[XTENSA] Add support for cache-aliasing
Add support for processors that have cache-aliasing issues, such as
the Stretch S5000 processor. Cache-aliasing means that the size of
the cache (for one way) is larger than the page size, thus, a page
can end up in several places in cache depending on the virtual to
physical translation. The method used here is to map a user page
temporarily through the auto-refill way 0 and of of the DTLB.
We probably will want to revisit this issue and use a better
approach with kmap/kunmap.
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c
index d0323cd..d5ffe7b 100644
--- a/arch/xtensa/kernel/asm-offsets.c
+++ b/arch/xtensa/kernel/asm-offsets.c
@@ -18,12 +18,13 @@
#include <linux/stddef.h>
#include <linux/thread_info.h>
#include <linux/ptrace.h>
+#include <linux/mm.h>
+
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#define DEFINE(sym, val) asm volatile("\n->" #sym " %0 " #val : : "i" (val))
-#define BLANK() asm volatile("\n->" : : )
int main(void)
{
@@ -63,7 +64,6 @@
DEFINE(PT_SIZE, sizeof(struct pt_regs));
DEFINE(PT_AREG_END, offsetof (struct pt_regs, areg[XCHAL_NUM_AREGS]));
DEFINE(PT_USER_SIZE, offsetof(struct pt_regs, areg[XCHAL_NUM_AREGS]));
- BLANK();
/* struct task_struct */
DEFINE(TASK_PTRACE, offsetof (struct task_struct, ptrace));
@@ -73,27 +73,26 @@
DEFINE(TASK_THREAD, offsetof (struct task_struct, thread));
DEFINE(TASK_THREAD_INFO, offsetof (struct task_struct, stack));
DEFINE(TASK_STRUCT_SIZE, sizeof (struct task_struct));
- BLANK();
/* struct thread_info (offset from start_struct) */
DEFINE(THREAD_RA, offsetof (struct task_struct, thread.ra));
DEFINE(THREAD_SP, offsetof (struct task_struct, thread.sp));
DEFINE(THREAD_CP_SAVE, offsetof (struct task_struct, thread.cp_save));
DEFINE(THREAD_CURRENT_DS, offsetof (struct task_struct, thread.current_ds));
- BLANK();
/* struct mm_struct */
DEFINE(MM_USERS, offsetof(struct mm_struct, mm_users));
DEFINE(MM_PGD, offsetof (struct mm_struct, pgd));
DEFINE(MM_CONTEXT, offsetof (struct mm_struct, context));
- BLANK();
- DEFINE(PT_SINGLESTEP_BIT, PT_SINGLESTEP_BIT);
+
+ /* struct page */
+ DEFINE(PAGE_FLAGS, offsetof(struct page, flags));
/* constants */
DEFINE(_CLONE_VM, CLONE_VM);
DEFINE(_CLONE_UNTRACED, CLONE_UNTRACED);
+ DEFINE(PG_ARCH_1, PG_arch_1);
return 0;
}
-
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 65741e3..91a689e 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -7,7 +7,7 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
- * Copyright (C) 2004-2005 by Tensilica Inc.
+ * Copyright (C) 2004-2007 by Tensilica Inc.
*
* Chris Zankel <chris@zankel.net>
*
@@ -169,7 +169,7 @@
* We have to save all registers up to the first '1' from
* the right, except the current frame (bit 0).
* Assume a2 is: 001001000110001
- * All regiser frames starting from the top fiel to the marked '1'
+ * All register frames starting from the top field to the marked '1'
* must be saved.
*/
@@ -1590,7 +1590,7 @@
* The messy computation for 'pteval' above really simplifies
* into the following:
*
- * pteval = ((pmdval - PAGE_OFFSET) & PAGE_MASK) | PAGE_KERNEL
+ * pteval = ((pmdval - PAGE_OFFSET) & PAGE_MASK) | PAGE_DIRECTORY
*/
movi a1, -PAGE_OFFSET
@@ -1602,7 +1602,7 @@
or a0, a0, a1 # ... | PAGE_DIRECTORY
/*
- * We utilize all three wired-ways (7-9( to hold pmd translations.
