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authorPaul Mundt <lethal@linux-sh.org>2008-02-13 20:14:10 +0900
committerPaul Mundt <lethal@linux-sh.org>2008-02-14 14:22:12 +0900
commit38350e0a00f973dd9c6556beeff0f7eb5ef3f58b (patch)
treea419a9c9b45a6cb20a2f4f809f628c10a3ce9ab9 /arch/sh/mm
parent5c8f82c64941594cdab53bf9f9a66c190781f4f6 (diff)
sh: Get SH-5 caches working again post-unification.
A number of cleanups to get the SH-5 cache management code in line with the rest of the SH backend. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/mm')
-rw-r--r--arch/sh/mm/cache-sh5.c1021
1 files changed, 411 insertions, 610 deletions
diff --git a/arch/sh/mm/cache-sh5.c b/arch/sh/mm/cache-sh5.c
index 5d1f615fe52..3877321fced 100644
--- a/arch/sh/mm/cache-sh5.c
+++ b/arch/sh/mm/cache-sh5.c
@@ -1,10 +1,10 @@
/*
* arch/sh/mm/cache-sh5.c
*
- * Original version Copyright (C) 2000, 2001 Paolo Alberelli
- * Second version Copyright (C) benedict.gaster@superh.com 2002
- * Third version Copyright Richard.Curnow@superh.com 2003
- * Hacks to third version Copyright (C) 2003 Paul Mundt
+ * Copyright (C) 2000, 2001 Paolo Alberelli
+ * Copyright (C) 2002 Benedict Gaster
+ * Copyright (C) 2003 Richard Curnow
+ * Copyright (C) 2003 - 2008 Paul Mundt
*
* 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
@@ -13,101 +13,20 @@
#include <linux/init.h>
#include <linux/mman.h>
#include <linux/mm.h>
-#include <linux/threads.h>
-#include <asm/page.h>
-#include <asm/pgtable.h>
+#include <asm/tlb.h>
#include <asm/processor.h>
#include <asm/cache.h>
-#include <asm/tlb.h>
-#include <asm/io.h>
+#include <asm/pgalloc.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
-#include <asm/pgalloc.h> /* for flush_itlb_range */
-
-#include <linux/proc_fs.h>
-
-/* This function is in entry.S */
-extern unsigned long switch_and_save_asid(unsigned long new_asid);
/* Wired TLB entry for the D-cache */
static unsigned long long dtlb_cache_slot;
-/**
- * sh64_cache_init()
- *
- * This is pretty much just a straightforward clone of the SH
- * detect_cpu_and_cache_system().
- *
- * This function is responsible for setting up all of the cache
- * info dynamically as well as taking care of CPU probing and
- * setting up the relevant subtype data.
- *
- * FIXME: For the time being, we only really support the SH5-101
- * out of the box, and don't support dynamic probing for things
- * like the SH5-103 or even cut2 of the SH5-101. Implement this
- * later!
- */
-int __init sh64_cache_init(void)
+void __init p3_cache_init(void)
{
- /*
- * First, setup some sane values for the I-cache.
- */
- cpu_data->icache.ways = 4;
- cpu_data->icache.sets = 256;
- cpu_data->icache.linesz = L1_CACHE_BYTES;
-
- /*
- * FIXME: This can probably be cleaned up a bit as well.. for example,
- * do we really need the way shift _and_ the way_step_shift ?? Judging
- * by the existing code, I would guess no.. is there any valid reason
- * why we need to be tracking this around?
- */
- cpu_data->icache.way_shift = 13;
- cpu_data->icache.entry_shift = 5;
- cpu_data->icache.set_shift = 4;
- cpu_data->icache.way_step_shift = 16;
- cpu_data->icache.asid_shift = 2;
-
- /*
- * way offset = cache size / associativity, so just don't factor in
- * associativity in the first place..
- */
- cpu_data->icache.way_ofs = cpu_data->icache.sets *
- cpu_data->icache.linesz;
-
- cpu_data->icache.asid_mask = 0x3fc;
- cpu_data->icache.idx_mask = 0x1fe0;
- cpu_data->icache.epn_mask = 0xffffe000;
- cpu_data->icache.flags = 0;
-
- /*
- * Next, setup some sane values for the D-cache.
- *
- * On the SH5, these are pretty consistent with the I-cache settings,
- * so we just copy over the existing definitions.. these can be fixed
- * up later, especially if we add runtime CPU probing.
- *
- * Though in the meantime it saves us from having to duplicate all of
- * the above definitions..
- */
- cpu_data->dcache = cpu_data->icache;
-
- /*
- * Setup any cache-related flags here
- */
-#if defined(CONFIG_DCACHE_WRITE_THROUGH)
- set_bit(SH_CACHE_MODE_WT, &(cpu_data->dcache.flags));
-#elif defined(CONFIG_DCACHE_WRITE_BACK)
- set_bit(SH_CACHE_MODE_WB, &(cpu_data->dcache.flags));
-#endif
-
- /*
- * We also need to reserve a slot for the D-cache in the DTLB, so we
- * do this now ..
- */
- dtlb_cache_slot = sh64_get_wired_dtlb_entry();
-
- return 0;
+ /* Reserve a slot for dcache colouring in the DTLB */
+ dtlb_cache_slot = sh64_get_wired_dtlb_entry();
}
#ifdef CONFIG_DCACHE_DISABLED
@@ -116,73 +35,48 @@ int __init sh64_cache_init(void)
#define sh64_dcache_purge_user_range(mm, start, end) do { } while (0)
#define sh64_dcache_purge_phy_page(paddr) do { } while (0)
#define sh64_dcache_purge_virt_page(mm, eaddr) do { } while (0)
-#define sh64_dcache_purge_kernel_range(start, end) do { } while (0)
-#define sh64_dcache_wback_current_user_range(start, end) do { } while (0)
#endif
-/*##########################################################################*/
-
-/* From here onwards, a rewrite of the implementation,
- by Richard.Curnow@superh.com.
-
- The major changes in this compared to the old version are;
- 1. use more selective purging through OCBP instead of using ALLOCO to purge
- by natural replacement. This avoids purging out unrelated cache lines
- that happen to be in the same set.
- 2. exploit the APIs copy_user_page and clear_user_page better
- 3. be more selective about I-cache purging, in particular use invalidate_all
- more sparingly.
-
- */
-
-/*##########################################################################
- SUPPORT FUNCTIONS
- ##########################################################################*/
-
-/****************************************************************************/
-/* The following group of functions deal with mapping and unmapping a temporary
- page into the DTLB slot that have been set aside for our exclusive use. */
-/* In order to accomplish this, we use the generic interface for adding and
- removing a wired slot entry as defined in arch/sh/mm/tlb-sh5.c */
-/****************************************************************************/
-
-static unsigned long slot_own_flags;
-
-static inline void sh64_setup_dtlb_cache_slot(unsigned long eaddr, unsigned long asid, unsigned long paddr)
+/*
+ * The following group of functions deal with mapping and unmapping a
+ * temporary page into a DTLB slot that has been set aside for exclusive
+ * use.
