From 3f65ce4d141e435e54c20ed2379d983d362a2cb5 Mon Sep 17 00:00:00 2001 From: Chris Zankel Date: Thu, 23 Jun 2005 22:01:24 -0700 Subject: [PATCH] xtensa: Architecture support for Tensilica Xtensa Part 5 The attached patches provides part 5 of an architecture implementation for the Tensilica Xtensa CPU series. Signed-off-by: Chris Zankel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/xtensa/mm/init.c | 551 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 551 insertions(+) create mode 100644 arch/xtensa/mm/init.c (limited to 'arch/xtensa/mm/init.c') diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c new file mode 100644 index 00000000000..56aace84aae --- /dev/null +++ b/arch/xtensa/mm/init.c @@ -0,0 +1,551 @@ +/* + * arch/xtensa/mm/init.c + * + * Derived from MIPS, PPC. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2005 Tensilica Inc. + * + * Chris Zankel + * Joe Taylor + * Marc Gauthier + * Kevin Chea + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include + + +#define DEBUG 0 + +DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); +//static DEFINE_SPINLOCK(tlb_lock); + +/* + * This flag is used to indicate that the page was mapped and modified in + * kernel space, so the cache is probably dirty at that address. + * If cache aliasing is enabled and the page color mismatches, update_mmu_cache + * synchronizes the caches if this bit is set. + */ + +#define PG_cache_clean PG_arch_1 + +/* References to section boundaries */ + +extern char _ftext, _etext, _fdata, _edata, _rodata_end; +extern char __init_begin, __init_end; + +/* + * mem_reserve(start, end, must_exist) + * + * Reserve some memory from the memory pool. + * + * Parameters: + * start Start of region, + * end End of region, + * must_exist Must exist in memory pool. + * + * Returns: + * 0 (memory area couldn't be mapped) + * -1 (success) + */ + +int __init mem_reserve(unsigned long start, unsigned long end, int must_exist) +{ + int i; + + if (start == end) + return 0; + + start = start & PAGE_MASK; + end = PAGE_ALIGN(end); + + for (i = 0; i < sysmem.nr_banks; i++) + if (start < sysmem.bank[i].end + && end >= sysmem.bank[i].start) + break; + + if (i == sysmem.nr_banks) { + if (must_exist) + printk (KERN_WARNING "mem_reserve: [0x%0lx, 0x%0lx) " + "not in any region!\n", start, end); + return 0; + } + + if (start > sysmem.bank[i].start) { + if (end < sysmem.bank[i].end) { + /* split entry */ + if (sysmem.nr_banks >= SYSMEM_BANKS_MAX) + panic("meminfo overflow\n"); + sysmem.bank[sysmem.nr_banks].start = end; + sysmem.bank[sysmem.nr_banks].end = sysmem.bank[i].end; + sysmem.nr_banks++; + } + sysmem.bank[i].end = start; + } else { + if (end < sysmem.bank[i].end) + sysmem.bank[i].start = end; + else { + /* remove entry */ + sysmem.nr_banks--; + sysmem.bank[i].start = sysmem.bank[sysmem.nr_banks].start; + sysmem.bank[i].end = sysmem.bank[sysmem.nr_banks].end; + } + } + return -1; +} + + +/* + * Initialize the bootmem system and give it all the memory we have available. + */ + +void __init bootmem_init(void) +{ + unsigned long pfn; + unsigned long bootmap_start, bootmap_size; + int i; + + max_low_pfn = max_pfn = 0; + min_low_pfn = ~0; + + for (i=0; i < sysmem.nr_banks; i++) { + pfn = PAGE_ALIGN(sysmem.bank[i].start) >> PAGE_SHIFT; + if (pfn < min_low_pfn) + min_low_pfn = pfn; + pfn = PAGE_ALIGN(sysmem.bank[i].end - 1) >> PAGE_SHIFT; + if (pfn > max_pfn) + max_pfn = pfn; + } + + if (min_low_pfn > max_pfn) + panic("No memory found!