Merge branch 'sh/cachetlb'
authorPaul Mundt <lethal@linux-sh.org>
Sat, 10 Oct 2009 12:36:53 +0000 (21:36 +0900)
committerPaul Mundt <lethal@linux-sh.org>
Sat, 10 Oct 2009 12:36:53 +0000 (21:36 +0900)
1  2 
arch/sh/mm/cache-sh4.c

diff --combined arch/sh/mm/cache-sh4.c
index a98c7d8984fa160d095fab7472d1c162049a25e8,8362d312ad94e222035e3df0edda34a90e6e7bc6..60588c5bf7f922e883baab120cf6ac767b58097d
@@@ -2,7 -2,7 +2,7 @@@
   * arch/sh/mm/cache-sh4.c
   *
   * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
-  * Copyright (C) 2001 - 2007  Paul Mundt
+  * Copyright (C) 2001 - 2009  Paul Mundt
   * Copyright (C) 2003  Richard Curnow
   * Copyright (c) 2007 STMicroelectronics (R&D) Ltd.
   *
@@@ -15,6 -15,8 +15,8 @@@
  #include <linux/io.h>
  #include <linux/mutex.h>
  #include <linux/fs.h>
+ #include <linux/highmem.h>
+ #include <asm/pgtable.h>
  #include <asm/mmu_context.h>
  #include <asm/cacheflush.h>
  
   * flushing. Anything exceeding this will simply flush the dcache in its
   * entirety.
   */
- #define MAX_DCACHE_PAGES      64      /* XXX: Tune for ways */
  #define MAX_ICACHE_PAGES      32
  
  static void __flush_cache_4096(unsigned long addr, unsigned long phys,
                               unsigned long exec_offset);
  
- /*
-  * This is initialised here to ensure that it is not placed in the BSS.  If
-  * that were to happen, note that cache_init gets called before the BSS is
-  * cleared, so this would get nulled out which would be hopeless.
-  */
- static void (*__flush_dcache_segment_fn)(unsigned long, unsigned long) =
-       (void (*)(unsigned long, unsigned long))0xdeadbeef;
  /*
   * Write back the range of D-cache, and purge the I-cache.
   *
   * Called from kernel/module.c:sys_init_module and routine for a.out format,
   * signal handler code and kprobes code
   */
 -static void sh4_flush_icache_range(void *args)
 +static void __uses_jump_to_uncached sh4_flush_icache_range(void *args)
  {
        struct flusher_data *data = args;
        unsigned long start, end;
@@@ -123,12 -116,12 +116,12 @@@ static void sh4_flush_dcache_page(void 
        else
  #endif
        {
-               unsigned long phys = PHYSADDR(page_address(page));
+               unsigned long phys = page_to_phys(page);
                unsigned long addr = CACHE_OC_ADDRESS_ARRAY;
                int i, n;
  
                /* Loop all the D-cache */
-               n = boot_cpu_data.dcache.n_aliases;
+               n = boot_cpu_data.dcache.way_incr >> 12;
                for (i = 0; i < n; i++, addr += 4096)
                        flush_cache_4096(addr, phys);
        }
@@@ -158,10 -151,27 +151,27 @@@ static void __uses_jump_to_uncached flu
        local_irq_restore(flags);
  }
  
- static inline void flush_dcache_all(void)
+ static void flush_dcache_all(void)
  {
-       (*__flush_dcache_segment_fn)(0UL, boot_cpu_data.dcache.way_size);
-       wmb();
+       unsigned long addr, end_addr, entry_offset;
+       end_addr = CACHE_OC_ADDRESS_ARRAY +
+               (current_cpu_data.dcache.sets <<
+                current_cpu_data.dcache.entry_shift) *
+                       current_cpu_data.dcache.ways;
+       entry_offset = 1 << current_cpu_data.dcache.entry_shift;
+       for (addr = CACHE_OC_ADDRESS_ARRAY; addr < end_addr; ) {
+               __raw_writel(0, addr); addr += entry_offset;
+               __raw_writel(0, addr); addr += entry_offset;
+               __raw_writel(0, addr); addr += entry_offset;
+               __raw_writel(0, addr); addr += entry_offset;
+               __raw_writel(0, addr); addr += entry_offset;
+               __raw_writel(0, addr); addr += entry_offset;
+               __raw_writel(0, addr); addr += entry_offset;
+               __raw_writel(0, addr); addr += entry_offset;
+       }
  }
  
