diff options
author | Palmer Dabbelt <palmer@sifive.com> | 2019-03-04 11:41:36 -0800 |
---|---|---|
committer | Palmer Dabbelt <palmer@sifive.com> | 2019-03-04 11:47:04 -0800 |
commit | 13fd5de06514458eb320188b7a815d65696efd99 (patch) | |
tree | faa6d1ce1c20eb3b909ccecf481b865869463083 /arch/riscv/mm/init.c | |
parent | f7ccc35aa3bd728ad8451f4d06e801cfe5c5498c (diff) | |
parent | 823900cd01301c4720b23afa9f3d08036e07245a (diff) |
RISC-V: Fixmap support and MM cleanups
This patchset does:
1. Moves MM related code from kernel/setup.c to mm/init.c
2. Implements compile-time fixed mappings
Using fixed mappings, we get earlyprints even without SBI calls.
For example, we can now use kernel parameter
"earlycon=uart8250,mmio,0x10000000"
to get early prints on QEMU virt machine without using SBI calls.
The patchset is tested on QEMU virt machine.
Palmer: It looks like some of the code movement here conflicted with the
patches to move hartid handling around. As far as I can tell the only
changed code was in smp_setup_processor_id(), and I've kept the one in
smp.c.
Diffstat (limited to 'arch/riscv/mm/init.c')
-rw-r--r-- | arch/riscv/mm/init.c | 156 |
1 files changed, 155 insertions, 1 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 658ebf645f42..b379a75ac6a6 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -17,7 +17,9 @@ #include <linux/initrd.h> #include <linux/swap.h> #include <linux/sizes.h> +#include <linux/of_fdt.h> +#include <asm/fixmap.h> #include <asm/tlbflush.h> #include <asm/sections.h> #include <asm/pgtable.h> @@ -66,7 +68,159 @@ void free_initmem(void) } #ifdef CONFIG_BLK_DEV_INITRD -void free_initrd_mem(unsigned long start, unsigned long end) +static void __init setup_initrd(void) { + unsigned long size; + + if (initrd_start >= initrd_end) { + pr_info("initrd not found or empty"); + goto disable; + } + if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) { + pr_err("initrd extends beyond end of memory"); + goto disable; + } + + size = initrd_end - initrd_start; + memblock_reserve(__pa(initrd_start), size); + initrd_below_start_ok = 1; + + pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n", + (void *)(initrd_start), size); + return; +disable: + pr_cont(" - disabling initrd\n"); + initrd_start = 0; + initrd_end = 0; +} + +void __init free_initrd_mem(unsigned long start, unsigned long end) +{ + free_reserved_area((void *)start, (void *)end, -1, "initrd"); } #endif /* CONFIG_BLK_DEV_INITRD */ + +void __init setup_bootmem(void) +{ + struct memblock_region *reg; + phys_addr_t mem_size = 0; + + /* Find the memory region containing the kernel */ + for_each_memblock(memory, reg) { + phys_addr_t vmlinux_end = __pa(_end); + phys_addr_t end = reg->base + reg->size; + + if (reg->base <= vmlinux_end && vmlinux_end <= end) { + /* + * Reserve from the start of the region to the end of + * the kernel + */ + memblock_reserve(reg->base, vmlinux_end - reg->base); + mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET); + } + } + BUG_ON(mem_size == 0); + + set_max_mapnr(PFN_DOWN(mem_size)); + max_low_pfn = PFN_DOWN(memblock_end_of_DRAM()); + +#ifdef CONFIG_BLK_DEV_INITRD + setup_initrd(); +#endif /* CONFIG_BLK_DEV_INITRD */ + + early_init_fdt_reserve_self(); + early_init_fdt_scan_reserved_mem(); + memblock_allow_resize(); + memblock_dump_all(); + + for_each_memblock(memory, reg) { + unsigned long start_pfn = memblock_region_memory_base_pfn(reg); + unsigned long end_pfn = memblock_region_memory_end_pfn(reg); + + memblock_set_node(PFN_PHYS(start_pfn), + PFN_PHYS(end_pfn - start_pfn), + &memblock.memory, 0); + } +} + +pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; +pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); + +#ifndef __PAGETABLE_PMD_FOLDED +#define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT) +pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss; +pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); +pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; +#endif + +pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; + +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *ptep; + + BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); + + ptep = &fixmap_pte[pte_index(addr)]; + + if (pgprot_val(prot)) { + set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot)); + } else { + pte_clear(&init_mm, addr, ptep); + local_flush_tlb_page(addr); + } +} + +asmlinkage void __init setup_vm(void) +{ + extern char _start; + uintptr_t i; + uintptr_t pa = (uintptr_t) &_start; + pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC); + + va_pa_offset = PAGE_OFFSET - pa; + pfn_base = PFN_DOWN(pa); + + /* Sanity check alignment and size */ + BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); + BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0); + +#ifndef __PAGETABLE_PMD_FOLDED + trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] = + pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd), + __pgprot(_PAGE_TABLE)); + trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot); + + for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) { + size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i; + + swapper_pg_dir[o] = + pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i, + __pgprot(_PAGE_TABLE)); + } + for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++) + swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot); + + swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] = + pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pmd), + __pgprot(_PAGE_TABLE)); + fixmap_pmd[(FIXADDR_START >> PMD_SHIFT) % PTRS_PER_PMD] = + pfn_pmd(PFN_DOWN((uintptr_t)fixmap_pte), + __pgprot(_PAGE_TABLE)); +#else + trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] = + pfn_pgd(PFN_DOWN(pa), prot); + + for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) { + size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i; + + swapper_pg_dir[o] = + pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot); + } + + swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] = + pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte), + __pgprot(_PAGE_TABLE)); +#endif +} |