LoongArch: Introduce hardware page table walker

Loongson-3A6000 and newer processors have hardware page table walker
(PTW) support. PTW can handle all fastpaths of TLBI/TLBL/TLBS/TLBM
exceptions by hardware, software only need to handle slowpaths (page
faults).

BTW, PTW doesn't append _PAGE_MODIFIED for page table entries, so we
change pmd_dirty() and pte_dirty() to also check _PAGE_DIRTY for the
"dirty" attribute.

Signed-off-by: Liang Gao <gaoliang@loongson.cn>
Signed-off-by: Jun Yi <yijun@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Huacai Chen 2023-06-29 20:58:44 +08:00
parent e031a5f3f1
commit 01158487af
10 changed files with 56 additions and 7 deletions

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@ -64,6 +64,6 @@
#define cpu_has_eiodecode cpu_opt(LOONGARCH_CPU_EIODECODE)
#define cpu_has_guestid cpu_opt(LOONGARCH_CPU_GUESTID)
#define cpu_has_hypervisor cpu_opt(LOONGARCH_CPU_HYPERVISOR)
#define cpu_has_ptw cpu_opt(LOONGARCH_CPU_PTW)
#endif /* __ASM_CPU_FEATURES_H */

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@ -98,6 +98,7 @@ enum cpu_type_enum {
#define CPU_FEATURE_EIODECODE 23 /* CPU has EXTIOI interrupt pin decode mode */
#define CPU_FEATURE_GUESTID 24 /* CPU has GuestID feature */
#define CPU_FEATURE_HYPERVISOR 25 /* CPU has hypervisor (running in VM) */
#define CPU_FEATURE_PTW 26 /* CPU has hardware page table walker */
#define LOONGARCH_CPU_CPUCFG BIT_ULL(CPU_FEATURE_CPUCFG)
#define LOONGARCH_CPU_LAM BIT_ULL(CPU_FEATURE_LAM)
@ -125,5 +126,6 @@ enum cpu_type_enum {
#define LOONGARCH_CPU_EIODECODE BIT_ULL(CPU_FEATURE_EIODECODE)
#define LOONGARCH_CPU_GUESTID BIT_ULL(CPU_FEATURE_GUESTID)
#define LOONGARCH_CPU_HYPERVISOR BIT_ULL(CPU_FEATURE_HYPERVISOR)
#define LOONGARCH_CPU_PTW BIT_ULL(CPU_FEATURE_PTW)
#endif /* _ASM_CPU_H */

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@ -135,6 +135,7 @@ __asm__(".macro parse_r var r\n\t"
#define CPUCFG2_MIPSBT BIT(20)
#define CPUCFG2_LSPW BIT(21)
#define CPUCFG2_LAM BIT(22)
#define CPUCFG2_PTW BIT(24)
#define LOONGARCH_CPUCFG3 0x3
#define CPUCFG3_CCDMA BIT(0)
@ -412,6 +413,9 @@ __asm__(".macro parse_r var r\n\t"
#define CSR_PWCTL0_PTBASE (_ULCAST_(0x1f) << CSR_PWCTL0_PTBASE_SHIFT)
#define LOONGARCH_CSR_PWCTL1 0x1d /* PWCtl1 */
#define CSR_PWCTL1_PTW_SHIFT 24
#define CSR_PWCTL1_PTW_WIDTH 1
#define CSR_PWCTL1_PTW (_ULCAST_(0x1) << CSR_PWCTL1_PTW_SHIFT)
#define CSR_PWCTL1_DIR3WIDTH_SHIFT 18
#define CSR_PWCTL1_DIR3WIDTH_WIDTH 5
#define CSR_PWCTL1_DIR3WIDTH (_ULCAST_(0x1f) << CSR_PWCTL1_DIR3WIDTH_SHIFT)

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@ -362,7 +362,7 @@ extern pgd_t invalid_pg_dir[];
*/
static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_MODIFIED; }
static inline int pte_dirty(pte_t pte) { return pte_val(pte) & (_PAGE_DIRTY | _PAGE_MODIFIED); }
static inline pte_t pte_mkold(pte_t pte)
{
@ -506,7 +506,7 @@ static inline pmd_t pmd_wrprotect(pmd_t pmd)
static inline int pmd_dirty(pmd_t pmd)
{
return !!(pmd_val(pmd) & _PAGE_MODIFIED);
return !!(pmd_val(pmd) & (_PAGE_DIRTY | _PAGE_MODIFIED));
}
static inline pmd_t pmd_mkclean(pmd_t pmd)

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@ -158,6 +158,9 @@ extern void handle_tlb_store(void);
extern void handle_tlb_modify(void);
extern void handle_tlb_refill(void);
extern void handle_tlb_protect(void);
extern void handle_tlb_load_ptw(void);
extern void handle_tlb_store_ptw(void);
extern void handle_tlb_modify_ptw(void);
extern void dump_tlb_all(void);
extern void dump_tlb_regs(void);