  static void sh4_flush_cache_all(void *unused)
        flush_icache_all();
  }
  
- static void __flush_cache_mm(struct mm_struct *mm, unsigned long start,
-                            unsigned long end)
- {
-       unsigned long d = 0, p = start & PAGE_MASK;
-       unsigned long alias_mask = boot_cpu_data.dcache.alias_mask;
-       unsigned long n_aliases = boot_cpu_data.dcache.n_aliases;
-       unsigned long select_bit;
-       unsigned long all_aliases_mask;
-       unsigned long addr_offset;
-       pgd_t *dir;
-       pmd_t *pmd;
-       pud_t *pud;
-       pte_t *pte;
-       int i;
-       dir = pgd_offset(mm, p);
-       pud = pud_offset(dir, p);
-       pmd = pmd_offset(pud, p);
-       end = PAGE_ALIGN(end);
-       all_aliases_mask = (1 << n_aliases) - 1;
-       do {
-               if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) {
-                       p &= PMD_MASK;
-                       p += PMD_SIZE;
-                       pmd++;
-                       continue;
-               }
-               pte = pte_offset_kernel(pmd, p);
-               do {
-                       unsigned long phys;
-                       pte_t entry = *pte;
-                       if (!(pte_val(entry) & _PAGE_PRESENT)) {
-                               pte++;
-                               p += PAGE_SIZE;
-                               continue;
-                       }
-                       phys = pte_val(entry) & PTE_PHYS_MASK;
-                       if ((p ^ phys) & alias_mask) {
-                               d |= 1 << ((p & alias_mask) >> PAGE_SHIFT);
-                               d |= 1 << ((phys & alias_mask) >> PAGE_SHIFT);
-                               if (d == all_aliases_mask)
-                                       goto loop_exit;
-                       }
-                       pte++;
-                       p += PAGE_SIZE;
-               } while (p < end && ((unsigned long)pte & ~PAGE_MASK));
-               pmd++;
-       } while (p < end);
- loop_exit:
-       addr_offset = 0;
-       select_bit = 1;
-       for (i = 0; i < n_aliases; i++) {
-               if (d & select_bit) {
-                       (*__flush_dcache_segment_fn)(addr_offset, PAGE_SIZE);
-                       wmb();
-               }
-               select_bit <<= 1;
-               addr_offset += PAGE_SIZE;
-       }
- }
  /*
   * Note : (RPC) since the caches are physically tagged, the only point
   * of flush_cache_mm for SH-4 is to get rid of aliases from the
   * D-cache.  The assumption elsewhere, e.g. flush_cache_range, is that
   * lines can stay resident so long as the virtual address they were
   * accessed with (hence cache set) is in accord with the physical
-  * address (i.e. tag).  It's no different here.  So I reckon we don't
-  * need to flush the I-cache, since aliases don't matter for that.  We
-  * should try that.
+  * address (i.e. tag).  It's no different here.
   *
   * Caller takes mm->mmap_sem.
   */
@@@ -263,33 -197,7 +197,7 @@@ static void sh4_flush_cache_mm(void *ar
        if (cpu_context(smp_processor_id(), mm) == NO_CONTEXT)
                return;
  