+ * We utilize all three wired-ways (7-9) to hold pmd translations.
* Memory regions are mapped to the DTLBs according to bits 28 and 29.
* This allows to map the three most common regions to three different
* DTLBs:
@@ -1652,6 +1652,73 @@
9: l32i a0, a1, TASK_ACTIVE_MM # unlikely case mm == 0
j 8b
+#if (DCACHE_WAY_SIZE > PAGE_SIZE)
+
+2: /* Special case for cache aliasing.
+ * We (should) only get here if a clear_user_page, copy_user_page
+ * or the aliased cache flush functions got preemptively interrupted
+ * by another task. Re-establish temporary mapping to the
+ * TLBTEMP_BASE areas.
+ */
+
+ /* We shouldn't be in a double exception */
+
+ l32i a0, a2, PT_DEPC
+ bgeui a0, VALID_DOUBLE_EXCEPTION_ADDRESS, 2f
+
+ /* Make sure the exception originated in the special functions */
+
+ movi a0, __tlbtemp_mapping_start
+ rsr a3, EPC_1
+ bltu a3, a0, 2f
+ movi a0, __tlbtemp_mapping_end
+ bgeu a3, a0, 2f
+
+ /* Check if excvaddr was in one of the TLBTEMP_BASE areas. */
+
+ movi a3, TLBTEMP_BASE_1
+ rsr a0, EXCVADDR
+ bltu a0, a3, 2f
+
+ addi a1, a0, -(2 << (DCACHE_ALIAS_ORDER + PAGE_SHIFT))
+ bgeu a1, a3, 2f
+
+ /* Check if we have to restore an ITLB mapping. */
+
+ movi a1, __tlbtemp_mapping_itlb
+ rsr a3, EPC_1
+ sub a3, a3, a1
+
+ /* Calculate VPN */
+
+ movi a1, PAGE_MASK
+ and a1, a1, a0
+
+ /* Jump for ITLB entry */
+
+ bgez a3, 1f
+
+ /* We can use up to two TLBTEMP areas, one for src and one for dst. */
+
+ extui a3, a0, PAGE_SHIFT + DCACHE_ALIAS_ORDER, 1
+ add a1, a3, a1
+
+ /* PPN is in a6 for the first TLBTEMP area and in a7 for the second. */
+
+ mov a0, a6
+ movnez a0, a7, a3
+ j 3b
+
+ /* ITLB entry. We only use dst in a6. */
+
+1: witlb a6, a1
+ isync
+ j 4b
+
+
+#endif // DCACHE_WAY_SIZE > PAGE_SIZE
+
+
2: /* Invalid PGD, default exception handling */
movi a3, exc_table
diff --git a/arch/xtensa/mm/Makefile b/arch/xtensa/mm/Makefile
index a5aed59..10aec22 100644
--- a/arch/xtensa/mm/Makefile
+++ b/arch/xtensa/mm/Makefile
@@ -5,9 +5,5 @@
# removes any old dependencies. DON'T put your own dependencies here
# unless it's something special (ie not a .c file).
#
-# Note 2! The CFLAGS definition is now in the main makefile...
-obj-y := init.o fault.o tlb.o misc.o
-obj-m :=
-obj-n :=
-obj- :=
+obj-y := init.o fault.o tlb.o misc.o cache.o
diff --git a/arch/xtensa/mm/cache.c b/arch/xtensa/mm/cache.c
new file mode 100644
index 0000000..9a1fa94
--- /dev/null
+++ b/arch/xtensa/mm/cache.c
@@ -0,0 +1,256 @@
+/*
+ * arch/xtensa/mm/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) 2001-2006 Tensilica Inc.
