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sh: Fix up the SH-5 build with caches enabled.
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Signed-off-by: Paul Mundt <lethal@linux-sh.org>
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Paul Mundt committed Aug 15, 2009
1 parent 1ee4ab0 commit 94ecd22
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Showing 6 changed files with 64 additions and 303 deletions.
14 changes: 1 addition & 13 deletions arch/sh/include/asm/system.h
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Original file line number Diff line number Diff line change
Expand Up @@ -14,18 +14,6 @@

#define AT_VECTOR_SIZE_ARCH 5 /* entries in ARCH_DLINFO */

#if defined(CONFIG_CPU_SH4A) || defined(CONFIG_CPU_SH5)
#define __icbi() \
{ \
unsigned long __addr; \
__addr = 0xa8000000; \
__asm__ __volatile__( \
"icbi %0\n\t" \
: /* no output */ \
: "m" (__m(__addr))); \
}
#endif

/*
* A brief note on ctrl_barrier(), the control register write barrier.
*
Expand All @@ -44,7 +32,7 @@
#define mb() __asm__ __volatile__ ("synco": : :"memory")
#define rmb() mb()
#define wmb() __asm__ __volatile__ ("synco": : :"memory")
#define ctrl_barrier() __icbi()
#define ctrl_barrier() __icbi(0xa8000000)
#define read_barrier_depends() do { } while(0)
#else
#define mb() __asm__ __volatile__ ("": : :"memory")
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10 changes: 10 additions & 0 deletions arch/sh/include/asm/system_32.h
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Expand Up @@ -63,6 +63,16 @@ do { \
#define __restore_dsp(tsk) do { } while (0)
#endif

#if defined(CONFIG_CPU_SH4A)
#define __icbi(addr) __asm__ __volatile__ ( "icbi @%0\n\t" : : "r" (addr))
#else
#define __icbi(addr) mb()
#endif

#define __ocbp(addr) __asm__ __volatile__ ( "ocbp @%0\n\t" : : "r" (addr))
#define __ocbi(addr) __asm__ __volatile__ ( "ocbi @%0\n\t" : : "r" (addr))
#define __ocbwb(addr) __asm__ __volatile__ ( "ocbwb @%0\n\t" : : "r" (addr))

struct task_struct *__switch_to(struct task_struct *prev,
struct task_struct *next);

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5 changes: 5 additions & 0 deletions arch/sh/include/asm/system_64.h
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Expand Up @@ -37,6 +37,11 @@ do { \
#define jump_to_uncached() do { } while (0)
#define back_to_cached() do { } while (0)

#define __icbi(addr) __asm__ __volatile__ ( "icbi %0, 0\n\t" : : "r" (addr))
#define __ocbp(addr) __asm__ __volatile__ ( "ocbp %0, 0\n\t" : : "r" (addr))
#define __ocbi(addr) __asm__ __volatile__ ( "ocbi %0, 0\n\t" : : "r" (addr))
#define __ocbwb(addr) __asm__ __volatile__ ( "ocbwb %0, 0\n\t" : : "r" (addr))

static inline reg_size_t register_align(void *val)
{
return (unsigned long long)(signed long long)(signed long)val;
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8 changes: 0 additions & 8 deletions arch/sh/kernel/sh_ksyms_64.c
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Original file line number Diff line number Diff line change
Expand Up @@ -30,14 +30,6 @@ extern int dump_fpu(struct pt_regs *, elf_fpregset_t *);
EXPORT_SYMBOL(dump_fpu);
EXPORT_SYMBOL(kernel_thread);

#if !defined(CONFIG_CACHE_OFF) && defined(CONFIG_MMU)
EXPORT_SYMBOL(clear_user_page);
#endif

#ifndef CONFIG_CACHE_OFF
EXPORT_SYMBOL(flush_dcache_page);
#endif

#ifdef CONFIG_VT
EXPORT_SYMBOL(screen_info);
#endif
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249 changes: 21 additions & 228 deletions arch/sh/mm/cache-sh5.c
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Original file line number Diff line number Diff line change
Expand Up @@ -25,29 +25,6 @@ extern void __weak sh4__flush_region_init(void);
/* Wired TLB entry for the D-cache */
static unsigned long long dtlb_cache_slot;

void __init cpu_cache_init(void)
{
/* Reserve a slot for dcache colouring in the DTLB */
dtlb_cache_slot = sh64_get_wired_dtlb_entry();

sh4__flush_region_init();
}

void __init kmap_coherent_init(void)
{
/* XXX ... */
}

void *kmap_coherent(struct page *page, unsigned long addr)
{
/* XXX ... */
return NULL;
}

void kunmap_coherent(void)
{
}

#ifdef CONFIG_DCACHE_DISABLED
#define sh64_dcache_purge_all() do { } while (0)
#define sh64_dcache_purge_coloured_phy_page(paddr, eaddr) do { } while (0)
Expand Down Expand Up @@ -233,52 +210,6 @@ 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)
{
unsigned long long eaddr = start;
unsigned long long eaddr_end = start + len;
unsigned long current_asid, mm_asid;
unsigned long flags;
unsigned long long epage_start;

