277 lines
8.7 KiB
C
277 lines
8.7 KiB
C
/*
|
|
* Copyright 2010 Tilera Corporation. All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation, version 2.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
|
|
* NON INFRINGEMENT. See the GNU General Public License for
|
|
* more details.
|
|
*/
|
|
|
|
#include <linux/string.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/module.h>
|
|
#include <linux/uaccess.h>
|
|
#include <asm/fixmap.h>
|
|
#include <asm/kmap_types.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <hv/hypervisor.h>
|
|
#include <arch/chip.h>
|
|
|
|
|
|
#if !CHIP_HAS_COHERENT_LOCAL_CACHE()
|
|
|
|
/* Defined in memcpy.S */
|
|
extern unsigned long __memcpy_asm(void *to, const void *from, unsigned long n);
|
|
extern unsigned long __copy_to_user_inatomic_asm(
|
|
void __user *to, const void *from, unsigned long n);
|
|
extern unsigned long __copy_from_user_inatomic_asm(
|
|
void *to, const void __user *from, unsigned long n);
|
|
extern unsigned long __copy_from_user_zeroing_asm(
|
|
void *to, const void __user *from, unsigned long n);
|
|
|
|
typedef unsigned long (*memcpy_t)(void *, const void *, unsigned long);
|
|
|
|
/* Size above which to consider TLB games for performance */
|
|
#define LARGE_COPY_CUTOFF 2048
|
|
|
|
/* Communicate to the simulator what we are trying to do. */
|
|
#define sim_allow_multiple_caching(b) \
|
|
__insn_mtspr(SPR_SIM_CONTROL, \
|
|
SIM_CONTROL_ALLOW_MULTIPLE_CACHING | ((b) << _SIM_CONTROL_OPERATOR_BITS))
|
|
|
|
/*
|
|
* Copy memory by briefly enabling incoherent cacheline-at-a-time mode.
|
|
*
|
|
* We set up our own source and destination PTEs that we fully control.
|
|
* This is the only way to guarantee that we don't race with another
|
|
* thread that is modifying the PTE; we can't afford to try the
|
|
* copy_{to,from}_user() technique of catching the interrupt, since
|
|
* we must run with interrupts disabled to avoid the risk of some
|
|
* other code seeing the incoherent data in our cache. (Recall that
|
|
* our cache is indexed by PA, so even if the other code doesn't use
|
|
* our kmap_atomic virtual addresses, they'll still hit in cache using
|
|
* the normal VAs that aren't supposed to hit in cache.)
|
|
*/
|
|
static void memcpy_multicache(void *dest, const void *source,
|
|
pte_t dst_pte, pte_t src_pte, int len)
|
|
{
|
|
int idx;
|
|
unsigned long flags, newsrc, newdst;
|
|
pmd_t *pmdp;
|
|
pte_t *ptep;
|
|
int type0, type1;
|
|
int cpu = get_cpu();
|
|
|
|
/*
|
|
* Disable interrupts so that we don't recurse into memcpy()
|
|
* in an interrupt handler, nor accidentally reference
|
|
* the PA of the source from an interrupt routine. Also
|
|
* notify the simulator that we're playing games so we don't
|
|
* generate spurious coherency warnings.
|
|
*/
|
|
local_irq_save(flags);
|
|
sim_allow_multiple_caching(1);
|
|
|
|
/* Set up the new dest mapping */
|
|
type0 = kmap_atomic_idx_push();
|
|
idx = FIX_KMAP_BEGIN + (KM_TYPE_NR * cpu) + type0;
|
|
newdst = __fix_to_virt(idx) + ((unsigned long)dest & (PAGE_SIZE-1));
|
|
pmdp = pmd_offset(pud_offset(pgd_offset_k(newdst), newdst), newdst);
|
|
ptep = pte_offset_kernel(pmdp, newdst);
|
|
if (pte_val(*ptep) != pte_val(dst_pte)) {
|
|
set_pte(ptep, dst_pte);
|
|
local_flush_tlb_page(NULL, newdst, PAGE_SIZE);
|
|
}
|
|
|
|
/* Set up the new source mapping */
|
|
type1 = kmap_atomic_idx_push();
|
|
idx += (type0 - type1);
|
|
src_pte = hv_pte_set_nc(src_pte);
|
|
src_pte = hv_pte_clear_writable(src_pte); /* be paranoid */
|
|
newsrc = __fix_to_virt(idx) + ((unsigned long)source & (PAGE_SIZE-1));
|
|
pmdp = pmd_offset(pud_offset(pgd_offset_k(newsrc), newsrc), newsrc);
|
|
ptep = pte_offset_kernel(pmdp, newsrc);
|
|
__set_pte(ptep, src_pte); /* set_pte() would be confused by this */
|
|
local_flush_tlb_page(NULL, newsrc, PAGE_SIZE);
|
|
|
|
/* Actually move the data. */
|
|
__memcpy_asm((void *)newdst, (const void *)newsrc, len);
|
|
|
|
/*
|
|
* Remap the source as locally-cached and not OLOC'ed so that
|
|
* we can inval without also invaling the remote cpu's cache.