+ */
+static inline void
+sh64_setup_dtlb_cache_slot(unsigned long eaddr, unsigned long asid,
+ unsigned long paddr)
{
- local_irq_save(slot_own_flags);
+ local_irq_disable();
sh64_setup_tlb_slot(dtlb_cache_slot, eaddr, asid, paddr);
}
static inline void sh64_teardown_dtlb_cache_slot(void)
{
sh64_teardown_tlb_slot(dtlb_cache_slot);
- local_irq_restore(slot_own_flags);
+ local_irq_enable();
}
-/****************************************************************************/
-
#ifndef CONFIG_ICACHE_DISABLED
-
-static void __inline__ sh64_icache_inv_all(void)
+static inline void sh64_icache_inv_all(void)
{
unsigned long long addr, flag, data;
unsigned int flags;
- addr=ICCR0;
- flag=ICCR0_ICI;
- data=0;
+ addr = ICCR0;
+ flag = ICCR0_ICI;
+ data = 0;
/* Make this a critical section for safety (probably not strictly necessary.) */
local_irq_save(flags);
/* Without %1 it gets unexplicably wrong */
- asm volatile("getcfg %3, 0, %0\n\t"
- "or %0, %2, %0\n\t"
- "putcfg %3, 0, %0\n\t"
- "synci"
- : "=&r" (data)
- : "0" (data), "r" (flag), "r" (addr));
+ __asm__ __volatile__ (
+ "getcfg %3, 0, %0\n\t"
+ "or %0, %2, %0\n\t"
+ "putcfg %3, 0, %0\n\t"
+ "synci"
+ : "=&r" (data)
+ : "0" (data), "r" (flag), "r" (addr));
local_irq_restore(flags);
}
@@ -193,20 +87,12 @@ static void sh64_icache_inv_kernel_range(unsigned long start, unsigned long end)
* the addresses lie in the kernel superpage. */
unsigned long long ullend, addr, aligned_start;
-#if (NEFF == 32)
aligned_start = (unsigned long long)(signed long long)(signed long) start;
-#else
-#error "NEFF != 32"
-#endif
- aligned_start &= L1_CACHE_ALIGN_MASK;
- addr = aligned_start;
-#if (NEFF == 32)
+ addr = L1_CACHE_ALIGN(aligned_start);
ullend = (unsigned long long) (signed long long) (signed long) end;
-#else
-#error "NEFF != 32"
-#endif
+
while (addr <= ullend) {
- asm __volatile__ ("icbi %0, 0" : : "r" (addr));
+ __asm__ __volatile__ ("icbi %0, 0" : : "r" (addr));
addr += L1_CACHE_BYTES;
}
}
@@ -215,7 +101,7 @@ static void sh64_icache_inv_user_page(struct vm_area_struct *vma, unsigned long
{
/* If we get called, we know that vma->vm_flags contains VM_EXEC.
Also, eaddr is page-aligned. */
-
+ unsigned int cpu = smp_processor_id();
unsigned long long addr, end_addr;
unsigned long flags = 0;
unsigned long running_asid, vma_asid;
@@ -237,17 +123,17 @@ static void sh64_icache_inv_user_page(struct vm_area_struct *vma, unsigned long
*/
running_asid = get_asid();
- vma_asid = (vma->vm_mm->context & MMU_CONTEXT_ASID_MASK);
+ vma_asid = cpu_asid(cpu, vma->vm_mm);
if (running_asid != vma_asid) {
local_irq_save(flags);
switch_and_save_asid(vma_asid);
}
while (addr < end_addr) {
/* Worth unrolling a little */
- asm __volatile__("icbi %0, 0" : : "r" (addr));
- asm __volatile__("icbi %0, 32" : : "r" (addr));
- asm __volatile__("icbi %0, 64" : : "r" (addr));
- asm __volatile__("icbi %0, 96" : : "r" (addr));
+ __asm__ __volatile__("icbi %0, 0" : : "r" (addr));
+ __asm__ __volatile__("icbi %0, 32" : : "r" (addr));
+ __asm__ __volatile__("icbi %0, 64" : : "r" (addr));
+ __asm__ __volatile__("icbi %0, 96" : : "r" (addr));
addr += 128;
}
if (running_asid != vma_asid) {
@@ -256,8 +142,6 @@ static void sh64_icache_inv_user_page(struct vm_area_struct *vma, unsigned long
}
}
-/****************************************************************************/
-
static void sh64_icache_inv_user_page_range(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
@@ -275,10 +159,10 @@ static void sh64_icache_inv_user_page_range(struct mm_struct *mm,
possible with the D-cache. Just assume 64 for now as a working
figure.
*/
-
int n_pages;
- if (!mm) return;
+ if (!mm)
+ return;
n_pages = ((end - start) >> PAGE_SHIFT);
if (n_pages >= 64) {
@@ -290,7 +174,7 @@ static void sh64_icache_inv_user_page_range(struct mm_struct *mm,
unsigned long mm_asid, current_asid;
unsigned long long flags = 0ULL;
- mm_asid = mm->context & MMU_CONTEXT_ASID_MASK;
+ mm_asid = cpu_asid(smp_processor_id(), mm);
current_asid = get_asid();
if (mm_asid != current_asid) {
@@ -322,6 +206,7 @@ static void sh64_icache_inv_user_page_range(struct mm_struct *mm,
}
aligned_start = vma->vm_end; /* Skip to start of next region */
}
+
if (mm_asid != current_asid) {
switch_and_save_asid(current_asid);
local_irq_restore(flags);
@@ -329,47 +214,46 @@ static void sh64_icache_inv_user_page_range(struct mm_struct *mm,
}
}
+/*
+ * Invalidate a small range of user context I-cache, not necessarily page
+ * (or even cache-line) aligned.
+ *
+ * Since this is used inside ptrace, the ASID in the mm context typically
+ * won't match current_asid. We'll have to switch ASID to do this. For
+ * safety, and given that the range will be small, do all this under cli.
+ *
+ * Note, there is a hazard that the ASID in mm->context is no longer
+ * actually associated with mm, i.e. if the mm->context has started a new
+ * cycle since mm was last active. However, this is just a performance
+ * issue: all that happens is that we invalidate lines belonging to
+ * another mm, so the owning process has to refill them when that mm goes
+ * live again. mm itself can't have any cache entries because there will
+ * have been a flush_cache_all when the new mm->context cycle started.
