linux/arch/loongarch/mm/tlb.c
Huacai Chen 1299a129a9 LoongArch: Flush TLB earlier at initialization
Move local_flush_tlb_all() earlier (just after setup_ptwalker() and
before page allocation). This can avoid stale TLB entries misguiding
the later page allocation. Without this patch the second kernel of
kexec/kdump fails to boot SMP.

BTW, move output_pgtable_bits_defines() into tlb_init() since it has
nothing to do with tlb handler setup.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-10-12 16:36:08 +08:00

308 lines
7.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/export.h>
#include <asm/cpu.h>
#include <asm/bootinfo.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/tlb.h>
void local_flush_tlb_all(void)
{
invtlb_all(INVTLB_CURRENT_ALL, 0, 0);
}
EXPORT_SYMBOL(local_flush_tlb_all);
void local_flush_tlb_user(void)
{
invtlb_all(INVTLB_CURRENT_GFALSE, 0, 0);
}
EXPORT_SYMBOL(local_flush_tlb_user);
void local_flush_tlb_kernel(void)
{
invtlb_all(INVTLB_CURRENT_GTRUE, 0, 0);
}
EXPORT_SYMBOL(local_flush_tlb_kernel);
/*
* All entries common to a mm share an asid. To effectively flush
* these entries, we just bump the asid.
*/
void local_flush_tlb_mm(struct mm_struct *mm)
{
int cpu;
preempt_disable();
cpu = smp_processor_id();
if (asid_valid(mm, cpu))
drop_mmu_context(mm, cpu);
else
cpumask_clear_cpu(cpu, mm_cpumask(mm));
preempt_enable();
}
void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
int cpu = smp_processor_id();
if (asid_valid(mm, cpu)) {
unsigned long size, flags;
local_irq_save(flags);
start = round_down(start, PAGE_SIZE << 1);
end = round_up(end, PAGE_SIZE << 1);
size = (end - start) >> (PAGE_SHIFT + 1);
if (size <= (current_cpu_data.tlbsizestlbsets ?
current_cpu_data.tlbsize / 8 :
current_cpu_data.tlbsize / 2)) {
int asid = cpu_asid(cpu, mm);
while (start < end) {
invtlb(INVTLB_ADDR_GFALSE_AND_ASID, asid, start);
start += (PAGE_SIZE << 1);
}
} else {
drop_mmu_context(mm, cpu);
}
local_irq_restore(flags);
} else {
cpumask_clear_cpu(cpu, mm_cpumask(mm));
}
}
void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
unsigned long size, flags;
local_irq_save(flags);
size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
size = (size + 1) >> 1;
if (size <= (current_cpu_data.tlbsizestlbsets ?
current_cpu_data.tlbsize / 8 :
current_cpu_data.tlbsize / 2)) {
start &= (PAGE_MASK << 1);
end += ((PAGE_SIZE << 1) - 1);
end &= (PAGE_MASK << 1);
while (start < end) {
invtlb_addr(INVTLB_ADDR_GTRUE_OR_ASID, 0, start);
start += (PAGE_SIZE << 1);
}
} else {
local_flush_tlb_kernel();
}
local_irq_restore(flags);
}
void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
int cpu = smp_processor_id();
if (asid_valid(vma->vm_mm, cpu)) {
int newpid;
newpid = cpu_asid(cpu, vma->vm_mm);
page &= (PAGE_MASK << 1);
invtlb(INVTLB_ADDR_GFALSE_AND_ASID, newpid, page);
} else {
cpumask_clear_cpu(cpu, mm_cpumask(vma->vm_mm));
}
}
/*
* This one is only used for pages with the global bit set so we don't care
* much about the ASID.
*/
void local_flush_tlb_one(unsigned long page)
{
page &= (PAGE_MASK << 1);
invtlb_addr(INVTLB_ADDR_GTRUE_OR_ASID, 0, page);
}
static void __update_hugetlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
{
#ifdef CONFIG_HUGETLB_PAGE
int idx;
unsigned long lo;
unsigned long flags;
local_irq_save(flags);
address &= (PAGE_MASK << 1);
write_csr_entryhi(address);
tlb_probe();
idx = read_csr_tlbidx();
write_csr_pagesize(PS_HUGE_SIZE);
lo = pmd_to_entrylo(pte_val(*ptep));
write_csr_entrylo0(lo);
write_csr_entrylo1(lo + (HPAGE_SIZE >> 1));
if (idx < 0)
tlb_write_random();
else
tlb_write_indexed();
write_csr_pagesize(PS_DEFAULT_SIZE);
local_irq_restore(flags);
#endif
}
void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
{
int idx;
unsigned long flags;
/*
* Handle debugger faulting in for debugee.
