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Merge patch series "RISC-V Hibernation Support" 

Sia Jee Heng <jeeheng.sia@starfivetech.com> says:

This series adds RISC-V Hibernation/suspend to disk support.
Low level Arch functions were created to support hibernation.
swsusp_arch_suspend() relies code from __cpu_suspend_enter() to write
cpu state onto the stack, then calling swsusp_save() to save the memory
image.

Arch specific hibernation header is implemented and is utilized by the
arch_hibernation_header_restore() and arch_hibernation_header_save()
functions. The arch specific hibernation header consists of satp, hartid,
and the cpu_resume address. The kernel built version is also need to be
saved into the hibernation image header to making sure only the same
kernel is restore when resume.

swsusp_arch_resume() creates a temporary page table that covering only
the linear map. It copies the restore code to a 'safe' page, then start to
restore the memory image. Once completed, it restores the original
kernel's page table. It then calls into __hibernate_cpu_resume()
to restore the CPU context. Finally, it follows the normal hibernation
path back to the hibernation core.

To enable hibernation/suspend to disk into RISCV, the below config
need to be enabled:
- CONFIG_HIBERNATION
- CONFIG_ARCH_HIBERNATION_HEADER
- CONFIG_ARCH_HIBERNATION_POSSIBLE

At high-level, this series includes the following changes:
1) Change suspend_save_csrs() and suspend_restore_csrs()
   to public function as these functions are common to
   suspend/hibernation. (patch 1)
2) Refactor the common code in the __cpu_resume_enter() function and
   __hibernate_cpu_resume() function. The common code are used by
   hibernation and suspend. (patch 2)
3) Enhance kernel_page_present() function to support huge page. (patch 3)
4) Add arch/riscv low level functions to support
   hibernation/suspend to disk. (patch 4)

* b4-shazam-merge:
  RISC-V: Add arch functions to support hibernation/suspend-to-disk
  RISC-V: mm: Enable huge page support to kernel_page_present() function
  RISC-V: Factor out common code of __cpu_resume_enter()
  RISC-V: Change suspend_save_csrs and suspend_restore_csrs to public function

Link: https://lore.kernel.org/r/20230330064321.1008373-1-jeeheng.sia@starfivetech.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Palmer Dabbelt 2023-04-29 11:25:15 -07:00
parent b3d6bdfea2 c031721001
commit 38dab744f7
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
10 changed files with 634 additions and 34 deletions
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8
arch/riscv/Kconfig
View File

@ -55,7 +55,7 @@ config RISCV
select CLINT_TIMER if !MMU
select CLONE_BACKWARDS
select COMMON_CLK
select CPU_PM if CPU_IDLE
select CPU_PM if CPU_IDLE || HIBERNATION
select EDAC_SUPPORT
select GENERIC_ARCH_TOPOLOGY
select GENERIC_ATOMIC64 if !64BIT
@ -799,6 +799,12 @@ menu "Power management options"
source "kernel/power/Kconfig"
config ARCH_HIBERNATION_POSSIBLE
def_bool y
config ARCH_HIBERNATION_HEADER
def_bool HIBERNATION
endmenu # "Power management options"
menu "CPU Power Management"

