Function pcpu_populate_pte and fixmap_pte are similar, they populate
one page from kernel address space. And there is confusion between
pgd and p4d in function fixmap_pte, such as pgd_none always returns
zero. This patch adds unified function populate_kernel_pte and replaces
pcpu_populate_pte and fixmap_pte.
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
arch/loongarch/include/asm/pgalloc.h | 1 +
arch/loongarch/kernel/numa.c | 40 +--------------------
arch/loongarch/mm/init.c | 52 ++++++++++++++++------------
3 files changed, 32 insertions(+), 61 deletions(-)
diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
index af1d1e4a6965..ca17b573dba6 100644
--- a/arch/loongarch/include/asm/pgalloc.h
+++ b/arch/loongarch/include/asm/pgalloc.h
@@ -91,4 +91,5 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
#endif /* __PAGETABLE_PUD_FOLDED */
+extern pte_t * __init populate_kernel_pte(unsigned long addr);
#endif /* _ASM_PGALLOC_H */
diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
index 778e1c20bfb0..24a693b76873 100644
--- a/arch/loongarch/kernel/numa.c
+++ b/arch/loongarch/kernel/numa.c
@@ -67,46 +67,8 @@ static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
void __init pcpu_populate_pte(unsigned long addr)
{
- pgd_t *pgd = pgd_offset_k(addr);
- p4d_t *p4d = p4d_offset(pgd, addr);
- pud_t *pud;
- pmd_t *pmd;
-
- if (p4d_none(*p4d)) {
- pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
- if (!pud)
- goto err_alloc;
- p4d_populate(&init_mm, p4d, pud);
-#ifndef __PAGETABLE_PUD_FOLDED
- pud_init(pud);
-#endif
- }
-
- pud = pud_offset(p4d, addr);
- if (pud_none(*pud)) {
- pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
- if (!pmd)
- goto err_alloc;
- pud_populate(&init_mm, pud, pmd);
-#ifndef __PAGETABLE_PMD_FOLDED
- pmd_init(pmd);
-#endif
- }
-
- pmd = pmd_offset(pud, addr);
- if (!pmd_present(*pmd)) {
- pte_t *pte;
-
- pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
- if (!pte)
- goto err_alloc;
- pmd_populate_kernel(&init_mm, pmd, pte);
- }
-
+ populate_kernel_pte(addr);
return;
-
-err_alloc:
- panic("%s: Failed to allocate memory\n", __func__);
}
void __init setup_per_cpu_areas(void)
diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
index 3b7d8129570b..6cd2948373ae 100644
--- a/arch/loongarch/mm/init.c
+++ b/arch/loongarch/mm/init.c
@@ -191,46 +191,49 @@ void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *al
#endif
#endif
-static pte_t *fixmap_pte(unsigned long addr)
+pte_t * __init populate_kernel_pte(unsigned long addr)
{
- pgd_t *pgd;
- p4d_t *p4d;
+ pgd_t *pgd = pgd_offset_k(addr);
+ p4d_t *p4d = p4d_offset(pgd, addr);
pud_t *pud;
pmd_t *pmd;
- pgd = pgd_offset_k(addr);
- p4d = p4d_offset(pgd, addr);
-
- if (pgd_none(*pgd)) {
- pud_t *new __maybe_unused;
-
- new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
- pgd_populate(&init_mm, pgd, new);
+ if (p4d_none(*p4d)) {
+ pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
+ if (!pud)
+ goto err_alloc;
+ p4d_populate(&init_mm, p4d, pud);
#ifndef __PAGETABLE_PUD_FOLDED
- pud_init(new);
+ pud_init(pud);
#endif
}
pud = pud_offset(p4d, addr);
if (pud_none(*pud)) {
- pmd_t *new __maybe_unused;
-
- new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
- pud_populate(&init_mm, pud, new);
+ pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
+ if (!pmd)
+ goto err_alloc;
+ pud_populate(&init_mm, pud, pmd);
#ifndef __PAGETABLE_PMD_FOLDED
- pmd_init(new);
+ pmd_init(pmd);
#endif
}
pmd = pmd_offset(pud, addr);
- if (pmd_none(*pmd)) {
- pte_t *new __maybe_unused;
+ if (!pmd_present(*pmd)) {
+ pte_t *pte;
- new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
- pmd_populate_kernel(&init_mm, pmd, new);
+ pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ if (!pte)
+ goto err_alloc;
+ pmd_populate_kernel(&init_mm, pmd, pte);
}
return pte_offset_kernel(pmd, addr);
+
+err_alloc:
+ panic("%s: Failed to allocate memory\n", __func__);
+ return NULL;
}
void __init __set_fixmap(enum fixed_addresses idx,
@@ -241,7 +244,12 @@ void __init __set_fixmap(enum fixed_addresses idx,
BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
- ptep = fixmap_pte(addr);
+ /*
+ * Now only FIX_EARLYCON_MEM_BASE fixed map is used
+ * __set_fixmap must be called before mem_init since function
+ * populate_kernel_pte allocates memory with memblock_alloc method.
+ */
+ ptep = populate_kernel_pte(addr);
if (!pte_none(*ptep)) {
pte_ERROR(*ptep);
return;
--
2.27.0On Wed, Jul 12, 2023 at 11:16 AM Bibo Mao <maobibo@loongson.cn> wrote:
>
> Function pcpu_populate_pte and fixmap_pte are similar, they populate
> one page from kernel address space. And there is confusion between
> pgd and p4d in function fixmap_pte, such as pgd_none always returns
> zero. This patch adds unified function populate_kernel_pte and replaces
> pcpu_populate_pte and fixmap_pte.
