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-rw-r--r--arch/arm64/kernel/sleep.S154
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diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S
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+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/errno.h>
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/assembler.h>
+#include <asm/smp.h>
+
+ .text
+/*
+ * Implementation of MPIDR_EL1 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
+ * @rs3: register containing affinity level 3 bit shift
+ * @mpidr: register containing MPIDR_EL1 value
+ * @mask: register containing MPIDR mask
+ *
+ * Pseudo C-code:
+ *
+ *u32 dst;
+ *
+ *compute_mpidr_hash(u32 rs0, u32 rs1, u32 rs2, u32 rs3, u64 mpidr, u64 mask) {
+ * u32 aff0, aff1, aff2, aff3;
+ * u64 mpidr_masked = mpidr & mask;
+ * aff0 = mpidr_masked & 0xff;
+ * aff1 = mpidr_masked & 0xff00;
+ * aff2 = mpidr_masked & 0xff0000;
+ * aff3 = mpidr_masked & 0xff00000000;
+ * dst = (aff0 >> rs0 | aff1 >> rs1 | aff2 >> rs2 | aff3 >> rs3);
+ *}
+ * Input registers: rs0, rs1, rs2, rs3, mpidr, mask
+ * Output register: dst
+ * Note: input and output registers must be disjoint register sets
+ (eg: a macro instance with mpidr = x1 and dst = x1 is invalid)
+ */
+ .macro compute_mpidr_hash dst, rs0, rs1, rs2, rs3, mpidr, mask
+ and \mpidr, \mpidr, \mask // mask out MPIDR bits
+ and \dst, \mpidr, #0xff // mask=aff0
+ lsr \dst ,\dst, \rs0 // dst=aff0>>rs0
+ and \mask, \mpidr, #0xff00 // mask = aff1
+ lsr \mask ,\mask, \rs1
+ orr \dst, \dst, \mask // dst|=(aff1>>rs1)
+ and \mask, \mpidr, #0xff0000 // mask = aff2
+ lsr \mask ,\mask, \rs2
+ orr \dst, \dst, \mask // dst|=(aff2>>rs2)
+ and \mask, \mpidr, #0xff00000000 // mask = aff3
+ lsr \mask ,\mask, \rs3
+ orr \dst, \dst, \mask // dst|=(aff3>>rs3)
+ .endm
+/*
+ * Save CPU state in the provided sleep_stack_data area, and publish its
+ * location for cpu_resume()'s use in sleep_save_stash.
+ *
+ * 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
+ */
+SYM_FUNC_START(__cpu_suspend_enter)
+ 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
+ str x2, [x0, #SLEEP_STACK_DATA_SYSTEM_REGS + CPU_CTX_SP]
+
+ /* find the mpidr_hash */
+ ldr_l x1, sleep_save_stash
+ mrs x7, mpidr_el1
+ adr_l x9, mpidr_hash
+ ldr x10, [x9, #MPIDR_HASH_MASK]
+ /*
+ * Following code relies on the struct mpidr_hash
+ * members size.
+ */
+ ldp w3, w4, [x9, #MPIDR_HASH_SHIFTS]
+ ldp w5, w6, [x9, #(MPIDR_HASH_SHIFTS + 8)]
+ compute_mpidr_hash x8, x3, x4, x5, x6, x7, x10
+ add x1, x1, x8, lsl #3
+
+ 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
+SYM_FUNC_END(__cpu_suspend_enter)
+
+ .pushsection ".idmap.text", "awx"
+SYM_CODE_START(cpu_resume)
+ bl init_kernel_el
+ bl finalise_el2
+#if VA_BITS > 48
+ ldr_l x0, vabits_actual
+#endif
+ bl __cpu_setup
+ /* enable the MMU early - so we can access sleep_save_stash by va */
+ adrp x1, swapper_pg_dir
+ adrp x2, idmap_pg_dir
+ bl __enable_mmu
+ ldr x8, =_cpu_resume
+ br x8
+SYM_CODE_END(cpu_resume)
+ .ltorg
+ .popsection
+
+SYM_FUNC_START(_cpu_resume)
+ mrs x1, mpidr_el1
+ adr_l x8, mpidr_hash // x8 = struct mpidr_hash virt address
+
+ /* retrieve mpidr_hash members to compute the hash */
+ ldr x2, [x8, #MPIDR_HASH_MASK]
+ ldp w3, w4, [x8, #MPIDR_HASH_SHIFTS]
+ 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_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]
+ mov sp, x2
+ /*
+ * cpu_do_resume expects x0 to contain context address pointer
+ */
+ bl cpu_do_resume
+
+#if defined(CONFIG_KASAN) && defined(CONFIG_KASAN_STACK)
+ mov x0, sp
+ bl kasan_unpoison_task_stack_below
+#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
+SYM_FUNC_END(_cpu_resume)