82
arch/riscv/include/asm/assembler.h Normal file
View File

@ -0,0 +1,82 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2023 StarFive Technology Co., Ltd.
*
* Author: Jee Heng Sia <jeeheng.sia@starfivetech.com>
*/
#ifndef __ASSEMBLY__
#error "Only include this from assembly code"
#endif
#ifndef __ASM_ASSEMBLER_H
#define __ASM_ASSEMBLER_H
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/csr.h>
/*
* suspend_restore_csrs - restore CSRs
*/
.macro suspend_restore_csrs
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_EPC)(a0)
csrw CSR_EPC, t0
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_STATUS)(a0)
csrw CSR_STATUS, t0
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_BADADDR)(a0)
csrw CSR_TVAL, t0
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_CAUSE)(a0)
csrw CSR_CAUSE, t0
.endm
/*
* suspend_restore_regs - Restore registers (except A0 and T0-T6)
*/
.macro suspend_restore_regs
REG_L ra, (SUSPEND_CONTEXT_REGS + PT_RA)(a0)
REG_L sp, (SUSPEND_CONTEXT_REGS + PT_SP)(a0)
REG_L gp, (SUSPEND_CONTEXT_REGS + PT_GP)(a0)
REG_L tp, (SUSPEND_CONTEXT_REGS + PT_TP)(a0)
REG_L s0, (SUSPEND_CONTEXT_REGS + PT_S0)(a0)
REG_L s1, (SUSPEND_CONTEXT_REGS + PT_S1)(a0)
REG_L a1, (SUSPEND_CONTEXT_REGS + PT_A1)(a0)
REG_L a2, (SUSPEND_CONTEXT_REGS + PT_A2)(a0)
REG_L a3, (SUSPEND_CONTEXT_REGS + PT_A3)(a0)
REG_L a4, (SUSPEND_CONTEXT_REGS + PT_A4)(a0)
REG_L a5, (SUSPEND_CONTEXT_REGS + PT_A5)(a0)
REG_L a6, (SUSPEND_CONTEXT_REGS + PT_A6)(a0)
REG_L a7, (SUSPEND_CONTEXT_REGS + PT_A7)(a0)
REG_L s2, (SUSPEND_CONTEXT_REGS + PT_S2)(a0)
REG_L s3, (SUSPEND_CONTEXT_REGS + PT_S3)(a0)
REG_L s4, (SUSPEND_CONTEXT_REGS + PT_S4)(a0)
REG_L s5, (SUSPEND_CONTEXT_REGS + PT_S5)(a0)
REG_L s6, (SUSPEND_CONTEXT_REGS + PT_S6)(a0)
REG_L s7, (SUSPEND_CONTEXT_REGS + PT_S7)(a0)
REG_L s8, (SUSPEND_CONTEXT_REGS + PT_S8)(a0)
REG_L s9, (SUSPEND_CONTEXT_REGS + PT_S9)(a0)
REG_L s10, (SUSPEND_CONTEXT_REGS + PT_S10)(a0)
REG_L s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
.endm
/*
* copy_page - copy 1 page (4KB) of data from source to destination
* @a0 - destination
* @a1 - source
*/
.macro copy_page a0, a1
lui a2, 0x1
add a2, a2, a0
1 :
REG_L t0, 0(a1)
REG_L t1, SZREG(a1)
REG_S t0, 0(a0)
REG_S t1, SZREG(a0)
addi a0, a0, 2 * SZREG
addi a1, a1, 2 * SZREG
bne a2, a0, 1b
.endm
#endif /* __ASM_ASSEMBLER_H */

22
arch/riscv/include/asm/suspend.h
View File

@ -21,6 +21,11 @@ struct suspend_context {
#endif
};
/*
* Used by hibernation core and cleared during resume sequence
*/
extern int in_suspend;
/* Low-level CPU suspend entry function */
int __cpu_suspend_enter(struct suspend_context *context);
@ -33,4 +38,21 @@ int cpu_suspend(unsigned long arg,
/* Low-level CPU resume entry function */
int __cpu_resume_enter(unsigned long hartid, unsigned long context);
/* Used to save and restore the CSRs */
void suspend_save_csrs(struct suspend_context *context);
void suspend_restore_csrs(struct suspend_context *context);
/* Low-level API to support hibernation */
int swsusp_arch_suspend(void);
int swsusp_arch_resume(void);
int arch_hibernation_header_save(void *addr, unsigned int max_size);
int arch_hibernation_header_restore(void *addr);
int __hibernate_cpu_resume(void);
/* Used to resume on the CPU we hibernated on */
int hibernate_resume_nonboot_cpu_disable(void);
asmlinkage void hibernate_restore_image(unsigned long resume_satp, unsigned long satp_temp,
unsigned long cpu_resume);
asmlinkage int hibernate_core_restore_code(void);
#endif

1
arch/riscv/kernel/Makefile
View File

@ -64,6 +64,7 @@ obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_MODULE_SECTIONS) += module-sections.o
obj-$(CONFIG_CPU_PM) += suspend_entry.o suspend.o
obj-$(CONFIG_HIBERNATION) += hibernate.o hibernate-asm.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o
obj-$(CONFIG_DYNAMIC_FTRACE) += mcount-dyn.o

