diff options
Diffstat (limited to 'arch/arm26/mm')
| -rw-r--r-- | arch/arm26/mm/Makefile | 6 | ||||
| -rw-r--r-- | arch/arm26/mm/extable.c | 25 | ||||
| -rw-r--r-- | arch/arm26/mm/fault.c | 318 | ||||
| -rw-r--r-- | arch/arm26/mm/fault.h | 5 | ||||
| -rw-r--r-- | arch/arm26/mm/init.c | 412 | ||||
| -rw-r--r-- | arch/arm26/mm/memc.c | 202 | ||||
| -rw-r--r-- | arch/arm26/mm/proc-funcs.S | 359 | ||||
| -rw-r--r-- | arch/arm26/mm/small_page.c | 194 |
8 files changed, 1521 insertions, 0 deletions
diff --git a/arch/arm26/mm/Makefile b/arch/arm26/mm/Makefile new file mode 100644 index 000000000000..a8fb166d5c6d --- /dev/null +++ b/arch/arm26/mm/Makefile @@ -0,0 +1,6 @@ +# +# Makefile for the linux arm26-specific parts of the memory manager. +# + +obj-y := init.o extable.o proc-funcs.o memc.o fault.o \ + small_page.o diff --git a/arch/arm26/mm/extable.c b/arch/arm26/mm/extable.c new file mode 100644 index 000000000000..2d9f5b5a78d6 --- /dev/null +++ b/arch/arm26/mm/extable.c @@ -0,0 +1,25 @@ +/* + * linux/arch/arm26/mm/extable.c + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <asm/uaccess.h> + +int fixup_exception(struct pt_regs *regs) +{ + const struct exception_table_entry *fixup; + + fixup = search_exception_tables(instruction_pointer(regs)); + + /* + * The kernel runs in SVC mode - make sure we keep running in SVC mode + * by frobbing the PSR appropriately (PSR and PC are in the same reg. + * on ARM26) + */ + if (fixup) + regs->ARM_pc = fixup->fixup | PSR_I_BIT | MODE_SVC26; + + return fixup != NULL; +} + diff --git a/arch/arm26/mm/fault.c b/arch/arm26/mm/fault.c new file mode 100644 index 000000000000..dacca8bb7744 --- /dev/null +++ b/arch/arm26/mm/fault.c @@ -0,0 +1,318 @@ +/* + * linux/arch/arm26/mm/fault.c + * + * Copyright (C) 1995 Linus Torvalds + * Modifications for ARM processor (c) 1995-2001 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/config.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/ptrace.h> +#include <linux/mman.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/proc_fs.h> +#include <linux/init.h> + +#include <asm/system.h> +#include <asm/pgtable.h> +#include <asm/uaccess.h> //FIXME this header may be bogusly included + +#include "fault.h" + +#define FAULT_CODE_LDRSTRPOST 0x80 +#define FAULT_CODE_LDRSTRPRE 0x40 +#define FAULT_CODE_LDRSTRREG 0x20 +#define FAULT_CODE_LDMSTM 0x10 +#define FAULT_CODE_LDCSTC 0x08 +#define FAULT_CODE_PREFETCH 0x04 +#define FAULT_CODE_WRITE 0x02 +#define FAULT_CODE_FORCECOW 0x01 + +#define DO_COW(m) ((m) & (FAULT_CODE_WRITE|FAULT_CODE_FORCECOW)) +#define READ_FAULT(m) (!((m) & FAULT_CODE_WRITE)) +#define DEBUG +/* + * This is useful to dump out the page tables associated with + * 'addr' in mm 'mm'. + */ +void show_pte(struct mm_struct *mm, unsigned long addr) +{ + pgd_t *pgd; + + if (!mm) + mm = &init_mm; + + printk(KERN_ALERT "pgd = %p\n", mm->pgd); + pgd = pgd_offset(mm, addr); + printk(KERN_ALERT "[%08lx] *pgd=%08lx", addr, pgd_val(*pgd)); + + do { + pmd_t *pmd; + pte_t *pte; + + pmd = pmd_offset(pgd, addr); + + if (pmd_none(*pmd)) + break; + + if (pmd_bad(*pmd)) { + printk("(bad)"); + break; + } + + /* We must not map this if we have highmem enabled */ + /* FIXME */ + pte = pte_offset_map(pmd, addr); + printk(", *pte=%08lx", pte_val(*pte)); + pte_unmap(pte); + } while(0); + + printk("\n"); +} + +/* + * Oops. The kernel tried to access some page that wasn't present. + */ +static void +__do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, + struct pt_regs *regs) +{ + /* + * Are we prepared to handle this kernel fault? + */ + if (fixup_exception(regs)) + return; + + /* + * No handler, we'll have to terminate things with extreme prejudice. + */ + bust_spinlocks(1); + printk(KERN_ALERT + "Unable to handle kernel %s at virtual address %08lx\n", + (addr < PAGE_SIZE) ? "NULL pointer dereference" : + "paging request", addr); + + show_pte(mm, addr); + die("Oops", regs, fsr); + bust_spinlocks(0); + do_exit(SIGKILL); +} + +/* + * Something tried to access memory that isn't in our memory map.. + * User mode accesses just cause a SIGSEGV + */ +static void +__do_user_fault(struct task_struct *tsk, unsigned long addr, + unsigned int fsr, int code, struct pt_regs *regs) +{ + struct siginfo si; + +#ifdef CONFIG_DEBUG_USER + printk("%s: unhandled page fault at 0x%08lx, code 0x%03x\n", + tsk->comm, addr, fsr); + show_pte(tsk->mm, addr); + show_regs(regs); + //dump_backtrace(regs, tsk); // FIXME ARM32 dropped this - why? + while(1); //FIXME - hack to stop debug going nutso +#endif + + tsk->thread.address = addr; + tsk->thread.error_code = fsr; + tsk->thread.trap_no = 14; + si.si_signo = SIGSEGV; + si.si_errno = 0; + si.si_code = code; + si.si_addr = (void *)addr; + force_sig_info(SIGSEGV, &si, tsk); +} + +static int +__do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, + struct task_struct *tsk) +{ + struct vm_area_struct *vma; + int fault, mask; + + vma = find_vma(mm, addr); + fault = -2; /* bad map area */ + if (!vma) + goto out; + if (vma->vm_start > addr) + goto check_stack; + + /* + * Ok, we have a good vm_area for this + * memory access, so we can handle it. + */ +good_area: + if (READ_FAULT(fsr)) /* read? */ + mask = VM_READ|VM_EXEC; + else + mask = VM_WRITE; + + fault = -1; /* bad access type */ + if (!