/*
* Handle cache congruency of kernel and userspace mappings of page when kernel
* writes-to/reads-from
*
* The idea is to defer flushing of kernel mapping after a WRITE, possible if:
* -dcache is NOT aliasing, hence any U/K-mappings of page are congruent
* -U-mapping doesn't exist yet for page (finalised in update_mmu_cache)
* -In SMP, if hardware caches are coherent
*
* There's a corollary case, where kernel READs from a userspace mapped page.
* If the U-mapping is not congruent to to K-mapping, former needs flushing.
*/
void flush_dcache_page(struct page *page)
{
struct address_space *mapping;
if (!cache_is_vipt_aliasing()) {
clear_bit(PG_dc_clean, &page->flags);
return;
}
/* don't handle anon pages here */
mapping = page_mapping(page);
if (!mapping)
return;
/*
* pagecache page, file not yet mapped to userspace
* Make a note that K-mapping is dirty
*/
if (!mapping_mapped(mapping)) {
clear_bit(PG_dc_clean, &page->flags);
} else if (page_mapped(page)) {
/* kernel reading from page with U-mapping */
void *paddr = page_address(page);
unsigned long vaddr = page->index << PAGE_CACHE_SHIFT;
if (addr_not_cache_congruent(paddr, vaddr))
__flush_dcache_page(paddr, vaddr);
}
}
/*
* 1. Validate the Cache Geomtery (compile time config matches hardware)
* 2. If I-cache suffers from aliasing, setup work arounds (difft flush rtn)
* (aliasing D-cache configurations are not supported YET)
* 3. Enable the Caches, setup default flush mode for D-Cache
* 3. Calculate the SHMLBA used by user space
*/
void arc_cache_init(void)
{
unsigned int __maybe_unused cpu = smp_processor_id();
struct cpuinfo_arc_cache __maybe_unused *ic, __maybe_unused *dc;
char str[256];
printk(arc_cache_mumbojumbo(0, str, sizeof(str)));
#ifdef CONFIG_ARC_HAS_ICACHE
ic = &cpuinfo_arc700[cpu].icache;
if (ic->ver) {
if (ic->line_len != L1_CACHE_BYTES)
panic("ICache line [%d] != kernel Config [%d]",
ic->line_len, L1_CACHE_BYTES);
if (ic->ver != CONFIG_ARC_MMU_VER)
panic("Cache ver [%d] doesn't match MMU ver [%d]\n",
ic->ver, CONFIG_ARC_MMU_VER);
}
#endif
#ifdef CONFIG_ARC_HAS_DCACHE
dc = &cpuinfo_arc700[cpu].dcache;
if (dc->ver) {
unsigned int dcache_does_alias;
if (dc->line_len != L1_CACHE_BYTES)
panic("DCache line [%d] != kernel Config [%d]",
dc->line_len, L1_CACHE_BYTES);
/* check for D-Cache aliasing */
dcache_does_alias = (dc->sz / dc->assoc) > PAGE_SIZE;
if (dcache_does_alias && !cache_is_vipt_aliasing())
panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
else if (!dcache_does_alias && cache_is_vipt_aliasing())
panic("Don't need CONFIG_ARC_CACHE_VIPT_ALIASING\n");
}
#endif
}
/*
* We need to ensure that shared mappings are correctly aligned to
* avoid aliasing issues with VIPT caches. We need to ensure that
* a specific page of an object is always mapped at a multiple of
* SHMLBA bytes.
*
* We unconditionally provide this function for all cases, however
* in the VIVT case, we optimise out the alignment rules.
*/
unsigned long
arch_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
int do_align = 0;
int aliasing = cache_is_vipt_aliasing();
struct vm_unmapped_area_info info;
/*
* We only need to do colour alignment if either the I or D
* caches alias.
*/
if (aliasing)
do_align = filp || (flags & MAP_SHARED);
/*
* We enforce the MAP_FIXED case.