5
arch/riscv/kernel/asm-offsets.c
View File

@ -9,6 +9,7 @@
#include <linux/kbuild.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/suspend.h>
#include <asm/kvm_host.h>
#include <asm/thread_info.h>
#include <asm/ptrace.h>
@ -116,6 +117,10 @@ void asm_offsets(void)
OFFSET(SUSPEND_CONTEXT_REGS, suspend_context, regs);
OFFSET(HIBERN_PBE_ADDR, pbe, address);
OFFSET(HIBERN_PBE_ORIG, pbe, orig_address);
OFFSET(HIBERN_PBE_NEXT, pbe, next);
OFFSET(KVM_ARCH_GUEST_ZERO, kvm_vcpu_arch, guest_context.zero);
OFFSET(KVM_ARCH_GUEST_RA, kvm_vcpu_arch, guest_context.ra);
OFFSET(KVM_ARCH_GUEST_SP, kvm_vcpu_arch, guest_context.sp);

77
arch/riscv/kernel/hibernate-asm.S Normal file
View File

@ -0,0 +1,77 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Hibernation low level support for RISCV.
*
* Copyright (C) 2023 StarFive Technology Co., Ltd.
*
* Author: Jee Heng Sia <jeeheng.sia@starfivetech.com>
*/
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
#include <asm/csr.h>
#include <linux/linkage.h>
/*
* int __hibernate_cpu_resume(void)
* Switch back to the hibernated image's page table prior to restoring the CPU
* context.
*
* Always returns 0
*/
ENTRY(__hibernate_cpu_resume)
/* switch to hibernated image's page table. */
csrw CSR_SATP, s0
sfence.vma
REG_L a0, hibernate_cpu_context
suspend_restore_csrs
suspend_restore_regs
/* Return zero value. */
mv a0, zero
ret
END(__hibernate_cpu_resume)
/*
* Prepare to restore the image.
* a0: satp of saved page tables.
* a1: satp of temporary page tables.
* a2: cpu_resume.
*/
ENTRY(hibernate_restore_image)
mv s0, a0
mv s1, a1
mv s2, a2
REG_L s4, restore_pblist
REG_L a1, relocated_restore_code
jalr a1
END(hibernate_restore_image)
/*
* The below code will be executed from a 'safe' page.
* It first switches to the temporary page table, then starts to copy the pages
* back to the original memory location. Finally, it jumps to __hibernate_cpu_resume()
* to restore the CPU context.
*/
ENTRY(hibernate_core_restore_code)
/* switch to temp page table. */
csrw satp, s1
sfence.vma
.Lcopy:
/* The below code will restore the hibernated image. */
REG_L a1, HIBERN_PBE_ADDR(s4)
REG_L a0, HIBERN_PBE_ORIG(s4)
copy_page a0, a1
REG_L s4, HIBERN_PBE_NEXT(s4)
bnez s4, .Lcopy
jalr s2
END(hibernate_core_restore_code)

