From 9ad98c5b4461e7dfa3754963200993a68825eab4 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 5 Oct 2005 15:12:00 -0700 Subject: [PATCH] [SPARC64]: Fix initrd when net booting. By allocating early memory for the firmware page tables, we can write over the beginning of the initrd image. So what we do now is: 1) Read in firmware translations table while still on the firmware's trap table. 2) Switch to Linux trap table. 3) Init bootmem. 4) Build firmware page tables using __alloc_bootmem(). And this keeps the initrd from being clobbered. Signed-off-by: David S. Miller --- arch/sparc64/mm/init.c | 156 +++++++++++++++-------------------------- 1 file changed, 56 insertions(+), 100 deletions(-) diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c index 4e2f71e0abc8..0d2e967c7200 100644 --- a/arch/sparc64/mm/init.c +++ b/arch/sparc64/mm/init.c @@ -368,6 +368,7 @@ struct linux_prom_translation { unsigned long data; }; static struct linux_prom_translation prom_trans[512] __initdata; +static unsigned int prom_trans_ents __initdata; extern unsigned long prom_boot_page; extern void prom_remap(unsigned long physpage, unsigned long virtpage, int mmu_ihandle); @@ -381,57 +382,7 @@ unsigned long kern_locked_tte_data; unsigned long prom_pmd_phys __read_mostly; unsigned int swapper_pgd_zero __read_mostly; -/* Allocate power-of-2 aligned chunks from the end of the - * kernel image. Return physical address. - */ -static inline unsigned long early_alloc_phys(unsigned long size) -{ - unsigned long base; - - BUILD_BUG_ON(size & (size - 1)); - - kern_size = (kern_size + (size - 1)) & ~(size - 1); - base = kern_base + kern_size; - kern_size += size; - - return base; -} - -static inline unsigned long load_phys32(unsigned long pa) -{ - unsigned long val; - - __asm__ __volatile__("lduwa [%1] %2, %0" - : "=&r" (val) - : "r" (pa), "i" (ASI_PHYS_USE_EC)); - - return val; -} - -static inline unsigned long load_phys64(unsigned long pa) -{ - unsigned long val; - - __asm__ __volatile__("ldxa [%1] %2, %0" - : "=&r" (val) - : "r" (pa), "i" (ASI_PHYS_USE_EC)); - - return val; -} - -static inline void store_phys32(unsigned long pa, unsigned long val) -{ - __asm__ __volatile__("stwa %0, [%1] %2" - : /* no outputs */ - : "r" (val), "r" (pa), "i" (ASI_PHYS_USE_EC)); -} - -static inline void store_phys64(unsigned long pa, unsigned long val) -{ - __asm__ __volatile__("stxa %0, [%1] %2" - : /* no outputs */ - : "r" (val), "r" (pa), "i" (ASI_PHYS_USE_EC)); -} +static pmd_t *prompmd __read_mostly; #define BASE_PAGE_SIZE 8192 @@ -441,34 +392,28 @@ static inline void store_phys64(unsigned long pa, unsigned long val) */ unsigned long prom_virt_to_phys(unsigned long promva, int *error) { - unsigned long pmd_phys = (prom_pmd_phys + - ((promva >> 23) & 0x7ff) * sizeof(pmd_t)); - unsigned long pte_phys; - pmd_t pmd_ent; - pte_t pte_ent; + pmd_t *pmdp = prompmd + ((promva >> 23) & 0x7ff); + pte_t *ptep; unsigned long base; - pmd_val(pmd_ent) = load_phys32(pmd_phys); - if (pmd_none(pmd_ent)) { + if (pmd_none(*pmdp)) { if (error) *error = 1; return 0; } - - pte_phys = (unsigned long)pmd_val(pmd_ent) << 11UL; - pte_phys += ((promva >> 13) & 0x3ff) * sizeof(pte_t); - pte_val(pte_ent) = load_phys64(pte_phys); - if (!pte_present(pte_ent)) { + ptep = (pte_t *)__pmd_page(*pmdp) + ((promva >> 13) & 0x3ff); + if (!pte_present(*ptep)) { if (error) *error = 1; return 0; } if (error) { *error = 0; - return pte_val(pte_ent); + return pte_val(*ptep); } - base = pte_val(pte_ent) & _PAGE_PADDR; - return (base + (promva & (BASE_PAGE_SIZE - 1))); + base = pte_val(*ptep) & _PAGE_PADDR; + + return base + (promva & (BASE_PAGE_SIZE - 1)); } /* The obp translations are saved based on 8k pagesize, since obp can @@ -481,25 +426,20 @@ static void __init build_obp_range(unsigned long start, unsigned long end, unsig unsigned long vaddr; for (vaddr = start; vaddr < end; vaddr += BASE_PAGE_SIZE) { - unsigned long val, pte_phys, pmd_phys; - pmd_t pmd_ent; - int i; - - pmd_phys = (prom_pmd_phys + - (((vaddr >> 23) & 0x7ff) * sizeof(pmd_t))); - pmd_val(pmd_ent) = load_phys32(pmd_phys); - if (pmd_none(pmd_ent)) { - pte_phys = early_alloc_phys(BASE_PAGE_SIZE); - - for (i = 0; i < BASE_PAGE_SIZE / sizeof(pte_t); i++) - store_phys64(pte_phys+i*sizeof(pte_t),0); + unsigned long val; + pmd_t *pmd; + pte_t *pte; - pmd_val(pmd_ent) = pte_phys >> 11UL; - store_phys32(pmd_phys, pmd_val(pmd_ent)); + pmd = prompmd + ((vaddr >> 23) & 0x7ff); + if (pmd_none(*pmd)) { + pte = __alloc_bootmem(BASE_PAGE_SIZE, BASE_PAGE_SIZE, + PAGE_SIZE); + if (!pte) + prom_halt(); + memset(pte, 0, BASE_PAGE_SIZE); + pmd_set(pmd, pte); } - - pte_phys = (unsigned long)pmd_val(pmd_ent) << 11UL; - pte_phys += (((vaddr >> 13) & 0x3ff) * sizeof(pte_t)); + pte = (pte_t *) __pmd_page(*pmd) + ((vaddr >> 13) & 0x3ff); val = data; @@ -507,7 +447,8 @@ static void __init build_obp_range(unsigned long start, unsigned long end, unsig if (tlb_type == spitfire) val &= ~0x0003fe0000000000UL; - store_phys64(pte_phys, val | _PAGE_MODIFIED); + set_pte_at(&init_mm, vaddr, pte, + __pte(val | _PAGE_MODIFIED)); data += BASE_PAGE_SIZE; } @@ -520,13 +461,17 @@ static inline int in_obp_range(unsigned long vaddr) } #define OBP_PMD_SIZE 2048 -static void __init build_obp_pgtable(int prom_trans_ents) +static void __init build_obp_pgtable(void) { unsigned long i; - prom_pmd_phys = early_alloc_phys(OBP_PMD_SIZE); - for (i = 0; i < OBP_PMD_SIZE; i += 4) - store_phys32(prom_pmd_phys + i, 0); + prompmd = __alloc_bootmem(OBP_PMD_SIZE, OBP_PMD_SIZE, PAGE_SIZE); + if (!prompmd) + prom_halt(); + + memset(prompmd, 0, OBP_PMD_SIZE); + + prom_pmd_phys = __pa(prompmd); for (i = 0; i < prom_trans_ents; i++) { unsigned long start, end; @@ -546,7 +491,7 @@ static void __init build_obp_pgtable(int prom_trans_ents) /* Read OBP translations property into 'prom_trans[]'. * Return the number of entries. */ -static int __init read_obp_translations(void) +static void __init read_obp_translations(void) { int n, node; @@ -567,8 +512,10 @@ static int __init read_obp_translations(void) prom_printf("prom_mappings: Couldn't get property.\n"); prom_halt(); } + n = n / sizeof(struct linux_prom_translation); - return n; + + prom_trans_ents = n; } static void __init remap_kernel(void) @@ -605,19 +552,21 @@ static void __init remap_kernel(void) } } -static void __init inherit_prom_mappings(void) -{ - int n; - n = read_obp_translations(); - build_obp_pgtable(n); +static void __init inherit_prom_mappings_pre(void) +{ + read_obp_translations(); /* Now fixup OBP's idea about where we really are mapped. */ prom_printf("Remapping the kernel... "); remap_kernel(); prom_printf("done.\n"); +} +static void __init inherit_prom_mappings_post(void) +{ + build_obp_pgtable(); register_prom_callbacks(); } @@ -1570,8 +1519,7 @@ void __init paging_init(void) swapper_pgd_zero = pgd_val(swapper_pg_dir[0]); - /* Inherit non-locked OBP mappings. */ - inherit_prom_mappings(); + inherit_prom_mappings_pre(); /* Ok, we can use our TLB miss and window trap handlers safely. * We need to do a quick peek here to see if we are on StarFire @@ -1582,15 +1530,23 @@ void __init paging_init(void) extern void setup_tba(int); setup_tba(this_is_starfire); } - - inherit_locked_prom_mappings(1); - __flush_tlb_all(); + /* Everything from this point forward, until we are done with + * inherit_prom_mappings_post(), must complete successfully + * without calling into the firmware. The firwmare page tables + * have not been built, but we are running on the Linux kernel's + * trap table. + */ + /* Setup bootmem... */ pages_avail = 0; last_valid_pfn = end_pfn = bootmem_init(&pages_avail); + inherit_prom_mappings_post(); + + inherit_locked_prom_mappings(1); + #ifdef CONFIG_DEBUG_PAGEALLOC kernel_physical_mapping_init(); #endif -- 2.20.1