[PATCH 4/4] memremap: provide a not device managed memremap_pages

The kvmppc ultravisor code wants a device private memory pool that is system wide and not attached to a device. Instead of faking up one provide a low-level memremap_pages for it. Signed-off-by: Christoph Hellwig <hch(a)lst.de&gt; Reviewed-by: Ira Weiny <ira.weiny(a)intel.com&gt; --- include/linux/memremap.h | 2 + kernel/memremap.c | 84 +++++++++++++++++++++++++--------------- 2 files changed, 54 insertions(+), 32 deletions(-) diff --git a/include/linux/memremap.h b/include/linux/memremap.h index 8f0013e18e14..fb2a0bd826b9 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -123,6 +123,8 @@ static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap) } #ifdef CONFIG_ZONE_DEVICE +void *memremap_pages(struct dev_pagemap *pgmap, int nid); +void memunmap_pages(struct dev_pagemap *pgmap); void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap); void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap); struct dev_pagemap *get_dev_pagemap(unsigned long pfn, diff --git a/kernel/memremap.c b/kernel/memremap.c index 09a087ca30ff..77a77704eb28 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -96,9 +96,8 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap) } } -static void devm_memremap_pages_release(void *data) +void memunmap_pages(struct dev_pagemap *pgmap) { - struct dev_pagemap *pgmap = data; struct resource *res = &pgmap->res; unsigned long pfn; int nid; @@ -128,6 +127,12 @@ static void devm_memremap_pages_release(void *data) WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n"); devmap_managed_enable_put(); } +EXPORT_SYMBOL_GPL(memunmap_pages); + +static void devm_memremap_pages_release(void *data) +{ + memunmap_pages(data); +} static void dev_pagemap_percpu_release(struct percpu_ref *ref) { @@ -137,27 +142,12 @@ static void dev_pagemap_percpu_release(struct percpu_ref *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 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 - * PGMAP_ALTMAP_VALID must be set in pgmap->flags. - * - * 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 - * this is not enforced. +/* + * Not device managed version of dev_memremap_pages, undone by + * memunmap_pages(). Please use dev_memremap_pages if you have a struct + * device available. */ -void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) +void *memremap_pages(struct dev_pagemap *pgmap, int nid) { struct resource *res = &pgmap->res; struct dev_pagemap *conflict_pgmap; @@ -168,7 +158,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) .altmap = pgmap_altmap(pgmap), }; pgprot_t pgprot = PAGE_KERNEL; - int error, nid, is_ram; + int error, is_ram; bool need_devmap_managed = true; switch (pgmap->type) { @@ -223,7 +213,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->start), NULL); if (conflict_pgmap) { - dev_WARN(dev, "Conflicting mapping in same section\n"); + WARN(1, "Conflicting mapping in same section\n"); put_dev_pagemap(conflict_pgmap); error = -ENOMEM; goto err_array; @@ -231,7 +221,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->end), NULL); if (conflict_pgmap) { - dev_WARN(dev, "Conflicting mapping in same section\n"); + WARN(1, "Conflicting mapping in same section\n"); put_dev_pagemap(conflict_pgmap); error = -ENOMEM; goto err_array; @@ -252,7 +242,6 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) if (error) goto err_array; - nid = dev_to_node(dev); if (nid < 0) nid = numa_mem_id(); @@ -308,12 +297,6 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) PHYS_PFN(res->start), PHYS_PFN(resource_size(res)), pgmap); percpu_ref_get_many(pgmap->ref, pfn_end(pgmap) - pfn_first(pgmap)); - - error = devm_add_action_or_reset(dev, devm_memremap_pages_release, - pgmap); - if (error) - return ERR_PTR(error); - return __va(res->start); err_add_memory: @@ -328,6 +311,43 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) devmap_managed_enable_put(); return ERR_PTR(error); } +EXPORT_SYMBOL_GPL(memremap_pages); + +/** + * 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 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 + * PGMAP_ALTMAP_VALID must be set in pgmap->flags. + * + * 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 + * this is not enforced. + */ +void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) +{ + int error; + void *ret; + + ret = memremap_pages(pgmap, dev_to_node(dev)); + if (IS_ERR(ret)) + return ret; + + error = devm_add_action_or_reset(dev, devm_memremap_pages_release, + pgmap); + if (error) + return ERR_PTR(error); + return ret; +} EXPORT_SYMBOL_GPL(devm_memremap_pages); void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap) -- 2.20.1