|
|
* This also avoids known errata with inv'ing cacheable oloc data.
|
|
*/
|
|
src_pte = hv_pte_set_mode(src_pte, HV_PTE_MODE_CACHE_NO_L3);
|
|
src_pte = hv_pte_set_writable(src_pte); /* need write access for inv */
|
|
__set_pte(ptep, src_pte); /* set_pte() would be confused by this */
|
|
local_flush_tlb_page(NULL, newsrc, PAGE_SIZE);
|
|
|
|
/*
|
|
* Do the actual invalidation, covering the full L2 cache line
|
|
* at the end since __memcpy_asm() is somewhat aggressive.
|
|
*/
|
|
__inv_buffer((void *)newsrc, len);
|
|
|
|
/*
|
|
* We're done: notify the simulator that all is back to normal,
|
|
* and re-enable interrupts and pre-emption.
|
|
*/
|
|
kmap_atomic_idx_pop();
|
|
kmap_atomic_idx_pop();
|
|
sim_allow_multiple_caching(0);
|
|
local_irq_restore(flags);
|
|
put_cpu();
|
|
}
|
|
|
|
/*
|
|
* Identify large copies from remotely-cached memory, and copy them
|
|
* via memcpy_multicache() if they look good, otherwise fall back
|
|
* to the particular kind of copying passed as the memcpy_t function.
|
|
*/
|
|
static unsigned long fast_copy(void *dest, const void *source, int len,
|
|
memcpy_t func)
|
|
{
|
|
/*
|
|
* Check if it's big enough to bother with. We may end up doing a
|
|
* small copy via TLB manipulation if we're near a page boundary,
|
|
* but presumably we'll make it up when we hit the second page.
|
|
*/
|
|
while (len >= LARGE_COPY_CUTOFF) {
|
|
int copy_size, bytes_left_on_page;
|
|
pte_t *src_ptep, *dst_ptep;
|
|
pte_t src_pte, dst_pte;
|
|
struct page *src_page, *dst_page;
|
|
|
|
/* Is the source page oloc'ed to a remote cpu? */
|
|
retry_source:
|
|
src_ptep = virt_to_pte(current->mm, (unsigned long)source);
|
|
if (src_ptep == NULL)
|
|
break;
|
|
src_pte = *src_ptep;
|
|
if (!hv_pte_get_present(src_pte) ||
|
|
!hv_pte_get_readable(src_pte) ||
|
|
hv_pte_get_mode(src_pte) != HV_PTE_MODE_CACHE_TILE_L3)
|
|
break;
|
|
if (get_remote_cache_cpu(src_pte) == smp_processor_id())
|
|
break;
|
|
src_page = pfn_to_page(pte_pfn(src_pte));
|
|
get_page(src_page);
|
|
if (pte_val(src_pte) != pte_val(*src_ptep)) {
|
|
put_page(src_page);
|
|
goto retry_source;
|
|
}
|
|
if (pte_huge(src_pte)) {
|
|
/* Adjust the PTE to correspond to a small page */
|
|
int pfn = pte_pfn(src_pte);
|
|
pfn += (((unsigned long)source & (HPAGE_SIZE-1))
|
|
>> PAGE_SHIFT);
|
|
src_pte = pfn_pte(pfn, src_pte);
|
|
src_pte = pte_mksmall(src_pte);
|
|
}
|
|
|
|
/* Is the destination page writable? */
|
|
retry_dest:
|
|
dst_ptep = virt_to_pte(current->mm, (unsigned long)dest);
|
|
if (dst_ptep == NULL) {
|
|
put_page(src_page);
|
|
break;
|
|
}
|
|
dst_pte = *dst_ptep;
|
|
if (!hv_pte_get_present(dst_pte) ||
|
|
!hv_pte_get_writable(dst_pte)) {
|
|
put_page(src_page);
|
|
break;
|
|
}
|
|
dst_page = pfn_to_page(pte_pfn(dst_pte));
|
|
if (dst_page == src_page) {
|
|
/*
|
|
* Source and dest are on the same page; this
|
|
* potentially exposes us to incoherence if any
|
|
* part of src and dest overlap on a cache line.