+ *
+ * Chris Zankel <chris@zankel.net>
+ * Joe Taylor
+ * Marc Gauthier
+ *
+ */
+
+#include <linux/init.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/bootmem.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+
+#include <asm/pgtable.h>
+#include <asm/bootparam.h>
+#include <asm/mmu_context.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+//#define printd(x...) printk(x)
+#define printd(x...) do { } while(0)
+
+/*
+ * Note:
+ * The kernel provides one architecture bit PG_arch_1 in the page flags that
+ * can be used for cache coherency.
+ *
+ * I$-D$ coherency.
+ *
+ * The Xtensa architecture doesn't keep the instruction cache coherent with
+ * the data cache. We use the architecture bit to indicate if the caches
+ * are coherent. The kernel clears this bit whenever a page is added to the
+ * page cache. At that time, the caches might not be in sync. We, therefore,
+ * define this flag as 'clean' if set.
+ *
+ * D-cache aliasing.
+ *
+ * With cache aliasing, we have to always flush the cache when pages are
+ * unmapped (see tlb_start_vma(). So, we use this flag to indicate a dirty
+ * page.
+ *
+ *
+ *
+ */
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
+
+/*
+ * 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.
+ *
+ */
+
+void flush_dcache_page(struct page *page)
+{
+ struct address_space *mapping = page_mapping(page);
+
+ /*
+ * If we have a mapping but the page is not mapped to user-space
+ * yet, we simply mark this page dirty and defer flushing the
+ * caches until update_mmu().
+ */
+
+ if (mapping && !mapping_mapped(mapping)) {
+ if (!test_bit(PG_arch_1, &page->flags))
+ set_bit(PG_arch_1, &page->flags);
+ return;
+
+ } else {
+
+ unsigned long phys = page_to_phys(page);
+ unsigned long temp = page->index << PAGE_SHIFT;
+ unsigned long alias = !(DCACHE_ALIAS_EQ(temp, phys));
+ unsigned long virt;
+
+ /*
+ * Flush the page in kernel space and user space.
+ * Note that we can omit that step if aliasing is not
+ * an issue, but we do have to synchronize I$ and D$
+ * if we have a mapping.
+ */
+
+ if (!alias && !mapping)
+ return;
+
+ __flush_invalidate_dcache_page((long)page_address(page));
+
+ virt = TLBTEMP_BASE_1 + (temp & DCACHE_ALIAS_MASK);
+
+ if (alias)
+ __flush_invalidate_dcache_page_alias(virt, phys);
+
+ if (mapping)
+ __invalidate_icache_page_alias(virt, phys);
+ }
+
+ /* There shouldn't be an entry in the cache for this page anymore. */
+}
+
+
+/*
+ * For now, flush the whole cache. FIXME??
+ */
+
+void flush_cache_range(struct vm_area_struct* vma,
+ unsigned long start, unsigned long end)
+{
+ __flush_invalidate_dcache_all();
+ __invalidate_icache_all();
+}
+
+/*
+ * Remove any entry in the cache for this page.
+ *
+ * Note that this function is only called for user pages, so use the
+ * alias versions of the cache flush functions.