/*
* 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);
current_asid = switch_and_save_asid(mm_asid);

epage_start = eaddr & PAGE_MASK;

while (eaddr < eaddr_end) {
__asm__ __volatile__("icbi %0, 0" : : "r" (eaddr));
eaddr += L1_CACHE_BYTES;
}
switch_and_save_asid(current_asid);
local_irq_restore(flags);
}

static void sh64_icache_inv_current_user_range(unsigned long start, unsigned long end)
{
/* The icbi instruction never raises ITLBMISS. i.e. if there's not a
Expand Down Expand Up @@ -564,7 +495,7 @@ static void sh64_dcache_purge_user_range(struct mm_struct *mm,
* Invalidate the entire contents of both caches, after writing back to
* memory any dirty data from the D-cache.
*/
void flush_cache_all(void)
static void sh5_flush_cache_all(void)
{
sh64_dcache_purge_all();
sh64_icache_inv_all();
Expand All @@ -591,7 +522,7 @@ void flush_cache_all(void)
* 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)
static void sh5_flush_cache_mm(struct mm_struct *mm)
{
sh64_dcache_purge_all();
}
Expand All @@ -603,8 +534,8 @@ void flush_cache_mm(struct mm_struct *mm)
*
* 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)
static void sh5_flush_cache_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;

Expand All @@ -621,16 +552,16 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
*
* Note, this is called with pte lock held.
*/
void flush_cache_page(struct vm_area_struct *vma, unsigned long eaddr,
unsigned long pfn)
static void sh5_flush_cache_page(struct vm_area_struct *vma,
unsigned long eaddr, unsigned long pfn)
{
sh64_dcache_purge_phy_page(pfn << PAGE_SHIFT);

if (vma->vm_flags & VM_EXEC)
sh64_icache_inv_user_page(vma, eaddr);
}

void flush_dcache_page(struct page *page)
static void sh5_flush_dcache_page(struct page *page)
{
sh64_dcache_purge_phy_page(page_to_phys(page));
wmb();
Expand All @@ -644,39 +575,20 @@ void flush_dcache_page(struct page *page)
* 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)
static void sh5_flush_icache_range(unsigned long start, unsigned long end)
{
__flush_purge_region((void *)start, end);
wmb();
sh64_icache_inv_kernel_range(start, end);
}

/*
* 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).
*/
static void flush_icache_user_range(struct vm_area_struct *vma,
struct page *page, unsigned long addr, int len)
{

sh64_dcache_purge_coloured_phy_page(page_to_phys(page), addr);
mb();

if (vma->vm_flags & VM_EXEC)
sh64_icache_inv_user_small_range(vma->vm_mm, addr, len);
}

/*
* 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)
static void sh5_flush_cache_sigtramp(unsigned long vaddr)
{
unsigned long end = vaddr + L1_CACHE_BYTES;

Expand All @@ -685,138 +597,19 @@ void flush_cache_sigtramp(unsigned long vaddr)
sh64_icache_inv_current_user_range(vaddr, end);
}

#ifdef CONFIG_MMU
/*
* 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)
{
static unsigned long current_pointer = UNIQUE_EADDR_START;
unsigned long coloured_pointer;

if (current_pointer == UNIQUE_EADDR_END) {
sh64_dcache_purge_all();
current_pointer = UNIQUE_EADDR_START;
}

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 *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));
copy_page(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);

coloured_to = (void *)sh64_make_unique_eaddr(address, __pa(to));
clear_page(coloured_to);

sh64_teardown_dtlb_cache_slot();
}

/*
* '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)
void __init sh5_cache_init(void)
{
if (((address ^ (unsigned long) from) & CACHE_OC_SYN_MASK) != 0)
sh64_dcache_purge_coloured_phy_page(__pa(from), address);
flush_cache_all = sh5_flush_cache_all;
flush_cache_mm = sh5_flush_cache_mm;
flush_cache_dup_mm = sh5_flush_cache_mm;
flush_cache_page = sh5_flush_cache_page;
flush_cache_range = sh5_flush_cache_range;
flush_dcache_page = sh5_flush_dcache_page;
flush_icache_range = sh5_flush_icache_range;
flush_cache_sigtramp = sh5_flush_cache_sigtramp;

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);
}

void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long vaddr, void *dst, const void *src,
unsigned long len)
{
flush_cache_page(vma, vaddr, page_to_pfn(page));
memcpy(dst, src, len);
flush_icache_user_range(vma, page, vaddr, len);
}
/* Reserve a slot for dcache colouring in the DTLB */
dtlb_cache_slot = sh64_get_wired_dtlb_entry();

void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long vaddr, void *dst, const void *src,
unsigned long len)
{
flush_cache_page(vma, vaddr, page_to_pfn(page));
memcpy(dst, src, len);
sh4__flush_region_init();
}
#endif
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