diff options
Diffstat (limited to 'arch/arm64/kernel/sleep.S')
| -rw-r--r-- | arch/arm64/kernel/sleep.S | 157 |
1 files changed, 58 insertions, 99 deletions
diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S index fd10eb663868..9a3aec97ac09 100644 --- a/arch/arm64/kernel/sleep.S +++ b/arch/arm64/kernel/sleep.S @@ -49,39 +49,32 @@ orr \dst, \dst, \mask // dst|=(aff3>>rs3) .endm /* - * Save CPU state for a suspend and execute the suspend finisher. - * On success it will return 0 through cpu_resume - ie through a CPU - * soft/hard reboot from the reset vector. - * On failure it returns the suspend finisher return value or force - * -EOPNOTSUPP if the finisher erroneously returns 0 (the suspend finisher - * is not allowed to return, if it does this must be considered failure). - * It saves callee registers, and allocates space on the kernel stack - * to save the CPU specific registers + some other data for resume. + * Save CPU state in the provided sleep_stack_data area, and publish its + * location for cpu_resume()'s use in sleep_save_stash. * - * x0 = suspend finisher argument - * x1 = suspend finisher function pointer + * cpu_resume() will restore this saved state, and return. Because the + * link-register is saved and restored, it will appear to return from this + * function. So that the caller can tell the suspend/resume paths apart, + * __cpu_suspend_enter() will always return a non-zero value, whereas the + * path through cpu_resume() will return 0. + * + * x0 = struct sleep_stack_data area */ ENTRY(__cpu_suspend_enter) - stp x29, lr, [sp, #-96]! - stp x19, x20, [sp,#16] - stp x21, x22, [sp,#32] - stp x23, x24, [sp,#48] - stp x25, x26, [sp,#64] - stp x27, x28, [sp,#80] - /* - * Stash suspend finisher and its argument in x20 and x19 - */ - mov x19, x0 - mov x20, x1 + stp x29, lr, [x0, #SLEEP_STACK_DATA_CALLEE_REGS] + stp x19, x20, [x0,#SLEEP_STACK_DATA_CALLEE_REGS+16] + stp x21, x22, [x0,#SLEEP_STACK_DATA_CALLEE_REGS+32] + stp x23, x24, [x0,#SLEEP_STACK_DATA_CALLEE_REGS+48] + stp x25, x26, [x0,#SLEEP_STACK_DATA_CALLEE_REGS+64] + stp x27, x28, [x0,#SLEEP_STACK_DATA_CALLEE_REGS+80] + + /* save the sp in cpu_suspend_ctx */ mov x2, sp - sub sp, sp, #CPU_SUSPEND_SZ // allocate cpu_suspend_ctx - mov x0, sp - /* - * x0 now points to struct cpu_suspend_ctx allocated on the stack - */ - str x2, [x0, #CPU_CTX_SP] - ldr x1, =sleep_save_sp - ldr x1, [x1, #SLEEP_SAVE_SP_VIRT] + str x2, [x0, #SLEEP_STACK_DATA_SYSTEM_REGS + CPU_CTX_SP] + + /* find the mpidr_hash */ + ldr x1, =sleep_save_stash + ldr x1, [x1] mrs x7, mpidr_el1 ldr x9, =mpidr_hash ldr x10, [x9, #MPIDR_HASH_MASK] @@ -93,74 +86,28 @@ ENTRY(__cpu_suspend_enter) ldp w5, w6, [x9, #(MPIDR_HASH_SHIFTS + 8)] compute_mpidr_hash x8, x3, x4, x5, x6, x7, x10 add x1, x1, x8, lsl #3 - bl __cpu_suspend_save - /* - * Grab suspend finisher in x20 and its argument in x19 - */ - mov x0, x19 - mov x1, x20 - /* - * We are ready for power down, fire off the suspend finisher - * in x1, with argument in x0 - */ - blr x1 - /* - * Never gets here, unless suspend finisher fails. - * Successful cpu_suspend should return from cpu_resume, returning - * through