parisc: fixes and cleanups in page cache flushing (4/4)

[linux-2.6/btrfs-unstable.git] / arch / parisc / kernel / cache.c

/*
 * 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) 1999-2006 Helge Deller <deller@gmx.de> (07-13-1999)
 * Copyright (C) 1999 SuSE GmbH Nuernberg
 * Copyright (C) 2000 Philipp Rumpf (prumpf@tux.org)
 *
 * Cache and TLB management
 *
 */
 
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/sched.h>
#include <asm/pdc.h>
#include <asm/cache.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/processor.h>
#include <asm/sections.h>
#include <asm/shmparam.h>

int split_tlb __read_mostly;
int dcache_stride __read_mostly;
int icache_stride __read_mostly;
EXPORT_SYMBOL(dcache_stride);

void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
EXPORT_SYMBOL(flush_dcache_page_asm);
void flush_icache_page_asm(unsigned long phys_addr, unsigned long vaddr);


/* On some machines (e.g. ones with the Merced bus), there can be
 * only a single PxTLB broadcast at a time; this must be guaranteed
 * by software.  We put a spinlock around all TLB flushes  to
 * ensure this.
 */
DEFINE_SPINLOCK(pa_tlb_lock);

struct pdc_cache_info cache_info __read_mostly;
#ifndef CONFIG_PA20
static struct pdc_btlb_info btlb_info __read_mostly;
#endif

#ifdef CONFIG_SMP
void
flush_data_cache(void)
{
        on_each_cpu(flush_data_cache_local, NULL, 1);
}
void 
flush_instruction_cache(void)
{
        on_each_cpu(flush_instruction_cache_local, NULL, 1);
}
#endif

void
flush_cache_all_local(void)
{
        flush_instruction_cache_local(NULL);
        flush_data_cache_local(NULL);
}
EXPORT_SYMBOL(flush_cache_all_local);

void
update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
{
        struct page *page = pte_page(*ptep);

        if (pfn_valid(page_to_pfn(page)) && page_mapping(page) &&
            test_bit(PG_dcache_dirty, &page->flags)) {

                flush_kernel_dcache_page(page);
                clear_bit(PG_dcache_dirty, &page->flags);
        } else if (parisc_requires_coherency())
                flush_kernel_dcache_page(page);
}

void
show_cache_info(struct seq_file *m)
{
        char buf[32];

        seq_printf(m, "I-cache\t\t: %ld KB\n", 
                cache_info.ic_size/1024 );
        if (cache_info.dc_loop != 1)
                snprintf(buf, 32, "%lu-way associative", cache_info.dc_loop);
        seq_printf(m, "D-cache\t\t: %ld KB (%s%s, %s)\n",
                cache_info.dc_size/1024,
                (cache_info.dc_conf.cc_wt ? "WT":"WB"),
                (cache_info.dc_conf.cc_sh ? ", shared I/D":""),
                ((cache_info.dc_loop == 1) ? "direct mapped" : buf));
        seq_printf(m, "ITLB entries\t: %ld\n" "DTLB entries\t: %ld%s\n",
                cache_info.it_size,
                cache_info.dt_size,
                cache_info.dt_conf.tc_sh ? " - shared with ITLB":""
        );
                
#ifndef CONFIG_PA20
        /* BTLB - Block TLB */
        if (btlb_info.max_size==0) {
                seq_printf(m, "BTLB\t\t: not supported\n" );
        } else {
                seq_printf(m, 
                "BTLB fixed\t: max. %d pages, pagesize=%d (%dMB)\n"
                "BTLB fix-entr.\t: %d instruction, %d data (%d combined)\n"
                "BTLB var-entr.\t: %d instruction, %d data (%d combined)\n",
                btlb_info.max_size, (int)4096,
                btlb_info.max_size>>8,
                btlb_info.fixed_range_info.num_i,
                btlb_info.fixed_range_info.num_d,
                btlb_info.fixed_range_info.num_comb, 
                btlb_info.variable_range_info.num_i,
                btlb_info.variable_range_info.num_d,
                btlb_info.variable_range_info.num_comb
                );
        }
#endif
}

void __init 
parisc_cache_init(void)
{
        if (pdc_cache_info(&cache_info) < 0)
                panic("parisc_cache_init: pdc_cache_info failed");