>
> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
> ---
> arch/loongarch/include/asm/pgalloc.h | 1 +
> arch/loongarch/kernel/numa.c | 40 +--------------------
> arch/loongarch/mm/init.c | 52 ++++++++++++++++------------
> 3 files changed, 32 insertions(+), 61 deletions(-)
>
> diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
> index af1d1e4a6965..ca17b573dba6 100644
> --- a/arch/loongarch/include/asm/pgalloc.h
> +++ b/arch/loongarch/include/asm/pgalloc.h
> @@ -91,4 +91,5 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
>
> #endif /* __PAGETABLE_PUD_FOLDED */
>
> +extern pte_t * __init populate_kernel_pte(unsigned long addr);
> #endif /* _ASM_PGALLOC_H */
> diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
> index 778e1c20bfb0..24a693b76873 100644
> --- a/arch/loongarch/kernel/numa.c
> +++ b/arch/loongarch/kernel/numa.c
> @@ -67,46 +67,8 @@ static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
>
> void __init pcpu_populate_pte(unsigned long addr)
> {
> - pgd_t *pgd = pgd_offset_k(addr);
> - p4d_t *p4d = p4d_offset(pgd, addr);
> - pud_t *pud;
> - pmd_t *pmd;
> -
> - if (p4d_none(*p4d)) {
> - pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> - if (!pud)
> - goto err_alloc;
> - p4d_populate(&init_mm, p4d, pud);
> -#ifndef __PAGETABLE_PUD_FOLDED
> - pud_init(pud);
> -#endif
> - }
> -
> - pud = pud_offset(p4d, addr);
> - if (pud_none(*pud)) {
> - pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> - if (!pmd)
> - goto err_alloc;
> - pud_populate(&init_mm, pud, pmd);
> -#ifndef __PAGETABLE_PMD_FOLDED
> - pmd_init(pmd);
> -#endif
> - }
> -
> - pmd = pmd_offset(pud, addr);
> - if (!pmd_present(*pmd)) {
> - pte_t *pte;
> -
> - pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> - if (!pte)
> - goto err_alloc;
> - pmd_populate_kernel(&init_mm, pmd, pte);
> - }
> -
> + populate_kernel_pte(addr);
> return;
> -
> -err_alloc:
> - panic("%s: Failed to allocate memory\n", __func__);
> }
>
> void __init setup_per_cpu_areas(void)
> diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
> index 3b7d8129570b..6cd2948373ae 100644
> --- a/arch/loongarch/mm/init.c
> +++ b/arch/loongarch/mm/init.c
> @@ -191,46 +191,49 @@ void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *al
> #endif
> #endif
>
> -static pte_t *fixmap_pte(unsigned long addr)
> +pte_t * __init populate_kernel_pte(unsigned long addr)
> {
> - pgd_t *pgd;
> - p4d_t *p4d;
> + pgd_t *pgd = pgd_offset_k(addr);
> + p4d_t *p4d = p4d_offset(pgd, addr);
> pud_t *pud;
> pmd_t *pmd;
>
> - pgd = pgd_offset_k(addr);
> - p4d = p4d_offset(pgd, addr);
> -
> - if (pgd_none(*pgd)) {
> - pud_t *new __maybe_unused;
> -
> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
> - pgd_populate(&init_mm, pgd, new);
> + if (p4d_none(*p4d)) {
> + pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> + if (!pud)
> + goto err_alloc;
> + p4d_populate(&init_mm, p4d, pud);
> #ifndef __PAGETABLE_PUD_FOLDED
> - pud_init(new);
> + pud_init(pud);
> #endif
> }
>
> pud = pud_offset(p4d, addr);
> if (pud_none(*pud)) {
> - pmd_t *new __maybe_unused;
> -
> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
> - pud_populate(&init_mm, pud, new);
> + pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> + if (!pmd)
> + goto err_alloc;
> + pud_populate(&init_mm, pud, pmd);
> #ifndef __PAGETABLE_PMD_FOLDED
> - pmd_init(new);
> + pmd_init(pmd);
> #endif
> }
>
> pmd = pmd_offset(pud, addr);
> - if (pmd_none(*pmd)) {
> - pte_t *new __maybe_unused;
> + if (!pmd_present(*pmd)) {
> + pte_t *pte;
>
> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
> - pmd_populate_kernel(&init_mm, pmd, new);
> + pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
I don't think memblock_alloc_low() here can be replaced by memblock_alloc().
Huacai
> + if (!pte)
> + goto err_alloc;
> + pmd_populate_kernel(&init_mm, pmd, pte);
> }
>
> return pte_offset_kernel(pmd, addr);
> +
> +err_alloc:
> + panic("%s: Failed to allocate memory\n", __func__);
> + return NULL;
> }
>
> void __init __set_fixmap(enum fixed_addresses idx,
> @@ -241,7 +244,12 @@ void __init __set_fixmap(enum fixed_addresses idx,
>
> BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
>
> - ptep = fixmap_pte(addr);
> + /*
> + * Now only FIX_EARLYCON_MEM_BASE fixed map is used
> + * __set_fixmap must be called before mem_init since function
> + * populate_kernel_pte allocates memory with memblock_alloc method.
> + */
> + ptep = populate_kernel_pte(addr);
> if (!pte_none(*ptep)) {
> pte_ERROR(*ptep);
> return;
> --
> 2.27.0
>
在 2023/7/31 22:15, Huacai Chen 写道:
> On Wed, Jul 12, 2023 at 11:16 AM Bibo Mao <maobibo@loongson.cn> wrote:
>>
>> Function pcpu_populate_pte and fixmap_pte are similar, they populate
>> one page from kernel address space. And there is confusion between
>> pgd and p4d in function fixmap_pte, such as pgd_none always returns
>> zero. This patch adds unified function populate_kernel_pte and replaces
>> pcpu_populate_pte and fixmap_pte.