+ */
+
+void flush_cache_page(struct vm_area_struct* vma, unsigned long address,
+ unsigned long pfn)
+{
+ /* Note that we have to use the 'alias' address to avoid multi-hit */
+
+ unsigned long phys = page_to_phys(pfn_to_page(pfn));
+ unsigned long virt = TLBTEMP_BASE_1 + (address & DCACHE_ALIAS_MASK);
+
+ __flush_invalidate_dcache_page_alias(virt, phys);
+ __invalidate_icache_page_alias(virt, phys);
+}
+
+#endif
+
+void
+update_mmu_cache(struct vm_area_struct * vma, unsigned long addr, pte_t pte)
+{
+ unsigned long pfn = pte_pfn(pte);
+ struct page *page;
+
+ if (!pfn_valid(pfn))
+ return;
+
+ page = pfn_to_page(pfn);
+
+ /* Invalidate old entry in TLBs */
+
+ invalidate_itlb_mapping(addr);
+ invalidate_dtlb_mapping(addr);
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
+
+ if (!PageReserved(page) && test_bit(PG_arch_1, &page->flags)) {
+
+ unsigned long vaddr = TLBTEMP_BASE_1 + (addr & DCACHE_ALIAS_MASK);
+ unsigned long paddr = (unsigned long) page_address(page);
+ unsigned long phys = page_to_phys(page);
+
+ __flush_invalidate_dcache_page(paddr);
+
+ __flush_invalidate_dcache_page_alias(vaddr, phys);
+ __invalidate_icache_page_alias(vaddr, phys);
+
+ clear_bit(PG_arch_1, &page->flags);
+ }
+#else
+ if (!PageReserved(page) && !test_bit(PG_arch_1, &page->flags)
+ && (vma->vm_flags & VM_EXEC) != 0) {
+ unsigned long vaddr = addr & PAGE_MASK;
+ __flush_dcache_page(vaddr);
+ __invalidate_icache_page(vaddr);
+ set_bit(PG_arch_1, &page->flags);
+ }
+#endif
+}
+
+/*
+ * access_process_vm() has called get_user_pages(), which has done a
+ * flush_dcache_page() on the page.
+ */
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
+
+void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
+ unsigned long vaddr, void *dst, const void *src,
+ unsigned long len)
+{
+ unsigned long phys = page_to_phys(page);
+ unsigned long alias = !(DCACHE_ALIAS_EQ(vaddr, phys));
+
+ /* Flush and invalidate user page if aliased. */
+
+ if (alias) {
+ unsigned long temp = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
+ __flush_invalidate_dcache_page_alias(temp, phys);
+ }
+
+ /* Copy data */
+
+ memcpy(dst, src, len);
+
+ /*
+ * Flush and invalidate kernel page if aliased and synchronize
+ * data and instruction caches for executable pages.
+ */
+
+ if (alias) {
+ unsigned long temp = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
+
+ __flush_invalidate_dcache_range((unsigned long) dst, len);
+ if ((vma->vm_flags & VM_EXEC) != 0) {
+ __invalidate_icache_page_alias(temp, phys);
+ }
+
+ } else if ((vma->vm_flags & VM_EXEC) != 0) {
+ __flush_dcache_range((unsigned long)dst,len);
+ __invalidate_icache_range((unsigned long) dst, len);
+ }
+}
+
+extern void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
+ unsigned long vaddr, void *dst, const void *src,
+ unsigned long len)
+{
+ unsigned long phys = page_to_phys(page);
+ unsigned long alias = !(DCACHE_ALIAS_EQ(vaddr, phys));
+
+ /*
+ * Flush user page if aliased.
+ * (Note: a simply flush would be sufficient)
+ */
+
+ if (alias) {
+ unsigned long temp = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
+ __flush_invalidate_dcache_page_alias(temp, phys);
+ }
+
+ memcpy(dst, src, len);
+}
+
+#endif
diff --git a/arch/xtensa/mm/fault.c b/arch/xtensa/mm/fault.c
index 1600406..45d28f2 100644
--- a/arch/xtensa/mm/fault.c
+++ b/arch/xtensa/mm/fault.c
@@ -24,6 +24,8 @@