+ */
static void sh64_icache_inv_user_small_range(struct mm_struct *mm,
unsigned long start, int len)
{
-
- /* Invalidate a small range of user context I-cache, not necessarily
- page (or even cache-line) aligned. */
-
unsigned long long eaddr = start;
unsigned long long eaddr_end = start + len;
unsigned long current_asid, mm_asid;
unsigned long long flags;
unsigned long long epage_start;
- /* Since this is used inside ptrace, the ASID in the mm context
- typically won't match current_asid. We'll have to switch ASID to do
- this. For safety, and given that the range will be small, do all
- this under cli.
-
- Note, there is a hazard that the ASID in mm->context is no longer
- actually associated with mm, i.e. if the mm->context has started a
- new cycle since mm was last active. However, this is just a
- performance issue: all that happens is that we invalidate lines
- belonging to another mm, so the owning process has to refill them
- when that mm goes live again. mm itself can't have any cache
- entries because there will have been a flush_cache_all when the new
- mm->context cycle started. */
-
- /* Align to start of cache line. Otherwise, suppose len==8 and start
- was at 32N+28 : the last 4 bytes wouldn't get invalidated. */
- eaddr = start & L1_CACHE_ALIGN_MASK;
+ /*
+ * Align to start of cache line. Otherwise, suppose len==8 and
+ * start was at 32N+28 : the last 4 bytes wouldn't get invalidated.
+ */
+ eaddr = L1_CACHE_ALIGN(start);
eaddr_end = start + len;
+ mm_asid = cpu_asid(smp_processor_id(), mm);
local_irq_save(flags);
- mm_asid = mm->context & MMU_CONTEXT_ASID_MASK;
current_asid = switch_and_save_asid(mm_asid);
epage_start = eaddr & PAGE_MASK;
- while (eaddr < eaddr_end)
- {
- asm __volatile__("icbi %0, 0" : : "r" (eaddr));
+ while (eaddr < eaddr_end) {
+ __asm__ __volatile__("icbi %0, 0" : : "r" (eaddr));
eaddr += L1_CACHE_BYTES;
}
switch_and_save_asid(current_asid);
@@ -394,30 +278,24 @@ static void sh64_icache_inv_current_user_range(unsigned long start, unsigned lon
been recycled since we were last active in which case we might just
invalidate another processes I-cache entries : no worries, just a
performance drop for him. */
- aligned_start = start & L1_CACHE_ALIGN_MASK;
+ aligned_start = L1_CACHE_ALIGN(start);
addr = aligned_start;
while (addr < ull_end) {
- asm __volatile__ ("icbi %0, 0" : : "r" (addr));
- asm __volatile__ ("nop");
- asm __volatile__ ("nop");
+ __asm__ __volatile__ ("icbi %0, 0" : : "r" (addr));
+ __asm__ __volatile__ ("nop");
+ __asm__ __volatile__ ("nop");
addr += L1_CACHE_BYTES;
}
}
-
#endif /* !CONFIG_ICACHE_DISABLED */
-/****************************************************************************/
-
#ifndef CONFIG_DCACHE_DISABLED
-
/* Buffer used as the target of alloco instructions to purge data from cache
sets by natural eviction. -- RPC */
-#define DUMMY_ALLOCO_AREA_SIZE L1_CACHE_SIZE_BYTES + (1024 * 4)
+#define DUMMY_ALLOCO_AREA_SIZE ((L1_CACHE_BYTES << 10) + (1024 * 4))
static unsigned char dummy_alloco_area[DUMMY_ALLOCO_AREA_SIZE] __cacheline_aligned = { 0, };
-/****************************************************************************/
-
-static void __inline__ sh64_dcache_purge_sets(int sets_to_purge_base, int n_sets)
+static void inline sh64_dcache_purge_sets(int sets_to_purge_base, int n_sets)
{
/* Purge all ways in a particular block of sets, specified by the base
set number and number of sets. Can handle wrap-around, if that's
@@ -428,102 +306,86 @@ static void __inline__ sh64_dcache_purge_sets(int sets_to_purge_base, int n_sets
int j;
int set_offset;
- dummy_buffer_base_set = ((int)&dummy_alloco_area & cpu_data->dcache.idx_mask) >> cpu_data->dcache.entry_shift;
+ dummy_buffer_base_set = ((int)&dummy_alloco_area &
+ cpu_data->dcache.entry_mask) >>
+ cpu_data->dcache.entry_shift;
set_offset = sets_to_purge_base - dummy_buffer_base_set;
- for (j=0; j<n_sets; j++, set_offset++) {
+ for (j = 0; j < n_sets; j++, set_offset++) {
set_offset &= (cpu_data->dcache.sets - 1);
- eaddr0 = (unsigned long long)dummy_alloco_area + (set_offset << cpu_data->dcache.entry_shift);
-
- /* Do one alloco which hits the required set per cache way. For
- write-back mode, this will purge the #ways resident lines. There's
- little point unrolling this loop because the allocos stall more if
- they're too close together. */
- eaddr1 = eaddr0 + cpu_data->dcache.way_ofs * cpu_data->dcache.ways;
- for (eaddr=eaddr0; eaddr<eaddr1; eaddr+=cpu_data->dcache.way_ofs) {
- asm __volatile__ ("alloco %0, 0" : : "r" (eaddr));
- asm __volatile__ ("synco"); /* TAKum03020 */
+ eaddr0 = (unsigned long long)dummy_alloco_area +
+ (set_offset << cpu_data->dcache.entry_shift);
+
+ /*
+ * Do one alloco which hits the required set per cache
+ * way. For write-back mode, this will purge the #ways
+ * resident lines. There's little point unrolling this
+ * loop because the allocos stall more if they're too
+ * close together.
+ */
+ eaddr1 = eaddr0 + cpu_data->dcache.way_size *
+ cpu_data->dcache.ways;
+
+ for (eaddr = eaddr0; eaddr < eaddr1;
+ eaddr += cpu_data->dcache.way_size) {
+ __asm__ __volatile__ ("alloco %0, 0" : : "r" (eaddr));
+ __asm__ __volatile__ ("synco"); /* TAKum03020 */
}
- eaddr1 = eaddr0 + cpu_data->dcache.way_ofs * cpu_data->dcache.ways;
- for (eaddr=eaddr0; eaddr<eaddr1; eaddr+=cpu_data->dcache.way_ofs) {
- /* Load from each address. Required because alloco is a NOP if
- the cache is write-through. Write-through is a config option. */
+ eaddr1 = eaddr0 + cpu_data->dcache.way_size *
+ cpu_data->dcache.ways;
+
+ for (eaddr = eaddr0; eaddr < eaddr1;
+ eaddr += cpu_data->dcache.way_size) {
+ /*
+ * Load from each address. Required because
+ * alloco is a NOP if the cache is write-through.
