static void uncached_ipi_visibility(void *data)
{
int status;
struct uncached_pool *uc_pool = (struct uncached_pool *)data;
status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL);
if ((status != PAL_VISIBILITY_OK) &&
(status != PAL_VISIBILITY_OK_REMOTE_NEEDED))
atomic_inc(&uc_pool->status);
}
/*
* Add a new chunk of uncached memory pages to the specified pool.
*
* @pool: pool to add new chunk of uncached memory to
* @nid: node id of node to allocate memory from, or -1
*
* This is accomplished by first allocating a granule of cached memory pages
* and then converting them to uncached memory pages.
*/
static int uncached_add_chunk(struct uncached_pool *uc_pool, int nid)
{
struct page *page;
int status, i, nchunks_added = uc_pool->nchunks_added;
unsigned long c_addr, uc_addr;
if (mutex_lock_interruptible(&uc_pool->add_chunk_mutex) != 0)
return -1; /* interrupted by a signal */
if (uc_pool->nchunks_added > nchunks_added) {
/* someone added a new chunk while we were waiting */
mutex_unlock(&uc_pool->add_chunk_mutex);
return 0;
}
if (uc_pool->nchunks_added >= MAX_CONVERTED_CHUNKS_PER_NODE) {
mutex_unlock(&uc_pool->add_chunk_mutex);
return -1;
}
/* attempt to allocate a granule's worth of cached memory pages */
page = alloc_pages_exact_node(nid,
GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
IA64_GRANULE_SHIFT-PAGE_SHIFT);
if (!page) {
mutex_unlock(&uc_pool->add_chunk_mutex);
return -1;
}
/* convert the memory pages from cached to uncached */
c_addr = (unsigned long)page_address(page);
uc_addr = c_addr - PAGE_OFFSET + __IA64_UNCACHED_OFFSET;
/*
* There's a small race here where it's possible for someone to
* access the page through /dev/mem halfway through the conversion
* to uncached - not sure it's really worth bothering about
*/
for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++)
SetPageUncached(&page[i]);
flush_tlb_kernel_range(uc_addr, uc_addr + IA64_GRANULE_SIZE);
status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL);
if (status == PAL_VISIBILITY_OK_REMOTE_NEEDED) {
atomic_set(&uc_pool->status, 0);
status = smp_call_function(uncached_ipi_visibility, uc_pool, 1);
if (status || atomic_read(&uc_pool->status))
goto failed;
} else if (status != PAL_VISIBILITY_OK)
goto failed;
preempt_disable();
if (ia64_platform_is("sn2"))
sn_flush_all_caches(uc_addr, IA64_GRANULE_SIZE);
else
flush_icache_range(uc_addr, uc_addr + IA64_GRANULE_SIZE);
/* flush the just introduced uncached translation from the TLB */
local_flush_tlb_all();
preempt_enable();
status = ia64_pal_mc_drain();
if (status != PAL_STATUS_SUCCESS)
goto failed;
atomic_set(&uc_pool->status, 0);
status = smp_call_function(uncached_ipi_mc_drain, uc_pool, 1);
if (status || atomic_read(&uc_pool->status))
goto failed;
/*
* The chunk of memory pages has been converted to uncached so now we
* can add it to the pool.
*/
status = gen_pool_add(uc_pool->pool, uc_addr, IA64_GRANULE_SIZE, nid);
if (status)
goto failed;
uc_pool->nchunks_added++;
mutex_unlock(&uc_pool->add_chunk_mutex);
return 0;
/* failed to convert or add the chunk so give it back to the kernel */
failed:
for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++)
ClearPageUncached(&page[i]);
free_pages(c_addr, IA64_GRANULE_SHIFT-PAGE_SHIFT);
mutex_unlock(&uc_pool->add_chunk_mutex);
return -1;
}
static int uncached_add_chunk(struct uncached_pool *uc_pool, int nid)
{
struct page *page;
int status, i, nchunks_added = uc_pool->nchunks_added;
unsigned long c_addr, uc_addr;
if (mutex_lock_interruptible(&uc_pool->add_chunk_mutex) != 0)
return -1; /* */
if (uc_pool->nchunks_added > nchunks_added) {
/* */
mutex_unlock(&uc_pool->add_chunk_mutex);
return 0;
}
if (uc_pool->nchunks_added >= MAX_CONVERTED_CHUNKS_PER_NODE) {
mutex_unlock(&uc_pool->add_chunk_mutex);
return -1;
}
/* */
page = alloc_pages_exact_node(nid,
GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
IA64_GRANULE_SHIFT-PAGE_SHIFT);
if (!page) {
mutex_unlock(&uc_pool->add_chunk_mutex);
return -1;
}
/* */
c_addr = (unsigned long)page_address(page);
uc_addr = c_addr - PAGE_OFFSET + __IA64_UNCACHED_OFFSET;
/*
*/
for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++)
SetPageUncached(&page[i]);
flush_tlb_kernel_range(uc_addr, uc_addr + IA64_GRANULE_SIZE);
status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL);
if (status == PAL_VISIBILITY_OK_REMOTE_NEEDED) {
atomic_set(&uc_pool->status, 0);
status = smp_call_function(uncached_ipi_visibility, uc_pool, 1);
if (status || atomic_read(&uc_pool->status))
goto failed;
} else if (status != PAL_VISIBILITY_OK)
goto failed;
preempt_disable();
if (ia64_platform_is("sn2"))
sn_flush_all_caches(uc_addr, IA64_GRANULE_SIZE);
else
flush_icache_range(uc_addr, uc_addr + IA64_GRANULE_SIZE);
/* */
local_flush_tlb_all();
preempt_enable();
status = ia64_pal_mc_drain();
if (status != PAL_STATUS_SUCCESS)
goto failed;
atomic_set(&uc_pool->status, 0);
status = smp_call_function(uncached_ipi_mc_drain, uc_pool, 1);
if (status || atomic_read(&uc_pool->status))
goto failed;
/*
*/
status = gen_pool_add(uc_pool->pool, uc_addr, IA64_GRANULE_SIZE, nid);
if (status)
goto failed;
uc_pool->nchunks_added++;
mutex_unlock(&uc_pool->add_chunk_mutex);
return 0;
/* */
failed:
for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++)
ClearPageUncached(&page[i]);
free_pages(c_addr, IA64_GRANULE_SHIFT-PAGE_SHIFT);
mutex_unlock(&uc_pool->add_chunk_mutex);
return -1;
}