427
arch/riscv/kernel/hibernate.c Normal file
View File

@ -0,0 +1,427 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Hibernation support for RISCV
*
* Copyright (C) 2023 StarFive Technology Co., Ltd.
*
* Author: Jee Heng Sia <jeeheng.sia@starfivetech.com>
*/
#include <asm/barrier.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/sections.h>
#include <asm/set_memory.h>
#include <asm/smp.h>
#include <asm/suspend.h>
#include <linux/cpu.h>
#include <linux/memblock.h>
#include <linux/pm.h>
#include <linux/sched.h>
#include <linux/suspend.h>
#include <linux/utsname.h>
/* The logical cpu number we should resume on, initialised to a non-cpu number. */
static int sleep_cpu = -EINVAL;
/* Pointer to the temporary resume page table. */
static pgd_t *resume_pg_dir;
/* CPU context to be saved. */
struct suspend_context *hibernate_cpu_context;
EXPORT_SYMBOL_GPL(hibernate_cpu_context);
unsigned long relocated_restore_code;
EXPORT_SYMBOL_GPL(relocated_restore_code);
/**
* struct arch_hibernate_hdr_invariants - container to store kernel build version.
* @uts_version: to save the build number and date so that we do not resume with
* a different kernel.
*/
struct arch_hibernate_hdr_invariants {
char uts_version[__NEW_UTS_LEN + 1];
};
/**
* struct arch_hibernate_hdr - helper parameters that help us to restore the image.
* @invariants: container to store kernel build version.
* @hartid: to make sure same boot_cpu executes the hibernate/restore code.
* @saved_satp: original page table used by the hibernated image.
* @restore_cpu_addr: the kernel's image address to restore the CPU context.
*/
static struct arch_hibernate_hdr {
struct arch_hibernate_hdr_invariants invariants;
unsigned long hartid;
unsigned long saved_satp;
unsigned long restore_cpu_addr;
} resume_hdr;
static void arch_hdr_invariants(struct arch_hibernate_hdr_invariants *i)
{
memset(i, 0, sizeof(*i));
memcpy(i->uts_version, init_utsname()->version, sizeof(i->uts_version));
}
/*
* Check if the given pfn is in the 'nosave' section.
*/
int pfn_is_nosave(unsigned long pfn)
{
unsigned long nosave_begin_pfn = sym_to_pfn(&__nosave_begin);
unsigned long nosave_end_pfn = sym_to_pfn(&__nosave_end - 1);
return ((pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn));
}
void notrace save_processor_state(void)
{
WARN_ON(num_online_cpus() != 1);
}
void notrace restore_processor_state(void)
{
}
/*
* Helper parameters need to be saved to the hibernation image header.
*/
int arch_hibernation_header_save(void *addr, unsigned int max_size)
{
struct arch_hibernate_hdr *hdr = addr;
if (max_size < sizeof(*hdr))
return -EOVERFLOW;
arch_hdr_invariants(&hdr->invariants);
hdr->hartid = cpuid_to_hartid_map(sleep_cpu);
hdr->saved_satp = csr_read(CSR_SATP);
hdr->restore_cpu_addr = (unsigned long)__hibernate_cpu_resume;
return 0;
}
EXPORT_SYMBOL_GPL(arch_hibernation_header_save);
/*
* Retrieve the helper parameters from the hibernation image header.
*/
int arch_hibernation_header_restore(void *addr)
{
struct arch_hibernate_hdr_invariants invariants;
struct arch_hibernate_hdr *hdr = addr;
int ret = 0;
arch_hdr_invariants(&invariants);
if (memcmp(&hdr->invariants, &invariants, sizeof(invariants))) {
pr_crit("Hibernate image not generated by this kernel!\n");
return -EINVAL;
}
sleep_cpu = riscv_hartid_to_cpuid(hdr->hartid);
if (sleep_cpu < 0) {