+ */
if (test_bit(SH_CACHE_MODE_WT, &(cpu_data->dcache.flags)))
- *(volatile unsigned char *)(int)eaddr;
+ ctrl_inb(eaddr);
}
}
- /* Don't use OCBI to invalidate the lines. That costs cycles directly.
- If the dummy block is just left resident, it will naturally get
- evicted as required. */
-
- return;
+ /*
+ * Don't use OCBI to invalidate the lines. That costs cycles
+ * directly. If the dummy block is just left resident, it will
+ * naturally get evicted as required.
+ */
}
-/****************************************************************************/
-
+/*
+ * Purge the entire contents of the dcache. The most efficient way to
+ * achieve this is to use alloco instructions on a region of unused
+ * memory equal in size to the cache, thereby causing the current
+ * contents to be discarded by natural eviction. The alternative, namely
+ * reading every tag, setting up a mapping for the corresponding page and
+ * doing an OCBP for the line, would be much more expensive.
+ */
static void sh64_dcache_purge_all(void)
{
- /* Purge the entire contents of the dcache. The most efficient way to
- achieve this is to use alloco instructions on a region of unused
- memory equal in size to the cache, thereby causing the current
- contents to be discarded by natural eviction. The alternative,
- namely reading every tag, setting up a mapping for the corresponding
- page and doing an OCBP for the line, would be much more expensive.
- */
sh64_dcache_purge_sets(0, cpu_data->dcache.sets);
-
- return;
-
}
-/****************************************************************************/
-
-static void sh64_dcache_purge_kernel_range(unsigned long start, unsigned long end)
-{
- /* Purge the range of addresses [start,end] from the D-cache. The
- addresses lie in the superpage mapping. There's no harm if we
- overpurge at either end - just a small performance loss. */
- unsigned long long ullend, addr, aligned_start;
-#if (NEFF == 32)
- aligned_start = (unsigned long long)(signed long long)(signed long) start;
-#else
-#error "NEFF != 32"
-#endif
- aligned_start &= L1_CACHE_ALIGN_MASK;
- addr = aligned_start;
-#if (NEFF == 32)
- ullend = (unsigned long long) (signed long long) (signed long) end;
-#else
-#error "NEFF != 32"
-#endif
- while (addr <= ullend) {
- asm __volatile__ ("ocbp %0, 0" : : "r" (addr));
- addr += L1_CACHE_BYTES;
- }
- return;
-}
/* Assumes this address (+ (2**n_synbits) pages up from it) aren't used for
anything else in the kernel */
#define MAGIC_PAGE0_START 0xffffffffec000000ULL
-static void sh64_dcache_purge_coloured_phy_page(unsigned long paddr, unsigned long eaddr)
+/* Purge the physical page 'paddr' from the cache. It's known that any
+ * cache lines requiring attention have the same page colour as the the
+ * address 'eaddr'.
+ *
+ * This relies on the fact that the D-cache matches on physical tags when
+ * no virtual tag matches. So we create an alias for the original page
+ * and purge through that. (Alternatively, we could have done this by
+ * switching ASID to match the original mapping and purged through that,
+ * but that involves ASID switching cost + probably a TLBMISS + refill
+ * anyway.)
+ */
+static void sh64_dcache_purge_coloured_phy_page(unsigned long paddr,
+ unsigned long eaddr)
{
- /* Purge the physical page 'paddr' from the cache. It's known that any
- cache lines requiring attention have the same page colour as the the
- address 'eaddr'.
-
- This relies on the fact that the D-cache matches on physical tags
- when no virtual tag matches. So we create an alias for the original
- page and purge through that. (Alternatively, we could have done
- this by switching ASID to match the original mapping and purged
- through that, but that involves ASID switching cost + probably a
- TLBMISS + refill anyway.)
- */
-
unsigned long long magic_page_start;
unsigned long long magic_eaddr, magic_eaddr_end;
@@ -531,47 +393,45 @@ static void sh64_dcache_purge_coloured_phy_page(unsigned long paddr, unsigned lo
/* As long as the kernel is not pre-emptible, this doesn't need to be
under cli/sti. */
-
sh64_setup_dtlb_cache_slot(magic_page_start, get_asid(), paddr);
magic_eaddr = magic_page_start;
magic_eaddr_end = magic_eaddr + PAGE_SIZE;
+
while (magic_eaddr < magic_eaddr_end) {
/* Little point in unrolling this loop - the OCBPs are blocking
and won't go any quicker (i.e. the loop overhead is parallel
to part of the OCBP execution.) */
- asm __volatile__ ("ocbp %0, 0" : : "r" (magic_eaddr));
+ __asm__ __volatile__ ("ocbp %0, 0" : : "r" (magic_eaddr));
magic_eaddr += L1_CACHE_BYTES;
}
sh64_teardown_dtlb_cache_slot();
}
-/****************************************************************************/
-
+/*
+ * Purge a page given its physical start address, by creating a temporary
+ * 1 page mapping and purging across that. Even if we know the virtual
+ * address (& vma or mm) of the page, the method here is more elegant
+ * because it avoids issues of coping with page faults on the purge
+ * instructions (i.e. no special-case code required in the critical path
+ * in the TLB miss handling).
