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-rw-r--r--arch/arm64/kernel/sleep.S157
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)