp, x5 +#endif + + /* + * We may have interrupted userspace, or a guest, or exit-from or + * return-to either of these. We can't trust sp_el0, restore it. + */ + mrs x28, sp_el0 + ldr_this_cpu dst=x0, sym=__entry_task, tmp=x1 + msr sp_el0, x0 + + /* If we interrupted the kernel point to the previous stack/frame. */ + and x0, x3, #0xc + mrs x1, CurrentEL + cmp x0, x1 + csel x29, x29, xzr, eq // fp, or zero + csel x4, x2, xzr, eq // elr, or zero + + stp x29, x4, [sp, #-16]! + mov x29, sp + + add x0, x19, #SDEI_EVENT_INTREGS + mov x1, x19 + bl __sdei_handler + + msr sp_el0, x28 + /* restore regs >x17 that we clobbered */ + mov x4, x19 // keep x4 for __sdei_asm_exit_trampoline + ldp x28, x29, [x4, #SDEI_EVENT_INTREGS + 16 * 14] + ldp x18, x19, [x4, #SDEI_EVENT_INTREGS + 16 * 9] + ldp lr, x1, [x4, #SDEI_EVENT_INTREGS + S_LR] + mov sp, x1 + + mov x1, x0 // address to complete_and_resume + /* x0 = (x0 <= 1) ? EVENT_COMPLETE:EVENT_COMPLETE_AND_RESUME */ + cmp x0, #1 + mov_q x2, SDEI_1_0_FN_SDEI_EVENT_COMPLETE + mov_q x3, SDEI_1_0_FN_SDEI_EVENT_COMPLETE_AND_RESUME + csel x0, x2, x3, ls + + ldr_l x2, sdei_exit_mode + +alternative_if_not ARM64_UNMAP_KERNEL_AT_EL0 + sdei_handler_exit exit_mode=x2 +alternative_else_nop_endif + +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 + tramp_alias dst=x5, sym=__sdei_asm_exit_trampoline + br x5 +#endif +ENDPROC(__sdei_asm_handler) +NOKPROBE(__sdei_asm_handler) +#endif /* CONFIG_ARM_SDE_INTERFACE */ |