(vma->vm_flags & mask)) + goto out; + + /* + * If for any reason at all we couldn't handle + * the fault, make sure we exit gracefully rather + * than endlessly redo the fault. + */ +survive: + fault = handle_mm_fault(mm, vma, addr & PAGE_MASK, DO_COW(fsr)); + + /* + * Handle the "normal" cases first - successful and sigbus + */ + switch (fault) { + case 2: + tsk->maj_flt++; + return fault; + case 1: + tsk->min_flt++; + case 0: + return fault; + } + + fault = -3; /* out of memory */ + if (tsk->pid != 1) + goto out; + + /* + * If we are out of memory for pid1, + * sleep for a while and retry + */ + yield(); + goto survive; + +check_stack: + if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) + goto good_area; +out: + return fault; +} + +int do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) +{ + struct task_struct *tsk; + struct mm_struct *mm; + int fault; + + tsk = current; + mm = tsk->mm; + + /* + * If we're in an interrupt or have no user + * context, we must not take the fault.. + */ + if (in_interrupt() || !mm) + goto no_context; + + down_read(&mm->mmap_sem); + fault = __do_page_fault(mm, addr, fsr, tsk); + up_read(&mm->mmap_sem); + + /* + * Handle the "normal" case first + */ + if (fault > 0) + return 0; + + /* + * We had some memory, but were unable to + * successfully fix up this page fault. + */ + if (fault == 0){ + goto do_sigbus; + } + + /* + * If we are in kernel mode at this point, we + * have no context to handle this fault with. + * FIXME - is this test right? + */ + if (!user_mode(regs)){ + goto no_context; + } + + if (fault == -3) { + /* + * We ran out of memory, or some other thing happened to + * us that made us unable to handle the page fault gracefully. + */ + printk("VM: killing process %s\n", tsk->comm); + do_exit(SIGKILL); + } + else{ + __do_user_fault(tsk, addr, fsr, fault == -1 ? SEGV_ACCERR : SEGV_MAPERR, regs); + } + + return 0; + + +/* + * We ran out of memory, or some other thing happened to us that made + * us unable to handle the page fault gracefully. + */ +do_sigbus: + /* + * Send a sigbus, regardless of whether we were in kernel + * or user mode. + */ + tsk->thread.address = addr; //FIXME - need other bits setting? + tsk->thread.error_code = fsr; + tsk->thread.trap_no = 14; + force_sig(SIGBUS, tsk); +#ifdef CONFIG_DEBUG_USER + printk(KERN_DEBUG "%s: sigbus at 0x%08lx, pc=0x%08lx\n", + current->comm, addr, instruction_pointer(regs)); +#endif + + /* Kernel mode? Handle exceptions or die */ + if (user_mode(regs)) + return 0; + +no_context: + __do_kernel_fault(mm, addr, fsr, regs); + return 0; +} + +/* + * Handle a data abort. Note that we have to handle a range of addresses + * on ARM2/3 for ldm. If both pages are zero-mapped, then we have to force + * a copy-on-write. However, on the second page, we always force COW. + */ +asmlinkage void +do_DataAbort(unsigned long min_addr, unsigned long max_addr, int mode, struct pt_regs *regs) +{ + do_page_fault(min_addr, mode, regs); + + if ((min_addr ^ max_addr) >> PAGE_SHIFT){ + do_page_fault(max_addr, mode | FAULT_CODE_FORCECOW, regs); + } +} + +asmlinkage int +do_PrefetchAbort(unsigned long addr, struct pt_regs *regs) +{ +#if 0 + if (the memc mapping for this page exists) { + printk ("Page in, but got abort (undefined instruction?)\n"); + return 0; + } +#endif + do_page_fault(addr, FAULT_CODE_PREFETCH, regs); + return 1; +} + diff --git a/arch/arm26/mm/fault.h b/arch/arm26/mm/fault.h new file mode 100644 index 000000000000..4442d00d86ac --- /dev/null +++ b/arch/arm26/mm/fault.h @@ -0,0 +1,5 @@ +void show_pte(struct mm_struct *mm, unsigned long addr); + +int do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs); + +unsigned long search_extable(unsigned long addr); //FIXME - is it right? diff --git a/arch/arm26/mm/init.c b/arch/arm26/mm/init.c new file mode 100644 index 000000000000..1f09a9d0fb83 --- /dev/null +++ b/arch/arm26/mm/init.c @@ -0,0 +1,412 @@ +/* + * linux/arch/arm26/mm/init.c + * + * Copyright (C) 1995-2002 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/config.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/ptrace.h> +#include <linux/mman.