pr_crit("Hibernated on a CPU not known to this kernel!\n");
sleep_cpu = -EINVAL;
return -EINVAL;
}
#ifdef CONFIG_SMP
ret = bringup_hibernate_cpu(sleep_cpu);
if (ret) {
sleep_cpu = -EINVAL;
return ret;
}
#endif
resume_hdr = *hdr;
return ret;
}
EXPORT_SYMBOL_GPL(arch_hibernation_header_restore);
int swsusp_arch_suspend(void)
{
int ret = 0;
if (__cpu_suspend_enter(hibernate_cpu_context)) {
sleep_cpu = smp_processor_id();
suspend_save_csrs(hibernate_cpu_context);
ret = swsusp_save();
} else {
suspend_restore_csrs(hibernate_cpu_context);
flush_tlb_all();
flush_icache_all();
/*
* Tell the hibernation core that we've just restored the memory.
*/
in_suspend = 0;
sleep_cpu = -EINVAL;
}
return ret;
}
static int temp_pgtable_map_pte(pmd_t *dst_pmdp, pmd_t *src_pmdp, unsigned long start,
unsigned long end, pgprot_t prot)
{
pte_t *src_ptep;
pte_t *dst_ptep;
if (pmd_none(READ_ONCE(*dst_pmdp))) {
dst_ptep = (pte_t *)get_safe_page(GFP_ATOMIC);
if (!dst_ptep)
return -ENOMEM;
pmd_populate_kernel(NULL, dst_pmdp, dst_ptep);
}
dst_ptep = pte_offset_kernel(dst_pmdp, start);
src_ptep = pte_offset_kernel(src_pmdp, start);
do {
pte_t pte = READ_ONCE(*src_ptep);
if (pte_present(pte))
set_pte(dst_ptep, __pte(pte_val(pte) | pgprot_val(prot)));
} while (dst_ptep++, src_ptep++, start += PAGE_SIZE, start < end);
return 0;
}
static int temp_pgtable_map_pmd(pud_t *dst_pudp, pud_t *src_pudp, unsigned long start,
unsigned long end, pgprot_t prot)
{
unsigned long next;
unsigned long ret;
pmd_t *src_pmdp;
pmd_t *dst_pmdp;
if (pud_none(READ_ONCE(*dst_pudp))) {
dst_pmdp = (pmd_t *)get_safe_page(GFP_ATOMIC);
if (!dst_pmdp)
return -ENOMEM;
pud_populate(NULL, dst_pudp, dst_pmdp);
}
dst_pmdp = pmd_offset(dst_pudp, start);
src_pmdp = pmd_offset(src_pudp, start);
do {
pmd_t pmd = READ_ONCE(*src_pmdp);
next = pmd_addr_end(start, end);
if (pmd_none(pmd))
continue;
if (pmd_leaf(pmd)) {
set_pmd(dst_pmdp, __pmd(pmd_val(pmd) | pgprot_val(prot)));
} else {
ret = temp_pgtable_map_pte(dst_pmdp, src_pmdp, start, next, prot);
if (ret)
return -ENOMEM;
}
} while (dst_pmdp++, src_pmdp++, start = next, start != end);
return 0;
}
static int temp_pgtable_map_pud(p4d_t *dst_p4dp, p4d_t *src_p4dp, unsigned long start,
unsigned long end, pgprot_t prot)
{
unsigned long next;
unsigned long ret;
pud_t *dst_pudp;
pud_t *src_pudp;
if (p4d_none(READ_ONCE(*dst_p4dp))) {
dst_pudp = (pud_t *)get_safe_page(GFP_ATOMIC);
if (!dst_pudp)
return -ENOMEM;
p4d_populate(NULL, dst_p4dp, dst_pudp);
}
dst_pudp = pud_offset(dst_p4dp, start);
src_pudp = pud_offset(src_p4dp, start);
do {
pud_t pud = READ_ONCE(*src_pudp);
next = pud_addr_end(start, end);
if (pud_none(pud))
continue;
if (pud_leaf(pud)) {
set_pud(dst_pudp, __pud(pud_val(pud) | pgprot_val(prot)));
} else {
ret = temp_pgtable_map_pmd(dst_pudp, src_pudp, start, next, prot);
if (ret)
return -ENOMEM;
}
} while (dst_pudp++, src_pudp++, start = next, start != end);
return 0;
}
static int temp_pgtable_map_p4d(pgd_t *dst_pgdp, pgd_t *src_pgdp, unsigned long start,
unsigned long end, pgprot_t prot)
{
unsigned long next;
unsigned long ret;
p4d_t *dst_p4dp;
p4d_t *src_p4dp;
if (pgd_none(READ_ONCE(*dst_pgdp))) {
dst_p4dp = (p4d_t *)get_safe_page(GFP_ATOMIC);
if (!dst_p4dp)
return -ENOMEM;
pgd_populate(NULL, dst_pgdp, dst_p4dp);
}
dst_p4dp = p4d_offset(dst_pgdp, start);
src_p4dp = p4d_offset(src_pgdp, start);
do {
p4d_t p4d = READ_ONCE(*src_p4dp);