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@ -16,5 +16,6 @@
#define HWCAP_LOONGARCH_LBT_X86 (1 << 10)
#define HWCAP_LOONGARCH_LBT_ARM (1 << 11)
#define HWCAP_LOONGARCH_LBT_MIPS (1 << 12)
#define HWCAP_LOONGARCH_PTW (1 << 13)
#endif /* _UAPI_ASM_HWCAP_H */

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@ -136,6 +136,10 @@ static void cpu_probe_common(struct cpuinfo_loongarch *c)
c->options |= LOONGARCH_CPU_CRYPTO;
elf_hwcap |= HWCAP_LOONGARCH_CRYPTO;
}
if (config & CPUCFG2_PTW) {
c->options |= LOONGARCH_CPU_PTW;
elf_hwcap |= HWCAP_LOONGARCH_PTW;
}
if (config & CPUCFG2_LVZP) {
c->options |= LOONGARCH_CPU_LVZ;
elf_hwcap |= HWCAP_LOONGARCH_LVZ;

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@ -80,6 +80,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
if (cpu_has_crc32) seq_printf(m, " crc32");
if (cpu_has_complex) seq_printf(m, " complex");
if (cpu_has_crypto) seq_printf(m, " crypto");
if (cpu_has_ptw) seq_printf(m, " ptw");
if (cpu_has_lvz) seq_printf(m, " lvz");
if (cpu_has_lbt_x86) seq_printf(m, " lbt_x86");
if (cpu_has_lbt_arm) seq_printf(m, " lbt_arm");

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@ -167,6 +167,9 @@ void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep
int idx;
unsigned long flags;
if (cpu_has_ptw)
return;
/*
* Handle debugger faulting in for debugee.
*/
@ -222,6 +225,9 @@ static void setup_ptwalker(void)
pwctl0 = pte_i | pte_w << 5 | pmd_i << 10 | pmd_w << 15 | pud_i << 20 | pud_w << 25;
pwctl1 = pgd_i | pgd_w << 6;
if (cpu_has_ptw)
pwctl1 |= CSR_PWCTL1_PTW;
csr_write64(pwctl0, LOONGARCH_CSR_PWCTL0);
csr_write64(pwctl1, LOONGARCH_CSR_PWCTL1);
csr_write64((long)swapper_pg_dir, LOONGARCH_CSR_PGDH);
@ -264,10 +270,17 @@ void setup_tlb_handler(int cpu)
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);
if (!cpu_has_ptw) {
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);
} else {
set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load_ptw, VECSIZE);
set_handler(EXCCODE_TLBL * VECSIZE, handle_tlb_load_ptw, VECSIZE);
set_handler(EXCCODE_TLBS * VECSIZE, handle_tlb_store_ptw, VECSIZE);
set_handler(EXCCODE_TLBM * VECSIZE, handle_tlb_modify_ptw, 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);

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@ -190,6 +190,13 @@ nopage_tlb_load:
jr t0
SYM_FUNC_END(handle_tlb_load)
SYM_FUNC_START(handle_tlb_load_ptw)
csrwr t0, LOONGARCH_CSR_KS0
csrwr t1, LOONGARCH_CSR_KS1
la_abs t0, tlb_do_page_fault_0
jr t0
SYM_FUNC_END(handle_tlb_load_ptw)
SYM_FUNC_START(handle_tlb_store)
csrwr t0, EXCEPTION_KS0
csrwr t1, EXCEPTION_KS1
@ -339,6 +346,13 @@ nopage_tlb_store:
jr t0
SYM_FUNC_END(handle_tlb_store)
SYM_FUNC_START(handle_tlb_store_ptw)
csrwr t0, LOONGARCH_CSR_KS0
csrwr t1, LOONGARCH_CSR_KS1
la_abs t0, tlb_do_page_fault_1
jr t0
SYM_FUNC_END(handle_tlb_store_ptw)
SYM_FUNC_START(handle_tlb_modify)
csrwr t0, EXCEPTION_KS0
csrwr t1, EXCEPTION_KS1
@ -486,6 +500,13 @@ nopage_tlb_modify:
jr t0
SYM_FUNC_END(handle_tlb_modify)
SYM_FUNC_START(handle_tlb_modify_ptw)
csrwr t0, LOONGARCH_CSR_KS0
csrwr t1, LOONGARCH_CSR_KS1
la_abs t0, tlb_do_page_fault_1
jr t0
SYM_FUNC_END(handle_tlb_modify_ptw)
SYM_FUNC_START(handle_tlb_refill)
csrwr t0, LOONGARCH_CSR_TLBRSAVE
csrrd t0, LOONGARCH_CSR_PGD