unsigned long asid_cache = ASID_USER_FIRST;
void bad_page_fault(struct pt_regs*, unsigned long, int);
+#undef DEBUG_PAGE_FAULT
+
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
@@ -64,7 +66,7 @@
exccause == EXCCAUSE_ITLB_MISS ||
exccause == EXCCAUSE_FETCH_CACHE_ATTRIBUTE) ? 1 : 0;
-#if 0
+#ifdef DEBUG_PAGE_FAULT
printk("[%s:%d:%08x:%d:%08x:%s%s]\n", current->comm, current->pid,
address, exccause, regs->pc, is_write? "w":"", is_exec? "x":"");
#endif
@@ -219,7 +221,7 @@
/* Are we prepared to handle this kernel fault? */
if ((entry = search_exception_tables(regs->pc)) != NULL) {
-#if 1
+#ifdef DEBUG_PAGE_FAULT
printk(KERN_DEBUG "%s: Exception at pc=%#010lx (%lx)\n",
current->comm, regs->pc, entry->fixup);
#endif
diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index 8415c76..b3086f3 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -15,40 +15,24 @@
* Kevin Chea
*/
-#include <linux/init.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/bootmem.h>
#include <linux/swap.h>
+#include <linux/mman.h>
+#include <linux/nodemask.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
#include <asm/pgtable.h>
#include <asm/bootparam.h>
#include <asm/mmu_context.h>
#include <asm/tlb.h>
-#include <asm/tlbflush.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
-#include <asm/pgtable.h>
-#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 */
@@ -323,228 +307,22 @@
printk("%d free pages\n", free);
}
-/* ------------------------------------------------------------------------- */
+struct kmem_cache *pgtable_cache __read_mostly;
-#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)
+static void pgd_ctor(void *addr, struct kmem_cache *cache, unsigned long flags)
{
+ pte_t* ptep = (pte_t*)addr;
+ int i;
- /* There shouldn't be any entries for this page. */
+ for (i = 0; i < 1024; i++, ptep++)
+ pte_clear(NULL, 0, ptep);
- __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)
+void __init pgtable_cache_init(void)
{
- /* 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);
+ pgtable_cache = kmem_cache_create("pgd",
+ PAGE_SIZE, PAGE_SIZE,
+ SLAB_HWCACHE_ALIGN,
+ pgd_ctor);
}
-
-
-
-/*
- * 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);
- }
- }
-}
-
diff --git a/arch/xtensa/mm/misc.S b/arch/xtensa/mm/misc.S
index ae08533..e1f8803 100644
--- a/arch/xtensa/mm/misc.S
+++ b/arch/xtensa/mm/misc.S
@@ -7,29 +7,33 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
- * Copyright (C) 2001 - 2005 Tensilica Inc.
+ * Copyright (C) 2001 - 2007 Tensilica Inc.
*
* Chris Zankel <chris@zankel.net>
*/
-/* Note: we might want to implement some of the loops as zero-overhead-loops,
- * where applicable and if supported by the processor.
- */
#include <linux/linkage.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/asmmacro.h>
#include <asm/cacheasm.h>
+#include <asm/tlbflush.h>
-/* clear_page (page) */
+
+/*
+ * clear_page and clear_user_page are the same for non-cache-aliased configs.
+ *
+ * clear_page (unsigned long page)
+ * a2
+ */
ENTRY(clear_page)
entry a1, 16
- addi a4, a2, PAGE_SIZE
- movi a3, 0
-1: s32i a3, a2, 0
+ movi a3, 0
+ __loopi a2, a7, PAGE_SIZE, 32
+ s32i a3, a2, 0
s32i a3, a2, 4
s32i a3, a2, 8
s32i a3, a2, 12
@@ -37,43 +41,278 @@
s32i a3, a2, 20
s32i a3, a2, 24
s32i a3, a2, 28
- addi a2, a2, 32
- blt a2, a4, 1b
+ __endla a2, a7, 32
retw
/*
+ * copy_page and copy_user_page are the same for non-cache-aliased configs.