next = p4d_addr_end(start, end);
if (p4d_none(p4d))
continue;
if (p4d_leaf(p4d)) {
set_p4d(dst_p4dp, __p4d(p4d_val(p4d) | pgprot_val(prot)));
} else {
ret = temp_pgtable_map_pud(dst_p4dp, src_p4dp, start, next, prot);
if (ret)
return -ENOMEM;
}
} while (dst_p4dp++, src_p4dp++, start = next, start != end);
return 0;
}
static int temp_pgtable_mapping(pgd_t *pgdp, unsigned long start, unsigned long end, pgprot_t prot)
{
pgd_t *dst_pgdp = pgd_offset_pgd(pgdp, start);
pgd_t *src_pgdp = pgd_offset_k(start);
unsigned long next;
unsigned long ret;
do {
pgd_t pgd = READ_ONCE(*src_pgdp);
next = pgd_addr_end(start, end);
if (pgd_none(pgd))
continue;
if (pgd_leaf(pgd)) {
set_pgd(dst_pgdp, __pgd(pgd_val(pgd) | pgprot_val(prot)));
} else {
ret = temp_pgtable_map_p4d(dst_pgdp, src_pgdp, start, next, prot);
if (ret)
return -ENOMEM;
}
} while (dst_pgdp++, src_pgdp++, start = next, start != end);
return 0;
}
static unsigned long relocate_restore_code(void)
{
void *page = (void *)get_safe_page(GFP_ATOMIC);
if (!page)
return -ENOMEM;
copy_page(page, hibernate_core_restore_code);
/* Make the page containing the relocated code executable. */
set_memory_x((unsigned long)page, 1);
return (unsigned long)page;
}
int swsusp_arch_resume(void)
{
unsigned long end = (unsigned long)pfn_to_virt(max_low_pfn);
unsigned long start = PAGE_OFFSET;
int ret;
/*
* Memory allocated by get_safe_page() will be dealt with by the hibernation core,
* we don't need to free it here.
*/
resume_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC);
if (!resume_pg_dir)
return -ENOMEM;
/*
* Create a temporary page table and map the whole linear region as executable and
* writable.
*/
ret = temp_pgtable_mapping(resume_pg_dir, start, end, __pgprot(_PAGE_WRITE | _PAGE_EXEC));
if (ret)
return ret;
/* Move the restore code to a new page so that it doesn't get overwritten by itself. */
relocated_restore_code = relocate_restore_code();
if (relocated_restore_code == -ENOMEM)
return -ENOMEM;
/*
* Map the __hibernate_cpu_resume() address to the temporary page table so that the
* restore code can jumps to it after finished restore the image. The next execution
* code doesn't find itself in a different address space after switching over to the
* original page table used by the hibernated image.
* The __hibernate_cpu_resume() mapping is unnecessary for RV32 since the kernel and
* linear addresses are identical, but different for RV64. To ensure consistency, we
* map it for both RV32 and RV64 kernels.
* Additionally, we should ensure that the page is writable before restoring the image.
*/
start = (unsigned long)resume_hdr.restore_cpu_addr;
end = start + PAGE_SIZE;
ret = temp_pgtable_mapping(resume_pg_dir, start, end, __pgprot(_PAGE_WRITE));
if (ret)
return ret;
hibernate_restore_image(resume_hdr.saved_satp, (PFN_DOWN(__pa(resume_pg_dir)) | satp_mode),
resume_hdr.restore_cpu_addr);
return 0;
}
#ifdef CONFIG_PM_SLEEP_SMP
int hibernate_resume_nonboot_cpu_disable(void)
{
if (sleep_cpu < 0) {
pr_err("Failing to resume from hibernate on an unknown CPU\n");
return -ENODEV;
}
return freeze_secondary_cpus(sleep_cpu);
}
#endif
static int __init riscv_hibernate_init(void)
{
hibernate_cpu_context = kzalloc(sizeof(*hibernate_cpu_context), GFP_KERNEL);
if (WARN_ON(!hibernate_cpu_context))
return -ENOMEM;
return 0;
}
early_initcall(riscv_hibernate_init);