-       /*
-        * If cache is only 4k-per-way, there are never any 'aliases'.  Since
-        * the cache is physically tagged, the data can just be left in there.
-        */
-       if (boot_cpu_data.dcache.n_aliases == 0)
-               return;
-       /*
-        * Don't bother groveling around the dcache for the VMA ranges
-        * if there are too many PTEs to make it worthwhile.
-        */
-       if (mm->nr_ptes >= MAX_DCACHE_PAGES)
-               flush_dcache_all();
-       else {
-               struct vm_area_struct *vma;
-               /*
-                * In this case there are reasonably sized ranges to flush,
-                * iterate through the VMA list and take care of any aliases.
-                */
-               for (vma = mm->mmap; vma; vma = vma->vm_next)
-                       __flush_cache_mm(mm, vma->vm_start, vma->vm_end);
-       }
-       /* Only touch the icache if one of the VMAs has VM_EXEC set. */
-       if (mm->exec_vm)
-               flush_icache_all();
+       flush_dcache_all();
  }
  
  /*
@@@ -302,44 -210,64 +210,64 @@@ static void sh4_flush_cache_page(void *
  {
        struct flusher_data *data = args;
        struct vm_area_struct *vma;
+       struct page *page;
        unsigned long address, pfn, phys;
-       unsigned int alias_mask;
+       int map_coherent = 0;
+       pgd_t *pgd;
+       pud_t *pud;
+       pmd_t *pmd;
+       pte_t *pte;
+       void *vaddr;
  
        vma = data->vma;
        address = data->addr1;
        pfn = data->addr2;
        phys = pfn << PAGE_SHIFT;
+       page = pfn_to_page(pfn);
  
        if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
                return;
  
-       alias_mask = boot_cpu_data.dcache.alias_mask;
-       /* We only need to flush D-cache when we have alias */
-       if ((address^phys) & alias_mask) {
-               /* Loop 4K of the D-cache */
-               flush_cache_4096(
-                       CACHE_OC_ADDRESS_ARRAY | (address & alias_mask),
-                       phys);
-               /* Loop another 4K of the D-cache */
-               flush_cache_4096(
-                       CACHE_OC_ADDRESS_ARRAY | (phys & alias_mask),
-                       phys);
-       }
+       address &= PAGE_MASK;
+       pgd = pgd_offset(vma->vm_mm, address);
+       pud = pud_offset(pgd, address);
+       pmd = pmd_offset(pud, address);
+       pte = pte_offset_kernel(pmd, address);
+       /* If the page isn't present, there is nothing to do here. */
+       if (!(pte_val(*pte) & _PAGE_PRESENT))
+               return;
  
-       alias_mask = boot_cpu_data.icache.alias_mask;
-       if (vma->vm_flags & VM_EXEC) {
+       if ((vma->vm_mm == current->active_mm))
+               vaddr = NULL;
+       else {
                /*
-                * Evict entries from the portion of the cache from which code
-                * may have been executed at this address (virtual).  There's
-                * no need to evict from the portion corresponding to the
-                * physical address as for the D-cache, because we know the
-                * kernel has never executed the code through its identity
-                * translation.
+                * Use kmap_coherent or kmap_atomic to do flushes for
+                * another ASID than the current one.
                 */
-               flush_cache_4096(
-                       CACHE_IC_ADDRESS_ARRAY | (address & alias_mask),
-                       phys);
+               map_coherent = (current_cpu_data.dcache.n_aliases &&
+                       !test_bit(PG_dcache_dirty, &page->flags) &&
+                       page_mapped(page));
+               if (map_coherent)
+                       vaddr = kmap_coherent(page, address);
+               else
+                       vaddr = kmap_atomic(page, KM_USER0);
+               address = (unsigned long)vaddr;
+       }
+       if (pages_do_alias(address, phys))
+               flush_cache_4096(CACHE_OC_ADDRESS_ARRAY |
+                       (address & shm_align_mask), phys);
+       if (vma->vm_flags & VM_EXEC)
+               flush_icache_all();
+       if (vaddr) {
+               if (map_coherent)
+                       kunmap_coherent(vaddr);
+               else
+                       kunmap_atomic(vaddr, KM_USER0);
        }
  }
  
@@@ -372,24 -300,10 +300,10 @@@ static void sh4_flush_cache_range(void 
        if (boot_cpu_data.dcache.n_aliases == 0)
                return;
  
