Alexandre Ghiti <alexghiti@xxxxxxxxxxxx> writes:
> On Tue, May 14, 2024 at 4:05 PM Björn Töpel <bjorn@xxxxxxxxxx> wrote:
>>
>> From: Björn Töpel <bjorn@xxxxxxxxxxxx>
>>
>> Prepare for memory hotplugging support by changing from __init to
>> __meminit for the page table functions that are used by the upcoming
>> architecture specific callbacks.
>>
>> Changing the __init attribute to __meminit, avoids that the functions
>> are removed after init. The __meminit attribute makes sure the
>> functions are kept in the kernel text post init, but only if memory
>> hotplugging is enabled for the build.
>>
>> Also, make sure that the altmap parameter is properly passed on to
>> vmemmap_populate_hugepages().
>>
>> Signed-off-by: Björn Töpel <bjorn@xxxxxxxxxxxx>
>> ---
>> arch/riscv/include/asm/mmu.h | 4 +--
>> arch/riscv/include/asm/pgtable.h | 2 +-
>> arch/riscv/mm/init.c | 58 ++++++++++++++------------------
>> 3 files changed, 29 insertions(+), 35 deletions(-)
>>
>> diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h
>> index 60be458e94da..c09c3c79f496 100644
>> --- a/arch/riscv/include/asm/mmu.h
>> +++ b/arch/riscv/include/asm/mmu.h
>> @@ -28,8 +28,8 @@ typedef struct {
>> #endif
>> } mm_context_t;
>>
>> -void __init create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa,
>> - phys_addr_t sz, pgprot_t prot);
>> +void __meminit create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
>> + pgprot_t prot);
>> #endif /* __ASSEMBLY__ */
>>
>> #endif /* _ASM_RISCV_MMU_H */
>> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
>> index 58fd7b70b903..7933f493db71 100644
>> --- a/arch/riscv/include/asm/pgtable.h
>> +++ b/arch/riscv/include/asm/pgtable.h
>> @@ -162,7 +162,7 @@ struct pt_alloc_ops {
>> #endif
>> };
>>
>> -extern struct pt_alloc_ops pt_ops __initdata;
>> +extern struct pt_alloc_ops pt_ops __meminitdata;
>>
>> #ifdef CONFIG_MMU
>> /* Number of PGD entries that a user-mode program can use */
>> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
>> index 5b8cdfafb52a..c969427eab88 100644
>> --- a/arch/riscv/mm/init.c
>> +++ b/arch/riscv/mm/init.c
>> @@ -295,7 +295,7 @@ static void __init setup_bootmem(void)
>> }
>>
>> #ifdef CONFIG_MMU
>> -struct pt_alloc_ops pt_ops __initdata;
>> +struct pt_alloc_ops pt_ops __meminitdata;
>>
>> pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
>> pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
>> @@ -357,7 +357,7 @@ static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
>> return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
>> }
>>
>> -static inline pte_t *__init get_pte_virt_late(phys_addr_t pa)
>> +static inline pte_t *__meminit get_pte_virt_late(phys_addr_t pa)
>> {
>> return (pte_t *) __va(pa);
>> }
>> @@ -376,7 +376,7 @@ static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
>> return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
>> }
>>
>> -static phys_addr_t __init alloc_pte_late(uintptr_t va)
>> +static phys_addr_t __meminit alloc_pte_late(uintptr_t va)
>> {
>> struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
>>
>> @@ -384,9 +384,8 @@ static phys_addr_t __init alloc_pte_late(uintptr_t va)
>> return __pa((pte_t *)ptdesc_address(ptdesc));
>> }
>>
>> -static void __init create_pte_mapping(pte_t *ptep,
>> - uintptr_t va, phys_addr_t pa,
>> - phys_addr_t sz, pgprot_t prot)
>> +static void __meminit create_pte_mapping(pte_t *ptep, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
>> + pgprot_t prot)
>> {
>> uintptr_t pte_idx = pte_index(va);
>>
>> @@ -440,7 +439,7 @@ static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
>> return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
>> }
>>
>> -static pmd_t *__init get_pmd_virt_late(phys_addr_t pa)
>> +static pmd_t *__meminit get_pmd_virt_late(phys_addr_t pa)
>> {
>> return (pmd_t *) __va(pa);
>> }
>> @@ -457,7 +456,7 @@ static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
>> return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
>> }
>>
>> -static phys_addr_t __init alloc_pmd_late(uintptr_t va)
>> +static phys_addr_t __meminit alloc_pmd_late(uintptr_t va)
>> {
>> struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
>>
>> @@ -465,9 +464,9 @@ static phys_addr_t __init alloc_pmd_late(uintptr_t va)
>> return __pa((pmd_t *)ptdesc_address(ptdesc));
>> }
>>
>> -static void __init create_pmd_mapping(pmd_t *pmdp,
>> - uintptr_t va, phys_addr_t pa,
>> - phys_addr_t sz, pgprot_t prot)
>> +static void __meminit create_pmd_mapping(pmd_t *pmdp,