#if 0
        printk("ic_size %lx dc_size %lx it_size %lx\n",
                cache_info.ic_size,
                cache_info.dc_size,
                cache_info.it_size);

        printk("DC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
                cache_info.dc_base,
                cache_info.dc_stride,
                cache_info.dc_count,
                cache_info.dc_loop);

        printk("dc_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
                *(unsigned long *) (&cache_info.dc_conf),
                cache_info.dc_conf.cc_alias,
                cache_info.dc_conf.cc_block,
                cache_info.dc_conf.cc_line,
                cache_info.dc_conf.cc_shift);
        printk("        wt %d sh %d cst %d hv %d\n",
                cache_info.dc_conf.cc_wt,
                cache_info.dc_conf.cc_sh,
                cache_info.dc_conf.cc_cst,
                cache_info.dc_conf.cc_hv);

        printk("IC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
                cache_info.ic_base,
                cache_info.ic_stride,
                cache_info.ic_count,
                cache_info.ic_loop);

        printk("ic_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
                *(unsigned long *) (&cache_info.ic_conf),
                cache_info.ic_conf.cc_alias,
                cache_info.ic_conf.cc_block,
                cache_info.ic_conf.cc_line,
                cache_info.ic_conf.cc_shift);
        printk("        wt %d sh %d cst %d hv %d\n",
                cache_info.ic_conf.cc_wt,
                cache_info.ic_conf.cc_sh,
                cache_info.ic_conf.cc_cst,
                cache_info.ic_conf.cc_hv);

        printk("D-TLB conf: sh %d page %d cst %d aid %d pad1 %d\n",
                cache_info.dt_conf.tc_sh,
                cache_info.dt_conf.tc_page,
                cache_info.dt_conf.tc_cst,
                cache_info.dt_conf.tc_aid,
                cache_info.dt_conf.tc_pad1);

        printk("I-TLB conf: sh %d page %d cst %d aid %d pad1 %d\n",
                cache_info.it_conf.tc_sh,
                cache_info.it_conf.tc_page,
                cache_info.it_conf.tc_cst,
                cache_info.it_conf.tc_aid,
                cache_info.it_conf.tc_pad1);
#endif

        split_tlb = 0;
        if (cache_info.dt_conf.tc_sh == 0 || cache_info.dt_conf.tc_sh == 2) {
                if (cache_info.dt_conf.tc_sh == 2)
                        printk(KERN_WARNING "Unexpected TLB configuration. "
                        "Will flush I/D separately (could be optimized).\n");

                split_tlb = 1;
        }

        /* "New and Improved" version from Jim Hull 
         *      (1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))
         * The following CAFL_STRIDE is an optimized version, see
         * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html
         * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html
         */
#define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))
        dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
        icache_stride = CAFL_STRIDE(cache_info.ic_conf);
#undef CAFL_STRIDE

#ifndef CONFIG_PA20
        if (pdc_btlb_info(&btlb_info) < 0) {
                memset(&btlb_info, 0, sizeof btlb_info);
        }
#endif

        if ((boot_cpu_data.pdc.capabilities & PDC_MODEL_NVA_MASK) ==
                                                PDC_MODEL_NVA_UNSUPPORTED) {
                printk(KERN_WARNING "parisc_cache_init: Only equivalent aliasing supported!\n");
#if 0
                panic("SMP kernel required to avoid non-equivalent aliasing");
#endif
        }
}

void disable_sr_hashing(void)
{
        int srhash_type, retval;
        unsigned long space_bits;

        switch (boot_cpu_data.cpu_type) {
        case pcx: /* We shouldn't get this far.  setup.c should prevent it. */
                BUG();
                return;

        case pcxs:
        case pcxt:
        case pcxt_:
                srhash_type = SRHASH_PCXST;
                break;

        case pcxl:
                srhash_type = SRHASH_PCXL;
                break;

        case pcxl2: /* pcxl2 doesn't support space register hashing */
                return;

        default: /* Currently all PA2.0 machines use the same ins. sequence */
                srhash_type = SRHASH_PA20;
                break;
        }

        disable_sr_hashing_asm(srhash_type);

        retval = pdc_spaceid_bits(&space_bits);
        /* If this procedure isn't implemented, don't panic. */
        if (retval < 0 && retval != PDC_BAD_OPTION)
                panic("pdc_spaceid_bits call failed.\n");
        if (space_bits != 0)
                panic("SpaceID hashing is still on!\n");
}

