#include <linux/types.h>
#include <linux/wait_bit.h>
#include <linux/xarray.h>
-#include <linux/hmm.h>
static DEFINE_XARRAY(pgmap_array);
#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1)
#define SECTION_SIZE (1UL << PA_SECTION_SHIFT)
-#if IS_ENABLED(CONFIG_DEVICE_PRIVATE)
-vm_fault_t device_private_entry_fault(struct vm_area_struct *vma,
- unsigned long addr,
- swp_entry_t entry,
- unsigned int flags,
- pmd_t *pmdp)
+#ifdef CONFIG_DEV_PAGEMAP_OPS
+DEFINE_STATIC_KEY_FALSE(devmap_managed_key);
+EXPORT_SYMBOL(devmap_managed_key);
+static atomic_t devmap_managed_enable;
+
+static void devmap_managed_enable_put(void *data)
{
- struct page *page = device_private_entry_to_page(entry);
- struct hmm_devmem *devmem;
+ if (atomic_dec_and_test(&devmap_managed_enable))
+ static_branch_disable(&devmap_managed_key);
+}
- devmem = container_of(page->pgmap, typeof(*devmem), pagemap);
+static int devmap_managed_enable_get(struct device *dev, struct dev_pagemap *pgmap)
+{
+ if (!pgmap->ops || !pgmap->ops->page_free) {
+ WARN(1, "Missing page_free method\n");
+ return -EINVAL;
+ }
- /*
- * The page_fault() callback must migrate page back to system memory
- * so that CPU can access it. This might fail for various reasons
- * (device issue, device was unsafely unplugged, ...). When such
- * error conditions happen, the callback must return VM_FAULT_SIGBUS.
- *
- * Note that because memory cgroup charges are accounted to the device
- * memory, this should never fail because of memory restrictions (but
- * allocation of regular system page might still fail because we are
- * out of memory).
- *
- * There is a more in-depth description of what that callback can and
- * cannot do, in include/linux/memremap.h
- */
- return devmem->page_fault(vma, addr, page, flags, pmdp);
+ if (atomic_inc_return(&devmap_managed_enable) == 1)
+ static_branch_enable(&devmap_managed_key);
+ return devm_add_action_or_reset(dev, devmap_managed_enable_put, NULL);
}
-#endif /* CONFIG_DEVICE_PRIVATE */
+#else
+static int devmap_managed_enable_get(struct device *dev, struct dev_pagemap *pgmap)
+{
+ return -EINVAL;
+}
+#endif /* CONFIG_DEV_PAGEMAP_OPS */
static void pgmap_array_delete(struct resource *res)
{
static unsigned long pfn_first(struct dev_pagemap *pgmap)
{
- const struct resource *res = &pgmap->res;
- struct vmem_altmap *altmap = &pgmap->altmap;
- unsigned long pfn;
-
- pfn = res->start >> PAGE_SHIFT;
- if (pgmap->altmap_valid)
- pfn += vmem_altmap_offset(altmap);
- return pfn;
+ return (pgmap->res.start >> PAGE_SHIFT) +
+ vmem_altmap_offset(pgmap_altmap(pgmap));
}
static unsigned long pfn_end(struct dev_pagemap *pgmap)
#define for_each_device_pfn(pfn, map) \
for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn))
+static void dev_pagemap_kill(struct dev_pagemap *pgmap)
+{
+ if (pgmap->ops && pgmap->ops->kill)
+ pgmap->ops->kill(pgmap);
+ else
+ percpu_ref_kill(pgmap->ref);
+}
+
+static void dev_pagemap_cleanup(struct dev_pagemap *pgmap)
+{
+ if (pgmap->ops && pgmap->ops->cleanup) {
+ pgmap->ops->cleanup(pgmap);
+ } else {
+ wait_for_completion(&pgmap->done);
+ percpu_ref_exit(pgmap->ref);
+ }
+}
+
static void devm_memremap_pages_release(void *data)
{
struct dev_pagemap *pgmap = data;
unsigned long pfn;
int nid;
- pgmap->kill(pgmap->ref);
+ dev_pagemap_kill(pgmap);
for_each_device_pfn(pfn, pgmap)
put_page(pfn_to_page(pfn));
- pgmap->cleanup(pgmap->ref);
+ dev_pagemap_cleanup(pgmap);
/* pages are dead and unused, undo the arch mapping */
align_start = res->start & ~(SECTION_SIZE - 1);
align_size >> PAGE_SHIFT, NULL);
} else {
arch_remove_memory(nid, align_start, align_size,
- pgmap->altmap_valid ? &pgmap->altmap : NULL);
+ pgmap_altmap(pgmap));
kasan_remove_zero_shadow(__va(align_start), align_size);
}
mem_hotplug_done();
"%s: failed to free all reserved pages\n", __func__);
}
+static void dev_pagemap_percpu_release(struct percpu_ref *ref)
+{
+ struct dev_pagemap *pgmap =
+ container_of(ref, struct dev_pagemap, internal_ref);
+
+ complete(&pgmap->done);
+}
+
/**
* devm_memremap_pages - remap and provide memmap backing for the given resource
* @dev: hosting device for @res
* @pgmap: pointer to a struct dev_pagemap
*
* Notes:
- * 1/ At a minimum the res, ref and type members of @pgmap must be initialized
+ * 1/ At a minimum the res and type members of @pgmap must be initialized
* by the caller before passing it to this function
*
- * 2/ The altmap field may optionally be initialized, in which case altmap_valid
- * must be set to true
+ * 2/ The altmap field may optionally be initialized, in which case
+ * PGMAP_ALTMAP_VALID must be set in pgmap->flags.