>>
>> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
>> ---
>> arch/loongarch/include/asm/pgalloc.h | 1 +
>> arch/loongarch/kernel/numa.c | 40 +--------------------
>> arch/loongarch/mm/init.c | 52 ++++++++++++++++------------
>> 3 files changed, 32 insertions(+), 61 deletions(-)
>>
>> diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
>> index af1d1e4a6965..ca17b573dba6 100644
>> --- a/arch/loongarch/include/asm/pgalloc.h
>> +++ b/arch/loongarch/include/asm/pgalloc.h
>> @@ -91,4 +91,5 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
>>
>> #endif /* __PAGETABLE_PUD_FOLDED */
>>
>> +extern pte_t * __init populate_kernel_pte(unsigned long addr);
>> #endif /* _ASM_PGALLOC_H */
>> diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
>> index 778e1c20bfb0..24a693b76873 100644
>> --- a/arch/loongarch/kernel/numa.c
>> +++ b/arch/loongarch/kernel/numa.c
>> @@ -67,46 +67,8 @@ static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
>>
>> void __init pcpu_populate_pte(unsigned long addr)
>> {
>> - pgd_t *pgd = pgd_offset_k(addr);
>> - p4d_t *p4d = p4d_offset(pgd, addr);
>> - pud_t *pud;
>> - pmd_t *pmd;
>> -
>> - if (p4d_none(*p4d)) {
>> - pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>> - if (!pud)
>> - goto err_alloc;
>> - p4d_populate(&init_mm, p4d, pud);
>> -#ifndef __PAGETABLE_PUD_FOLDED
>> - pud_init(pud);
>> -#endif
>> - }
>> -
>> - pud = pud_offset(p4d, addr);
>> - if (pud_none(*pud)) {
>> - pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>> - if (!pmd)
>> - goto err_alloc;
>> - pud_populate(&init_mm, pud, pmd);
>> -#ifndef __PAGETABLE_PMD_FOLDED
>> - pmd_init(pmd);
>> -#endif
>> - }
>> -
>> - pmd = pmd_offset(pud, addr);
>> - if (!pmd_present(*pmd)) {
>> - pte_t *pte;
>> -
>> - pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
>> - if (!pte)
>> - goto err_alloc;
>> - pmd_populate_kernel(&init_mm, pmd, pte);
>> - }
>> -
>> + populate_kernel_pte(addr);
>> return;
>> -
>> -err_alloc:
>> - panic("%s: Failed to allocate memory\n", __func__);
>> }
>>
>> void __init setup_per_cpu_areas(void)
>> diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
>> index 3b7d8129570b..6cd2948373ae 100644
>> --- a/arch/loongarch/mm/init.c
>> +++ b/arch/loongarch/mm/init.c
>> @@ -191,46 +191,49 @@ void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *al
>> #endif
>> #endif
>>
>> -static pte_t *fixmap_pte(unsigned long addr)
>> +pte_t * __init populate_kernel_pte(unsigned long addr)
>> {
>> - pgd_t *pgd;
>> - p4d_t *p4d;
>> + pgd_t *pgd = pgd_offset_k(addr);
>> + p4d_t *p4d = p4d_offset(pgd, addr);
>> pud_t *pud;
>> pmd_t *pmd;
>>
>> - pgd = pgd_offset_k(addr);
>> - p4d = p4d_offset(pgd, addr);
>> -
>> - if (pgd_none(*pgd)) {
>> - pud_t *new __maybe_unused;
>> -
>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
>> - pgd_populate(&init_mm, pgd, new);
>> + if (p4d_none(*p4d)) {
>> + pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>> + if (!pud)
>> + goto err_alloc;
>> + p4d_populate(&init_mm, p4d, pud);
>> #ifndef __PAGETABLE_PUD_FOLDED
>> - pud_init(new);
>> + pud_init(pud);
>> #endif
>> }
>>
>> pud = pud_offset(p4d, addr);
>> if (pud_none(*pud)) {
>> - pmd_t *new __maybe_unused;
>> -
>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
>> - pud_populate(&init_mm, pud, new);
>> + pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>> + if (!pmd)
>> + goto err_alloc;
>> + pud_populate(&init_mm, pud, pmd);
>> #ifndef __PAGETABLE_PMD_FOLDED
>> - pmd_init(new);
>> + pmd_init(pmd);
>> #endif
>> }
>>
>> pmd = pmd_offset(pud, addr);
>> - if (pmd_none(*pmd)) {
>> - pte_t *new __maybe_unused;
>> + if (!pmd_present(*pmd)) {
>> + pte_t *pte;
>>
>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
>> - pmd_populate_kernel(&init_mm, pmd, new);
>> + pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> I don't think memblock_alloc_low() here can be replaced by memblock_alloc().
Can you share me the points that pte table must be allocated with memblock_alloc_low
in this place?
Regards
Bibo Mao
>
>
> Huacai
>> + if (!pte)
>> + goto err_alloc;
>> + pmd_populate_kernel(&init_mm, pmd, pte);
>> }
>>
>> return pte_offset_kernel(pmd, addr);
>> +
>> +err_alloc:
>> + panic("%s: Failed to allocate memory\n", __func__);
>> + return NULL;
>> }
>>
>> void __init __set_fixmap(enum fixed_addresses idx,
>> @@ -241,7 +244,12 @@ void __init __set_fixmap(enum fixed_addresses idx,
>>
>> BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
>>
>> - ptep = fixmap_pte(addr);
>> + /*
>> + * Now only FIX_EARLYCON_MEM_BASE fixed map is used
>> + * __set_fixmap must be called before mem_init since function
>> + * populate_kernel_pte allocates memory with memblock_alloc method.
>> + */
>> + ptep = populate_kernel_pte(addr);
>> if (!pte_none(*ptep)) {
>> pte_ERROR(*ptep);
>> return;
>> --
>> 2.27.0
>>
On Tue, Aug 1, 2023 at 9:22 AM bibo mao <maobibo@loongson.cn> wrote:
>
>
>
> 在 2023/7/31 22:15, Huacai Chen 写道:
> > On Wed, Jul 12, 2023 at 11:16 AM Bibo Mao <maobibo@loongson.cn> wrote:
> >>
> >> Function pcpu_populate_pte and fixmap_pte are similar, they populate
> >> one page from kernel address space. And there is confusion between
> >> pgd and p4d in function fixmap_pte, such as pgd_none always returns
> >> zero. This patch adds unified function populate_kernel_pte and replaces
> >> pcpu_populate_pte and fixmap_pte.