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/smp.h> +#include <linux/init.h> +#include <linux/initrd.h> +#include <linux/bootmem.h> +#include <linux/blkdev.h> + +#include <asm/segment.h> +#include <asm/mach-types.h> +#include <asm/dma.h> +#include <asm/hardware.h> +#include <asm/setup.h> +#include <asm/tlb.h> + +#include <asm/map.h> + + +#define TABLE_SIZE PTRS_PER_PTE * sizeof(pte_t)) + +struct mmu_gather mmu_gathers[NR_CPUS]; + +extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; +extern char _stext, _text, _etext, _end, __init_begin, __init_end; +#ifdef CONFIG_XIP_KERNEL +extern char _endtext, _sdata; +#endif +extern unsigned long phys_initrd_start; +extern unsigned long phys_initrd_size; + +/* + * The sole use of this is to pass memory configuration + * data from paging_init to mem_init. + */ +static struct meminfo meminfo __initdata = { 0, }; + +/* + * empty_zero_page is a special page that is used for + * zero-initialized data and COW. + */ +struct page *empty_zero_page; + +void show_mem(void) +{ + int free = 0, total = 0, reserved = 0; + int shared = 0, cached = 0, slab = 0; + struct page *page, *end; + + printk("Mem-info:\n"); + show_free_areas(); + printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); + + + page = NODE_MEM_MAP(0); + end = page + NODE_DATA(0)->node_spanned_pages; + + do { + total++; + if (PageReserved(page)) + reserved++; + else if (PageSwapCache(page)) + cached++; + else if (PageSlab(page)) + slab++; + else if (!page_count(page)) + free++; + else + shared += page_count(page) - 1; + page++; + } while (page < end); + + printk("%d pages of RAM\n", total); + printk("%d free pages\n", free); + printk("%d reserved pages\n", reserved); + printk("%d slab pages\n", slab); + printk("%d pages shared\n", shared); + printk("%d pages swap cached\n", cached); +} + +struct node_info { + unsigned int start; + unsigned int end; + int bootmap_pages; +}; + +#define PFN_DOWN(x) ((x) >> PAGE_SHIFT) +#define PFN_UP(x) (PAGE_ALIGN(x) >> PAGE_SHIFT) +#define PFN_SIZE(x) ((x) >> PAGE_SHIFT) +#define PFN_RANGE(s,e) PFN_SIZE(PAGE_ALIGN((unsigned long)(e)) - \ + (((unsigned long)(s)) & PAGE_MASK)) + +/* + * FIXME: We really want to avoid allocating the bootmap bitmap + * over the top of the initrd. Hopefully, this is located towards + * the start of a bank, so if we allocate the bootmap bitmap at + * the end, we won't clash. + */ +static unsigned int __init +find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages) +{ + unsigned int start_pfn, bootmap_pfn; + unsigned int start, end; + + start_pfn = PFN_UP((unsigned long)&_end); + bootmap_pfn = 0; + + /* ARM26 machines only have one node */ + if (mi->bank->node != 0) + BUG(); + + start = PFN_UP(mi->bank->start); + end = PFN_DOWN(mi->bank->size + mi->bank->start); + + if (start < start_pfn) + start = start_pfn; + + if (end <= start) + BUG(); + + if (end - start >= bootmap_pages) + bootmap_pfn = start; + else + BUG(); + + return bootmap_pfn; +} + +/* + * Scan the memory info structure and pull out: + * - the end of memory + * - the number of nodes + * - the pfn range of each node + * - the number of bootmem bitmap pages + */ +static void __init +find_memend_and_nodes(struct meminfo *mi, struct node_info *np) +{ + unsigned int memend_pfn = 0; + + nodes_clear(node_online_map); + node_set_online(0); + + np->bootmap_pages = 0; + + if (mi->bank->size == 0) { + BUG(); + } + + /* + * Get the start and end pfns for this bank + */ + np->start = PFN_UP(mi->bank->start); + np->end = PFN_DOWN(mi->bank->start + mi->bank->size); + + if (memend_pfn < np->end) + memend_pfn = np->end; + + /* + * Calculate the number of pages we require to + * store the bootmem bitmaps. + */ + np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start); + + /* + * This doesn't seem to be used by the Linux memory + * manager any more. If we can get rid of it, we + * also get rid of some of the stuff above as well. + */ + max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET); + max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET); + mi->end = memend_pfn << PAGE_SHIFT; + +} + +/* + * Initialise the bootmem allocator for all nodes. This is called + * early during the architecture specific initialisation. + */ +void __init bootmem_init(struct meminfo *mi) +{ + struct node_info node_info; + unsigned int bootmap_pfn; + pg_data_t *pgdat = NODE_DATA(0); + + find_memend_and_nodes(mi, &node_info); + + bootmap_pfn = find_bootmap_pfn(mi, node_info.bootmap_pages); + + /* + * Note that node 0 must always have some pages. + */ + if (node_info.end == 0) + BUG(); + + /* + * Initialise the bootmem allocator. + */ + init_bootmem_node(pgdat, bootmap_pfn, node_info.start, node_info.end); + + /* + * Register all available RAM in this node with the