*/
if (flags & MAP_FIXED) {
if (aliasing && flags & MAP_SHARED &&
(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
return -EINVAL;
return addr;
}
if (len > TASK_SIZE)
return -ENOMEM;
if (addr) {
if (do_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
vma = find_vma(mm, addr);
if (TASK_SIZE - len >= addr &&
(!vma || addr + len <= vma->vm_start))
return addr;
}
info.flags = 0;
info.length = len;
info.low_limit = mm->mmap_base;
info.high_limit = TASK_SIZE;
info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
info.align_offset = pgoff << PAGE_SHIFT;
return vm_unmapped_area(&info);
}
static int __init v6_userpage_init(void)
{
if (cache_is_vipt_aliasing()) {
pgd_t *pgd;
pmd_t *pmd;
pgd = pgd_offset_k(from_address);
pmd = pmd_alloc(&init_mm, pgd, from_address);
if (!pmd)
BUG();
from_pte = pte_alloc_kernel(&init_mm, pmd, from_address);
if (!from_pte)
BUG();
to_pte = pte_alloc_kernel(&init_mm, pmd, to_address);
if (!to_pte)
BUG();
cpu_user.cpu_clear_user_page = v6_clear_user_page_aliasing;
cpu_user.cpu_copy_user_page = v6_copy_user_page_aliasing;
}
return 0;
}
/*
* We need to ensure that shared mappings are correctly aligned to
* avoid aliasing issues with VIPT caches. We need to ensure that
* a specific page of an object is always mapped at a multiple of
* SHMLBA bytes.
*
* We unconditionally provide this function for all cases, however
* in the VIVT case, we optimise out the alignment rules.
*/
unsigned long
arch_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long start_addr = addr;
int do_align = 0;
int aliasing = cache_is_vipt_aliasing();
/*
* We only need to do colour alignment if either the I or D
* caches alias.
*/
if (aliasing)
do_align = filp || (flags & MAP_SHARED);
#ifdef CONFIG_ARM_FCSE
start_addr = addr;
#endif /* CONFIG_ARM_FCSE */
/*
* We enforce the MAP_FIXED case.
*/
if (flags & MAP_FIXED) {
if (aliasing && flags & MAP_SHARED &&
(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
return -EINVAL;
goto found_addr;
}
if (len > TASK_SIZE)
return -ENOMEM;
if (addr) {
if (do_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
vma = find_vma(mm, addr);
if (TASK_SIZE - len >= addr &&
(!vma || addr + len <= vma->vm_start))
goto found_addr;
}
if (len > mm->cached_hole_size) {
start_addr = addr = mm->free_area_cache;
} else {
start_addr = addr = TASK_UNMAPPED_BASE;
mm->cached_hole_size = 0;
}
/* 8 bits of randomness in 20 address space bits */
if ((current->flags & PF_RANDOMIZE) &&
!(current->personality & ADDR_NO_RANDOMIZE))
addr += (get_random_int() % (1 << 8)) << PAGE_SHIFT;
full_search:
if (do_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
/* At this point: (!vma || addr < vma->vm_end). */
if (TASK_SIZE - len < addr) {
/*
* Start a new search - just in case we missed
* some holes.
*/
if (start_addr != TASK_UNMAPPED_BASE) {
start_addr = addr = TASK_UNMAPPED_BASE;
mm->cached_hole_size = 0;
goto full_search;
}
return -ENOMEM;
}
if (!vma || addr + len <= vma->vm_start) {
/*
* Remember the place where we stopped the search:
*/
mm->free_area_cache = addr + len;
goto found_addr;
}
if (addr + mm->cached_hole_size < vma->vm_start)
mm->cached_hole_size = vma->vm_start - addr;
addr = vma->vm_end;
if (do_align)
addr = COLOUR_ALIGN(addr, pgoff);
}
found_addr:
#ifdef CONFIG_ARM_FCSE
{
unsigned long new_addr = fcse_check_mmap_addr(mm, start_addr,
addr, len, flags);
if (new_addr != addr) {
addr = new_addr;
if (!(addr & ~PAGE_MASK)) {
start_addr = TASK_UNMAPPED_BASE;
mm->cached_hole_size = 0;
goto full_search;
}
}
}
#endif /* CONFIG_ARM_FCSE */
return addr;
}
/*
* We need to ensure that shared mappings are correctly aligned to
* avoid aliasing issues with VIPT caches. We need to ensure that
* a specific page of an object is always mapped at a multiple of
* SHMLBA bytes.
*
* We unconditionally provide this function for all cases, however
* in the VIVT case, we optimise out the alignment rules.
*/
unsigned long
arch_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long start_addr;
int do_align = 0;
int aliasing = cache_is_vipt_aliasing();
/*
* We only need to do colour alignment if either the I or D
* caches alias.