> >>
> >> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
> >> ---
> >> arch/loongarch/include/asm/pgalloc.h | 1 +
> >> arch/loongarch/kernel/numa.c | 40 +--------------------
> >> arch/loongarch/mm/init.c | 52 ++++++++++++++++------------
> >> 3 files changed, 32 insertions(+), 61 deletions(-)
> >>
> >> diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
> >> index af1d1e4a6965..ca17b573dba6 100644
> >> --- a/arch/loongarch/include/asm/pgalloc.h
> >> +++ b/arch/loongarch/include/asm/pgalloc.h
> >> @@ -91,4 +91,5 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
> >>
> >> #endif /* __PAGETABLE_PUD_FOLDED */
> >>
> >> +extern pte_t * __init populate_kernel_pte(unsigned long addr);
> >> #endif /* _ASM_PGALLOC_H */
> >> diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
> >> index 778e1c20bfb0..24a693b76873 100644
> >> --- a/arch/loongarch/kernel/numa.c
> >> +++ b/arch/loongarch/kernel/numa.c
> >> @@ -67,46 +67,8 @@ static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
> >>
> >> void __init pcpu_populate_pte(unsigned long addr)
> >> {
> >> - pgd_t *pgd = pgd_offset_k(addr);
> >> - p4d_t *p4d = p4d_offset(pgd, addr);
> >> - pud_t *pud;
> >> - pmd_t *pmd;
> >> -
> >> - if (p4d_none(*p4d)) {
> >> - pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> >> - if (!pud)
> >> - goto err_alloc;
> >> - p4d_populate(&init_mm, p4d, pud);
> >> -#ifndef __PAGETABLE_PUD_FOLDED
> >> - pud_init(pud);
> >> -#endif
> >> - }
> >> -
> >> - pud = pud_offset(p4d, addr);
> >> - if (pud_none(*pud)) {
> >> - pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> >> - if (!pmd)
> >> - goto err_alloc;
> >> - pud_populate(&init_mm, pud, pmd);
> >> -#ifndef __PAGETABLE_PMD_FOLDED
> >> - pmd_init(pmd);
> >> -#endif
> >> - }
> >> -
> >> - pmd = pmd_offset(pud, addr);
> >> - if (!pmd_present(*pmd)) {
> >> - pte_t *pte;
> >> -
> >> - pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> >> - if (!pte)
> >> - goto err_alloc;
> >> - pmd_populate_kernel(&init_mm, pmd, pte);
> >> - }
> >> -
> >> + populate_kernel_pte(addr);
> >> return;
> >> -
> >> -err_alloc:
> >> - panic("%s: Failed to allocate memory\n", __func__);
> >> }
> >>
> >> void __init setup_per_cpu_areas(void)
> >> diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
> >> index 3b7d8129570b..6cd2948373ae 100644
> >> --- a/arch/loongarch/mm/init.c
> >> +++ b/arch/loongarch/mm/init.c
> >> @@ -191,46 +191,49 @@ void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *al
> >> #endif
> >> #endif
> >>
> >> -static pte_t *fixmap_pte(unsigned long addr)
> >> +pte_t * __init populate_kernel_pte(unsigned long addr)
> >> {
> >> - pgd_t *pgd;
> >> - p4d_t *p4d;
> >> + pgd_t *pgd = pgd_offset_k(addr);
> >> + p4d_t *p4d = p4d_offset(pgd, addr);
> >> pud_t *pud;
> >> pmd_t *pmd;
> >>
> >> - pgd = pgd_offset_k(addr);
> >> - p4d = p4d_offset(pgd, addr);
> >> -
> >> - if (pgd_none(*pgd)) {
> >> - pud_t *new __maybe_unused;
> >> -
> >> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
> >> - pgd_populate(&init_mm, pgd, new);
> >> + if (p4d_none(*p4d)) {
> >> + pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> >> + if (!pud)
> >> + goto err_alloc;
> >> + p4d_populate(&init_mm, p4d, pud);
> >> #ifndef __PAGETABLE_PUD_FOLDED
> >> - pud_init(new);
> >> + pud_init(pud);
> >> #endif
> >> }
> >>
> >> pud = pud_offset(p4d, addr);
> >> if (pud_none(*pud)) {
> >> - pmd_t *new __maybe_unused;
> >> -
> >> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
> >> - pud_populate(&init_mm, pud, new);
> >> + pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> >> + if (!pmd)
> >> + goto err_alloc;
> >> + pud_populate(&init_mm, pud, pmd);
> >> #ifndef __PAGETABLE_PMD_FOLDED
> >> - pmd_init(new);
> >> + pmd_init(pmd);
> >> #endif
> >> }
> >>
> >> pmd = pmd_offset(pud, addr);
> >> - if (pmd_none(*pmd)) {
> >> - pte_t *new __maybe_unused;
> >> + if (!pmd_present(*pmd)) {
> >> + pte_t *pte;
> >>
> >> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
> >> - pmd_populate_kernel(&init_mm, pmd, new);
> >> + pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> > I don't think memblock_alloc_low() here can be replaced by memblock_alloc().
> Can you share me the points that pte table must be allocated with memblock_alloc_low
> in this place?
I forget the reason now, so if you confirm memblock_alloc() works well
here, you can use it. But please don't use memblock_alloc_raw().
Huacai
>
> Regards
> Bibo Mao
> >
> >
> > Huacai
> >> + if (!pte)
> >> + goto err_alloc;
> >> + pmd_populate_kernel(&init_mm, pmd, pte);
> >> }
> >>
> >> return pte_offset_kernel(pmd, addr);
> >> +
> >> +err_alloc:
> >> + panic("%s: Failed to allocate memory\n", __func__);
> >> + return NULL;
> >> }
> >>
> >> void __init __set_fixmap(enum fixed_addresses idx,
> >> @@ -241,7 +244,12 @@ void __init __set_fixmap(enum fixed_addresses idx,
> >>
> >> BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
> >>
> >> - ptep = fixmap_pte(addr);
> >> + /*
> >> + * Now only FIX_EARLYCON_MEM_BASE fixed map is used
> >> + * __set_fixmap must be called before mem_init since function
> >> + * populate_kernel_pte allocates memory with memblock_alloc method.
> >> + */
> >> + ptep = populate_kernel_pte(addr);
> >> if (!pte_none(*ptep)) {
> >> pte_ERROR(*ptep);
> >> return;
> >> --
> >> 2.27.0
> >>
>
>
在 2023/8/2 15:25, Huacai Chen 写道:
> On Tue, Aug 1, 2023 at 9:22 AM bibo mao <maobibo@loongson.cn> wrote:
>>
>>
>>
>> 在 2023/7/31 22:15, Huacai Chen 写道:
>>> On Wed, Jul 12, 2023 at 11:16 AM Bibo Mao <maobibo@loongson.cn> wrote:
>>>>
>>>> Function pcpu_populate_pte and fixmap_pte are similar, they populate
>>>> one page from kernel address space. And there is confusion between
>>>> pgd and p4d in function fixmap_pte, such as pgd_none always returns
>>>> zero. This patch adds unified function populate_kernel_pte and replaces
>>>> pcpu_populate_pte and fixmap_pte.