static inline void
__flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
                   unsigned long physaddr)
{
        flush_dcache_page_asm(physaddr, vmaddr);
        if (vma->vm_flags & VM_EXEC)
                flush_icache_page_asm(physaddr, vmaddr);
}

void flush_dcache_page(struct page *page)
{
        struct address_space *mapping = page_mapping(page);
        struct vm_area_struct *mpnt;
        unsigned long offset;
        unsigned long addr, old_addr = 0;
        pgoff_t pgoff;

        if (mapping && !mapping_mapped(mapping)) {
                set_bit(PG_dcache_dirty, &page->flags);
                return;
        }

        flush_kernel_dcache_page(page);

        if (!mapping)
                return;

        pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);

        /* We have carefully arranged in arch_get_unmapped_area() that
         * *any* mappings of a file are always congruently mapped (whether
         * declared as MAP_PRIVATE or MAP_SHARED), so we only need
         * to flush one address here for them all to become coherent */

        flush_dcache_mmap_lock(mapping);
        vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
                offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
                addr = mpnt->vm_start + offset;

                /* The TLB is the engine of coherence on parisc: The
                 * CPU is entitled to speculate any page with a TLB
                 * mapping, so here we kill the mapping then flush the
                 * page along a special flush only alias mapping.
                 * This guarantees that the page is no-longer in the
                 * cache for any process and nor may it be
                 * speculatively read in (until the user or kernel
                 * specifically accesses it, of course) */

                flush_tlb_page(mpnt, addr);
                if (old_addr == 0 || (old_addr & (SHMLBA - 1)) != (addr & (SHMLBA - 1))) {
                        __flush_cache_page(mpnt, addr, page_to_phys(page));
                        if (old_addr)
                                printk(KERN_ERR "INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %s\n", old_addr, addr, mpnt->vm_file ? (char *)mpnt->vm_file->f_path.dentry->d_name.name : "(null)");
                        old_addr = addr;
                }
        }
        flush_dcache_mmap_unlock(mapping);
}
EXPORT_SYMBOL(flush_dcache_page);

/* Defined in arch/parisc/kernel/pacache.S */
EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
EXPORT_SYMBOL(flush_kernel_dcache_page_asm);
EXPORT_SYMBOL(flush_data_cache_local);
EXPORT_SYMBOL(flush_kernel_icache_range_asm);

#define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
int parisc_cache_flush_threshold __read_mostly = FLUSH_THRESHOLD;

void __init parisc_setup_cache_timing(void)
{
        unsigned long rangetime, alltime;
        unsigned long size;

        alltime = mfctl(16);
        flush_data_cache();
        alltime = mfctl(16) - alltime;

        size = (unsigned long)(_end - _text);
        rangetime = mfctl(16);
        flush_kernel_dcache_range((unsigned long)_text, size);
        rangetime = mfctl(16) - rangetime;

        printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
                alltime, size, rangetime);

        /* Racy, but if we see an intermediate value, it's ok too... */
        parisc_cache_flush_threshold = size * alltime / rangetime;

        parisc_cache_flush_threshold = (parisc_cache_flush_threshold + L1_CACHE_BYTES - 1) &~ (L1_CACHE_BYTES - 1); 
        if (!parisc_cache_flush_threshold)
                parisc_cache_flush_threshold = FLUSH_THRESHOLD;

        if (parisc_cache_flush_threshold > cache_info.dc_size)
                parisc_cache_flush_threshold = cache_info.dc_size;

        printk(KERN_INFO "Setting cache flush threshold to %x (%d CPUs online)\n", parisc_cache_flush_threshold, num_online_cpus());
}

extern void purge_kernel_dcache_page_asm(unsigned long);
extern void clear_user_page_asm(void *, unsigned long);
extern void copy_user_page_asm(void *, void *, unsigned long);

void flush_kernel_dcache_page_addr(void *addr)
{
        unsigned long flags;

        flush_kernel_dcache_page_asm(addr);
        purge_tlb_start(flags);
        pdtlb_kernel(addr);
        purge_tlb_end(flags);
}
EXPORT_SYMBOL(flush_kernel_dcache_page_addr);

