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Diffstat (limited to 'arch/arm/kernel/sleep.S')
| -rw-r--r-- | arch/arm/kernel/sleep.S | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S new file mode 100644 index 000000000..a86a1d4f3 --- /dev/null +++ b/arch/arm/kernel/sleep.S @@ -0,0 +1,194 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/linkage.h> +#include <linux/threads.h> +#include <asm/asm-offsets.h> +#include <asm/assembler.h> +#include <asm/glue-cache.h> +#include <asm/glue-proc.h> + .text + +/* + * Implementation of MPIDR hash algorithm through shifting + * and OR'ing. + * + * @dst: register containing hash result + * @rs0: register containing affinity level 0 bit shift + * @rs1: register containing affinity level 1 bit shift + * @rs2: register containing affinity level 2 bit shift + * @mpidr: register containing MPIDR value + * @mask: register containing MPIDR mask + * + * Pseudo C-code: + * + *u32 dst; + * + *compute_mpidr_hash(u32 rs0, u32 rs1, u32 rs2, u32 mpidr, u32 mask) { + * u32 aff0, aff1, aff2; + * u32 mpidr_masked = mpidr & mask; + * aff0 = mpidr_masked & 0xff; + * aff1 = mpidr_masked & 0xff00; + * aff2 = mpidr_masked & 0xff0000; + * dst = (aff0 >> rs0 | aff1 >> rs1 | aff2 >> rs2); + *} + * Input registers: rs0, rs1, rs2, mpidr, mask + * Output register: dst + * Note: input and output registers must be disjoint register sets + (eg: a macro instance with mpidr = r1 and dst = r1 is invalid) + */ + .macro compute_mpidr_hash dst, rs0, rs1, rs2, mpidr, mask + and \mpidr, \mpidr, \mask @ mask out MPIDR bits + and \dst, \mpidr, #0xff @ mask=aff0 + ARM( mov \dst, \dst, lsr \rs0 ) @ dst=aff0>>rs0 + THUMB( lsr \dst, \dst, \rs0 ) + and \mask, \mpidr, #0xff00 @ mask = aff1 + ARM( orr \dst, \dst, \mask, lsr \rs1 ) @ dst|=(aff1>>rs1) + THUMB( lsr \mask, \mask, \rs1 ) + THUMB( orr \dst, \dst, \mask ) + and \mask, \mpidr, #0xff0000 @ mask = aff2 + ARM( orr \dst, \dst, \mask, lsr \rs2 ) @ dst|=(aff2>>rs2) + THUMB( lsr \mask, \mask, \rs2 ) + THUMB( orr \dst, \dst, \mask ) + .endm + +/* + * Save CPU state for a suspend. This saves the CPU general purpose + * registers, and allocates space on the kernel stack to save the CPU + * specific registers and some other data for resume. + * r0 = suspend function arg0 + * r1 = suspend function + * r2 = MPIDR value the resuming CPU will use + */ +ENTRY(__cpu_suspend) + stmfd sp!, {r4 - r11, lr} +#ifdef MULTI_CPU + ldr r10, =processor + ldr r4, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state +#else + ldr r4, =cpu_suspend_size +#endif + mov r5, sp @ current virtual SP +#ifdef CONFIG_VMAP_STACK + @ Run the suspend code from the overflow stack so we don't have to rely + @ on vmalloc-to-phys conversions anywhere in the arch suspend code. + @ The original SP value captured in R5 will be restored on the way out. + ldr_this_cpu sp, overflow_stack_ptr, r6, r7 +#endif + add r4, r4, #12 @ Space for pgd, virt sp, phys resume fn + sub sp, sp, r4 @ allocate CPU state on stack + ldr r3, =sleep_save_sp + stmfd sp!, {r0, r1} @ save suspend func arg and pointer + ldr r3, [r3, #SLEEP_SAVE_SP_VIRT] + ALT_SMP(W(nop)) @ don't use adr_l inside ALT_SMP() + ALT_UP_B(1f) + adr_l r0, mpidr_hash + /* This ldmia relies on the memory layout of the mpidr_hash struct */ + ldmia r0, {r1, r6-r8} @ r1 = mpidr mask (r6,r7,r8) = l[0,1,2] shifts + compute_mpidr_hash r0, r6, r7, r8, r2, r1 + add r3, r3, r0, lsl #2 +1: mov r2, r5 @ virtual SP + mov r1, r4 @ size of save block + add r0, sp, #8 @ pointer to save block + bl __cpu_suspend_save + badr lr, cpu_suspend_abort + ldmfd sp!, {r0, pc} @ call suspend fn +ENDPROC(__cpu_suspend) + .ltorg + +cpu_suspend_abort: + ldmia sp!, {r1 - r3} @ pop phys pgd, virt SP, phys resume fn + teq r0, #0 + moveq r0, #1 @ force non-zero value + mov sp, r2 + ldmfd sp!, {r4 - r11, pc} +ENDPROC(cpu_suspend_abort) + +/* + * r0 = control register value + */ + .align 5 + .pushsection .idmap.text,"ax" +ENTRY(cpu_resume_mmu) + ldr r3, =cpu_resume_after_mmu + instr_sync + mcr p15, 0, r0, c1, c0, 0 @ turn on MMU, I-cache, etc + mrc p15, 0, r0, c0, c0, 0 @ read id reg + instr_sync + mov r0, r0 + mov r0, r0 + ret r3 @ jump to virtual address +ENDPROC(cpu_resume_mmu) + .popsection +cpu_resume_after_mmu: +#if defined(CONFIG_VMAP_STACK) && !defined(CONFIG_ARM_LPAE) + @ Before using the vmap'ed stack, we have to switch to swapper_pg_dir + @ as the ID map does not cover the vmalloc region. + mrc p15, 0, ip, c2, c0, 1 @ read TTBR1 + mcr p15, 0, ip, c2, c0, 0 @ set TTBR0 + instr_sync +#endif + bl cpu_init @ restore the und/abt/irq banked regs + mov r0, #0 @ return zero on success + ldmfd sp!, {r4 - r11, pc} +ENDPROC(cpu_resume_after_mmu) + + .text + .align + +#ifdef CONFIG_MCPM + .arm +THUMB( .thumb ) +ENTRY(cpu_resume_no_hyp) +ARM_BE8(setend be) @ ensure we are in BE mode + b no_hyp +#endif + +#ifdef CONFIG_MMU + .arm +ENTRY(cpu_resume_arm) + THUMB( badr r9, 1f ) @ Kernel is entered in ARM. + THUMB( bx r9 ) @ If this is a Thumb-2 kernel, + THUMB( .thumb ) @ switch to Thumb now. + THUMB(1: ) +#endif + +ENTRY(cpu_resume) +ARM_BE8(setend be) @ ensure we are in BE mode +#ifdef CONFIG_ARM_VIRT_EXT + bl __hyp_stub_install_secondary +#endif + safe_svcmode_maskall r1 +no_hyp: + mov r1, #0 + ALT_SMP(mrc p15, 0, r0, c0, c0, 5) + ALT_UP_B(1f) + adr_l r2, mpidr_hash @ r2 = struct mpidr_hash phys address + + /* + * This ldmia relies on the memory layout of the mpidr_hash + * struct mpidr_hash. + */ + ldmia r2, { r3-r6 } @ r3 = mpidr mask (r4,r5,r6) = l[0,1,2] shifts + compute_mpidr_hash r1, r4, r5, r6, r0, r3 +1: + ldr_l r0, sleep_save_sp + SLEEP_SAVE_SP_PHYS + ldr r0, [r0, r1, lsl #2] + + @ load phys pgd, stack, resume fn + ARM( ldmia r0!, {r1, sp, pc} ) +THUMB( ldmia r0!, {r1, r2, r3} ) +THUMB( mov sp, r2 ) +THUMB( bx r3 ) +ENDPROC(cpu_resume) + +#ifdef CONFIG_MMU +ENDPROC(cpu_resume_arm) +#endif +#ifdef CONFIG_MCPM +ENDPROC(cpu_resume_no_hyp) +#endif + + .data + .align 2 + .type sleep_save_sp, #object +ENTRY(sleep_save_sp) + .space SLEEP_SAVE_SP_SZ @ struct sleep_save_sp |