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Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/mm/nohash/8xx.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c new file mode 100644 index 0000000000..a642a79298 --- /dev/null +++ b/arch/powerpc/mm/nohash/8xx.c @@ -0,0 +1,211 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * This file contains the routines for initializing the MMU + * on the 8xx series of chips. + * -- christophe + * + * Derived from arch/powerpc/mm/40x_mmu.c: + */ + +#include <linux/memblock.h> +#include <linux/hugetlb.h> + +#include <mm/mmu_decl.h> + +#define IMMR_SIZE (FIX_IMMR_SIZE << PAGE_SHIFT) + +static unsigned long block_mapped_ram; + +/* + * Return PA for this VA if it is in an area mapped with LTLBs or fixmap. + * Otherwise, returns 0 + */ +phys_addr_t v_block_mapped(unsigned long va) +{ + unsigned long p = PHYS_IMMR_BASE; + + if (va >= VIRT_IMMR_BASE && va < VIRT_IMMR_BASE + IMMR_SIZE) + return p + va - VIRT_IMMR_BASE; + if (va >= PAGE_OFFSET && va < PAGE_OFFSET + block_mapped_ram) + return __pa(va); + return 0; +} + +/* + * Return VA for a given PA mapped with LTLBs or fixmap + * Return 0 if not mapped + */ +unsigned long p_block_mapped(phys_addr_t pa) +{ + unsigned long p = PHYS_IMMR_BASE; + + if (pa >= p && pa < p + IMMR_SIZE) + return VIRT_IMMR_BASE + pa - p; + if (pa < block_mapped_ram) + return (unsigned long)__va(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_off_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)), psize); + + return 0; +} + +/* + * MMU_init_hw does the chip-specific initialization of the MMU hardware. + */ +void __init MMU_init_hw(void) +{ +} + +static bool immr_is_mapped __initdata; + +void __init mmu_mapin_immr(void) +{ + if (immr_is_mapped) + return; + + immr_is_mapped = true; + + __early_map_kernel_hugepage(VIRT_IMMR_BASE, PHYS_IMMR_BASE, + PAGE_KERNEL_NCG, MMU_PAGE_512K, true); +} + +static void mmu_mapin_ram_chunk(unsigned long offset, unsigned long top, + pgprot_t prot, bool new) +{ + unsigned long v = PAGE_OFFSET + offset; + unsigned long p = offset; + + WARN_ON(!IS_ALIGNED(offset, SZ_512K) || !IS_ALIGNED(top, SZ_512K)); + + for (; p < ALIGN(p, SZ_8M) && p < top; p += SZ_512K, v += SZ_512K) + __early_map_kernel_hugepage(v, p, prot, MMU_PAGE_512K, new); + for (; p < ALIGN_DOWN(top, SZ_8M) && p < top; p += SZ_8M, v += SZ_8M) + __early_map_kernel_hugepage(v, p, prot, MMU_PAGE_8M, new); + for (; p < ALIGN_DOWN(top, SZ_512K) && p < top; p += SZ_512K, v += SZ_512K) + __early_map_kernel_hugepage(v, p, prot, MMU_PAGE_512K, new); + + if (!new) + flush_tlb_kernel_range(PAGE_OFFSET + v, PAGE_OFFSET + top); +} + +unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) +{ + unsigned long etext8 = ALIGN(__pa(_etext), SZ_8M); + unsigned long sinittext = __pa(_sinittext); + bool strict_boundary = strict_kernel_rwx_enabled() || debug_pagealloc_enabled_or_kfence(); + unsigned long boundary = strict_boundary ? sinittext : etext8; + unsigned long einittext8 = ALIGN(__pa(_einittext), SZ_8M); + + WARN_ON(top < einittext8); + + mmu_mapin_immr(); + + mmu_mapin_ram_chunk(0, boundary, PAGE_KERNEL_TEXT, true); + if (debug_pagealloc_enabled_or_kfence()) { + top = boundary; + } else { + mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL_TEXT, true); + mmu_mapin_ram_chunk(einittext8, top, PAGE_KERNEL, true); + } + + if (top > SZ_32M) + memblock_set_current_limit(top); + + block_mapped_ram = top; + + return top; +} + +void mmu_mark_initmem_nx(void) +{ + unsigned long etext8 = ALIGN(__pa(_etext), SZ_8M); + unsigned long sinittext = __pa(_sinittext); + unsigned long boundary = strict_kernel_rwx_enabled() ? sinittext : etext8; + unsigned long einittext8 = ALIGN(__pa(_einittext), SZ_8M); + + if (!debug_pagealloc_enabled_or_kfence()) + mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL, false); + + mmu_pin_tlb(block_mapped_ram, false); +} + +#ifdef CONFIG_STRICT_KERNEL_RWX +void mmu_mark_rodata_ro(void) +{ + unsigned long sinittext = __pa(_sinittext); + + mmu_mapin_ram_chunk(0, sinittext, PAGE_KERNEL_ROX, false); + if (IS_ENABLED(CONFIG_PIN_TLB_DATA)) + mmu_pin_tlb(block_mapped_ram, true); +} +#endif + +void __init setup_initial_memory_limit(phys_addr_t first_memblock_base, + phys_addr_t first_memblock_size) +{ + /* We don't currently support the first MEMBLOCK not mapping 0 + * physical on those processors + */ + BUG_ON(first_memblock_base != 0); + + /* 8xx can only access 32MB at the moment */ + memblock_set_current_limit(min_t(u64, first_memblock_size, SZ_32M)); +} + +int pud_clear_huge(pud_t *pud) +{ + return 0; +} + +int pmd_clear_huge(pmd_t *pmd) +{ + return 0; +} |