\n"); + + max_low_pfn = max_pfn < MAX_LOW_MEMORY >> PAGE_SHIFT ? + max_pfn : MAX_LOW_MEMORY >> PAGE_SHIFT; + + /* Find an area to use for the bootmem bitmap. */ + + bootmap_size = bootmem_bootmap_pages(max_low_pfn) << PAGE_SHIFT; + bootmap_start = ~0; + + for (i=0; i= bootmap_size) { + bootmap_start = sysmem.bank[i].start; + break; + } + + if (bootmap_start == ~0UL) + panic("Cannot find %ld bytes for bootmap\n", bootmap_size); + + /* Reserve the bootmem bitmap area */ + + mem_reserve(bootmap_start, bootmap_start + bootmap_size, 1); + bootmap_size = init_bootmem_node(NODE_DATA(0), min_low_pfn, + bootmap_start >> PAGE_SHIFT, + max_low_pfn); + + /* Add all remaining memory pieces into the bootmem map */ + + for (i=0; iTLBCFG special registers ensure + * that valid values exist in the register. For existing + * PGSZID fields, zero selects the first element of the + * page-size array. For nonexistant PGSZID fields, zero is + * the best value to write. Also, when changing PGSZID + * fields, the corresponding TLB must be flushed. + */ + set_itlbcfg_register (0); + set_dtlbcfg_register (0); + flush_tlb_all (); + + /* Set rasid register to a known value. */ + + set_rasid_register (ASID_ALL_RESERVED); + + /* Set PTEVADDR special register to the start of the page + * table, which is in kernel mappable space (ie. not + * statically mapped). This register's value is undefined on + * reset. + */ + set_ptevaddr_register (PGTABLE_START); +} + +/* + * Initialize memory pages. + */ + +void __init mem_init(void) +{ + unsigned long codesize, reservedpages, datasize, initsize; + unsigned long highmemsize, tmp, ram; + + max_mapnr = num_physpages = max_low_pfn; + high_memory = (void *) __va(max_mapnr << PAGE_SHIFT); + highmemsize = 0; + +#if CONFIG_HIGHMEM +#error HIGHGMEM not implemented in init.c +#endif + + totalram_pages += free_all_bootmem(); + + reservedpages = ram = 0; + for (tmp = 0; tmp < max_low_pfn; tmp++) { + ram++; + if (PageReserved(mem_map+tmp)) + reservedpages++; + } + + codesize = (unsigned long) &_etext - (unsigned long) &_ftext; + datasize = (unsigned long) &_edata - (unsigned long) &_fdata; + initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; + + printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, " + "%ldk data, %ldk init %ldk highmem)\n", + (unsigned long) nr_free_pages() << (PAGE_SHIFT-10), + ram << (PAGE_SHIFT-10), + codesize >> 10, + reservedpages << (PAGE_SHIFT-10), + datasize >> 10, + initsize >> 10, + highmemsize >> 10); +} + +void +free_reserved_mem(void *start, void *end) +{ + for (; start < end; start += PAGE_SIZE) { + ClearPageReserved(virt_to_page(start)); + set_page_count(virt_to_page(start), 1); + free_page((unsigned long)start); + totalram_pages++; + } +} + +#ifdef CONFIG_BLK_DEV_INITRD +extern int initrd_is_mapped; + +void free_initrd_mem(unsigned long start, unsigned long end) +{ + if (initrd_is_mapped) { + free_reserved_mem((void*)start, (void*)end); + printk ("Freeing initrd memory: %ldk freed\n",(end-start)>>10); + } +} +#endif + +void free_initmem(void) +{ + free_reserved_mem(&__init_begin, &__init_end); + printk("Freeing unused kernel memory: %dk freed\n", + (&__init_end - &__init_begin) >> 10); +} + +void show_mem(void) +{ + int i, free = 0, total = 0, reserved = 0; + int shared = 0, cached = 0; + + printk("Mem-info:\n"); + show_free_areas(); + printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); + i = max_mapnr; + while (i-- > 0) { + total++; + if (PageReserved(mem_map+i)) + reserved++; + else if (PageSwapCache(mem_map+i)) + cached++; + else if (!page_count(mem_map + i)) + free++; + else + shared += page_count(mem_map + i) - 1; + } + printk("%d pages of RAM\n", total); + printk("%d reserved pages\n", reserved); + printk("%d pages shared\n", shared); + printk("%d pages swap cached\n",cached); + printk("%d free pages\n", free); +} + +/* ------------------------------------------------------------------------- */ + +#if (DCACHE_WAY_SIZE > PAGE_SIZE) + +/* + * With cache aliasing, the page color of the page in kernel space and user + * space might mismatch. We temporarily map the page to a different virtual + * address with the same color and clear the page there. + */ + +void clear_user_page(void *kaddr, unsigned long vaddr, struct page* page) +{ + + /* There shouldn't be any entries for this page. */ + + __flush_invalidate_dcache_page_phys(__pa(page_address(page))); + + if (!PAGE_COLOR_EQ(vaddr, kaddr)) { + unsigned long v, p; + + /* Temporarily map page to DTLB_WAY_DCACHE_ALIAS0. */ + + spin_lock(&tlb_lock); + + p = (unsigned long)pte_val((mk_pte(page,PAGE_KERNEL))); + kaddr = (void*)PAGE_COLOR_MAP0(vaddr); + v = (unsigned long)kaddr | DTLB_WAY_DCACHE_ALIAS0; + __asm__ __volatile__("wdtlb %0,%1; dsync" : :"a" (p), "a" (v)); + + clear_page(kaddr); + + spin_unlock(&tlb_lock); + } else { + clear_page(kaddr); + } + + /* We need to make sure that i$ and d$ are coherent. */ + + clear_bit(PG_cache_clean, &page->flags); +} + +/* + * With cache aliasing, we have to make sure that the page color of the page + * in kernel space matches that of the virtual user address before we read + * the page. If the page color differ, we create a temporary DTLB entry with + * the corrent page color and use this 'temporary' address as the source. + * We then use the same approach as in clear_user_page and copy the data + * to the kernel space and clear the PG_cache_clean bit to synchronize caches + * later. + * + * Note: + * Instead of using another 'way' for the temporary DTLB entry, we could + * probably use the same entry that points to the kernel address (after + * saving the original value and restoring it when we are done). + */ + +void copy_user_page(void* to, void* from, unsigned long vaddr, + struct page* to_page) +{ + /* There shouldn't be any entries for the new page. */ + + __flush_invalidate_dcache_page_phys(__pa(page_address(to_page))); + + spin_lock(&tlb_lock); + + if (!PAGE_COLOR_EQ(vaddr, from)) { + unsigned long v, p, t; + + __asm__ __volatile__ ("pdtlb %1,%2; rdtlb1 %0,%1" + : "=a"(p), "=a"(t) : "a"(from)); + from = (void*)PAGE_COLOR_MAP0(vaddr); + v = (unsigned long)from | DTLB_WAY_DCACHE_ALIAS0; + __asm__ __volatile__ ("wdtlb %0,%1; dsync" ::"a" (p), "a" (v)); + } + + if (!PAGE_COLOR_EQ(vaddr, to)) { + unsigned long v, p; + + p = (unsigned long)pte_val((mk_pte(to_page,PAGE_KERNEL))); + to = (void*)PAGE_COLOR_MAP1(vaddr); + v = (unsigned long)to | DTLB_WAY_DCACHE_ALIAS1; + __asm__ __volatile__ ("wdtlb %0,%1; dsync" ::"a" (p), "a" (v)); + } + copy_page(to, from); + + spin_unlock(&tlb_lock); + + /* We