>>>>
>>>> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
>>>> ---
>>>> arch/loongarch/include/asm/pgalloc.h | 1 +
>>>> arch/loongarch/kernel/numa.c | 40 +--------------------
>>>> arch/loongarch/mm/init.c | 52 ++++++++++++++++------------
>>>> 3 files changed, 32 insertions(+), 61 deletions(-)
>>>>
>>>> diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
>>>> index af1d1e4a6965..ca17b573dba6 100644
>>>> --- a/arch/loongarch/include/asm/pgalloc.h
>>>> +++ b/arch/loongarch/include/asm/pgalloc.h
>>>> @@ -91,4 +91,5 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
>>>>
>>>> #endif /* __PAGETABLE_PUD_FOLDED */
>>>>
>>>> +extern pte_t * __init populate_kernel_pte(unsigned long addr);
>>>> #endif /* _ASM_PGALLOC_H */
>>>> diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
>>>> index 778e1c20bfb0..24a693b76873 100644
>>>> --- a/arch/loongarch/kernel/numa.c
>>>> +++ b/arch/loongarch/kernel/numa.c
>>>> @@ -67,46 +67,8 @@ static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
>>>>
>>>> void __init pcpu_populate_pte(unsigned long addr)
>>>> {
>>>> - pgd_t *pgd = pgd_offset_k(addr);
>>>> - p4d_t *p4d = p4d_offset(pgd, addr);
>>>> - pud_t *pud;
>>>> - pmd_t *pmd;
>>>> -
>>>> - if (p4d_none(*p4d)) {
>>>> - pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>>>> - if (!pud)
>>>> - goto err_alloc;
>>>> - p4d_populate(&init_mm, p4d, pud);
>>>> -#ifndef __PAGETABLE_PUD_FOLDED
>>>> - pud_init(pud);
>>>> -#endif
>>>> - }
>>>> -
>>>> - pud = pud_offset(p4d, addr);
>>>> - if (pud_none(*pud)) {
>>>> - pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>>>> - if (!pmd)
>>>> - goto err_alloc;
>>>> - pud_populate(&init_mm, pud, pmd);
>>>> -#ifndef __PAGETABLE_PMD_FOLDED
>>>> - pmd_init(pmd);
>>>> -#endif
>>>> - }
>>>> -
>>>> - pmd = pmd_offset(pud, addr);
>>>> - if (!pmd_present(*pmd)) {
>>>> - pte_t *pte;
>>>> -
>>>> - pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
>>>> - if (!pte)
>>>> - goto err_alloc;
>>>> - pmd_populate_kernel(&init_mm, pmd, pte);
>>>> - }
>>>> -
>>>> + populate_kernel_pte(addr);
>>>> return;
>>>> -
>>>> -err_alloc:
>>>> - panic("%s: Failed to allocate memory\n", __func__);
>>>> }
>>>>
>>>> void __init setup_per_cpu_areas(void)
>>>> diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
>>>> index 3b7d8129570b..6cd2948373ae 100644
>>>> --- a/arch/loongarch/mm/init.c
>>>> +++ b/arch/loongarch/mm/init.c
>>>> @@ -191,46 +191,49 @@ void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *al
>>>> #endif
>>>> #endif
>>>>
>>>> -static pte_t *fixmap_pte(unsigned long addr)
>>>> +pte_t * __init populate_kernel_pte(unsigned long addr)
>>>> {
>>>> - pgd_t *pgd;
>>>> - p4d_t *p4d;
>>>> + pgd_t *pgd = pgd_offset_k(addr);
>>>> + p4d_t *p4d = p4d_offset(pgd, addr);
>>>> pud_t *pud;
>>>> pmd_t *pmd;
>>>>
>>>> - pgd = pgd_offset_k(addr);
>>>> - p4d = p4d_offset(pgd, addr);
>>>> -
>>>> - if (pgd_none(*pgd)) {
>>>> - pud_t *new __maybe_unused;
>>>> -
>>>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
>>>> - pgd_populate(&init_mm, pgd, new);
>>>> + if (p4d_none(*p4d)) {
>>>> + pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>>>> + if (!pud)
>>>> + goto err_alloc;
>>>> + p4d_populate(&init_mm, p4d, pud);
>>>> #ifndef __PAGETABLE_PUD_FOLDED
>>>> - pud_init(new);
>>>> + pud_init(pud);
>>>> #endif
>>>> }
>>>>
>>>> pud = pud_offset(p4d, addr);
>>>> if (pud_none(*pud)) {
>>>> - pmd_t *new __maybe_unused;
>>>> -
>>>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
>>>> - pud_populate(&init_mm, pud, new);
>>>> + pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>>>> + if (!pmd)
>>>> + goto err_alloc;
>>>> + pud_populate(&init_mm, pud, pmd);
>>>> #ifndef __PAGETABLE_PMD_FOLDED
>>>> - pmd_init(new);
>>>> + pmd_init(pmd);
>>>> #endif
>>>> }
>>>>
>>>> pmd = pmd_offset(pud, addr);
>>>> - if (pmd_none(*pmd)) {
>>>> - pte_t *new __maybe_unused;
>>>> + if (!pmd_present(*pmd)) {
>>>> + pte_t *pte;
>>>>
>>>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
>>>> - pmd_populate_kernel(&init_mm, pmd, new);
>>>> + pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
>>> I don't think memblock_alloc_low() here can be replaced by memblock_alloc().
>> Can you share me the points that pte table must be allocated with memblock_alloc_low
>> in this place?
> I forget the reason now, so if you confirm memblock_alloc() works well
> here, you can use it. But please don't use memblock_alloc_raw().
what a mess, there is more comments if there is special reason, else everyone can
forgot by elapsed time.
why the function memblock_alloc_raw can not be use? there is one useless page copy.