-       /*
-        * Don't bother with the lookup and alias check if we have a
-        * wide range to cover, just blow away the dcache in its
-        * entirety instead. -- PFM.
-        */
-       if (((end - start) >> PAGE_SHIFT) >= MAX_DCACHE_PAGES)
-               flush_dcache_all();
-       else
-               __flush_cache_mm(vma->vm_mm, start, end);
+       flush_dcache_all();
  
-       if (vma->vm_flags & VM_EXEC) {
-               /*
-                * TODO: Is this required???  Need to look at how I-cache
-                * coherency is assured when new programs are loaded to see if
-                * this matters.
-                */
+       if (vma->vm_flags & VM_EXEC)
                flush_icache_all();
-       }
  }
  
  /**
@@@ -443,7 -357,7 +357,7 @@@ static void __flush_cache_4096(unsigne
         * pointless nead-of-loop check for 0 iterations.
         */
        do {
-               ea = base_addr + PAGE_SIZE;
+               ea = base_addr + 4096;
                a = base_addr;
                p = phys;
  
        } while (--way_count != 0);
  }
  
- /*
-  * Break the 1, 2 and 4 way variants of this out into separate functions to
-  * avoid nearly all the overhead of having the conditional stuff in the function
-  * bodies (+ the 1 and 2 way cases avoid saving any registers too).
-  *
-  * We want to eliminate unnecessary bus transactions, so this code uses
-  * a non-obvious technique.
-  *
-  * Loop over a cache way sized block of, one cache line at a time. For each
-  * line, use movca.a to cause the current cache line contents to be written
-  * back, but without reading anything from main memory. However this has the
-  * side effect that the cache is now caching that memory location. So follow
-  * this with a cache invalidate to mark the cache line invalid. And do all
-  * this with interrupts disabled, to avoid the cache line being accidently
-  * evicted while it is holding garbage.
-  *
-  * This also breaks in a number of circumstances:
-  * - if there are modifications to the region of memory just above
-  *   empty_zero_page (for example because a breakpoint has been placed
-  *   there), then these can be lost.
-  *
-  *   This is because the the memory address which the cache temporarily
-  *   caches in the above description is empty_zero_page. So the
-  *   movca.l hits the cache (it is assumed that it misses, or at least
-  *   isn't dirty), modifies the line and then invalidates it, losing the
-  *   required change.
-  *
-  * - If caches are disabled or configured in write-through mode, then
-  *   the movca.l writes garbage directly into memory.
-  */
- static void __flush_dcache_segment_writethrough(unsigned long start,
-                                               unsigned long extent_per_way)
- {
-       unsigned long addr;
-       int i;
-       addr = CACHE_OC_ADDRESS_ARRAY | (start & cpu_data->dcache.entry_mask);
-       while (extent_per_way) {
-               for (i = 0; i < cpu_data->dcache.ways; i++)
-                       __raw_writel(0, addr + cpu_data->dcache.way_incr * i);
-               addr += cpu_data->dcache.linesz;
-               extent_per_way -= cpu_data->dcache.linesz;
-       }
- }
- static void __flush_dcache_segment_1way(unsigned long start,
-                                       unsigned long extent_per_way)
- {
-       unsigned long orig_sr, sr_with_bl;
-       unsigned long base_addr;
-       unsigned long way_incr, linesz, way_size;
-       struct cache_info *dcache;
-       register unsigned long a0, a0e;
-       asm volatile("stc sr, %0" : "=r" (orig_sr));
-       sr_with_bl = orig_sr | (1<<28);
-       base_addr = ((unsigned long)&empty_zero_page[0]);
-       /*
-        * The previous code aligned base_addr to 16k, i.e. the way_size of all
-        * existing SH-4 D-caches.  Whilst I don't see a need to have this
-        * aligned to any better than the cache line size (which it will be
-        * anyway by construction), let's align it to at least the way_size of