*/
if (aliasing)
do_align = filp || (flags & MAP_SHARED);
/*
* We enforce the MAP_FIXED case.
*/
if (flags & MAP_FIXED) {
if (aliasing && flags & MAP_SHARED &&
(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
return -EINVAL;
return addr;
}
if (len > TASK_SIZE)
return -ENOMEM;
if (addr) {
if (do_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
vma = find_vma(mm, addr);
if (TASK_SIZE - len >= addr &&
(!vma || addr + len <= vma->vm_start))
return addr;
}
if (len > mm->cached_hole_size) {
start_addr = addr = mm->free_area_cache;
} else {
start_addr = addr = mm->mmap_base;
mm->cached_hole_size = 0;
}
full_search:
if (do_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
/* At this point: (!vma || addr < vma->vm_end). */
if (TASK_SIZE - len < addr) {
/*
* Start a new search - just in case we missed
* some holes.
*/
if (start_addr != TASK_UNMAPPED_BASE) {
start_addr = addr = TASK_UNMAPPED_BASE;
mm->cached_hole_size = 0;
goto full_search;
}
return -ENOMEM;
}
if (!vma || addr + len <= vma->vm_start) {
/*
* Remember the place where we stopped the search:
*/
mm->free_area_cache = addr + len;
return addr;
}
if (addr + mm->cached_hole_size < vma->vm_start)
mm->cached_hole_size = vma->vm_start - addr;
addr = vma->vm_end;
if (do_align)
addr = COLOUR_ALIGN(addr, pgoff);
}
}
unsigned long
arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
const unsigned long len, const unsigned long pgoff,
const unsigned long flags)
{
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
unsigned long addr = addr0;
int do_align = 0;
int aliasing = cache_is_vipt_aliasing();
/*
* We only need to do colour alignment if either the I or D
* caches alias.
*/
if (aliasing)
do_align = filp || (flags & MAP_SHARED);
/* requested length too big for entire address space */
if (len > TASK_SIZE)
return -ENOMEM;
if (flags & MAP_FIXED) {
if (aliasing && flags & MAP_SHARED &&
(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
return -EINVAL;
return addr;
}
/* requesting a specific address */
if (addr) {
if (do_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
vma = find_vma(mm, addr);
if (TASK_SIZE - len >= addr &&
(!vma || addr + len <= vma->vm_start))
return addr;
}
/* check if free_area_cache is useful for us */
if (len <= mm->cached_hole_size) {
mm->cached_hole_size = 0;
mm->free_area_cache = mm->mmap_base;
}
/* either no address requested or can't fit in requested address hole */
addr = mm->free_area_cache;
if (do_align) {
unsigned long base = COLOUR_ALIGN_DOWN(addr - len, pgoff);
addr = base + len;
}
/* make sure it can fit in the remaining address space */
if (addr > len) {
vma = find_vma(mm, addr-len);
if (!vma || addr <= vma->vm_start)
/* remember the address as a hint for next time */
return (mm->free_area_cache = addr-len);
}
if (mm->mmap_base < len)
goto bottomup;
addr = mm->mmap_base - len;
if (do_align)
addr = COLOUR_ALIGN_DOWN(addr, pgoff);
do {
/*
* Lookup failure means no vma is above this address,
* else if new region fits below vma->vm_start,
* return with success:
*/
vma = find_vma(mm, addr);
if (!vma || addr+len <= vma->vm_start)
/* remember the address as a hint for next time */
return (mm->free_area_cache = addr);
/* remember the largest hole we saw so far */
if (addr + mm->cached_hole_size < vma->vm_start)
mm->cached_hole_size = vma->vm_start - addr;
/* try just below the current vma->vm_start */
addr = vma->vm_start - len;
if (do_align)
addr = COLOUR_ALIGN_DOWN(addr, pgoff);
} while (len < vma->vm_start);
bottomup:
/*
* A failed mmap() very likely causes application failure,
* so fall back to the bottom-up function here. This scenario
* can happen with large stack limits and large mmap()
* allocations.
*/
mm->cached_hole_size = ~0UL;
mm->free_area_cache = TASK_UNMAPPED_BASE;
addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
/*
* Restore the topdown base:
*/
mm->free_area_cache = mm->mmap_base;
mm->cached_hole_size = ~0UL;
return addr;
}
unsigned long
arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
const unsigned long len, const unsigned long pgoff,
const unsigned long flags)
{
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
unsigned long addr = addr0;
int do_align = 0;
int aliasing = cache_is_vipt_aliasing();
struct vm_unmapped_area_info info;
/*
* We only need to do colour alignment if either the I or D
* caches alias.