Regards
Bibo Mao
>
> Huacai
>>
>> Regards
>> Bibo Mao
>>>
>>>
>>> Huacai
>>>> + if (!pte)
>>>> + goto err_alloc;
>>>> + pmd_populate_kernel(&init_mm, pmd, pte);
>>>> }
>>>>
>>>> return pte_offset_kernel(pmd, addr);
>>>> +
>>>> +err_alloc:
>>>> + panic("%s: Failed to allocate memory\n", __func__);
>>>> + return NULL;
>>>> }
>>>>
>>>> void __init __set_fixmap(enum fixed_addresses idx,
>>>> @@ -241,7 +244,12 @@ void __init __set_fixmap(enum fixed_addresses idx,
>>>>
>>>> BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
>>>>
>>>> - ptep = fixmap_pte(addr);
>>>> + /*
>>>> + * Now only FIX_EARLYCON_MEM_BASE fixed map is used
>>>> + * __set_fixmap must be called before mem_init since function
>>>> + * populate_kernel_pte allocates memory with memblock_alloc method.
>>>> + */
>>>> + ptep = populate_kernel_pte(addr);
>>>> if (!pte_none(*ptep)) {
>>>> pte_ERROR(*ptep);
>>>> return;
>>>> --
>>>> 2.27.0
>>>>
>>
>>
On Thu, Aug 10, 2023 at 12:09 PM bibo mao <maobibo@loongson.cn> wrote:
>
>
>
> 在 2023/8/2 15:25, Huacai Chen 写道:
> > On Tue, Aug 1, 2023 at 9:22 AM bibo mao <maobibo@loongson.cn> wrote:
> >>
> >>
> >>
> >> 在 2023/7/31 22:15, Huacai Chen 写道:
> >>> On Wed, Jul 12, 2023 at 11:16 AM Bibo Mao <maobibo@loongson.cn> wrote:
> >>>>
> >>>> Function pcpu_populate_pte and fixmap_pte are similar, they populate
> >>>> one page from kernel address space. And there is confusion between
> >>>> pgd and p4d in function fixmap_pte, such as pgd_none always returns
> >>>> zero. This patch adds unified function populate_kernel_pte and replaces
> >>>> pcpu_populate_pte and fixmap_pte.
> >>>>
> >>>> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
> >>>> ---
> >>>> arch/loongarch/include/asm/pgalloc.h | 1 +
> >>>> arch/loongarch/kernel/numa.c | 40 +--------------------
> >>>> arch/loongarch/mm/init.c | 52 ++++++++++++++++------------
> >>>> 3 files changed, 32 insertions(+), 61 deletions(-)
> >>>>
> >>>> diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
> >>>> index af1d1e4a6965..ca17b573dba6 100644
> >>>> --- a/arch/loongarch/include/asm/pgalloc.h
> >>>> +++ b/arch/loongarch/include/asm/pgalloc.h
> >>>> @@ -91,4 +91,5 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
> >>>>
> >>>> #endif /* __PAGETABLE_PUD_FOLDED */
> >>>>
> >>>> +extern pte_t * __init populate_kernel_pte(unsigned long addr);
> >>>> #endif /* _ASM_PGALLOC_H */
> >>>> diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
> >>>> index 778e1c20bfb0..24a693b76873 100644
> >>>> --- a/arch/loongarch/kernel/numa.c
> >>>> +++ b/arch/loongarch/kernel/numa.c
> >>>> @@ -67,46 +67,8 @@ static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
> >>>>
> >>>> void __init pcpu_populate_pte(unsigned long addr)
> >>>> {
> >>>> - pgd_t *pgd = pgd_offset_k(addr);
> >>>> - p4d_t *p4d = p4d_offset(pgd, addr);
> >>>> - pud_t *pud;
> >>>> - pmd_t *pmd;
> >>>> -
> >>>> - if (p4d_none(*p4d)) {
> >>>> - pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> >>>> - if (!pud)
> >>>> - goto err_alloc;
> >>>> - p4d_populate(&init_mm, p4d, pud);
> >>>> -#ifndef __PAGETABLE_PUD_FOLDED
> >>>> - pud_init(pud);
> >>>> -#endif
> >>>> - }
> >>>> -
> >>>> - pud = pud_offset(p4d, addr);
> >>>> - if (pud_none(*pud)) {
> >>>> - pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> >>>> - if (!pmd)
> >>>> - goto err_alloc;
> >>>> - pud_populate(&init_mm, pud, pmd);
> >>>> -#ifndef __PAGETABLE_PMD_FOLDED
> >>>> - pmd_init(pmd);
> >>>> -#endif
> >>>> - }
> >>>> -
> >>>> - pmd = pmd_offset(pud, addr);
> >>>> - if (!pmd_present(*pmd)) {
> >>>> - pte_t *pte;
> >>>> -
> >>>> - pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> >>>> - if (!pte)
> >>>> - goto err_alloc;
> >>>> - pmd_populate_kernel(&init_mm, pmd, pte);
> >>>> - }
> >>>> -
> >>>> + populate_kernel_pte(addr);
> >>>> return;
> >>>> -
> >>>> -err_alloc:
> >>>> - panic("%s: Failed to allocate memory\n", __func__);
> >>>> }
> >>>>
> >>>> void __init setup_per_cpu_areas(void)
> >>>> diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
> >>>> index 3b7d8129570b..6cd2948373ae 100644
> >>>> --- a/arch/loongarch/mm/init.c
> >>>> +++ b/arch/loongarch/mm/init.c
> >>>> @@ -191,46 +191,49 @@ void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *al
> >>>> #endif
> >>>> #endif
> >>>>
> >>>> -static pte_t *fixmap_pte(unsigned long addr)
> >>>> +pte_t * __init populate_kernel_pte(unsigned long addr)
> >>>> {
> >>>> - pgd_t *pgd;
> >>>> - p4d_t *p4d;
> >>>> + pgd_t *pgd = pgd_offset_k(addr);
> >>>> + p4d_t *p4d = p4d_offset(pgd, addr);
> >>>> pud_t *pud;
> >>>> pmd_t *pmd;
> >>>>
> >>>> - pgd = pgd_offset_k(addr);
> >>>> - p4d = p4d_offset(pgd, addr);
> >>>> -
> >>>> - if (pgd_none(*pgd)) {
> >>>> - pud_t *new __maybe_unused;
> >>>> -
> >>>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
> >>>> - pgd_populate(&init_mm, pgd, new);
> >>>> + if (p4d_none(*p4d)) {
> >>>> + pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> >>>> + if (!pud)
> >>>> + goto err_alloc;
> >>>> + p4d_populate(&init_mm, p4d, pud);
> >>>> #ifndef __PAGETABLE_PUD_FOLDED
> >>>> - pud_init(new);
> >>>> + pud_init(pud);
> >>>> #endif
> >>>> }
> >>>>
> >>>> pud = pud_offset(p4d, addr);
> >>>> if (pud_none(*pud)) {
> >>>> - pmd_t *new __maybe_unused;
> >>>> -
> >>>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
> >>>> - pud_populate(&init_mm, pud, new);
> >>>> + pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
> >>>> + if (!pmd)
> >>>> + goto err_alloc;
> >>>> + pud_populate(&init_mm, pud, pmd);
> >>>> #ifndef __PAGETABLE_PMD_FOLDED
> >>>> - pmd_init(new);
> >>>> + pmd_init(pmd);
> >>>> #endif
> >>>> }
> >>>>
> >>>> pmd = pmd_offset(pud, addr);
> >>>> - if (pmd_none(*pmd)) {
> >>>> - pte_t *new __maybe_unused;
> >>>> + if (!pmd_present(*pmd)) {
> >>>> + pte_t *pte;
> >>>>
> >>>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
> >>>> - pmd_populate_kernel(&init_mm, pmd, new);
> >>>> + pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> >>> I don't think memblock_alloc_low() here can be replaced by memblock_alloc().
