PMEM: Pre reserve virtual address range for on demand devices.
Since the PMEM driver establishes ioremaps on the fly for
on demand devices it is possible for the virtual address space
to become quickly fragmented. For such devices, pre-reserve the
virtual address range and only set up page table mappings when
required.
CRs-Fixed: 299510
Signed-off-by: Naveen Ramaraj <nramaraj@codeaurora.org>
diff --git a/drivers/misc/pmem.c b/drivers/misc/pmem.c
index a9d1990..b94de48 100644
--- a/drivers/misc/pmem.c
+++ b/drivers/misc/pmem.c
@@ -24,12 +24,17 @@
#include <linux/android_pmem.h>
#include <linux/mempolicy.h>
#include <linux/kobject.h>
+#include <linux/pm_runtime.h>
+#include <linux/memory_alloc.h>
+#include <linux/vmalloc.h>
+#include <linux/io.h>
+#include <linux/mm_types.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/sizes.h>
-#include <linux/pm_runtime.h>
-#include <linux/memory_alloc.h>
+#include <asm/mach/map.h>
+#include <asm/page.h>
#define PMEM_MAX_DEVICES (10)
@@ -148,6 +153,8 @@
/* index of the garbage page in the pmem space */
int garbage_index;
+ /* reserved virtual address range */
+ struct vm_struct *area;
enum pmem_allocator_type allocator_type;
@@ -597,7 +604,11 @@
DLOG("PMEMDEBUG: unmapping for %s", pmem[id].name);
BUG_ON(!pmem[id].vbase);
if (pmem[id].map_on_demand) {
- iounmap(pmem[id].vbase);
+ /* unmap_kernel_range() flushes the caches
+ * and removes the page table entries
+ */
+ unmap_kernel_range((unsigned long)pmem[id].vbase,
+ pmem[id].size);
pmem[id].vbase = NULL;
if (pmem[id].mem_release)
pmem[id].mem_release(pmem[id].region_data);
@@ -2521,17 +2532,40 @@
static void ioremap_pmem(int id)
{
- DLOG("PMEMDEBUG: ioremaping for %s\n", pmem[id].name);
+ unsigned long addr;
+ const struct mem_type *type;
- if (pmem[id].cached)
- pmem[id].vbase = ioremap_cached(pmem[id].base, pmem[id].size);
-#ifdef ioremap_ext_buffered
- else if (pmem[id].buffered)
- pmem[id].vbase = ioremap_ext_buffered(pmem[id].base,
- pmem[id].size);
-#endif
- else
- pmem[id].vbase = ioremap(pmem[id].base, pmem[id].size);
+ DLOG("PMEMDEBUG: ioremaping for %s\n", pmem[id].name);
+ if (pmem[id].map_on_demand) {
+ addr = (unsigned long)pmem[id].area->addr;
+ if (pmem[id].cached)
+ type = get_mem_type(MT_DEVICE_CACHED);
+ else
+ type = get_mem_type(MT_DEVICE);
+ DLOG("PMEMDEBUG: Remap phys %lx to virt %lx on %s\n",
+ pmem[id].base, addr, pmem[id].name);
+ if (ioremap_page_range(addr, addr + pmem[id].size,
+ pmem[id].base, __pgprot(type->prot_pte))) {
+ pr_err("pmem: Failed to map pages\n");
+ BUG();
+ }
+ pmem[id].vbase = pmem[id].area->addr;
+ /* Flush the cache after installing page table entries to avoid
+ * aliasing when these pages are remapped to user space.
+ */
+ flush_cache_vmap(addr, addr + pmem[id].size);
+ } else {
+ if (pmem[id].cached)
+ pmem[id].vbase = ioremap_cached(pmem[id].base,
+ pmem[id].size);
+ #ifdef ioremap_ext_buffered
+ else if (pmem[id].buffered)
+ pmem[id].vbase = ioremap_ext_buffered(pmem[id].base,
+ pmem[id].size);
+ #endif
+ else
+ pmem[id].vbase = ioremap(pmem[id].base, pmem[id].size);
+ }
}
int pmem_setup(struct android_pmem_platform_data *pdata,
@@ -2539,6 +2573,7 @@
int (*release)(struct inode *, struct file *))
{
int i, index = 0, id;
+ struct vm_struct *pmem_vma = NULL;
if (id_count >= PMEM_MAX_DEVICES) {
pr_alert("pmem: %s: unable to register driver(%s) - no more "
@@ -2743,9 +2778,24 @@
pr_info("allocating %lu bytes at %p (%lx physical) for %s\n",
pmem[id].size, pmem[id].vbase, pmem[id].base, pmem[id].name);
+ pmem[id].map_on_demand = pdata->map_on_demand;
+ if (pmem[id].map_on_demand) {
+ pmem_vma = get_vm_area(pmem[id].size, VM_IOREMAP);
+ if (!pmem_vma) {
+ pr_err("pmem: Failed to allocate virtual space for "
+ "%s\n", pdata->name);
+ goto out_put_kobj;
+ }
+ pr_err("pmem: Reserving virtual address range %lx - %lx for"
+ " %s\n", (unsigned long) pmem_vma->addr,
+ (unsigned long) pmem_vma->addr + pmem[id].size,
+ pdata->name);
+ pmem[id].area = pmem_vma;
+ } else
+ pmem[id].area = NULL;
+
pmem[id].garbage_pfn = page_to_pfn(alloc_page(GFP_KERNEL));
atomic_set(&pmem[id].allocation_cnt, 0);
- pmem[id].map_on_demand = pdata->map_on_demand;
if (pdata->setup_region)
pmem[id].region_data = pdata->setup_region();