void clear_user_page(void *vto, unsigned long vaddr, struct page *page)
{
        clear_page_asm(vto);
        if (!parisc_requires_coherency())
                flush_kernel_dcache_page_asm(vto);
}
EXPORT_SYMBOL(clear_user_page);

void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
        struct page *pg)
{
        /* Copy using kernel mapping.  No coherency is needed
           (all in kmap/kunmap) on machines that don't support
           non-equivalent aliasing.  However, the `from' page
           needs to be flushed before it can be accessed through
           the kernel mapping. */
        preempt_disable();
        flush_dcache_page_asm(__pa(vfrom), vaddr);
        preempt_enable();
        copy_page_asm(vto, vfrom);
        if (!parisc_requires_coherency())
                flush_kernel_dcache_page_asm(vto);
}
EXPORT_SYMBOL(copy_user_page);

#ifdef CONFIG_PA8X00

void kunmap_parisc(void *addr)
{
        if (parisc_requires_coherency())
                flush_kernel_dcache_page_addr(addr);
}
EXPORT_SYMBOL(kunmap_parisc);
#endif

void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
{
        unsigned long flags;

        /* Note: purge_tlb_entries can be called at startup with
           no context.  */

        /* Disable preemption while we play with %sr1.  */
        preempt_disable();
        mtsp(mm->context, 1);
        purge_tlb_start(flags);
        pdtlb(addr);
        pitlb(addr);
        purge_tlb_end(flags);
        preempt_enable();
}
EXPORT_SYMBOL(purge_tlb_entries);

void __flush_tlb_range(unsigned long sid, unsigned long start,
                       unsigned long end)
{
        unsigned long npages;

        npages = ((end - (start & PAGE_MASK)) + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
        if (npages >= 512)  /* 2MB of space: arbitrary, should be tuned */
                flush_tlb_all();
        else {
                unsigned long flags;

                mtsp(sid, 1);
                purge_tlb_start(flags);
                if (split_tlb) {
                        while (npages--) {
                                pdtlb(start);
                                pitlb(start);
                                start += PAGE_SIZE;
                        }
                } else {
                        while (npages--) {
                                pdtlb(start);
                                start += PAGE_SIZE;
                        }
                }
                purge_tlb_end(flags);
        }
}

static void cacheflush_h_tmp_function(void *dummy)
{
        flush_cache_all_local();
}

void flush_cache_all(void)
{
        on_each_cpu(cacheflush_h_tmp_function, NULL, 1);
}

static inline unsigned long mm_total_size(struct mm_struct *mm)
{
        struct vm_area_struct *vma;
        unsigned long usize = 0;

        for (vma = mm->mmap; vma; vma = vma->vm_next)
                usize += vma->vm_end - vma->vm_start;
        return usize;
}

static inline pte_t *get_ptep(pgd_t *pgd, unsigned long addr)
{
        pte_t *ptep = NULL;

        if (!pgd_none(*pgd)) {
                pud_t *pud = pud_offset(pgd, addr);
                if (!pud_none(*pud)) {
                        pmd_t *pmd = pmd_offset(pud, addr);
                        if (!pmd_none(*pmd))
                                ptep = pte_offset_map(pmd, addr);
                }
        }
        return ptep;
}

void flush_cache_mm(struct mm_struct *mm)
{
        /* Flushing the whole cache on each cpu takes forever on
           rp3440, etc.  So, avoid it if the mm isn't too big.  */
        if (mm_total_size(mm) < parisc_cache_flush_threshold) {
                struct vm_area_struct *vma;

                if (mm->context == mfsp(3)) {
                        for (vma = mm->mmap; vma; vma = vma->vm_next) {
                                flush_user_dcache_range_asm(vma->vm_start,
                                        vma->vm_end);
                                if (vma->vm_flags & VM_EXEC)
                                        flush_user_icache_range_asm(
                                          vma->vm_start, vma->vm_end);
                        }
                } else {
                        pgd_t *pgd = mm->pgd;

                        for (vma = mm->mmap; vma; vma = vma->vm_next) {
                                unsigned long addr;

                                for (addr = vma->vm_start; addr < vma->vm_end;
                                     addr += PAGE_SIZE) {
                                        pte_t *ptep = get_ptep(pgd, addr);
                                        if (ptep != NULL) {
                                                pte_t pte = *ptep;
                                                __flush_cache_page(vma, addr,
                                                  page_to_phys(pte_page(pte)));
                                        }
                                }
                        }
                }
                return;
        }

