From 34536d78068318def0a370462cbc3319e1ca9014 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 19 May 2020 05:49:22 +0000 Subject: [PATCH] powerpc/8xx: Add a function to early map kernel via huge pages Add a function to early map kernel memory using huge pages. For 512k pages, just use standard page table and map in using 512k pages. For 8M pages, create a hugepd table and populate the two PGD entries with it. This function can only be used to create page tables at startup. Once the regular SLAB allocation functions replace memblock functions, this function cannot allocate new pages anymore. However it can still update existing mappings with new protections. hugepd_none() macro is moved into asm/hugetlb.h to be usable outside of mm/hugetlbpage.c early_pte_alloc_kernel() is made visible. _PAGE_HUGE flag is now displayed by ptdump. Signed-off-by: Christophe Leroy [mpe: Change ptdump display to use "huge"] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/68325bcd3b6f93127f7810418a2352c3519066d6.1589866984.git.christophe.leroy@csgroup.eu --- arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h | 5 +++ arch/powerpc/include/asm/pgtable.h | 2 + arch/powerpc/mm/nohash/8xx.c | 52 ++++++++++++++++++++++++ arch/powerpc/mm/pgtable_32.c | 2 +- arch/powerpc/mm/ptdump/8xx.c | 5 +++ arch/powerpc/platforms/Kconfig.cputype | 1 + 6 files changed, 66 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h index 1c7d4693..e752a58 100644 --- a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h @@ -35,6 +35,11 @@ static inline void hugepd_populate(hugepd_t *hpdp, pte_t *new, unsigned int pshi *hpdp = __hugepd(__pa(new) | _PMD_USER | _PMD_PRESENT | _PMD_PAGE_8M); } +static inline void hugepd_populate_kernel(hugepd_t *hpdp, pte_t *new, unsigned int pshift) +{ + *hpdp = __hugepd(__pa(new) | _PMD_PRESENT | _PMD_PAGE_8M); +} + static inline int check_and_get_huge_psize(int shift) { return shift_to_mmu_psize(shift); diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index b1f1d53..961895b 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -107,6 +107,8 @@ unsigned long vmalloc_to_phys(void *vmalloc_addr); void pgtable_cache_add(unsigned int shift); +pte_t *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va); + #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_PPC32) void mark_initmem_nx(void); #else diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c index b735482..72fb75f 100644 --- a/arch/powerpc/mm/nohash/8xx.c +++ b/arch/powerpc/mm/nohash/8xx.c @@ -9,9 +9,11 @@ #include #include +#include #include #include #include +#include #include @@ -55,6 +57,56 @@ unsigned long p_block_mapped(phys_addr_t pa) return 0; } +static pte_t __init *early_hugepd_alloc_kernel(hugepd_t *pmdp, unsigned long va) +{ + if (hpd_val(*pmdp) == 0) { + pte_t *ptep = memblock_alloc(sizeof(pte_basic_t), SZ_4K); + + if (!ptep) + return NULL; + + hugepd_populate_kernel((hugepd_t *)pmdp, ptep, PAGE_SHIFT_8M); + hugepd_populate_kernel((hugepd_t *)pmdp + 1, ptep, PAGE_SHIFT_8M); + } + return hugepte_offset(*(hugepd_t *)pmdp, va, PGDIR_SHIFT); +} + +static int __ref __early_map_kernel_hugepage(unsigned long va, phys_addr_t pa, + pgprot_t prot, int psize, bool new) +{ + pmd_t *pmdp = pmd_ptr_k(va); + pte_t *ptep; + + if (WARN_ON(psize != MMU_PAGE_512K && psize != MMU_PAGE_8M)) + return -EINVAL; + + if (new) { + if (WARN_ON(slab_is_available())) + return -EINVAL; + + if (psize == MMU_PAGE_512K) + ptep = early_pte_alloc_kernel(pmdp, va); + else + ptep = early_hugepd_alloc_kernel((hugepd_t *)pmdp, va); + } else { + if (psize == MMU_PAGE_512K) + ptep = pte_offset_kernel(pmdp, va); + else + ptep = hugepte_offset(*(hugepd_t *)pmdp, va, PGDIR_SHIFT); + } + + if (WARN_ON(!ptep)) + return -ENOMEM; + + /* The PTE should never be already present */ + if (new && WARN_ON(pte_present(*ptep) && pgprot_val(prot))) + return -EINVAL; + + set_huge_pte_at(&init_mm, va, ptep, pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot))); + + return 0; +} + /* * MMU_init_hw does the chip-specific initialization of the MMU hardware. */ diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index bd0cb6e..05902bb 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -61,7 +61,7 @@ static void __init *early_alloc_pgtable(unsigned long size) return ptr; } -static pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va) +pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va) { if (pmd_none(*pmdp)) { pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE); diff --git a/arch/powerpc/mm/ptdump/8xx.c b/arch/powerpc/mm/ptdump/8xx.c index 9e2d8e8..4bc3507 100644 --- a/arch/powerpc/mm/ptdump/8xx.c +++ b/arch/powerpc/mm/ptdump/8xx.c @@ -11,6 +11,11 @@ static const struct flag_info flag_array[] = { { + .mask = _PAGE_HUGE, + .val = _PAGE_HUGE, + .set = "huge", + .clear = " ", + }, { .mask = _PAGE_SH, .val = 0, .set = "user", diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype index b0587b8..404f269 100644 --- a/arch/powerpc/platforms/Kconfig.cputype +++ b/arch/powerpc/platforms/Kconfig.cputype @@ -56,6 +56,7 @@ config PPC_8xx select PPC_HAVE_KUEP select PPC_HAVE_KUAP select HAVE_ARCH_VMAP_STACK + select HUGETLBFS config 40x bool "AMCC 40x" -- 2.7.4