> >> Can you share me the points that pte table must be allocated with memblock_alloc_low
> >> in this place?
> > I forget the reason now, so if you confirm memblock_alloc() works well
> > here, you can use it. But please don't use memblock_alloc_raw().
> what a mess, there is more comments if there is special reason, else everyone can
> forgot by elapsed time.
>
> why the function memblock_alloc_raw can not be use? there is one useless page copy.
This is not a performance critical path, keeping consistency with
mm/percpu.c can make life easier.
Huacai
>
> Regards
> Bibo Mao
>
>
> >
> > Huacai
> >>
> >> Regards
> >> Bibo Mao
> >>>
> >>>
> >>> Huacai
> >>>> + if (!pte)
> >>>> + goto err_alloc;
> >>>> + pmd_populate_kernel(&init_mm, pmd, pte);
> >>>> }
> >>>>
> >>>> return pte_offset_kernel(pmd, addr);
> >>>> +
> >>>> +err_alloc:
> >>>> + panic("%s: Failed to allocate memory\n", __func__);
> >>>> + return NULL;
> >>>> }
> >>>>
> >>>> void __init __set_fixmap(enum fixed_addresses idx,
> >>>> @@ -241,7 +244,12 @@ void __init __set_fixmap(enum fixed_addresses idx,
> >>>>
> >>>> BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
> >>>>
> >>>> - ptep = fixmap_pte(addr);
> >>>> + /*
> >>>> + * Now only FIX_EARLYCON_MEM_BASE fixed map is used
> >>>> + * __set_fixmap must be called before mem_init since function
> >>>> + * populate_kernel_pte allocates memory with memblock_alloc method.
> >>>> + */
> >>>> + ptep = populate_kernel_pte(addr);
> >>>> if (!pte_none(*ptep)) {
> >>>> pte_ERROR(*ptep);
> >>>> return;
> >>>> --
> >>>> 2.27.0
> >>>>
> >>
> >>
>
>
在 2023/8/10 12:27, Huacai Chen 写道:
> On Thu, Aug 10, 2023 at 12:09 PM bibo mao <maobibo@loongson.cn> wrote:
>>
>>
>>
>> 在 2023/8/2 15:25, Huacai Chen 写道:
>>> On Tue, Aug 1, 2023 at 9:22 AM bibo mao <maobibo@loongson.cn> wrote:
>>>>
>>>>
>>>>
>>>> 在 2023/7/31 22:15, Huacai Chen 写道:
>>>>> On Wed, Jul 12, 2023 at 11:16 AM Bibo Mao <maobibo@loongson.cn> wrote:
>>>>>>
>>>>>> Function pcpu_populate_pte and fixmap_pte are similar, they populate
>>>>>> one page from kernel address space. And there is confusion between
>>>>>> pgd and p4d in function fixmap_pte, such as pgd_none always returns
>>>>>> zero. This patch adds unified function populate_kernel_pte and replaces
>>>>>> pcpu_populate_pte and fixmap_pte.
>>>>>>
>>>>>> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
>>>>>> ---
>>>>>> arch/loongarch/include/asm/pgalloc.h | 1 +
>>>>>> arch/loongarch/kernel/numa.c | 40 +--------------------
>>>>>> arch/loongarch/mm/init.c | 52 ++++++++++++++++------------
>>>>>> 3 files changed, 32 insertions(+), 61 deletions(-)
>>>>>>
>>>>>> diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h
>>>>>> index af1d1e4a6965..ca17b573dba6 100644
>>>>>> --- a/arch/loongarch/include/asm/pgalloc.h
>>>>>> +++ b/arch/loongarch/include/asm/pgalloc.h
>>>>>> @@ -91,4 +91,5 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
>>>>>>
>>>>>> #endif /* __PAGETABLE_PUD_FOLDED */
>>>>>>
>>>>>> +extern pte_t * __init populate_kernel_pte(unsigned long addr);
>>>>>> #endif /* _ASM_PGALLOC_H */
>>>>>> diff --git a/arch/loongarch/kernel/numa.c b/arch/loongarch/kernel/numa.c
>>>>>> index 778e1c20bfb0..24a693b76873 100644
>>>>>> --- a/arch/loongarch/kernel/numa.c
>>>>>> +++ b/arch/loongarch/kernel/numa.c
>>>>>> @@ -67,46 +67,8 @@ static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
>>>>>>
>>>>>> void __init pcpu_populate_pte(unsigned long addr)
>>>>>> {
>>>>>> - pgd_t *pgd = pgd_offset_k(addr);
>>>>>> - p4d_t *p4d = p4d_offset(pgd, addr);
>>>>>> - pud_t *pud;
>>>>>> - pmd_t *pmd;
>>>>>> -
>>>>>> - if (p4d_none(*p4d)) {
>>>>>> - pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>>>>>> - if (!pud)
>>>>>> - goto err_alloc;
>>>>>> - p4d_populate(&init_mm, p4d, pud);
>>>>>> -#ifndef __PAGETABLE_PUD_FOLDED
>>>>>> - pud_init(pud);
>>>>>> -#endif
>>>>>> - }
>>>>>> -
>>>>>> - pud = pud_offset(p4d, addr);
>>>>>> - if (pud_none(*pud)) {
>>>>>> - pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>>>>>> - if (!pmd)
>>>>>> - goto err_alloc;
>>>>>> - pud_populate(&init_mm, pud, pmd);
>>>>>> -#ifndef __PAGETABLE_PMD_FOLDED
>>>>>> - pmd_init(pmd);
>>>>>> -#endif
>>>>>> - }
>>>>>> -
>>>>>> - pmd = pmd_offset(pud, addr);
>>>>>> - if (!pmd_present(*pmd)) {
>>>>>> - pte_t *pte;