*
- * 3/ pgmap->ref must be 'live' on entry and will be killed and reaped
- * at devm_memremap_pages_release() time, or if this routine fails.
+ * 3/ The ref field may optionally be provided, in which pgmap->ref must be
+ * 'live' on entry and will be killed and reaped at
+ * devm_memremap_pages_release() time, or if this routine fails.
*
* 4/ res is expected to be a host memory range that could feasibly be
* treated as a "System RAM" range, i.e. not a device mmio range, but
void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
resource_size_t align_start, align_size, align_end;
- struct vmem_altmap *altmap = pgmap->altmap_valid ?
- &pgmap->altmap : NULL;
struct resource *res = &pgmap->res;
struct dev_pagemap *conflict_pgmap;
struct mhp_restrictions restrictions = {
/*
* We do not want any optional features only our own memmap
*/
- .altmap = altmap,
+ .altmap = pgmap_altmap(pgmap),
};
pgprot_t pgprot = PAGE_KERNEL;
int error, nid, is_ram;
+ bool need_devmap_managed = true;
+
+ switch (pgmap->type) {
+ case MEMORY_DEVICE_PRIVATE:
+ if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) {
+ WARN(1, "Device private memory not supported\n");
+ return ERR_PTR(-EINVAL);
+ }
+ if (!pgmap->ops || !pgmap->ops->migrate_to_ram) {
+ WARN(1, "Missing migrate_to_ram method\n");
+ return ERR_PTR(-EINVAL);
+ }
+ break;
+ case MEMORY_DEVICE_FS_DAX:
+ if (!IS_ENABLED(CONFIG_ZONE_DEVICE) ||
+ IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
+ WARN(1, "File system DAX not supported\n");
+ return ERR_PTR(-EINVAL);
+ }
+ break;
+ case MEMORY_DEVICE_DEVDAX:
+ case MEMORY_DEVICE_PCI_P2PDMA:
+ need_devmap_managed = false;
+ break;
+ default:
+ WARN(1, "Invalid pgmap type %d\n", pgmap->type);
+ break;
+ }
+
+ if (!pgmap->ref) {
+ if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup))
+ return ERR_PTR(-EINVAL);
+
+ init_completion(&pgmap->done);
+ error = percpu_ref_init(&pgmap->internal_ref,
+ dev_pagemap_percpu_release, 0, GFP_KERNEL);
+ if (error)
+ return ERR_PTR(error);
+ pgmap->ref = &pgmap->internal_ref;
+ } else {
+ if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) {
+ WARN(1, "Missing reference count teardown definition\n");
+ return ERR_PTR(-EINVAL);
+ }
+ }
- if (!pgmap->ref || !pgmap->kill || !pgmap->cleanup) {
- WARN(1, "Missing reference count teardown definition\n");
- return ERR_PTR(-EINVAL);
+ if (need_devmap_managed) {
+ error = devmap_managed_enable_get(dev, pgmap);
+ if (error)
+ return ERR_PTR(error);
}
align_start = res->start & ~(SECTION_SIZE - 1);
zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
move_pfn_range_to_zone(zone, align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, altmap);
+ align_size >> PAGE_SHIFT, pgmap_altmap(pgmap));
}
mem_hotplug_done();
err_pfn_remap:
pgmap_array_delete(res);
err_array:
- pgmap->kill(pgmap->ref);
- pgmap->cleanup(pgmap->ref);
-
+ dev_pagemap_kill(pgmap);
+ dev_pagemap_cleanup(pgmap);
return ERR_PTR(error);
}
EXPORT_SYMBOL_GPL(devm_memremap_pages);
unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
{
/* number of pfns from base where pfn_to_page() is valid */
- return altmap->reserve + altmap->free;
+ if (altmap)
+ return altmap->reserve + altmap->free;
+ return 0;
}
void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns)
EXPORT_SYMBOL_GPL(get_dev_pagemap);
#ifdef CONFIG_DEV_PAGEMAP_OPS
-DEFINE_STATIC_KEY_FALSE(devmap_managed_key);
-EXPORT_SYMBOL(devmap_managed_key);
-static atomic_t devmap_enable;
-
-/*
- * Toggle the static key for ->page_free() callbacks when dev_pagemap
- * pages go idle.
- */
-void dev_pagemap_get_ops(void)
-{
- if (atomic_inc_return(&devmap_enable) == 1)
- static_branch_enable(&devmap_managed_key);
-}
-EXPORT_SYMBOL_GPL(dev_pagemap_get_ops);
-
-void dev_pagemap_put_ops(void)
-{
- if (atomic_dec_and_test(&devmap_enable))
- static_branch_disable(&devmap_managed_key);
-}
-EXPORT_SYMBOL_GPL(dev_pagemap_put_ops);
-
void __put_devmap_managed_page(struct page *page)
{
int count = page_ref_dec_return(page);
mem_cgroup_uncharge(page);
- page->pgmap->page_free(page, page->pgmap->data);
+ page->pgmap->ops->page_free(page);
} else if (!count)
__put_page(page);
}
projects / linux-2.6-block.git / blobdiff