#ifdef CONFIG_SMP
        flush_cache_all();
#else
        flush_cache_all_local();
#endif
}

void
flush_user_dcache_range(unsigned long start, unsigned long end)
{
        if ((end - start) < parisc_cache_flush_threshold)
                flush_user_dcache_range_asm(start,end);
        else
                flush_data_cache();
}

void
flush_user_icache_range(unsigned long start, unsigned long end)
{
        if ((end - start) < parisc_cache_flush_threshold)
                flush_user_icache_range_asm(start,end);
        else
                flush_instruction_cache();
}

void flush_cache_range(struct vm_area_struct *vma,
                unsigned long start, unsigned long end)
{
        BUG_ON(!vma->vm_mm->context);

        if ((end - start) < parisc_cache_flush_threshold) {
                if (vma->vm_mm->context == mfsp(3)) {
                        flush_user_dcache_range_asm(start, end);
                        if (vma->vm_flags & VM_EXEC)
                                flush_user_icache_range_asm(start, end);
                } else {
                        unsigned long addr;
                        pgd_t *pgd = vma->vm_mm->pgd;

                        for (addr = start & PAGE_MASK; addr < end;
                             addr += PAGE_SIZE) {
                                pte_t *ptep = get_ptep(pgd, addr);
                                if (ptep != NULL) {
                                        pte_t pte = *ptep;
                                        flush_cache_page(vma,
                                           addr, pte_pfn(pte));
                                }
                        }
                }
        } else {
#ifdef CONFIG_SMP
                flush_cache_all();
#else
                flush_cache_all_local();
#endif
        }
}

void
flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
{
        BUG_ON(!vma->vm_mm->context);

        flush_tlb_page(vma, vmaddr);
        __flush_cache_page(vma, vmaddr, page_to_phys(pfn_to_page(pfn)));

}

#ifdef CONFIG_PARISC_TMPALIAS

void clear_user_highpage(struct page *page, unsigned long vaddr)
{
        void *vto;
        unsigned long flags;

        /* Clear using TMPALIAS region.  The page doesn't need to
           be flushed but the kernel mapping needs to be purged.  */

        vto = kmap_atomic(page, KM_USER0);

        /* The PA-RISC 2.0 Architecture book states on page F-6:
           "Before a write-capable translation is enabled, *all*
           non-equivalently-aliased translations must be removed
           from the page table and purged from the TLB.  (Note
           that the caches are not required to be flushed at this
           time.)  Before any non-equivalent aliased translation
           is re-enabled, the virtual address range for the writeable
           page (the entire page) must be flushed from the cache,
           and the write-capable translation removed from the page
           table and purged from the TLB."  */

        purge_kernel_dcache_page_asm((unsigned long)vto);
        purge_tlb_start(flags);
        pdtlb_kernel(vto);
        purge_tlb_end(flags);
        preempt_disable();
        clear_user_page_asm(vto, vaddr);
        preempt_enable();

        pagefault_enable();             /* kunmap_atomic(addr, KM_USER0); */
}

void copy_user_highpage(struct page *to, struct page *from,
        unsigned long vaddr, struct vm_area_struct *vma)
{
        void *vfrom, *vto;
        unsigned long flags;

        /* Copy using TMPALIAS region.  This has the advantage
           that the `from' page doesn't need to be flushed.  However,
           the `to' page must be flushed in copy_user_page_asm since
           it can be used to bring in executable code.  */

        vfrom = kmap_atomic(from, KM_USER0);
        vto = kmap_atomic(to, KM_USER1);

        purge_kernel_dcache_page_asm((unsigned long)vto);
        purge_tlb_start(flags);
        pdtlb_kernel(vto);
        pdtlb_kernel(vfrom);
        purge_tlb_end(flags);
        preempt_disable();
        copy_user_page_asm(vto, vfrom, vaddr);
        flush_dcache_page_asm(__pa(vto), vaddr);
        preempt_enable();

        pagefault_enable();             /* kunmap_atomic(addr, KM_USER1); */
        pagefault_enable();             /* kunmap_atomic(addr, KM_USER0); */
}

#endif /* CONFIG_PARISC_TMPALIAS */