bootmem allocator. + */ + free_bootmem_node(pgdat, mi->bank->start, mi->bank->size); + + /* + * Register the kernel text and data with bootmem. + * Note: with XIP we dont register .text since + * its in ROM. + */ +#ifdef CONFIG_XIP_KERNEL + reserve_bootmem_node(pgdat, __pa(&_sdata), &_end - &_sdata); +#else + reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext); +#endif + + /* + * And don't forget to reserve the allocator bitmap, + * which will be freed later. + */ + reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT, + node_info.bootmap_pages << PAGE_SHIFT); + + /* + * These should likewise go elsewhere. They pre-reserve + * the screen memory region at the start of main system + * memory. FIXME - screen RAM is not 512K! + */ + reserve_bootmem_node(pgdat, 0x02000000, 0x00080000); + +#ifdef CONFIG_BLK_DEV_INITRD + initrd_start = phys_initrd_start; + initrd_end = initrd_start + phys_initrd_size; + + /* Achimedes machines only have one node, so initrd is in node 0 */ +#ifdef CONFIG_XIP_KERNEL + /* Only reserve initrd space if it is in RAM */ + if(initrd_start && initrd_start < 0x03000000){ +#else + if(initrd_start){ +#endif + reserve_bootmem_node(pgdat, __pa(initrd_start), + initrd_end - initrd_start); + } +#endif /* CONFIG_BLK_DEV_INITRD */ + + +} + +/* + * paging_init() sets up the page tables, initialises the zone memory + * maps, and sets up the zero page, bad page and bad page tables. + */ +void __init paging_init(struct meminfo *mi) +{ + void *zero_page; + unsigned long zone_size[MAX_NR_ZONES]; + unsigned long zhole_size[MAX_NR_ZONES]; + struct bootmem_data *bdata; + pg_data_t *pgdat; + int i; + + memcpy(&meminfo, mi, sizeof(meminfo)); + + /* + * allocate the zero page. Note that we count on this going ok. + */ + zero_page = alloc_bootmem_low_pages(PAGE_SIZE); + + /* + * initialise the page tables. + */ + memtable_init(mi); + flush_tlb_all(); + + /* + * initialise the zones in node 0 (archimedes have only 1 node) + */ + + for (i = 0; i < MAX_NR_ZONES; i++) { + zone_size[i] = 0; + zhole_size[i] = 0; + } + + pgdat = NODE_DATA(0); + bdata = pgdat->bdata; + zone_size[0] = bdata->node_low_pfn - + (bdata->node_boot_start >> PAGE_SHIFT); + if (!zone_size[0]) + BUG(); + pgdat->node_mem_map = NULL; + free_area_init_node(0, pgdat, zone_size, + bdata->node_boot_start >> PAGE_SHIFT, zhole_size); + + /* + * finish off the bad pages once + * the mem_map is initialised + */ + memzero(zero_page, PAGE_SIZE); + empty_zero_page = virt_to_page(zero_page); +} + +static inline void free_area(unsigned long addr, unsigned long end, char *s) +{ + unsigned int size = (end - addr) >> 10; + + for (; addr < end; addr += PAGE_SIZE) { + struct page *page = virt_to_page(addr); + ClearPageReserved(page); + set_page_count(page, 1); + free_page(addr); + totalram_pages++; + } + + if (size && s) + printk(KERN_INFO "Freeing %s memory: %dK\n", s, size); +} + +/* + * mem_init() marks the free areas in the mem_map and tells us how much + * memory is free. This is done after various parts of the system have + * claimed their memory after the kernel image. + */ +void __init mem_init(void) +{ + unsigned int codepages, datapages, initpages; + pg_data_t *pgdat = NODE_DATA(0); + extern int sysctl_overcommit_memory; + + + /* Note: data pages includes BSS */ +#ifdef CONFIG_XIP_KERNEL + codepages = &_endtext - &_text; + datapages = &_end - &_sdata; +#else + codepages = &_etext - &_text; + datapages = &_end - &_etext; +#endif + initpages = &__init_end - &__init_begin; + + high_memory = (void *)__va(meminfo.end); + max_mapnr = virt_to_page(high_memory) - mem_map; + + /* this will put all unused low memory onto the freelists */ + if (pgdat->node_spanned_pages != 0) + totalram_pages += free_all_bootmem_node(pgdat); + + num_physpages = meminfo.bank[0].size >> PAGE_SHIFT; + + printk(KERN_INFO "Memory: %luMB total\n", num_physpages >> (20 - PAGE_SHIFT)); + printk(KERN_NOTICE "Memory: %luKB available (%dK code, " + "%dK data, %dK init)\n", + (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), + codepages >> 10, datapages >> 10, initpages >> 10); + + /* + * Turn on overcommit on tiny machines + */ + if (PAGE_SIZE >= 16384 && num_physpages <= 128) { + sysctl_overcommit_memory = OVERCOMMIT_ALWAYS; + printk("Turning on overcommit\n"); + } +} + +void free_initmem(void){ +#ifndef CONFIG_XIP_KERNEL + free_area((unsigned long)(&__init_begin), + (unsigned long)(&__init_end), + "init"); +#endif +} + +#ifdef CONFIG_BLK_DEV_INITRD + +static int keep_initrd; + +void free_initrd_mem(unsigned long start, unsigned long end) +{ +#ifdef CONFIG_XIP_KERNEL + /* Only bin initrd if it is in RAM... */ + if(!keep_initrd && start < 0x03000000) +#else + if (!keep_initrd) +#endif + free_area(start, end, "initrd"); +} + +static int __init keepinitrd_setup(char *__unused) +{ + keep_initrd = 1; + return 1; +} + +__setup("keepinitrd", keepinitrd_setup); +#endif diff --git a/arch/arm26/mm/memc.c b/arch/arm26/mm/memc.c new file mode 100644 index 000000000000..8e8a2bb2487d --- /dev/null +++ b/arch/arm26/mm/memc.c @@ -0,0 +1,202 @@ +/* + * linux/arch/arm26/mm/memc.c + * + * Copyright (C) 1998-2000 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Page table sludge for older ARM processor architectures. + */ +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/bootmem.h> + +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/page.h> +#include <asm/memory.h> +#include <asm/hardware.h> + +#include <asm/map.h> + +#define MEMC_TABLE_SIZE (256*sizeof(unsigned long)) + +kmem_cache_t *pte_cache, *pgd_cache; +int page_nr; + +/* + * Allocate space for a page table and a MEMC table. + * Note that we place the MEMC + * table before the page directory. This means we can + * easily get to both tightly-associated data structures + * with a single pointer. + */ +static inline pgd_t *alloc_pgd_table(void) +{ + void *pg2k = kmem_cache_alloc(pgd_cache, GFP_KERNEL); + + if (pg2k) + pg2k += MEMC_TABLE_SIZE; + + return (pgd_t *)pg2k; +} + +/* + * Free a page table. this function is the counterpart to get_pgd_slow + * below, not alloc_pgd_table above. + */ +void free_pgd_slow(pgd_t *pgd) +{ + unsigned long tbl = (unsigned long)pgd; + + tbl -= MEMC_TABLE_SIZE; + + kmem_cache_free(pgd_cache, (void *)tbl); +} + +/* + * Allocate a new pgd and fill it in ready for use + * + * A new tasks pgd is completely empty (all pages !present) except for: + * + * o The machine vectors at virtual address 0x0 + * o The vmalloc region at the top of address space + * + */ +#define FIRST_KERNEL_PGD_NR (FIRST_USER_PGD_NR + USER_PTRS_PER_PGD) + +pgd_t *get_pgd_slow(struct mm_struct *mm) +{ + pgd_t *new_pgd, *init_pgd; + pmd_t *new_pmd, *init_pmd; + pte_t *new_pte, *init_pte; + + new_pgd = alloc_pgd_table(); + if (!new_pgd) + goto no_pgd; + + /* + * This lock is here just to satisfy pmd_alloc and pte_lock + * FIXME: I bet we could avoid taking it pretty much altogether + */ + spin_lock(&mm->page_table_lock); + + /* + * On ARM, first page must always be allocated since it contains + * the machine vectors. + */ + new_pmd = pmd_alloc(mm, new_pgd, 0); + if (!new_pmd) + goto no_pmd; + + new_pte = pte_alloc_kernel(mm, new_pmd, 0); + if (!new_pte) + goto no_pte; + + init_pgd = pgd_offset(&init_mm, 0); + init_pmd = pmd_offset(init_pgd, 0); + init_pte = pte_offset(init_pmd, 0); + + set_pte(new_pte, *init_pte); + + /* + * the page table entries are zeroed + * when the table is created. (see the cache_ctor functions below) + * Now we need to plonk the kernel (vmalloc) area at the end of + * the address space. We copy this from the init thread, just like + * the init_pte we copied above... + */ + memcpy(new_pgd + FIRST_KERNEL_PGD_NR, init_pgd + FIRST_KERNEL_PGD_NR, + (PTRS_PER_PGD - FIRST_KERNEL_PGD_NR) * sizeof(pgd_t)); + + spin_unlock(&mm->page_table_lock); + + /* update MEMC tables */ + cpu_memc_update_all(new_pgd); + return new_pgd; + +no_pte: + spin_unlock(&mm->page_table_lock); + pmd_free(new_pmd); + free_pgd_slow(new_pgd); + return NULL; + +no_pmd: + spin_unlock(&mm->page_table_lock); + free_pgd_slow(new_pgd); + return NULL; + +no_pgd: + return NULL; +} + +/* + * No special code is required here. + */ +void setup_mm_for_reboot(char mode) +{ +} + +/* + * This contains the code to setup the memory map on an ARM2/ARM250/ARM3 + * o swapper_pg_dir = 0x0207d000 + * o kernel proper starts at 0x0208000 + * o create (allocate) a pte to contain the machine vectors + * o populate the pte (points to 0x02078000) (FIXME - is it zeroed?) + * o populate the init tasks page directory (pgd) with the new pte + * o zero the rest of the init tasks pgdir (FIXME - what about vmalloc?!) + */ +void __init memtable_init(struct meminfo *mi) +{ + pte_t *pte; + int i; + + page_nr = max_low_pfn; + + pte = alloc_bootmem_low_pages(PTRS_PER_PTE * sizeof(pte_t)); + pte[0] = mk_pte_phys(PAGE_OFFSET + SCREEN_SIZE, PAGE_READONLY); + pmd_populate(&init_mm, pmd_offset(swapper_pg_dir, 0), pte); + + for (i = 1; i < PTRS_PER_PGD; i++) + pgd_val(swapper_pg_dir[i]) = 0; +} + +void __init iotable_init(struct map_desc *io_desc) +{ + /* nothing to do */ +} + +/* + * We never have holes in the memmap + */ +void __init create_memmap_holes(struct meminfo *mi) +{ +} + +static void pte_cache_ctor(void *pte, kmem_cache_t *cache, unsigned long flags) +{ + memzero(pte, sizeof(pte_t) * PTRS_PER_PTE); +} + +static void pgd_cache_ctor(void *pgd, kmem_cache_t *cache, unsigned long flags) +{ + memzero(pgd + MEMC_TABLE_SIZE, USER_PTRS_PER_PGD * sizeof(pgd_t)); +} + +void __init pgtable_cache_init(void) +{ + pte_cache = kmem_cache_create("pte-cache", + sizeof(pte_t) * PTRS_PER_PTE, + 0, 0, pte_cache_ctor, NULL); + if (!pte_cache) + BUG(); + + pgd_cache = kmem_cache_create("pgd-cache", MEMC_TABLE_SIZE + + sizeof(pgd_t) * PTRS_PER_PGD, + 0, 0, pgd_cache_ctor, NULL); + if (!pgd_cache) + BUG(); +} diff --git a/arch/arm26/mm/proc-funcs.S b/arch/arm26/mm/proc-funcs.S new file mode 100644 index 000000000000..c3d4cd3f457e --- /dev/null +++ b/arch/arm26/mm/proc-funcs.S @@ -0,0 +1,359 @@ +/* + * linux/arch/arm26/mm/proc-arm2,3.S + * + * Copyright (C) 1997-1999 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * MMU functions for ARM2,3 + * + * These are the low level assembler for performing cache + * and memory functions on ARM2, ARM250 and ARM3 processors. + */ +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/asm_offsets.h> +#include <asm/procinfo.h> +#include <asm/ptrace.h> + +/* + * MEMC workhorse code. It's both a horse which things it's a pig. + */ +/* + * Function: cpu_memc_update_entry(pgd_t *pgd, unsigned long phys_pte, unsigned long addr) + * Params : pgd Page tables/MEMC mapping + * : phys_pte physical address, or PTE + * : addr virtual address + */ +ENTRY(cpu_memc_update_entry) + tst r1, #PAGE_PRESENT @ is the page present + orreq r1, r1, #PAGE_OLD | PAGE_CLEAN + moveq r2, #0x01f00000 + mov r3, r1, lsr #13 @ convert to physical page nr + and r3, r3, #0x3fc + adr ip, memc_phys_table_32 + ldr r3, [ip, r3] + tst r1, #PAGE_OLD | PAGE_NOT_USER + biceq r3, r3, #0x200 + tsteq r1, #PAGE_READONLY | PAGE_CLEAN + biceq r3, r3, #0x300 + mov r2, r2, lsr #15 @ virtual -> nr + orr r3, r3, r2, lsl #15 + and r2, r2, #0x300 + orr r3, r3, r2, lsl #2 + and r2, r3, #255 + sub r0, r0, #256 * 4 + str r3, [r0, r2, lsl #2] + strb r3, [r3] + movs pc, lr +/* + * Params : r0 = preserved + * : r1 = memc table base (preserved) + * : r2 = page table entry + * : r3 = preserved + * : r4 = unused + * : r5 = memc physical address translation table + * : ip = virtual address (preserved) + */ +update_pte: + mov r4, r2, lsr #13 + and r4, r4, #0x3fc + ldr r4, [r5, r4] @ covert to MEMC page + + tst r2, #PAGE_OLD | PAGE_NOT_USER @ check for MEMC read + biceq r4, r4, #0x200 + tsteq r2, #PAGE_READONLY | PAGE_CLEAN @ check for MEMC write + biceq r4, r4, #0x300 + + orr r4, r4, ip + and r2, ip, #0x01800000 + orr r4, r4, r2, lsr #13 + + and r2, r4, #255 + str r4, [r1, r2, lsl #2] + movs pc, lr + +/* + * Params : r0 = preserved + * : r1 = memc table base (preserved) + * : r2 = page table base + * : r3 = preserved + * : r4 = unused + * : r5 = memc physical address translation table + * : ip = virtual address (updated) + */ +update_pte_table: + stmfd sp!, {r0, lr} + bic r0, r2, #3 +1: ldr r2, [r0], #4 @ get entry + tst r2, #PAGE_PRESENT @ page present + blne update_pte @ process pte + add ip, ip, #32768 @ increment virt addr + ldr r2, [r0], #4 @ get entry + tst r2, #PAGE_PRESENT @ page present + blne update_pte @ process pte + add ip, ip, #32768 @ increment virt addr + ldr r2, [r0], #4 @ get entry + tst r2, #PAGE_PRESENT @ page present + blne update_pte @ process pte + add ip, ip, #32768 @ increment virt addr + ldr r2, [r0], #4 @ get entry + tst r2, #PAGE_PRESENT @ page present + blne update_pte @ process pte + add ip, ip, #32768 @ increment virt addr + tst ip, #32768 * 31 @ finished? + bne 1b + ldmfd sp!, {r0, pc}^ + +/* + * Function: cpu_memc_update_all(pgd_t *pgd) + * Params : pgd Page tables/MEMC mapping + * Notes : this is optimised for 32k pages + */ +ENTRY(cpu_memc_update_all) + stmfd sp!, {r4, r5, lr} + bl clear_tables + sub r1, r0, #256 * 4 @ start of MEMC tables + adr r5, memc_phys_table_32 @ Convert to logical page number + mov ip, #0 @ virtual address +1: ldmia r0!, {r2, r3} @ load two pgd entries + tst r2, #PAGE_PRESENT @ is pgd entry present? + addeq ip, ip, #1048576 @FIXME - PAGE_PRESENT is for PTEs technically... + blne update_pte_table + mov r2, r3 + tst r2, #PAGE_PRESENT @ is pgd entry present? + addeq ip, ip, #1048576 + blne update_pte_table + teq ip, #32 * 1048576 + bne 1b + ldmfd sp!, {r4, r5, pc}^ + +/* + * Build the table to map from physical page number to memc page number + */ + .type memc_phys_table_32, #object +memc_phys_table_32: + .irp b7, 0x00, 0x80 + .irp b6, 0x00, 0x02 + .irp b5, 0x00, 0x04 + .irp b4, 0x00, 0x01 + + .irp b3, 0x00, 0x40 + .irp b2, 0x00, 0x20 + .irp b1, 0x00, 0x10 + .irp b0, 0x00, 0x08 + .long 0x03800300 + \b7 + \b6 + \b5 + \b4 + \b3 + \b2 + \b1 + \b0 + .endr + .endr + .endr + .endr + + .endr + .endr + .endr + .endr + .size memc_phys_table_32, . - memc_phys_table_32 + +/* + * helper for cpu_memc_update_all, this clears out all + * mappings, setting them