+ */
static void sh64_dcache_purge_phy_page(unsigned long paddr)
{
- /* Pure a page given its physical start address, by creating a
- temporary 1 page mapping and purging across that. Even if we know
- the virtual address (& vma or mm) of the page, the method here is
- more elegant because it avoids issues of coping with page faults on
- the purge instructions (i.e. no special-case code required in the
- critical path in the TLB miss handling). */
-
unsigned long long eaddr_start, eaddr, eaddr_end;
int i;
/* As long as the kernel is not pre-emptible, this doesn't need to be
under cli/sti. */
-
eaddr_start = MAGIC_PAGE0_START;
- for (i=0; i < (1 << CACHE_OC_N_SYNBITS); i++) {
+ for (i = 0; i < (1 << CACHE_OC_N_SYNBITS); i++) {
sh64_setup_dtlb_cache_slot(eaddr_start, get_asid(), paddr);
eaddr = eaddr_start;
eaddr_end = eaddr + PAGE_SIZE;
while (eaddr < eaddr_end) {
- asm __volatile__ ("ocbp %0, 0" : : "r" (eaddr));
+ __asm__ __volatile__ ("ocbp %0, 0" : : "r" (eaddr));
eaddr += L1_CACHE_BYTES;
}
@@ -584,6 +444,7 @@ static void sh64_dcache_purge_user_pages(struct mm_struct *mm,
unsigned long addr, unsigned long end)
{
pgd_t *pgd;
+ pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pte_t entry;
@@ -597,7 +458,11 @@ static void sh64_dcache_purge_user_pages(struct mm_struct *mm,
if (pgd_bad(*pgd))
return;
- pmd = pmd_offset(pgd, addr);
+ pud = pud_offset(pgd, addr);
+ if (pud_none(*pud) || pud_bad(*pud))
+ return;
+
+ pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd) || pmd_bad(*pmd))
return;
@@ -611,421 +476,357 @@ static void sh64_dcache_purge_user_pages(struct mm_struct *mm,
} while (pte++, addr += PAGE_SIZE, addr != end);
pte_unmap_unlock(pte - 1, ptl);
}
-/****************************************************************************/
+/*
+ * There are at least 5 choices for the implementation of this, with
+ * pros (+), cons(-), comments(*):
+ *
+ * 1. ocbp each line in the range through the original user's ASID
+ * + no lines spuriously evicted
+ * - tlbmiss handling (must either handle faults on demand => extra
+ * special-case code in tlbmiss critical path), or map the page in
+ * advance (=> flush_tlb_range in advance to avoid multiple hits)
+ * - ASID switching
+ * - expensive for large ranges
+ *
+ * 2. temporarily map each page in the range to a special effective
+ * address and ocbp through the temporary mapping; relies on the
+ * fact that SH-5 OCB* always do TLB lookup and match on ptags (they
+ * never look at the etags)
+ * + no spurious evictions
+ * - expensive for large ranges
+ * * surely cheaper than (1)
+ *
+ * 3. walk all the lines in the cache, check the tags, if a match
+ * occurs create a page mapping to ocbp the line through
+ * + no spurious evictions
+ * - tag inspection overhead
+ * - (especially for small ranges)
+ * - potential cost of setting up/tearing down page mapping for
+ * every line that matches the range
+ * * cost partly independent of range size
+ *
+ * 4. walk all the lines in the cache, check the tags, if a match
+ * occurs use 4 * alloco to purge the line (+3 other probably
+ * innocent victims) by natural eviction
+ * + no tlb mapping overheads
+ * - spurious evictions
+ * - tag inspection overhead
+ *
+ * 5. implement like flush_cache_all
+ * + no tag inspection overhead
+ * - spurious evictions
+ * - bad for small ranges
+ *
+ * (1) can be ruled out as more expensive than (2). (2) appears best
+ * for small ranges. The choice between (3), (4) and (5) for large
+ * ranges and the range size for the large/small boundary need
+ * benchmarking to determine.
+ *
+ * For now use approach (2) for small ranges and (5) for large ones.
+ */
static void sh64_dcache_purge_user_range(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
- /* There are at least 5 choices for the implementation of this, with
- pros (+), cons(-), comments(*):
-
- 1. ocbp each line in the range through the original user's ASID
- + no lines spuriously evicted
- - tlbmiss handling (must either handle faults on demand => extra
- special-case code in tlbmiss critical path), or map the page in
- advance (=> flush_tlb_range in advance to avoid multiple hits)
- - ASID switching
- - expensive for large ranges
-
- 2. temporarily map each page in the range to a special effective
- address and ocbp through the temporary mapping; relies on the
- fact that SH-5 OCB* always do TLB lookup and match on ptags (they
- never look at the etags)
- + no spurious evictions
- - expensive for large ranges
- * surely cheaper than (1)
-
- 3. walk all the lines in the cache, check the tags, if a match
- occurs create a page mapping to ocbp the line through
- + no spurious evictions
- - tag inspection overhead
- - (especially for small ranges)
- - potential cost of setting up/tearing down page mapping for
- every line that matches the range
- * cost partly independent of range size
-
- 4. walk all the lines in the cache, check the tags, if a match
- occurs use 4 * alloco to purge the line (+3 other probably
- innocent victims) by natural eviction
- + no tlb mapping overheads
- - spurious evictions
- - tag inspection overhead
-
- 5. implement like flush_cache_all
- + no tag inspection overhead
- - spurious evictions
- - bad for small ranges
-
- (1) can be ruled out as more expensive than (2). (2) appears best
- for small ranges. The choice between (3), (4) and (5) for large
- ranges and the range size for the large/small boundary need
- benchmarking to determine.
-
- For now use approach (2) for small ranges and (5) for large ones.
-
- */
+ int n_pages = ((end - start) >> PAGE_SHIFT);
- int n_pages;
-
- n_pages = ((end - start) >> PAGE_SHIFT);
if (n_pages >= 64 || ((start ^ (end - 1)) & PMD_MASK)) {
-#if 1
sh64_dcache_purge_all();
-#else
- unsigned long long set, way;
- unsigned long mm_asid = mm->context & MMU_CONTEXT_ASID_MASK;
- for (set = 0; set < cpu_data->dcache.sets; set++) {
- unsigned long long set_base_config_addr = CACHE_OC_ADDRESS_ARRAY + (set << cpu_data->dcache.set_shift);
- for (way = 0; way < cpu_data->dcache.ways; way++) {
- unsigned long long config_addr = set_base_config_addr + (way << cpu_data->dcache.way_step_shift);
- unsigned long long tag0;
- unsigned long line_valid;
-
- asm __volatile__("getcfg %1, 0, %0" : "=r" (tag0) : "r" (config_addr));
- line_valid = tag0 & SH_CACHE_VALID;
- if (line_valid) {
- unsigned long cache_asid;
- unsigned long epn;
-
- cache_asid = (tag0 & cpu_data->dcache.asid_mask) >> cpu_data->dcache.asid_shift;
- /* The next line needs some
- explanation. The virtual tags
- encode bits [31:13] of the virtual
- address, bit [12] of the 'tag' being
- implied by the cache set index. */
- epn = (tag0 & cpu_data->dcache.epn_mask) | ((set & 0x80) << cpu_data->dcache.entry_shift);
-
- if ((cache_asid == mm_asid) && (start <= epn) && (epn < end)) {
- /* TODO : could optimise this
- call by batching multiple
- adjacent sets together. */
- sh64_dcache_purge_sets(set, 1);
- break; /* Don't waste time inspecting other ways for this set */
- }
- }
- }
- }
-#endif
} else {
/* Small range, covered by a single page table page */
start &= PAGE_MASK; /* should already be so */
end = PAGE_ALIGN(end); /* should already be so */
sh64_dcache_purge_user_pages(mm, start, end);
}
- return;
}
-static void sh64_dcache_wback_current_user_range(unsigned long start, unsigned long end)
+/*
+ * Purge the range of addresses from the D-cache.
+ *
+ * The addresses lie in the superpage mapping. There's no harm if we
+ * overpurge at either end - just a small performance loss.
+ */
+void __flush_purge_region(void *start, int size)
{
- unsigned long long aligned_start;
- unsigned long long ull_end;
- unsigned long long addr;
-
- ull_end = end;
+ unsigned long long ullend, addr, aligned_start;
- /* Just wback over the range using the natural addresses. TLB miss
- handling will be OK (TBC) : the range has just been written to by
- the signal frame setup code, so the PTEs must exist.