+ *
* copy_page (void *to, void *from)
- * a2 a3
+ * a2 a3
*/
ENTRY(copy_page)
entry a1, 16
- addi a4, a2, PAGE_SIZE
-1: l32i a5, a3, 0
- l32i a6, a3, 4
- l32i a7, a3, 8
- s32i a5, a2, 0
- s32i a6, a2, 4
- s32i a7, a2, 8
- l32i a5, a3, 12
- l32i a6, a3, 16
- l32i a7, a3, 20
- s32i a5, a2, 12
- s32i a6, a2, 16
- s32i a7, a2, 20
- l32i a5, a3, 24
- l32i a6, a3, 28
- s32i a5, a2, 24
- s32i a6, a2, 28
- addi a2, a2, 32
- addi a3, a3, 32
- blt a2, a4, 1b
+ __loopi a2, a4, PAGE_SIZE, 32
+
+ l32i a8, a3, 0
+ l32i a9, a3, 4
+ s32i a8, a2, 0
+ s32i a9, a2, 4
+
+ l32i a8, a3, 8
+ l32i a9, a3, 12
+ s32i a8, a2, 8
+ s32i a9, a2, 12
+
+ l32i a8, a3, 16
+ l32i a9, a3, 20
+ s32i a8, a2, 16
+ s32i a9, a2, 20
+
+ l32i a8, a3, 24
+ l32i a9, a3, 28
+ s32i a8, a2, 24
+ s32i a9, a2, 28
+
+ addi a2, a2, 32
+ addi a3, a3, 32
+
+ __endl a2, a4
retw
/*
+ * If we have to deal with cache aliasing, we use temporary memory mappings
+ * to ensure that the source and destination pages have the same color as
+ * the virtual address. We use way 0 and 1 for temporary mappings in such cases.
+ *
+ * The temporary DTLB entries shouldn't be flushed by interrupts, but are
+ * flushed by preemptive task switches. Special code in the
+ * fast_second_level_miss handler re-established the temporary mapping.
+ * It requires that the PPNs for the destination and source addresses are
+ * in a6, and a7, respectively.
+ */
+
+/* TLB miss exceptions are treated special in the following region */
+
+ENTRY(__tlbtemp_mapping_start)
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE)
+
+/*
+ * clear_user_page (void *addr, unsigned long vaddr, struct page *page)
+ * a2 a3 a4
+ */
+
+ENTRY(clear_user_page)
+ entry a1, 32
+
+ /* Mark page dirty and determine alias. */
+
+ movi a7, (1 << PG_ARCH_1)
+ l32i a5, a4, PAGE_FLAGS
+ xor a6, a2, a3
+ extui a3, a3, PAGE_SHIFT, DCACHE_ALIAS_ORDER
+ extui a6, a6, PAGE_SHIFT, DCACHE_ALIAS_ORDER
+ or a5, a5, a7
+ slli a3, a3, PAGE_SHIFT
+ s32i a5, a4, PAGE_FLAGS
+
+ /* Skip setting up a temporary DTLB if not aliased. */
+
+ beqz a6, 1f
+
+ /* Invalidate kernel page. */
+
+ mov a10, a2
+ call8 __invalidate_dcache_page
+
+ /* Setup a temporary DTLB with the color of the VPN */
+
+ movi a4, -PAGE_OFFSET + (PAGE_KERNEL | _PAGE_HW_WRITE)
+ movi a5, TLBTEMP_BASE_1 # virt
+ add a6, a2, a4 # ppn
+ add a2, a5, a3 # add 'color'
+
+ wdtlb a6, a2
+ dsync
+
+1: movi a3, 0
+ __loopi a2, a7, PAGE_SIZE, 32
+ s32i a3, a2, 0
+ s32i a3, a2, 4
+ s32i a3, a2, 8
+ s32i a3, a2, 12
+ s32i a3, a2, 16
+ s32i a3, a2, 20
+ s32i a3, a2, 24
+ s32i a3, a2, 28
+ __endla a2, a7, 32
+
+ bnez a6, 1f
+ retw
+
+ /* We need to invalidate the temporary idtlb entry, if any. */
+
+1: addi a2, a2, -PAGE_SIZE
+ idtlb a2
+ dsync
+