close to the top of memory, + * and inaccessible (0x01f00000). + * Params : r0 = page table pointer + */ +clear_tables: ldr r1, _arm3_set_pgd - 4 + ldr r2, [r1] + sub r1, r0, #256 * 4 @ start of MEMC tables + add r2, r1, r2, lsl #2 @ end of tables + mov r3, #0x03f00000 @ Default mapping (null mapping) + orr r3, r3, #0x00000f00 + orr r4, r3, #1 + orr r5, r3, #2 + orr ip, r3, #3 +1: stmia r1!, {r3, r4, r5, ip} + add r3, r3, #4 + add r4, r4, #4 + add r5, r5, #4 + add ip, ip, #4 + stmia r1!, {r3, r4, r5, ip} + add r3, r3, #4 + add r4, r4, #4 + add r5, r5, #4 + add ip, ip, #4 + teq r1, r2 + bne 1b + mov pc, lr + +/* + * Function: *_set_pgd(pgd_t *pgd) + * Params : pgd New page tables/MEMC mapping + * Purpose : update MEMC hardware with new mapping + */ + .word page_nr @ extern - declared in mm-memc.c +_arm3_set_pgd: mcr p15, 0, r1, c1, c0, 0 @ flush cache +_arm2_set_pgd: stmfd sp!, {lr} + ldr r1, _arm3_set_pgd - 4 + ldr r2, [r1] + sub r0, r0, #256 * 4 @ start of MEMC tables + add r1, r0, r2, lsl #2 @ end of tables +1: ldmia r0!, {r2, r3, ip, lr} + strb r2, [r2] + strb r3, [r3] + strb ip, [ip] + strb lr, [lr] + ldmia r0!, {r2, r3, ip, lr} + strb r2, [r2] + strb r3, [r3] + strb ip, [ip] + strb lr, [lr] + teq r0, r1 + bne 1b + ldmfd sp!, {pc}^ + +/* + * Function: *_proc_init (void) + * Purpose : Initialise the cache control registers + */ +_arm3_proc_init: + mov r0, #0x001f0000 + orr r0, r0, #0x0000ff00 + orr r0, r0, #0x000000ff + mcr p15, 0, r0, c3, c0 @ ARM3 Cacheable + mcr p15, 0, r0, c4, c0 @ ARM3 Updateable + mov r0, #0 + mcr p15, 0, r0, c5, c0 @ ARM3 Disruptive + mcr p15, 0, r0, c1, c0 @ ARM3 Flush + mov r0, #3 + mcr p15, 0, r0, c2, c0 @ ARM3 Control +_arm2_proc_init: + movs pc, lr + +/* + * Function: *_proc_fin (void) + * Purpose : Finalise processor (disable caches) + */ +_arm3_proc_fin: mov r0, #2 + mcr p15, 0, r0, c2, c0 +_arm2_proc_fin: orrs pc, lr, #PSR_I_BIT|PSR_F_BIT + +/* + * Function: *_xchg_1 (int new, volatile void *ptr) + * Params : new New value to store at... + * : ptr pointer to byte-wide location + * Purpose : Performs an exchange operation + * Returns : Original byte data at 'ptr' + */ +_arm2_xchg_1: mov r2, pc + orr r2, r2, #PSR_I_BIT + teqp r2, #0 + ldrb r2, [r1] + strb r0, [r1] + mov r0, r2 + movs pc, lr + +_arm3_xchg_1: swpb r0, r0, [r1] + movs pc, lr + +/* + * Function: *_xchg_4 (int new, volatile void *ptr) + * Params : new New value to store at... + * : ptr pointer to word-wide location + * Purpose : Performs an exchange operation + * Returns : Original word data at 'ptr' + */ +_arm2_xchg_4: mov r2, pc + orr r2, r2, #PSR_I_BIT + teqp r2, #0 + ldr r2, [r1] + str r0, [r1] + mov r0, r2 + movs pc, lr + +_arm3_xchg_4: swp r0, r0, [r1] + movs pc, lr + +_arm2_3_check_bugs: + bics pc, lr, #PSR_F_BIT @ Clear FIQ disable bit + +armvlsi_name: .asciz "ARM/VLSI" +_arm2_name: .asciz "ARM 2" +_arm250_name: .asciz "ARM 250" +_arm3_name: .asciz "ARM 3" + + .section ".init.text", #alloc, #execinstr +/* + * Purpose : Function pointers used to access above functions - all calls + * come through these + */ + .globl arm2_processor_functions +arm2_processor_functions: + .word _arm2_3_check_bugs + .word _arm2_proc_init + .word _arm2_proc_fin + .word _arm2_set_pgd + .word _arm2_xchg_1 + .word _arm2_xchg_4 + +cpu_arm2_info: + .long armvlsi_name + .long _arm2_name + + .globl arm250_processor_functions +arm250_processor_functions: + .word _arm2_3_check_bugs + .word _arm2_proc_init + .word _arm2_proc_fin + .word _arm2_set_pgd + .word _arm3_xchg_1 + .word _arm3_xchg_4 + +cpu_arm250_info: + .long armvlsi_name + .long _arm250_name + + .globl arm3_processor_functions +arm3_processor_functions: + .word _arm2_3_check_bugs + .word _arm3_proc_init + .word _arm3_proc_fin + .word _arm3_set_pgd + .word _arm3_xchg_1 + .word _arm3_xchg_4 + +cpu_arm3_info: + .long armvlsi_name + .long _arm3_name + +arm2_arch_name: .asciz "armv1" +arm3_arch_name: .asciz "armv2" +arm2_elf_name: .asciz "v1" +arm3_elf_name: .asciz "v2" + .align + + .section ".proc.info", #alloc, #execinstr + + .long 0x41560200 + .long 0xfffffff0 + .long arm2_arch_name + .long arm2_elf_name + .long 0 + .long cpu_arm2_info + .long arm2_processor_functions + + .long 0x41560250 + .long 0xfffffff0 + .long arm3_arch_name + .long arm3_elf_name + .long 0 + .long cpu_arm250_info + .long arm250_processor_functions + + .long 0x41560300 + .long 0xfffffff0 + .long arm3_arch_name + .long arm3_elf_name + .long 0 + .long cpu_arm3_info + .long arm3_processor_functions + diff --git a/arch/arm26/mm/small_page.c b/arch/arm26/mm/small_page.c new file mode 100644 index 000000000000..77be86cca789 --- /dev/null +++ b/arch/arm26/mm/small_page.c @@ -0,0 +1,194 @@ +/* + * linux/arch/arm26/mm/small_page.c + * + * Copyright (C) 1996 Russell King + * Copyright (C) 2003 Ian Molton + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Changelog: + * 26/01/1996 RMK Cleaned up various areas to make little more generic + * 07/02/1999 RMK Support added for 16K and 32K page sizes + * containing 8K blocks + * 23/05/2004 IM Fixed to use struct page->lru (thanks wli) + * + */ +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/ptrace.h> +#include <linux/mman.