*/
if (current->active_mm != vma->vm_mm)
return;
if (pte_val(*ptep) & _PAGE_HUGE) {
__update_hugetlb(vma, address, ptep);
return;
}
local_irq_save(flags);
if ((unsigned long)ptep & sizeof(pte_t))
ptep--;
address &= (PAGE_MASK << 1);
write_csr_entryhi(address);
tlb_probe();
idx = read_csr_tlbidx();
write_csr_pagesize(PS_DEFAULT_SIZE);
write_csr_entrylo0(pte_val(*ptep++));
write_csr_entrylo1(pte_val(*ptep));
if (idx < 0)
tlb_write_random();
else
tlb_write_indexed();
local_irq_restore(flags);
}
static void setup_ptwalker(void)
{
unsigned long pwctl0, pwctl1;
unsigned long pgd_i = 0, pgd_w = 0;
unsigned long pud_i = 0, pud_w = 0;
unsigned long pmd_i = 0, pmd_w = 0;
unsigned long pte_i = 0, pte_w = 0;
pgd_i = PGDIR_SHIFT;
pgd_w = PAGE_SHIFT - 3;
#if CONFIG_PGTABLE_LEVELS > 3
pud_i = PUD_SHIFT;
pud_w = PAGE_SHIFT - 3;
#endif
#if CONFIG_PGTABLE_LEVELS > 2
pmd_i = PMD_SHIFT;
pmd_w = PAGE_SHIFT - 3;
#endif
pte_i = PAGE_SHIFT;
pte_w = PAGE_SHIFT - 3;
pwctl0 = pte_i | pte_w << 5 | pmd_i << 10 | pmd_w << 15 | pud_i << 20 | pud_w << 25;
pwctl1 = pgd_i | pgd_w << 6;
csr_write64(pwctl0, LOONGARCH_CSR_PWCTL0);
csr_write64(pwctl1, LOONGARCH_CSR_PWCTL1);
csr_write64((long)swapper_pg_dir, LOONGARCH_CSR_PGDH);
csr_write64((long)invalid_pg_dir, LOONGARCH_CSR_PGDL);
csr_write64((long)smp_processor_id(), LOONGARCH_CSR_TMID);
}
static void output_pgtable_bits_defines(void)
{
#define pr_define(fmt, ...) \
pr_debug("#define " fmt, ##__VA_ARGS__)
pr_debug("#include <asm/asm.h>\n");
pr_debug("#include <asm/regdef.h>\n");
pr_debug("\n");
pr_define("_PAGE_VALID_SHIFT %d\n", _PAGE_VALID_SHIFT);
pr_define("_PAGE_DIRTY_SHIFT %d\n", _PAGE_DIRTY_SHIFT);
pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
pr_define("_PAGE_GLOBAL_SHIFT %d\n", _PAGE_GLOBAL_SHIFT);
pr_define("_PAGE_PRESENT_SHIFT %d\n", _PAGE_PRESENT_SHIFT);
pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT);
pr_debug("\n");
}
#ifdef CONFIG_NUMA
static unsigned long pcpu_handlers[NR_CPUS];
#endif
extern long exception_handlers[VECSIZE * 128 / sizeof(long)];
void setup_tlb_handler(int cpu)
{
setup_ptwalker();
local_flush_tlb_all();
/* The tlb handlers are generated only once */
if (cpu == 0) {
memcpy((void *)tlbrentry, handle_tlb_refill, 0x80);
local_flush_icache_range(tlbrentry, tlbrentry + 0x80);
set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load, VECSIZE);
set_handler(EXCCODE_TLBL * VECSIZE, handle_tlb_load, VECSIZE);
set_handler(EXCCODE_TLBS * VECSIZE, handle_tlb_store, VECSIZE);
set_handler(EXCCODE_TLBM * VECSIZE, handle_tlb_modify, VECSIZE);
set_handler(EXCCODE_TLBNR * VECSIZE, handle_tlb_protect, VECSIZE);
set_handler(EXCCODE_TLBNX * VECSIZE, handle_tlb_protect, VECSIZE);
set_handler(EXCCODE_TLBPE * VECSIZE, handle_tlb_protect, VECSIZE);
}
#ifdef CONFIG_NUMA
else {
void *addr;
struct page *page;
const int vec_sz = sizeof(exception_handlers);
if (pcpu_handlers[cpu])
return;
page = alloc_pages_node(cpu_to_node(cpu), GFP_ATOMIC, get_order(vec_sz));
if (!page)
return;
addr = page_address(page);
pcpu_handlers[cpu] = (unsigned long)addr;
memcpy((void *)addr, (void *)eentry, vec_sz);
local_flush_icache_range((unsigned long)addr, (unsigned long)addr + vec_sz);
csr_write64(pcpu_handlers[cpu], LOONGARCH_CSR_EENTRY);
csr_write64(pcpu_handlers[cpu], LOONGARCH_CSR_MERRENTRY);
csr_write64(pcpu_handlers[cpu] + 80*VECSIZE, LOONGARCH_CSR_TLBRENTRY);
}
#endif
}
void tlb_init(int cpu)
{
write_csr_pagesize(PS_DEFAULT_SIZE);
write_csr_stlbpgsize(PS_DEFAULT_SIZE);
write_csr_tlbrefill_pagesize(PS_DEFAULT_SIZE);
setup_tlb_handler(cpu);
output_pgtable_bits_defines();
}