+ aligned_start = (unsigned long long)(signed long long)(signed long) start;
+ addr = L1_CACHE_ALIGN(aligned_start);
+ ullend = (unsigned long long) (signed long long) (signed long) start + size;
- Note, if we have CONFIG_PREEMPT and get preempted inside this loop,
- it doesn't matter, even if the pid->ASID mapping changes whilst
- we're away. In that case the cache will have been flushed when the
- mapping was renewed. So the writebacks below will be nugatory (and
- we'll doubtless have to fault the TLB entry/ies in again with the
- new ASID), but it's a rare case.
- */
- aligned_start = start & L1_CACHE_ALIGN_MASK;
- addr = aligned_start;
- while (addr < ull_end) {
- asm __volatile__ ("ocbwb %0, 0" : : "r" (addr));
+ while (addr <= ullend) {
+ __asm__ __volatile__ ("ocbp %0, 0" : : "r" (addr));
addr += L1_CACHE_BYTES;
}
}
-/****************************************************************************/
-
-/* These *MUST* lie in an area of virtual address space that's otherwise unused. */
-#define UNIQUE_EADDR_START 0xe0000000UL
-#define UNIQUE_EADDR_END 0xe8000000UL
-
-static unsigned long sh64_make_unique_eaddr(unsigned long user_eaddr, unsigned long paddr)
+void __flush_wback_region(void *start, int size)
{
- /* Given a physical address paddr, and a user virtual address
- user_eaddr which will eventually be mapped to it, create a one-off
- kernel-private eaddr mapped to the same paddr. This is used for
- creating special destination pages for copy_user_page and
- clear_user_page */
+ unsigned long long ullend, addr, aligned_start;
- static unsigned long current_pointer = UNIQUE_EADDR_START;
- unsigned long coloured_pointer;
+ aligned_start = (unsigned long long)(signed long long)(signed long) start;
+ addr = L1_CACHE_ALIGN(aligned_start);
+ ullend = (unsigned long long) (signed long long) (signed long) start + size;
- if (current_pointer == UNIQUE_EADDR_END) {
- sh64_dcache_purge_all();
- current_pointer = UNIQUE_EADDR_START;
+ while (addr < ullend) {
+ __asm__ __volatile__ ("ocbwb %0, 0" : : "r" (addr));
+ addr += L1_CACHE_BYTES;
}
-
- coloured_pointer = (current_pointer & ~CACHE_OC_SYN_MASK) | (user_eaddr & CACHE_OC_SYN_MASK);
- sh64_setup_dtlb_cache_slot(coloured_pointer, get_asid(), paddr);
-
- current_pointer += (PAGE_SIZE << CACHE_OC_N_SYNBITS);
-
- return coloured_pointer;
}
-/****************************************************************************/
-
-static void sh64_copy_user_page_coloured(void *to, void *from, unsigned long address)
+void __flush_invalidate_region(void *start, int size)
{
- void *coloured_to;
-
- /* Discard any existing cache entries of the wrong colour. These are
- present quite often, if the kernel has recently used the page
- internally, then given it up, then it's been allocated to the user.
- */
- sh64_dcache_purge_coloured_phy_page(__pa(to), (unsigned long) to);
-
- coloured_to = (void *) sh64_make_unique_eaddr(address, __pa(to));
- sh64_page_copy(from, coloured_to);
-
- sh64_teardown_dtlb_cache_slot();
-}
-
-static void sh64_clear_user_page_coloured(void *to, unsigned long address)
-{
- void *coloured_to;
-
- /* Discard any existing kernel-originated lines of the wrong colour (as
- above) */
- sh64_dcache_purge_coloured_phy_page(__pa(to), (unsigned long) to);
+ unsigned long long ullend, addr, aligned_start;
- coloured_to = (void *) sh64_make_unique_eaddr(address, __pa(to));
- sh64_page_clear(coloured_to);
+ aligned_start = (unsigned long long)(signed long long)(signed long) start;
+ addr = L1_CACHE_ALIGN(aligned_start);
+ ullend = (unsigned long long) (signed long long) (signed long) start + size;
- sh64_teardown_dtlb_cache_slot();
+ while (addr < ullend) {
+ __asm__ __volatile__ ("ocbi %0, 0" : : "r" (addr));
+ addr += L1_CACHE_BYTES;
+ }
}
-
#endif /* !CONFIG_DCACHE_DISABLED */
-/****************************************************************************/
-
-/*##########################################################################
- EXTERNALLY CALLABLE API.
- ##########################################################################*/
-
-/* These functions are described in Documentation/cachetlb.txt.
- Each one of these functions varies in behaviour depending on whether the
- I-cache and/or D-cache are configured out.
-
- Note that the Linux term 'flush' corresponds to what is termed 'purge' in
- the sh/sh64 jargon for the D-cache, i.e. write back dirty data then
- invalidate the cache lines, and 'invalidate' for the I-cache.
- */
-
-#undef FLUSH_TRACE
-
+/*
+ * Invalidate the entire contents of both caches, after writing back to
+ * memory any dirty data from the D-cache.
+ */
void flush_cache_all(void)
{
- /* Invalidate the entire contents of both caches, after writing back to
- memory any dirty data from the D-cache. */
sh64_dcache_purge_all();
sh64_icache_inv_all();
}
-/****************************************************************************/
-
+/*
+ * Invalidate an entire user-address space from both caches, after
+ * writing back dirty data (e.g. for shared mmap etc).
+ *
+ * This could be coded selectively by inspecting all the tags then
+ * doing 4*alloco on any set containing a match (as for
+ * flush_cache_range), but fork/exit/execve (where this is called from)
+ * are expensive anyway.
+ *
+ * Have to do a purge here, despite the comments re I-cache below.
+ * There could be odd-coloured dirty data associated with the mm still
+ * in the cache - if this gets written out through natural eviction
+ * after the kernel has reused the page there will be chaos.
+ *
+ * The mm being torn down won't ever be active again, so any Icache
+ * lines tagged with its ASID won't be visible for the rest of the
+ * lifetime of this ASID cycle. Before the ASID gets reused, there
+ * will be a flush_cache_all. Hence we don't need to touch the
+ * I-cache. This is similar to the lack of action needed in
+ * flush_tlb_mm - see fault.c.
+ */
void flush_cache_mm(struct mm_struct *mm)
{
- /* Invalidate an entire user-address space from both caches, after
- writing back dirty data (e.g. for shared mmap etc). */
-
- /* This could be coded selectively by inspecting all the tags then
- doing 4*alloco on any set containing a match (as for
- flush_cache_range), but fork/exit/execve (where this is called from)
- are expensive anyway. */
-
- /* Have to do a purge here, despite the comments re I-cache below.