|
|
* Just give up rather than trying to be precise.
|
|
*/
|
|
put_page(src_page);
|
|
break;
|
|
}
|
|
get_page(dst_page);
|
|
if (pte_val(dst_pte) != pte_val(*dst_ptep)) {
|
|
put_page(dst_page);
|
|
goto retry_dest;
|
|
}
|
|
if (pte_huge(dst_pte)) {
|
|
/* Adjust the PTE to correspond to a small page */
|
|
int pfn = pte_pfn(dst_pte);
|
|
pfn += (((unsigned long)dest & (HPAGE_SIZE-1))
|
|
>> PAGE_SHIFT);
|
|
dst_pte = pfn_pte(pfn, dst_pte);
|
|
dst_pte = pte_mksmall(dst_pte);
|
|
}
|
|
|
|
/* All looks good: create a cachable PTE and copy from it */
|
|
copy_size = len;
|
|
bytes_left_on_page =
|
|
PAGE_SIZE - (((int)source) & (PAGE_SIZE-1));
|
|
if (copy_size > bytes_left_on_page)
|
|
copy_size = bytes_left_on_page;
|
|
bytes_left_on_page =
|
|
PAGE_SIZE - (((int)dest) & (PAGE_SIZE-1));
|
|
if (copy_size > bytes_left_on_page)
|
|
copy_size = bytes_left_on_page;
|
|
memcpy_multicache(dest, source, dst_pte, src_pte, copy_size);
|
|
|
|
/* Release the pages */
|
|
put_page(dst_page);
|
|
put_page(src_page);
|
|
|
|
/* Continue on the next page */
|
|
dest += copy_size;
|
|
source += copy_size;
|
|
len -= copy_size;
|
|
}
|
|
|
|
return func(dest, source, len);
|
|
}
|
|
|
|
void *memcpy(void *to, const void *from, __kernel_size_t n)
|
|
{
|
|
if (n < LARGE_COPY_CUTOFF)
|
|
return (void *)__memcpy_asm(to, from, n);
|
|
else
|
|
return (void *)fast_copy(to, from, n, __memcpy_asm);
|
|
}
|
|
|
|
unsigned long __copy_to_user_inatomic(void __user *to, const void *from,
|
|
unsigned long n)
|
|
{
|
|
if (n < LARGE_COPY_CUTOFF)
|
|
return __copy_to_user_inatomic_asm(to, from, n);
|
|
else
|
|
return fast_copy(to, from, n, __copy_to_user_inatomic_asm);
|
|
}
|
|
|
|
unsigned long __copy_from_user_inatomic(void *to, const void __user *from,
|
|
unsigned long n)
|
|
{
|
|
if (n < LARGE_COPY_CUTOFF)
|
|
return __copy_from_user_inatomic_asm(to, from, n);
|
|
else
|
|
return fast_copy(to, from, n, __copy_from_user_inatomic_asm);
|
|
}
|
|
|
|
unsigned long __copy_from_user_zeroing(void *to, const void __user *from,
|
|
unsigned long n)
|
|
{
|
|
if (n < LARGE_COPY_CUTOFF)
|
|
return __copy_from_user_zeroing_asm(to, from, n);
|
|
else
|
|
return fast_copy(to, from, n, __copy_from_user_zeroing_asm);
|
|
}
|
|
|
|
#endif /* !CHIP_HAS_COHERENT_LOCAL_CACHE() */
|