-        * any existing or conceivable SH-4 D-cache.  -- RPC
-        */
-       base_addr = ((base_addr >> 16) << 16);
-       base_addr |= start;
-       dcache = &boot_cpu_data.dcache;
-       linesz = dcache->linesz;
-       way_incr = dcache->way_incr;
-       way_size = dcache->way_size;
-       a0 = base_addr;
-       a0e = base_addr + extent_per_way;
-       do {
-               asm volatile("ldc %0, sr" : : "r" (sr_with_bl));
-               asm volatile("movca.l r0, @%0\n\t"
-                            "ocbi @%0" : : "r" (a0));
-               a0 += linesz;
-               asm volatile("movca.l r0, @%0\n\t"
-                            "ocbi @%0" : : "r" (a0));
-               a0 += linesz;
-               asm volatile("movca.l r0, @%0\n\t"
-                            "ocbi @%0" : : "r" (a0));
-               a0 += linesz;
-               asm volatile("movca.l r0, @%0\n\t"
-                            "ocbi @%0" : : "r" (a0));
-               asm volatile("ldc %0, sr" : : "r" (orig_sr));
-               a0 += linesz;
-       } while (a0 < a0e);
- }
- static void __flush_dcache_segment_2way(unsigned long start,
-                                       unsigned long extent_per_way)
- {
-       unsigned long orig_sr, sr_with_bl;
-       unsigned long base_addr;
-       unsigned long way_incr, linesz, way_size;
-       struct cache_info *dcache;
-       register unsigned long a0, a1, a0e;
-       asm volatile("stc sr, %0" : "=r" (orig_sr));
-       sr_with_bl = orig_sr | (1<<28);
-       base_addr = ((unsigned long)&empty_zero_page[0]);
-       /* See comment under 1-way above */
-       base_addr = ((base_addr >> 16) << 16);
-       base_addr |= start;
-       dcache = &boot_cpu_data.dcache;
-       linesz = dcache->linesz;
-       way_incr = dcache->way_incr;
-       way_size = dcache->way_size;
-       a0 = base_addr;
-       a1 = a0 + way_incr;
-       a0e = base_addr + extent_per_way;
-       do {
-               asm volatile("ldc %0, sr" : : "r" (sr_with_bl));
-               asm volatile("movca.l r0, @%0\n\t"
-                            "movca.l r0, @%1\n\t"
-                            "ocbi @%0\n\t"
-                            "ocbi @%1" : :
-                            "r" (a0), "r" (a1));
-               a0 += linesz;
-               a1 += linesz;
-               asm volatile("movca.l r0, @%0\n\t"
-                            "movca.l r0, @%1\n\t"
-                            "ocbi @%0\n\t"
-                            "ocbi @%1" : :
-                            "r" (a0), "r" (a1));
-               a0 += linesz;
-               a1 += linesz;
-               asm volatile("movca.l r0, @%0\n\t"
-                            "movca.l r0, @%1\n\t"
-                            "ocbi @%0\n\t"
-                            "ocbi @%1" : :
-                            "r" (a0), "r" (a1));
-               a0 += linesz;
-               a1 += linesz;
-               asm volatile("movca.l r0, @%0\n\t"
-                            "movca.l r0, @%1\n\t"
-                            "ocbi @%0\n\t"
-                            "ocbi @%1" : :
-                            "r" (a0), "r" (a1));
-               asm volatile("ldc %0, sr" : : "r" (orig_sr));
-               a0 += linesz;
-               a1 += linesz;
-       } while (a0 < a0e);
- }
- static void __flush_dcache_segment_4way(unsigned long start,
-                                       unsigned long extent_per_way)
- {
-       unsigned long orig_sr, sr_with_bl;
-       unsigned long base_addr;
-       unsigned long way_incr, linesz, way_size;
-       struct cache_info *dcache;
-       register unsigned long a0, a1, a2, a3, a0e;
-       asm volatile("stc sr, %0" : "=r" (orig_sr));
-       sr_with_bl = orig_sr | (1<<28);
-       base_addr = ((unsigned long)&empty_zero_page[0]);
-       /* See comment under 1-way above */
-       base_addr = ((base_addr >> 16) << 16);
-       base_addr |= start;
-       dcache = &boot_cpu_data.dcache;
