Merge branch 'sh/cachetlb'

3 files changed, 84 insertions, 422 deletions

diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c
index a98c7d8984fa..60588c5bf7f9 100644
--- a/arch/sh/mm/cache-sh4.c
+++ b/arch/sh/mm/cache-sh4.c
@@ -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 @@
 #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>
 
@@ -23,21 +25,12 @@
  * 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,
@@ -123,12 +116,12 @@ static void sh4_flush_dcache_page(void *arg)
         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 @@ static void __uses_jump_to_uncached flush_icache_all(void)
         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)
@@ -170,89 +180,13 @@ 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 @@ static void sh4_flush_cache_mm(void *arg)
         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 @@ static void sh4_flush_cache_page(void *args)
 {
         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 @@ static void sh4_flush_cache_range(void *args)
         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 @@ static void __flush_cache_4096(unsigned long addr, unsigned long phys,
          * pointless nead-of-loop check for 0 iterations.
          */
         do {
-                ea = base_addr + PAGE_SIZE;
+                ea = base_addr + 4096;
                 a = base_addr;
                 p = phys;
 
@@ -463,245 +377,6 @@ static void __flush_cache_4096(unsigned long addr, unsigned long 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);
 
 /*
@@ -709,32 +384,11 @@ 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;
diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c
index 35c37b7f717a..4aa926054531 100644
--- a/arch/sh/mm/cache.c
+++ b/arch/sh/mm/cache.c
@@ -164,11 +164,17 @@ void flush_cache_all(void)
 
 void flush_cache_mm(struct mm_struct *mm)
 {
+        if (boot_cpu_data.dcache.n_aliases == 0)
+                return;
+
         cacheop_on_each_cpu(local_flush_cache_mm, mm, 1);
 }
 
 void flush_cache_dup_mm(struct mm_struct *mm)
 {
+        if (boot_cpu_data.dcache.n_aliases == 0)
+                return;
+
         cacheop_on_each_cpu(local_flush_cache_dup_mm, mm, 1);
 }
 
diff --git a/arch/sh/mm/kmap.c b/arch/sh/mm/kmap.c
index 16e01b5fed04..15d74ea42094 100644
--- a/arch/sh/mm/kmap.c
+++ b/arch/sh/mm/kmap.c
@@ -39,7 +39,9 @@ void *kmap_coherent(struct page *page, unsigned long addr)
         pagefault_disable();
 
         idx = FIX_CMAP_END -
-                ((addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT);
+                (((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) +
+                 (FIX_N_COLOURS * smp_processor_id()));
+
         vaddr = __fix_to_virt(idx);
 
         BUG_ON(!pte_none(*(kmap_coherent_pte - idx)));