- There could be odd-coloured dirty data associated with the mm still
- in the cache - if this gets written out through natural eviction
- after the kernel has reused the page there will be chaos.
- */
-
sh64_dcache_purge_all();
-
- /* The mm being torn down won't ever be active again, so any Icache
- lines tagged with its ASID won't be visible for the rest of the
- lifetime of this ASID cycle. Before the ASID gets reused, there
- will be a flush_cache_all. Hence we don't need to touch the
- I-cache. This is similar to the lack of action needed in
- flush_tlb_mm - see fault.c. */
}
-/****************************************************************************/
-
+/*
+ * Invalidate (from both caches) the range [start,end) of virtual
+ * addresses from the user address space specified by mm, after writing
+ * back any dirty data.
+ *
+ * Note, 'end' is 1 byte beyond the end of the range to flush.
+ */
void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
- /* Invalidate (from both caches) the range [start,end) of virtual
- addresses from the user address space specified by mm, after writing
- back any dirty data.
-
- Note, 'end' is 1 byte beyond the end of the range to flush. */
-
sh64_dcache_purge_user_range(mm, start, end);
sh64_icache_inv_user_page_range(mm, start, end);
}
-/****************************************************************************/
-
-void flush_cache_page(struct vm_area_struct *vma, unsigned long eaddr, unsigned long pfn)
+/*
+ * Invalidate any entries in either cache for the vma within the user
+ * address space vma->vm_mm for the page starting at virtual address
+ * 'eaddr'. This seems to be used primarily in breaking COW. Note,
+ * the I-cache must be searched too in case the page in question is
+ * both writable and being executed from (e.g. stack trampolines.)
+ *
+ * Note, this is called with pte lock held.
+ */
+void flush_cache_page(struct vm_area_struct *vma, unsigned long eaddr,
+ unsigned long pfn)
{
- /* Invalidate any entries in either cache for the vma within the user
- address space vma->vm_mm for the page starting at virtual address
- 'eaddr'. This seems to be used primarily in breaking COW. Note,
- the I-cache must be searched too in case the page in question is
- both writable and being executed from (e.g. stack trampolines.)
-
- Note, this is called with pte lock held.
- */
-
sh64_dcache_purge_phy_page(pfn << PAGE_SHIFT);
- if (vma->vm_flags & VM_EXEC) {
+ if (vma->vm_flags & VM_EXEC)
sh64_icache_inv_user_page(vma, eaddr);
- }
}
-/****************************************************************************/
+void flush_dcache_page(struct page *page)
+{
+ sh64_dcache_purge_phy_page(page_to_phys(page));
+ wmb();
+}
-#ifndef CONFIG_DCACHE_DISABLED
+/*
+ * Flush the range [start,end] of kernel virtual adddress space from
+ * the I-cache. The corresponding range must be purged from the
+ * D-cache also because the SH-5 doesn't have cache snooping between
+ * the caches. The addresses will be visible through the superpage
+ * mapping, therefore it's guaranteed that there no cache entries for
+ * the range in cache sets of the wrong colour.
+ */
+void flush_icache_range(unsigned long start, unsigned long end)
+{
+ __flush_purge_region((void *)start, end);
+ wmb();
+ sh64_icache_inv_kernel_range(start, end);
+}
-void copy_user_page(void *to, void *from, unsigned long address, struct page *page)
+/*
+ * Flush the range of user (defined by vma->vm_mm) address space starting
+ * at 'addr' for 'len' bytes from the cache. The range does not straddle
+ * a page boundary, the unique physical page containing the range is
+ * 'page'. This seems to be used mainly for invalidating an address
+ * range following a poke into the program text through the ptrace() call
+ * from another process (e.g. for BRK instruction insertion).
+ */
+void flush_icache_user_range(struct vm_area_struct *vma,
+ struct page *page, unsigned long addr, int len)
{
- /* 'from' and 'to' are kernel virtual addresses (within the superpage
- mapping of the physical RAM). 'address' is the user virtual address
- where the copy 'to' will be mapped after. This allows a custom
- mapping to be used to ensure that the new copy is placed in the
- right cache sets for the user to see it without having to bounce it
- out via memory. Note however : the call to flush_page_to_ram in
- (generic)/mm/memory.c:(break_cow) undoes all this good work in that one
- very important case!
-
- TBD : can we guarantee that on every call, any cache entries for
- 'from' are in the same colour sets as 'address' also? i.e. is this
- always used just to deal with COW? (I suspect not). */
-
- /* There are two possibilities here for when the page 'from' was last accessed:
- * by the kernel : this is OK, no purge required.
- * by the/a user (e.g. for break_COW) : need to purge.
-
- If the potential user mapping at 'address' is the same colour as
- 'from' there is no need to purge any cache lines from the 'from'
- page mapped into cache sets of colour 'address'. (The copy will be
- accessing the page through 'from').
- */
- if (((address ^ (unsigned long) from) & CACHE_OC_SYN_MASK) != 0) {
- sh64_dcache_purge_coloured_phy_page(__pa(from), address);
- }
+ sh64_dcache_purge_coloured_phy_page(page_to_phys(page), addr);
+ mb();
- if (((address ^ (unsigned long) to) & CACHE_OC_SYN_MASK) == 0) {
- /* No synonym problem on destination */
- sh64_page_copy(from, to);
- } else {
- sh64_copy_user_page_coloured(to, from, address);
- }
+ if (vma->vm_flags & VM_EXEC)
+ sh64_icache_inv_user_small_range(vma->vm_mm, addr, len);
+}
- /* Note, don't need to flush 'from' page from the cache again - it's
- done anyway by the generic code */
+/*
+ * For the address range [start,end), write back the data from the
+ * D-cache and invalidate the corresponding region of the I-cache for the
+ * current process. Used to flush signal trampolines on the stack to
+ * make them executable.
+ */
+void flush_cache_sigtramp(unsigned long vaddr)
+{
+ unsigned long end = vaddr + L1_CACHE_BYTES;
+
+ __flush_wback_region((void *)vaddr, L1_CACHE_BYTES);
+ wmb();
+ sh64_icache_inv_current_user_range(vaddr, end);
}
-void clear_user_page(void *to, unsigned long address, struct page *page)
+/*
+ * These *MUST* lie in an area of virtual address space that's otherwise
+ * unused.
+ */
+#define UNIQUE_EADDR_START 0xe0000000UL
+#define UNIQUE_EADDR_END 0xe8000000UL
+
+/*
+ * Given a physical address paddr, and a user virtual address user_eaddr
+ * which will eventually be mapped to it, create a one-off kernel-private
+ * eaddr mapped to the same paddr. This is used for creating special
+ * destination pages for copy_user_page and clear_user_page.