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/smp.h> +#include <linux/bitops.h> + +#include <asm/pgtable.h> + +#define PEDANTIC + +/* + * Requirement: + * We need to be able to allocate naturally aligned memory of finer + * granularity than the page size. This is typically used for the + * second level page tables on 32-bit ARMs. + * + * FIXME - this comment is *out of date* + * Theory: + * We "misuse" the Linux memory management system. We use alloc_page + * to allocate a page and then mark it as reserved. The Linux memory + * management system will then ignore the "offset", "next_hash" and + * "pprev_hash" entries in the mem_map for this page. + * + * We then use a bitstring in the "offset" field to mark which segments + * of the page are in use, and manipulate this as required during the + * allocation and freeing of these small pages. + * + * We also maintain a queue of pages being used for this purpose using + * the "next_hash" and "pprev_hash" entries of mem_map; + */ + +struct order { + struct list_head queue; + unsigned int mask; /* (1 << shift) - 1 */ + unsigned int shift; /* (1 << shift) size of page */ + unsigned int block_mask; /* nr_blocks - 1 */ + unsigned int all_used; /* (1 << nr_blocks) - 1 */ +}; + + +static struct order orders[] = { +#if PAGE_SIZE == 32768 + { LIST_HEAD_INIT(orders[0].queue), 2047, 11, 15, 0x0000ffff }, + { LIST_HEAD_INIT(orders[1].queue), 8191, 13, 3, 0x0000000f } +#else +#error unsupported page size (ARGH!) +#endif +}; + +#define USED_MAP(pg) ((pg)->index) +#define TEST_AND_CLEAR_USED(pg,off) (test_and_clear_bit(off, &USED_MAP(pg))) +#define SET_USED(pg,off) (set_bit(off, &USED_MAP(pg))) + +static DEFINE_SPINLOCK(small_page_lock); + +static unsigned long __get_small_page(int priority, struct order *order) +{ + unsigned long flags; + struct page *page; + int offset; + + do { + spin_lock_irqsave(&small_page_lock, flags); + + if (list_empty(&order->queue)) + goto need_new_page; + + page = list_entry(order->queue.next, struct page, lru); +again: +#ifdef PEDANTIC + if (USED_MAP(page) & ~order->all_used) + PAGE_BUG(page); +#endif + offset = ffz(USED_MAP(page)); + SET_USED(page, offset); + if (USED_MAP(page) == order->all_used) + list_del_init(&page->lru); + spin_unlock_irqrestore(&small_page_lock, flags); + + return (unsigned long) page_address(page) + (offset << order->shift); + +need_new_page: + spin_unlock_irqrestore(&small_page_lock, flags); + page = alloc_page(priority); + spin_lock_irqsave(&small_page_lock, flags); + + if (list_empty(&order->queue)) { + if (!page) + goto no_page; + SetPageReserved(page); + USED_MAP(page) = 0; + list_add(&page->lru, &order->queue); + goto again; + } + + spin_unlock_irqrestore(&small_page_lock, flags); + __free_page(page); + } while (1); + +no_page: + spin_unlock_irqrestore(&small_page_lock, flags); + return 0; +} + +static void __free_small_page(unsigned long spage, struct order *order) +{ + unsigned long flags; + struct page *page; + + if (virt_addr_valid(spage)) { + page = virt_to_page(spage); + + /* + * The container-page must be marked Reserved + */ + if (!PageReserved(page) || spage & order->mask) + goto non_small; + +#ifdef PEDANTIC + if (USED_MAP(page) & ~order->all_used) + PAGE_BUG(page); +#endif + + spage = spage >> order->shift; + spage &= order->block_mask; + + /* + * the following must be atomic wrt get_page + */ + spin_lock_irqsave(&small_page_lock, flags); + + if (USED_MAP(page) == order->all_used) + list_add(&page->lru, &order->queue); + + if (!TEST_AND_CLEAR_USED(page, spage)) + goto already_free; + + if (USED_MAP(page) == 0) + goto free_page; + + spin_unlock_irqrestore(&small_page_lock, flags); + } + return; + +free_page: + /* + * unlink the page from the small page queue and free it + */ + list_del_init(&page->lru); + spin_unlock_irqrestore(&small_page_lock, flags); + ClearPageReserved(page); + __free_page(page); + return; + +non_small: + printk("Trying to free non-small page from %p\n", __builtin_return_address(0)); + return; +already_free: + printk("Trying to free free small page from %p\n", __builtin_return_address(0)); +} + +unsigned long get_page_8k(int priority) +{ + return __get_small_page(priority, orders+1); +} + +void free_page_8k(unsigned long spage) +{ + __free_small_page(spage, orders+1); +} |