--- /dev/null
+#include <linux/errno.h>
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/assembler.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;
+ * aff2 = 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 for a suspend. This saves callee registers, and allocates
+ * space on the kernel stack to save the CPU specific registers + some
+ * other data for resume.
+ *
+ * x0 = suspend finisher argument
+ */
+ENTRY(__cpu_suspend)
+ 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]
+ mov x2, sp
+ sub sp, sp, #CPU_SUSPEND_SZ // allocate cpu_suspend_ctx
+ mov x1, sp
+ /*
+ * x1 now points to struct cpu_suspend_ctx allocated on the stack
+ */
+ str x2, [x1, #CPU_CTX_SP]
+ ldr x2, =sleep_save_sp
+ ldr x2, [x2, #SLEEP_SAVE_SP_VIRT]
+#ifdef CONFIG_SMP
+ mrs x7, mpidr_el1
+ ldr 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 x2, x2, x8, lsl #3
+#endif
+ bl __cpu_suspend_finisher
+ /*
+ * Never gets here, unless suspend 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
+ ret
+ENDPROC(__cpu_suspend)
+ .ltorg
+
+/*
+ * x0 must contain the sctlr value retrieved from restored context
+ */
+ENTRY(cpu_resume_mmu)
+ ldr x3, =cpu_resume_after_mmu
+ msr sctlr_el1, x0 // restore sctlr_el1
+ isb
+ br x3 // global jump to virtual address
+ENDPROC(cpu_resume_mmu)
+cpu_resume_after_mmu:
+ 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)
+
+ .data
+ENTRY(cpu_resume)
+ bl el2_setup // if in EL2 drop to EL1 cleanly
+#ifdef CONFIG_SMP
+ mrs x1, mpidr_el1
+ adr x4, mpidr_hash_ptr
+ ldr x5, [x4]
+ add x8, x4, x5 // x8 = struct mpidr_hash phys 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 */
+#else
+ mov x7, xzr
+#endif
+ adr x0, sleep_save_sp
+ ldr x0, [x0, #SLEEP_SAVE_SP_PHYS]
+ ldr x0, [x0, x7, lsl #3]
+ /* load sp from context */
+ ldr x2, [x0, #CPU_CTX_SP]
+ adr x1, sleep_idmap_phys
+ /* load physical address of identity map page table in x1 */
+ ldr x1, [x1]
+ mov sp, x2
+ /*
+ * cpu_do_resume expects x0 to contain context physical address
+ * pointer and x1 to contain physical address of 1:1 page tables
+ */
+ bl cpu_do_resume // PC relative jump, MMU off
+ b cpu_resume_mmu // Resume MMU, never returns
+ENDPROC(cpu_resume)
+
+ .align 3
+mpidr_hash_ptr:
+ /*
+ * offset of mpidr_hash symbol from current location
+ * used to obtain run-time mpidr_hash address with MMU off
+ */
+ .quad mpidr_hash - .
+/*
+ * physical address of identity mapped page tables
+ */
+ .type sleep_idmap_phys, #object
+ENTRY(sleep_idmap_phys)
+ .quad 0
+/*
+ * struct sleep_save_sp {
+ * phys_addr_t *save_ptr_stash;
+ * phys_addr_t save_ptr_stash_phys;
+ * };
+ */
+ .type sleep_save_sp, #object
+ENTRY(sleep_save_sp)
+ .space SLEEP_SAVE_SP_SZ // struct sleep_save_sp
--- /dev/null
+#include <linux/slab.h>
+#include <asm/cacheflush.h>
+#include <asm/cpu_ops.h>
+#include <asm/debug-monitors.h>
+#include <asm/pgtable.h>
+#include <asm/memory.h>
+#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+#include <asm/tlbflush.h>
+
+extern int __cpu_suspend(unsigned long);
+/*
+ * This is called by __cpu_suspend() to save the state, and do whatever
+ * flushing is required to ensure that when the CPU goes to sleep we have
+ * the necessary data available when the caches are not searched.
+ *
+ * @arg: Argument to pass to suspend operations
+ * @ptr: CPU context virtual address
+ * @save_ptr: address of the location where the context physical address
+ * must be saved
+ */
+int __cpu_suspend_finisher(unsigned long arg, struct cpu_suspend_ctx *ptr,
+ phys_addr_t *save_ptr)
+{
+ int cpu = smp_processor_id();
+
+ *save_ptr = virt_to_phys(ptr);
+
+ cpu_do_suspend(ptr);
+ /*
+ * Only flush the context that must be retrieved with the MMU
+ * off. VA primitives ensure the flush is applied to all
+ * cache levels so context is pushed to DRAM.
+ */
+ __flush_dcache_area(ptr, sizeof(*ptr));
+ __flush_dcache_area(save_ptr, sizeof(*save_ptr));
+
+ return cpu_ops[cpu]->cpu_suspend(arg);
+}
+
+/**
+ * cpu_suspend
+ *
+ * @arg: argument to pass to the finisher function
+ */
+int cpu_suspend(unsigned long arg)
+{
+ struct mm_struct *mm = current->active_mm;
+ int ret, cpu = smp_processor_id();
+ unsigned long flags;
+
+ /*
+ * If cpu_ops have not been registered or suspend
+ * has not been initialized, cpu_suspend call fails early.
+ */
+ if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend)
+ return -EOPNOTSUPP;
+
+ /*
+ * From this point debug exceptions are disabled to prevent
+ * updates to mdscr register (saved and restored along with
+ * general purpose registers) from kernel debuggers.
+ */
+ local_dbg_save(flags);
+
+ /*
+ * mm context saved on the stack, it will be restored when
+ * the cpu comes out of reset through the identity mapped
+ * page tables, so that the thread address space is properly
+ * set-up on function return.
+ */
+ ret = __cpu_suspend(arg);
+ if (ret == 0) {
+ cpu_switch_mm(mm->pgd, mm);
+ flush_tlb_all();
+ }
+
+ /*
+ * Restore pstate flags. OS lock and mdscr have been already
+ * restored, so from this point onwards, debugging is fully
+ * renabled if it was enabled when core started shutdown.
+ */
+ local_dbg_restore(flags);
+
+ return ret;
+}
+
+extern struct sleep_save_sp sleep_save_sp;
+extern phys_addr_t sleep_idmap_phys;
+
+static int cpu_suspend_init(void)
+{
+ void *ctx_ptr;
+
+ /* ctx_ptr is an array of physical addresses */
+ ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(phys_addr_t), GFP_KERNEL);
+
+ if (WARN_ON(!ctx_ptr))
+ return -ENOMEM;
+
+ sleep_save_sp.save_ptr_stash = ctx_ptr;
+ sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
+ sleep_idmap_phys = virt_to_phys(idmap_pg_dir);
+ __flush_dcache_area(&sleep_save_sp, sizeof(struct sleep_save_sp));
+ __flush_dcache_area(&sleep_idmap_phys, sizeof(sleep_idmap_phys));
+
+ return 0;
+}
+early_initcall(cpu_suspend_init);
projects / cascardo / linux.git / commitdiff