need to make sure that i$ and d$ are coherent. */ + + clear_bit(PG_cache_clean, &to_page->flags); +} + + + +/* + * Any time the kernel writes to a user page cache page, or it is about to + * read from a page cache page this routine is called. + * + * Note: + * The kernel currently only provides one architecture bit in the page + * flags that we use for I$/D$ coherency. Maybe, in future, we can + * use a sepearte bit for deferred dcache aliasing: + * If the page is not mapped yet, we only need to set a flag, + * if mapped, we need to invalidate the page. + */ +// FIXME: we probably need this for WB caches not only for Page Coloring.. + +void flush_dcache_page(struct page *page) +{ + unsigned long addr = __pa(page_address(page)); + struct address_space *mapping = page_mapping(page); + + __flush_invalidate_dcache_page_phys(addr); + + if (!test_bit(PG_cache_clean, &page->flags)) + return; + + /* If this page hasn't been mapped, yet, handle I$/D$ coherency later.*/ +#if 0 + if (mapping && !mapping_mapped(mapping)) + clear_bit(PG_cache_clean, &page->flags); + else +#endif + __invalidate_icache_page_phys(addr); +} + +void flush_cache_range(struct vm_area_struct* vma, unsigned long s, + unsigned long e) +{ + __flush_invalidate_cache_all(); +} + +void flush_cache_page(struct vm_area_struct* vma, unsigned long address, + unsigned long pfn) +{ + struct page *page = pfn_to_page(pfn); + + /* Remove any entry for the old mapping. */ + + if (current->active_mm == vma->vm_mm) { + unsigned long addr = __pa(page_address(page)); + __flush_invalidate_dcache_page_phys(addr); + if ((vma->vm_flags & VM_EXEC) != 0) + __invalidate_icache_page_phys(addr); + } else { + BUG(); + } +} + +#endif /* (DCACHE_WAY_SIZE > PAGE_SIZE) */ + + +pte_t* pte_alloc_one_kernel (struct mm_struct* mm, unsigned long addr) +{ + pte_t* pte = (pte_t*)__get_free_pages(GFP_KERNEL|__GFP_REPEAT, 0); + if (likely(pte)) { + pte_t* ptep = (pte_t*)(pte_val(*pte) + PAGE_OFFSET); + int i; + for (i = 0; i < 1024; i++, ptep++) + pte_clear(mm, addr, ptep); + } + return pte; +} + +struct page* pte_alloc_one(struct mm_struct *mm, unsigned long addr) +{ + struct page *page; + + page = alloc_pages(GFP_KERNEL | __GFP_REPEAT, 0); + + if (likely(page)) { + pte_t* ptep = kmap_atomic(page, KM_USER0); + int i; + + for (i = 0; i < 1024; i++, ptep++) + pte_clear(mm, addr, ptep); + + kunmap_atomic(ptep, KM_USER0); + } + return page; +} + + +/* + * Handle D$/I$ coherency. + * + * Note: + * We only have one architecture bit for the page flags, so we cannot handle + * cache aliasing, yet. + */ + +void +update_mmu_cache(struct vm_area_struct * vma, unsigned long addr, pte_t pte) +{ + unsigned long pfn = pte_pfn(pte); + struct page *page; + unsigned long vaddr = addr & PAGE_MASK; + + if (!pfn_valid(pfn)) + return; + + page = pfn_to_page(pfn); + + invalidate_itlb_mapping(addr); + invalidate_dtlb_mapping(addr); + + /* We have a new mapping. Use it. */ + + write_dtlb_entry(pte, dtlb_probe(addr)); + + /* If the processor can execute from this page, synchronize D$/I$. */ + + if ((vma->vm_flags & VM_EXEC) != 0) { + + write_itlb_entry(pte, itlb_probe(addr)); + + /* Synchronize caches, if not clean. */ + + if (!test_and_set_bit(PG_cache_clean, &page->flags)) { + __flush_dcache_page(vaddr); + __invalidate_icache_page(vaddr); + } + } +} + -- cgit v1.2.3-70-g09d2