this code path is considered an error - * If the return value is set to 0 force x0 = -EOPNOTSUPP - * to make sure a proper error condition is propagated - */ - cmp x0, #0 - mov x3, #-EOPNOTSUPP - csel x0, x3, x0, eq - add sp, sp, #CPU_SUSPEND_SZ // rewind stack pointer - ldp x19, x20, [sp, #16] - ldp x21, x22, [sp, #32] - ldp x23, x24, [sp, #48] - ldp x25, x26, [sp, #64] - ldp x27, x28, [sp, #80] - ldp x29, lr, [sp], #96 + + str x0, [x1] + add x0, x0, #SLEEP_STACK_DATA_SYSTEM_REGS + stp x29, lr, [sp, #-16]! + bl cpu_do_suspend + ldp x29, lr, [sp], #16 + mov x0, #1 ret ENDPROC(__cpu_suspend_enter) .ltorg -/* - * x0 must contain the sctlr value retrieved from restored context - */ - .pushsection ".idmap.text", "ax" -ENTRY(cpu_resume_mmu) - ldr x3, =cpu_resume_after_mmu - msr sctlr_el1, x0 // restore sctlr_el1 - isb - /* - * Invalidate the local I-cache so that any instructions fetched - * speculatively from the PoC are discarded, since they may have - * been dynamically patched at the PoU. - */ - ic iallu - dsb nsh - isb - br x3 // global jump to virtual address -ENDPROC(cpu_resume_mmu) - .popsection -cpu_resume_after_mmu: -#ifdef CONFIG_KASAN - mov x0, sp - bl kasan_unpoison_remaining_stack -#endif - mov x0, #0 // return zero on success - ldp x19, x20, [sp, #16] - ldp x21, x22, [sp, #32] - ldp x23, x24, [sp, #48] - ldp x25, x26, [sp, #64] - ldp x27, x28, [sp, #80] - ldp x29, lr, [sp], #96 - ret -ENDPROC(cpu_resume_after_mmu) - ENTRY(cpu_resume) bl el2_setup // if in EL2 drop to EL1 cleanly + /* enable the MMU early - so we can access sleep_save_stash by va */ + adr_l lr, __enable_mmu /* __cpu_setup will return here */ + ldr x27, =_cpu_resume /* __enable_mmu will branch here */ + adrp x25, idmap_pg_dir + adrp x26, swapper_pg_dir + b __cpu_setup +ENDPROC(cpu_resume) + +ENTRY(_cpu_resume) mrs x1, mpidr_el1 adrp x8, mpidr_hash add x8, x8, #:lo12:mpidr_hash // x8 = struct mpidr_hash phys address @@ -170,20 +117,32 @@ ENTRY(cpu_resume) ldp w5, w6, [x8, #(MPIDR_HASH_SHIFTS + 8)] compute_mpidr_hash x7, x3, x4, x5, x6, x1, x2 /* x7 contains hash index, let's use it to grab context pointer */ - ldr_l x0, sleep_save_sp + SLEEP_SAVE_SP_PHYS + ldr_l x0, sleep_save_stash ldr x0, [x0, x7, lsl #3] + add x29, x0, #SLEEP_STACK_DATA_CALLEE_REGS + add x0, x0, #SLEEP_STACK_DATA_SYSTEM_REGS /* load sp from context */ ldr x2, [x0, #CPU_CTX_SP] - /* load physical address of identity map page table in x1 */ - adrp x1, idmap_pg_dir mov sp, x2 /* save thread_info */ and x2, x2, #~(THREAD_SIZE - 1) msr sp_el0, x2 /* - * cpu_do_resume expects x0 to contain context physical address - * pointer and x1 to contain physical address of 1:1 page tables + * cpu_do_resume expects x0 to contain context address pointer */ - bl cpu_do_resume // PC relative jump, MMU off - b cpu_resume_mmu // Resume MMU, never returns -ENDPROC(cpu_resume) + bl cpu_do_resume + +#ifdef CONFIG_KASAN + mov x0, sp + bl kasan_unpoison_remaining_stack +#endif + + ldp x19, x20, [x29, #16] + ldp x21, x22, [x29, #32] + ldp x23, x24, [x29, #48] + ldp x25, x26, [x29, #64] + ldp x27, x28, [x29, #80] + ldp x29, lr, [x29] + mov x0, #0 + ret +ENDPROC(_cpu_resume) |