+ retw
+
+/*
+ * copy_page_user (void *to, void *from, unsigned long vaddr, struct page *page)
+ * a2 a3 a4 a5
+ */
+
+ENTRY(copy_user_page)
+
+ entry a1, 32
+
+ /* Mark page dirty and determine alias for destination. */
+
+ movi a8, (1 << PG_ARCH_1)
+ l32i a9, a5, PAGE_FLAGS
+ xor a6, a2, a4
+ xor a7, a3, a4
+ extui a4, a4, PAGE_SHIFT, DCACHE_ALIAS_ORDER
+ extui a6, a6, PAGE_SHIFT, DCACHE_ALIAS_ORDER
+ extui a7, a7, PAGE_SHIFT, DCACHE_ALIAS_ORDER
+ or a9, a9, a8
+ slli a4, a4, PAGE_SHIFT
+ s32i a9, a5, PAGE_FLAGS
+ movi a5, -PAGE_OFFSET + (PAGE_KERNEL | _PAGE_HW_WRITE)
+
+ beqz a6, 1f
+
+ /* Invalidate dcache */
+
+ mov a10, a2
+ call8 __invalidate_dcache_page
+
+ /* Setup a temporary DTLB with a matching color. */
+
+ movi a8, TLBTEMP_BASE_1 # base
+ add a6, a2, a5 # ppn
+ add a2, a8, a4 # add 'color'
+
+ wdtlb a6, a2
+ dsync
+
+ /* Skip setting up a temporary DTLB for destination if not aliased. */
+
+1: beqz a7, 1f
+
+ /* Setup a temporary DTLB with a matching color. */
+
+ movi a8, TLBTEMP_BASE_2 # base
+ add a7, a3, a5 # ppn
+ add a3, a8, a4
+ addi a8, a3, 1 # way1
+
+ wdtlb a7, a8
+ dsync
+
+1: __loopi a2, a4, PAGE_SIZE, 32
+
+ l32i a8, a3, 0
+ l32i a9, a3, 4
+ s32i a8, a2, 0
+ s32i a9, a2, 4
+
+ l32i a8, a3, 8
+ l32i a9, a3, 12
+ s32i a8, a2, 8
+ s32i a9, a2, 12
+
+ l32i a8, a3, 16
+ l32i a9, a3, 20
+ s32i a8, a2, 16
+ s32i a9, a2, 20
+
+ l32i a8, a3, 24
+ l32i a9, a3, 28
+ s32i a8, a2, 24
+ s32i a9, a2, 28
+
+ addi a2, a2, 32
+ addi a3, a3, 32
+
+ __endl a2, a4
+
+ /* We need to invalidate any temporary mapping! */
+
+ bnez a6, 1f
+ bnez a7, 2f
+ retw
+
+1: addi a2, a2, -PAGE_SIZE
+ idtlb a2
+ dsync
+ bnez a7, 2f
+ retw
+
+2: addi a3, a3, -PAGE_SIZE+1
+ idtlb a3
+ dsync
+
+ retw
+
+#endif
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE)
+
+/*
+ * void __flush_invalidate_dcache_page_alias (addr, phys)
+ * a2 a3
+ */
+
+ENTRY(__flush_invalidate_dcache_page_alias)
+ entry sp, 16
+
+ movi a7, 0 # required for exception handler
+ addi a6, a3, (PAGE_KERNEL | _PAGE_HW_WRITE)
+ mov a4, a2
+ wdtlb a6, a2
+ dsync
+
+ ___flush_invalidate_dcache_page a2 a3
+
+ idtlb a4
+ dsync
+
+ retw
+
+#endif
+
+ENTRY(__tlbtemp_mapping_itlb)
+
+#if (ICACHE_WAY_SIZE > PAGE_SIZE)
+
+ENTRY(__invalidate_icache_page_alias)
+ entry sp, 16
+
+ addi a6, a3, (PAGE_KERNEL | _PAGE_HW_WRITE)
+ mov a4, a2
+ witlb a6, a2
+ isync
+
+ ___invalidate_icache_page a2 a3
+
+ iitlb a4
+ isync
+ retw
+
+#endif
+
+/* End of special treatment in tlb miss exception */
+
+ENTRY(__tlbtemp_mapping_end)
+
+/*
* void __invalidate_icache_page(ulong start)
*/
@@ -121,8 +360,6 @@
dsync
retw
-
-
/*
* void __invalidate_icache_range(ulong start, ulong size)
*/
@@ -168,7 +405,6 @@
___invalidate_dcache_range a2 a3 a4
-
retw
/*