+ */
+static unsigned long sh64_make_unique_eaddr(unsigned long user_eaddr,
+ unsigned long paddr)
{
- /* 'to' is a kernel virtual address (within the superpage
- mapping of the physical RAM). 'address' is the user virtual address
- where the 'to' page will be mapped after. This allows a custom
- mapping to be used to ensure that the new copy is placed in the
- right cache sets for the user to see it without having to bounce it
- out via memory.
- */
+ static unsigned long current_pointer = UNIQUE_EADDR_START;
+ unsigned long coloured_pointer;
- if (((address ^ (unsigned long) to) & CACHE_OC_SYN_MASK) == 0) {
- /* No synonym problem on destination */
- sh64_page_clear(to);
- } else {
- sh64_clear_user_page_coloured(to, address);
+ if (current_pointer == UNIQUE_EADDR_END) {
+ sh64_dcache_purge_all();
+ current_pointer = UNIQUE_EADDR_START;
}
-}
-#endif /* !CONFIG_DCACHE_DISABLED */
+ coloured_pointer = (current_pointer & ~CACHE_OC_SYN_MASK) |
+ (user_eaddr & CACHE_OC_SYN_MASK);
+ sh64_setup_dtlb_cache_slot(coloured_pointer, get_asid(), paddr);
-/****************************************************************************/
+ current_pointer += (PAGE_SIZE << CACHE_OC_N_SYNBITS);
-void flush_dcache_page(struct page *page)
-{
- sh64_dcache_purge_phy_page(page_to_phys(page));
- wmb();
+ return coloured_pointer;
}
-/****************************************************************************/
-
-void flush_icache_range(unsigned long start, unsigned long end)
+static void sh64_copy_user_page_coloured(void *to, void *from,
+ unsigned long address)
{
- /* Flush the range [start,end] of kernel virtual adddress space from
- the I-cache. The corresponding range must be purged from the
- D-cache also because the SH-5 doesn't have cache snooping between
- the caches. The addresses will be visible through the superpage
- mapping, therefore it's guaranteed that there no cache entries for
- the range in cache sets of the wrong colour.
+ void *coloured_to;
- Primarily used for cohering the I-cache after a module has
- been loaded. */
+ /*
+ * Discard any existing cache entries of the wrong colour. These are
+ * present quite often, if the kernel has recently used the page
+ * internally, then given it up, then it's been allocated to the user.
+ */
+ sh64_dcache_purge_coloured_phy_page(__pa(to), (unsigned long)to);
- /* We also make sure to purge the same range from the D-cache since
- flush_page_to_ram() won't be doing this for us! */
+ coloured_to = (void *)sh64_make_unique_eaddr(address, __pa(to));
+ copy_page(from, coloured_to);
- sh64_dcache_purge_kernel_range(start, end);
- wmb();
- sh64_icache_inv_kernel_range(start, end);
+ sh64_teardown_dtlb_cache_slot();
}
-/****************************************************************************/
-
-void flush_icache_user_range(struct vm_area_struct *vma,
- struct page *page, unsigned long addr, int len)
+static void sh64_clear_user_page_coloured(void *to, unsigned long address)
{
- /* Flush the range of user (defined by vma->vm_mm) address space
- starting at 'addr' for 'len' bytes from the cache. The range does
- not straddle a page boundary, the unique physical page containing
- the range is 'page'. This seems to be used mainly for invalidating
- an address range following a poke into the program text through the
- ptrace() call from another process (e.g. for BRK instruction
- insertion). */
+ void *coloured_to;
- sh64_dcache_purge_coloured_phy_page(page_to_phys(page), addr);
- mb();
+ /*
+ * Discard any existing kernel-originated lines of the wrong
+ * colour (as above)
+ */
+ sh64_dcache_purge_coloured_phy_page(__pa(to), (unsigned long)to);
- if (vma->vm_flags & VM_EXEC) {
- sh64_icache_inv_user_small_range(vma->vm_mm, addr, len);
- }
-}
+ coloured_to = (void *)sh64_make_unique_eaddr(address, __pa(to));
+ clear_page(coloured_to);
-/*##########################################################################
- ARCH/SH64 PRIVATE CALLABLE API.
- ##########################################################################*/
+ sh64_teardown_dtlb_cache_slot();
+}
-void flush_cache_sigtramp(unsigned long vaddr)
+/*
+ * 'from' and 'to' are kernel virtual addresses (within the superpage
+ * mapping of the physical RAM). 'address' is the user virtual address
+ * where the copy 'to' will be mapped after. This allows a custom
+ * mapping to be used to ensure that the new copy is placed in the
+ * right cache sets for the user to see it without having to bounce it
+ * out via memory. Note however : the call to flush_page_to_ram in
+ * (generic)/mm/memory.c:(break_cow) undoes all this good work in that one
+ * very important case!
+ *
+ * TBD : can we guarantee that on every call, any cache entries for
+ * 'from' are in the same colour sets as 'address' also? i.e. is this
+ * always used just to deal with COW? (I suspect not).
+ *
+ * There are two possibilities here for when the page 'from' was last accessed:
+ * - by the kernel : this is OK, no purge required.
+ * - by the/a user (e.g. for break_COW) : need to purge.
+ *
+ * If the potential user mapping at 'address' is the same colour as
+ * 'from' there is no need to purge any cache lines from the 'from'
+ * page mapped into cache sets of colour 'address'. (The copy will be
+ * accessing the page through 'from').
+ */
+void copy_user_page(void *to, void *from, unsigned long address,
+ struct page *page)
{
- unsigned long end = vaddr + L1_CACHE_BYTES;
-
- /* For the address range [start,end), write back the data from the
- D-cache and invalidate the corresponding region of the I-cache for
- the current process. Used to flush signal trampolines on the stack
- to make them executable. */
+ if (((address ^ (unsigned long) from) & CACHE_OC_SYN_MASK) != 0)
+ sh64_dcache_purge_coloured_phy_page(__pa(from), address);
- sh64_dcache_wback_current_user_range(vaddr, end);
- wmb();
- sh64_icache_inv_current_user_range(vaddr, end);
+ if (((address ^ (unsigned long) to) & CACHE_OC_SYN_MASK) == 0)
+ copy_page(to, from);
+ else
+ sh64_copy_user_page_coloured(to, from, address);
}
+/*
+ * 'to' is a kernel virtual address (within the superpage mapping of the
+ * physical RAM). 'address' is the user virtual address where the 'to'
+ * page will be mapped after. This allows a custom mapping to be used to
+ * ensure that the new copy is placed in the right cache sets for the
+ * user to see it without having to bounce it out via memory.
+ */
+void clear_user_page(void *to, unsigned long address, struct page *page)
+{
+ if (((address ^ (unsigned long) to) & CACHE_OC_SYN_MASK) == 0)
+ clear_page(to);
+ else
+ sh64_clear_user_page_coloured(to, address);
+}