>>>>>> -
>>>>>> - pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
>>>>>> - if (!pte)
>>>>>> - goto err_alloc;
>>>>>> - pmd_populate_kernel(&init_mm, pmd, pte);
>>>>>> - }
>>>>>> -
>>>>>> + populate_kernel_pte(addr);
>>>>>> return;
>>>>>> -
>>>>>> -err_alloc:
>>>>>> - panic("%s: Failed to allocate memory\n", __func__);
>>>>>> }
>>>>>>
>>>>>> void __init setup_per_cpu_areas(void)
>>>>>> diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
>>>>>> index 3b7d8129570b..6cd2948373ae 100644
>>>>>> --- a/arch/loongarch/mm/init.c
>>>>>> +++ b/arch/loongarch/mm/init.c
>>>>>> @@ -191,46 +191,49 @@ void vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *al
>>>>>> #endif
>>>>>> #endif
>>>>>>
>>>>>> -static pte_t *fixmap_pte(unsigned long addr)
>>>>>> +pte_t * __init populate_kernel_pte(unsigned long addr)
>>>>>> {
>>>>>> - pgd_t *pgd;
>>>>>> - p4d_t *p4d;
>>>>>> + pgd_t *pgd = pgd_offset_k(addr);
>>>>>> + p4d_t *p4d = p4d_offset(pgd, addr);
>>>>>> pud_t *pud;
>>>>>> pmd_t *pmd;
>>>>>>
>>>>>> - pgd = pgd_offset_k(addr);
>>>>>> - p4d = p4d_offset(pgd, addr);
>>>>>> -
>>>>>> - if (pgd_none(*pgd)) {
>>>>>> - pud_t *new __maybe_unused;
>>>>>> -
>>>>>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
>>>>>> - pgd_populate(&init_mm, pgd, new);
>>>>>> + if (p4d_none(*p4d)) {
>>>>>> + pud = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>>>>>> + if (!pud)
>>>>>> + goto err_alloc;
>>>>>> + p4d_populate(&init_mm, p4d, pud);
>>>>>> #ifndef __PAGETABLE_PUD_FOLDED
>>>>>> - pud_init(new);
>>>>>> + pud_init(pud);
>>>>>> #endif
>>>>>> }
>>>>>>
>>>>>> pud = pud_offset(p4d, addr);
>>>>>> if (pud_none(*pud)) {
>>>>>> - pmd_t *new __maybe_unused;
>>>>>> -
>>>>>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
>>>>>> - pud_populate(&init_mm, pud, new);
>>>>>> + pmd = memblock_alloc_raw(PAGE_SIZE, PAGE_SIZE);
>>>>>> + if (!pmd)
>>>>>> + goto err_alloc;
>>>>>> + pud_populate(&init_mm, pud, pmd);
>>>>>> #ifndef __PAGETABLE_PMD_FOLDED
>>>>>> - pmd_init(new);
>>>>>> + pmd_init(pmd);
>>>>>> #endif
>>>>>> }
>>>>>>
>>>>>> pmd = pmd_offset(pud, addr);
>>>>>> - if (pmd_none(*pmd)) {
>>>>>> - pte_t *new __maybe_unused;
>>>>>> + if (!pmd_present(*pmd)) {
>>>>>> + pte_t *pte;
>>>>>>
>>>>>> - new = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
>>>>>> - pmd_populate_kernel(&init_mm, pmd, new);
>>>>>> + pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
>>>>> I don't think memblock_alloc_low() here can be replaced by memblock_alloc().
>>>> Can you share me the points that pte table must be allocated with memblock_alloc_low
>>>> in this place?
>>> I forget the reason now, so if you confirm memblock_alloc() works well
>>> here, you can use it. But please don't use memblock_alloc_raw().
>> what a mess, there is more comments if there is special reason, else everyone can
>> forgot by elapsed time.
>>
>> why the function memblock_alloc_raw can not be use? there is one useless page copy.
> This is not a performance critical path, keeping consistency with
> mm/percpu.c can make life easier.
yes, it is not critical path, it influences boot speed. Can we make it better? else it
will be just so so.
Regards
Bibo Mao
>
> Huacai
>
>>
>> Regards
>> Bibo Mao
>>
>>
>>>
>>> Huacai
>>>>
>>>> Regards
>>>> Bibo Mao
>>>>>
>>>>>
>>>>> Huacai
>>>>>> + if (!pte)
>>>>>> + goto err_alloc;
>>>>>> + pmd_populate_kernel(&init_mm, pmd, pte);
>>>>>> }
>>>>>>
>>>>>> return pte_offset_kernel(pmd, addr);
>>>>>> +
>>>>>> +err_alloc:
>>>>>> + panic("%s: Failed to allocate memory\n", __func__);
>>>>>> + return NULL;
>>>>>> }
>>>>>>
>>>>>> void __init __set_fixmap(enum fixed_addresses idx,
>>>>>> @@ -241,7 +244,12 @@ void __init __set_fixmap(enum fixed_addresses idx,
>>>>>>
>>>>>> BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
>>>>>>
>>>>>> - ptep = fixmap_pte(addr);
>>>>>> + /*
>>>>>> + * Now only FIX_EARLYCON_MEM_BASE fixed map is used
>>>>>> + * __set_fixmap must be called before mem_init since function
>>>>>> + * populate_kernel_pte allocates memory with memblock_alloc method.
>>>>>> + */
>>>>>> + ptep = populate_kernel_pte(addr);
>>>>>> if (!pte_none(*ptep)) {
>>>>>> pte_ERROR(*ptep);
>>>>>> return;
>>>>>> --
>>>>>> 2.27.0
>>>>>>
>>>>
>>>>
>>
>>
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