4
arch/riscv/kernel/suspend.c
View File

@ -8,7 +8,7 @@
#include <asm/csr.h>
#include <asm/suspend.h>
static void suspend_save_csrs(struct suspend_context *context)
void suspend_save_csrs(struct suspend_context *context)
{
context->scratch = csr_read(CSR_SCRATCH);
context->tvec = csr_read(CSR_TVEC);
@ -29,7 +29,7 @@ static void suspend_save_csrs(struct suspend_context *context)
#endif
}
static void suspend_restore_csrs(struct suspend_context *context)
void suspend_restore_csrs(struct suspend_context *context)
{
csr_write(CSR_SCRATCH, context->scratch);
csr_write(CSR_TVEC, context->tvec);

34
arch/riscv/kernel/suspend_entry.S
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@ -7,6 +7,7 @@
#include <linux/linkage.h>
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
#include <asm/csr.h>
#include <asm/xip_fixup.h>
@ -83,39 +84,10 @@ ENTRY(__cpu_resume_enter)
add a0, a1, zero
/* Restore CSRs */
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_EPC)(a0)
csrw CSR_EPC, t0
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_STATUS)(a0)
csrw CSR_STATUS, t0
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_BADADDR)(a0)
csrw CSR_TVAL, t0
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_CAUSE)(a0)
csrw CSR_CAUSE, t0
suspend_restore_csrs
/* Restore registers (except A0 and T0-T6) */
REG_L ra, (SUSPEND_CONTEXT_REGS + PT_RA)(a0)
REG_L sp, (SUSPEND_CONTEXT_REGS + PT_SP)(a0)
REG_L gp, (SUSPEND_CONTEXT_REGS + PT_GP)(a0)
REG_L tp, (SUSPEND_CONTEXT_REGS + PT_TP)(a0)
REG_L s0, (SUSPEND_CONTEXT_REGS + PT_S0)(a0)
REG_L s1, (SUSPEND_CONTEXT_REGS + PT_S1)(a0)
REG_L a1, (SUSPEND_CONTEXT_REGS + PT_A1)(a0)
REG_L a2, (SUSPEND_CONTEXT_REGS + PT_A2)(a0)
REG_L a3, (SUSPEND_CONTEXT_REGS + PT_A3)(a0)
REG_L a4, (SUSPEND_CONTEXT_REGS + PT_A4)(a0)
REG_L a5, (SUSPEND_CONTEXT_REGS + PT_A5)(a0)
REG_L a6, (SUSPEND_CONTEXT_REGS + PT_A6)(a0)
REG_L a7, (SUSPEND_CONTEXT_REGS + PT_A7)(a0)
REG_L s2, (SUSPEND_CONTEXT_REGS + PT_S2)(a0)
REG_L s3, (SUSPEND_CONTEXT_REGS + PT_S3)(a0)
REG_L s4, (SUSPEND_CONTEXT_REGS + PT_S4)(a0)
REG_L s5, (SUSPEND_CONTEXT_REGS + PT_S5)(a0)
REG_L s6, (SUSPEND_CONTEXT_REGS + PT_S6)(a0)
REG_L s7, (SUSPEND_CONTEXT_REGS + PT_S7)(a0)
REG_L s8, (SUSPEND_CONTEXT_REGS + PT_S8)(a0)
REG_L s9, (SUSPEND_CONTEXT_REGS + PT_S9)(a0)
REG_L s10, (SUSPEND_CONTEXT_REGS + PT_S10)(a0)
REG_L s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
suspend_restore_regs
/* Return zero value */
add a0, zero, zero

8
arch/riscv/mm/pageattr.c
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@ -217,18 +217,26 @@ bool kernel_page_present(struct page *page)
pgd = pgd_offset_k(addr);
if (!pgd_present(*pgd))
return false;
if (pgd_leaf(*pgd))
return true;
p4d = p4d_offset(pgd, addr);
if (!p4d_present(*p4d))
return false;
if (p4d_leaf(*p4d))
return true;
pud = pud_offset(p4d, addr);
if (!pud_present(*pud))
return false;
if (pud_leaf(*pud))
return true;
pmd = pmd_offset(pud, addr);
if (!pmd_present(*pmd))
return false;
if (pmd_leaf(*pmd))
return true;
pte = pte_offset_kernel(pmd, addr);
return pte_present(*pte);