*/
if (aliasing)
do_align = filp || (flags & MAP_SHARED);
/* requested length too big for entire address space */
if (len > TASK_SIZE)
return -ENOMEM;
if (flags & MAP_FIXED) {
if (aliasing && flags & MAP_SHARED &&
(addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
return -EINVAL;
return addr;
}
/* requesting a specific address */
if (addr) {
if (do_align)
addr = COLOUR_ALIGN(addr, pgoff);
else
addr = PAGE_ALIGN(addr);
vma = find_vma(mm, addr);
if (TASK_SIZE - len >= addr &&
(!vma || addr + len <= vma->vm_start))
return addr;
}
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
info.length = len;
info.low_limit = FIRST_USER_ADDRESS;
info.high_limit = mm->mmap_base;
info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
info.align_offset = pgoff << PAGE_SHIFT;
addr = vm_unmapped_area(&info);
/*
* A failed mmap() very likely causes application failure,
* so fall back to the bottom-up function here. This scenario
* can happen with large stack limits and large mmap()
* allocations.
*/
if (addr & ~PAGE_MASK) {
VM_BUG_ON(addr != -ENOMEM);
info.flags = 0;
info.low_limit = mm->mmap_base;
info.high_limit = TASK_SIZE;
addr = vm_unmapped_area(&info);
}
return addr;
}
/*
* 1. Validate the Cache Geomtery (compile time config matches hardware)
* 2. If I-cache suffers from aliasing, setup work arounds (difft flush rtn)
* (aliasing D-cache configurations are not supported YET)
* 3. Enable the Caches, setup default flush mode for D-Cache
* 3. Calculate the SHMLBA used by user space
*/
void arc_cache_init(void)
{
unsigned int cpu = smp_processor_id();
struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;
struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache;
unsigned int dcache_does_alias, temp;
char str[256];
printk(arc_cache_mumbojumbo(0, str, sizeof(str)));
if (!ic->ver)
goto chk_dc;
#ifdef CONFIG_ARC_HAS_ICACHE
/* 1. Confirm some of I-cache params which Linux assumes */
if (ic->line_len != ARC_ICACHE_LINE_LEN)
panic("Cache H/W doesn't match kernel Config");
if (ic->ver != CONFIG_ARC_MMU_VER)
panic("Cache ver doesn't match MMU ver\n");
#endif
/* Enable/disable I-Cache */
temp = read_aux_reg(ARC_REG_IC_CTRL);
#ifdef CONFIG_ARC_HAS_ICACHE
temp &= ~IC_CTRL_CACHE_DISABLE;
#else
temp |= IC_CTRL_CACHE_DISABLE;
#endif
write_aux_reg(ARC_REG_IC_CTRL, temp);
chk_dc:
if (!dc->ver)
return;
#ifdef CONFIG_ARC_HAS_DCACHE
if (dc->line_len != ARC_DCACHE_LINE_LEN)
panic("Cache H/W doesn't match kernel Config");
/* check for D-Cache aliasing */
dcache_does_alias = (dc->sz / dc->assoc) > PAGE_SIZE;
if (dcache_does_alias && !cache_is_vipt_aliasing())
panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
else if (!dcache_does_alias && cache_is_vipt_aliasing())
panic("Don't need CONFIG_ARC_CACHE_VIPT_ALIASING\n");
#endif
/* Set the default Invalidate Mode to "simpy discard dirty lines"
* as this is more frequent then flush before invalidate
* Ofcourse we toggle this default behviour when desired
*/
temp = read_aux_reg(ARC_REG_DC_CTRL);
temp &= ~DC_CTRL_INV_MODE_FLUSH;
#ifdef CONFIG_ARC_HAS_DCACHE
/* Enable D-Cache: Clear Bit 0 */
write_aux_reg(ARC_REG_DC_CTRL, temp & ~IC_CTRL_CACHE_DISABLE);
#else
/* Flush D cache */
write_aux_reg(ARC_REG_DC_FLSH, 0x1);
/* Disable D cache */
write_aux_reg(ARC_REG_DC_CTRL, temp | IC_CTRL_CACHE_DISABLE);
#endif
return;
}