-       linesz = dcache->linesz;
-       way_incr = dcache->way_incr;
-       way_size = dcache->way_size;
-       a0 = base_addr;
-       a1 = a0 + way_incr;
-       a2 = a1 + way_incr;
-       a3 = a2 + way_incr;
-       a0e = base_addr + extent_per_way;
-       do {
-               asm volatile("ldc %0, sr" : : "r" (sr_with_bl));
-               asm volatile("movca.l r0, @%0\n\t"
-                            "movca.l r0, @%1\n\t"
-                            "movca.l r0, @%2\n\t"
-                            "movca.l r0, @%3\n\t"
-                            "ocbi @%0\n\t"
-                            "ocbi @%1\n\t"
-                            "ocbi @%2\n\t"
-                            "ocbi @%3\n\t" : :
-                            "r" (a0), "r" (a1), "r" (a2), "r" (a3));
-               a0 += linesz;
-               a1 += linesz;
-               a2 += linesz;
-               a3 += linesz;
-               asm volatile("movca.l r0, @%0\n\t"
-                            "movca.l r0, @%1\n\t"
-                            "movca.l r0, @%2\n\t"
-                            "movca.l r0, @%3\n\t"
-                            "ocbi @%0\n\t"
-                            "ocbi @%1\n\t"
-                            "ocbi @%2\n\t"
-                            "ocbi @%3\n\t" : :
-                            "r" (a0), "r" (a1), "r" (a2), "r" (a3));
-               a0 += linesz;
-               a1 += linesz;
-               a2 += linesz;
-               a3 += linesz;
-               asm volatile("movca.l r0, @%0\n\t"
-                            "movca.l r0, @%1\n\t"
-                            "movca.l r0, @%2\n\t"
-                            "movca.l r0, @%3\n\t"
-                            "ocbi @%0\n\t"
-                            "ocbi @%1\n\t"
-                            "ocbi @%2\n\t"
-                            "ocbi @%3\n\t" : :
-                            "r" (a0), "r" (a1), "r" (a2), "r" (a3));
-               a0 += linesz;
-               a1 += linesz;
-               a2 += linesz;
-               a3 += linesz;
-               asm volatile("movca.l r0, @%0\n\t"
-                            "movca.l r0, @%1\n\t"
-                            "movca.l r0, @%2\n\t"
-                            "movca.l r0, @%3\n\t"
-                            "ocbi @%0\n\t"
-                            "ocbi @%1\n\t"
-                            "ocbi @%2\n\t"
-                            "ocbi @%3\n\t" : :
-                            "r" (a0), "r" (a1), "r" (a2), "r" (a3));
-               asm volatile("ldc %0, sr" : : "r" (orig_sr));
-               a0 += linesz;
-               a1 += linesz;
-               a2 += linesz;
-               a3 += linesz;
-       } while (a0 < a0e);
- }
  extern void __weak sh4__flush_region_init(void);
  
  /*
   */
  void __init sh4_cache_init(void)
  {
-       unsigned int wt_enabled = !!(__raw_readl(CCR) & CCR_CACHE_WT);
        printk("PVR=%08x CVR=%08x PRR=%08x\n",
                ctrl_inl(CCN_PVR),
                ctrl_inl(CCN_CVR),
                ctrl_inl(CCN_PRR));
  
-       if (wt_enabled)
-               __flush_dcache_segment_fn = __flush_dcache_segment_writethrough;
-       else {
-               switch (boot_cpu_data.dcache.ways) {
-               case 1:
-                       __flush_dcache_segment_fn = __flush_dcache_segment_1way;
-                       break;
-               case 2:
-                       __flush_dcache_segment_fn = __flush_dcache_segment_2way;
-                       break;
-               case 4:
-                       __flush_dcache_segment_fn = __flush_dcache_segment_4way;
-                       break;
-               default:
-                       panic("unknown number of cache ways\n");
-                       break;
-               }
-       }
        local_flush_icache_range        = sh4_flush_icache_range;
        local_flush_dcache_page         = sh4_flush_dcache_page;
        local_flush_cache_all           = sh4_flush_cache_all;