>> + uintptr_t va, phys_addr_t pa,
>> + phys_addr_t sz, pgprot_t prot)
>> {
>> pte_t *ptep;
>> phys_addr_t pte_phys;
>> @@ -503,7 +502,7 @@ static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa)
>> return (pud_t *)set_fixmap_offset(FIX_PUD, pa);
>> }
>>
>> -static pud_t *__init get_pud_virt_late(phys_addr_t pa)
>> +static pud_t *__meminit get_pud_virt_late(phys_addr_t pa)
>> {
>> return (pud_t *)__va(pa);
>> }
>> @@ -521,7 +520,7 @@ static phys_addr_t __init alloc_pud_fixmap(uintptr_t va)
>> return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
>> }
>>
>> -static phys_addr_t alloc_pud_late(uintptr_t va)
>> +static phys_addr_t __meminit alloc_pud_late(uintptr_t va)
>> {
>> unsigned long vaddr;
>>
>> @@ -541,7 +540,7 @@ static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa)
>> return (p4d_t *)set_fixmap_offset(FIX_P4D, pa);
>> }
>>
>> -static p4d_t *__init get_p4d_virt_late(phys_addr_t pa)
>> +static p4d_t *__meminit get_p4d_virt_late(phys_addr_t pa)
>> {
>> return (p4d_t *)__va(pa);
>> }
>> @@ -559,7 +558,7 @@ static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va)
>> return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
>> }
>>
>> -static phys_addr_t alloc_p4d_late(uintptr_t va)
>> +static phys_addr_t __meminit alloc_p4d_late(uintptr_t va)
>> {
>> unsigned long vaddr;
>>
>> @@ -568,9 +567,8 @@ static phys_addr_t alloc_p4d_late(uintptr_t va)
>> return __pa(vaddr);
>> }
>>
>> -static void __init create_pud_mapping(pud_t *pudp,
>> - uintptr_t va, phys_addr_t pa,
>> - phys_addr_t sz, pgprot_t prot)
>> +static void __meminit create_pud_mapping(pud_t *pudp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
>> + pgprot_t prot)
>> {
>> pmd_t *nextp;
>> phys_addr_t next_phys;
>> @@ -595,9 +593,8 @@ static void __init create_pud_mapping(pud_t *pudp,
>> create_pmd_mapping(nextp, va, pa, sz, prot);
>> }
>>
>> -static void __init create_p4d_mapping(p4d_t *p4dp,
>> - uintptr_t va, phys_addr_t pa,
>> - phys_addr_t sz, pgprot_t prot)
>> +static void __meminit create_p4d_mapping(p4d_t *p4dp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
>> + pgprot_t prot)
>> {
>> pud_t *nextp;
>> phys_addr_t next_phys;
>> @@ -653,9 +650,8 @@ static void __init create_p4d_mapping(p4d_t *p4dp,
>> #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
>> #endif /* __PAGETABLE_PMD_FOLDED */
>>
>> -void __init create_pgd_mapping(pgd_t *pgdp,
>> - uintptr_t va, phys_addr_t pa,
>> - phys_addr_t sz, pgprot_t prot)
>> +void __meminit create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
>> + pgprot_t prot)
>> {
>> pgd_next_t *nextp;
>> phys_addr_t next_phys;
>> @@ -680,8 +676,7 @@ void __init create_pgd_mapping(pgd_t *pgdp,
>> create_pgd_next_mapping(nextp, va, pa, sz, prot);
>> }
>>
>> -static uintptr_t __init best_map_size(phys_addr_t pa, uintptr_t va,
>> - phys_addr_t size)
>> +static uintptr_t __meminit best_map_size(phys_addr_t pa, uintptr_t va, phys_addr_t size)
>> {
>> if (pgtable_l5_enabled &&
>> !(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE)
>> @@ -714,7 +709,7 @@ asmlinkage void __init __copy_data(void)
>> #endif
>>
>> #ifdef CONFIG_STRICT_KERNEL_RWX
>> -static __init pgprot_t pgprot_from_va(uintptr_t va)
>> +static __meminit pgprot_t pgprot_from_va(uintptr_t va)
>> {
>> if (is_va_kernel_text(va))
>> return PAGE_KERNEL_READ_EXEC;
>> @@ -739,7 +734,7 @@ void mark_rodata_ro(void)
>> set_memory_ro);
>> }
>> #else
>> -static __init pgprot_t pgprot_from_va(uintptr_t va)
>> +static __meminit pgprot_t pgprot_from_va(uintptr_t va)
>> {
>> if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
>> return PAGE_KERNEL;
>> @@ -1231,9 +1226,8 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
>> pt_ops_set_fixmap();
>> }
>>
>> -static void __init create_linear_mapping_range(phys_addr_t start,
>> - phys_addr_t end,
>> - uintptr_t fixed_map_size)
>> +static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t end,
>> + uintptr_t fixed_map_size)
>> {
>> phys_addr_t pa;
>> uintptr_t va, map_size;
>> @@ -1435,7 +1429,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
>> * memory hotplug, we are not able to update all the page tables with
>> * the new PMDs.
>> */
>> - return vmemmap_populate_hugepages(start, end, node, NULL);
>> + return vmemmap_populate_hugepages(start, end, node, altmap);
>
> Is this a fix? Does this deserve to be split into another patch then?
It's enablement. The altmap can't be used unless there's ZONE_DEVICE
support AFAIU.
Björn
