diff options
author | Dan Williams <dan.j.williams@intel.com> | 2019-06-14 01:56:27 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-06-14 06:34:56 +0300 |
commit | 795ee30648c708502da9df637f83c33361d68dcc (patch) | |
tree | 83a9204335deb0f02dfcb2e6a033a9cc6d1d21c5 /include/linux/genalloc.h | |
parent | e615a191216e3fb4e9c0d239007f2b0cd48f28bf (diff) |
lib/genalloc: introduce chunk owners
The p2pdma facility enables a provider to publish a pool of dma
addresses for a consumer to allocate. A genpool is used internally by
p2pdma to collect dma resources, 'chunks', to be handed out to
consumers. Whenever a consumer allocates a resource it needs to pin the
'struct dev_pagemap' instance that backs the chunk selected by
pci_alloc_p2pmem().
Currently that reference is taken globally on the entire provider
device. That sets up a lifetime mismatch whereby the p2pdma core needs
to maintain hacks to make sure the percpu_ref is not released twice.
This lifetime mismatch also stands in the way of a fix to
devm_memremap_pages() whereby devm_memremap_pages_release() must wait for
the percpu_ref ->release() callback to complete before it can proceed to
teardown pages.
So, towards fixing this situation, introduce the ability to store a 'chunk
owner' at gen_pool_add() time, and a facility to retrieve the owner at
gen_pool_{alloc,free}() time. For p2pdma this will be used to store and
recall individual dev_pagemap reference counter instances per-chunk.
Link: http://lkml.kernel.org/r/155727338118.292046.13407378933221579644.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/genalloc.h')
-rw-r--r-- | include/linux/genalloc.h | 55 |
1 files changed, 49 insertions, 6 deletions
diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h index dd0a452373e7..a337313e064f 100644 --- a/include/linux/genalloc.h +++ b/include/linux/genalloc.h @@ -75,6 +75,7 @@ struct gen_pool_chunk { struct list_head next_chunk; /* next chunk in pool */ atomic_long_t avail; phys_addr_t phys_addr; /* physical starting address of memory chunk */ + void *owner; /* private data to retrieve at alloc time */ unsigned long start_addr; /* start address of memory chunk */ unsigned long end_addr; /* end address of memory chunk (inclusive) */ unsigned long bits[0]; /* bitmap for allocating memory chunk */ @@ -96,8 +97,15 @@ struct genpool_data_fixed { extern struct gen_pool *gen_pool_create(int, int); extern phys_addr_t gen_pool_virt_to_phys(struct gen_pool *pool, unsigned long); -extern int gen_pool_add_virt(struct gen_pool *, unsigned long, phys_addr_t, - size_t, int); +extern int gen_pool_add_owner(struct gen_pool *, unsigned long, phys_addr_t, + size_t, int, void *); + +static inline int gen_pool_add_virt(struct gen_pool *pool, unsigned long addr, + phys_addr_t phys, size_t size, int nid) +{ + return gen_pool_add_owner(pool, addr, phys, size, nid, NULL); +} + /** * gen_pool_add - add a new chunk of special memory to the pool * @pool: pool to add new memory chunk to @@ -116,12 +124,47 @@ static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr, return gen_pool_add_virt(pool, addr, -1, size, nid); } extern void gen_pool_destroy(struct gen_pool *); -extern unsigned long gen_pool_alloc(struct gen_pool *, size_t); -extern unsigned long gen_pool_alloc_algo(struct gen_pool *, size_t, - genpool_algo_t algo, void *data); +unsigned long gen_pool_alloc_algo_owner(struct gen_pool *pool, size_t size, + genpool_algo_t algo, void *data, void **owner); + +static inline unsigned long gen_pool_alloc_owner(struct gen_pool *pool, + size_t size, void **owner) +{ + return gen_pool_alloc_algo_owner(pool, size, pool->algo, pool->data, + owner); +} + +static inline unsigned long gen_pool_alloc_algo(struct gen_pool *pool, + size_t size, genpool_algo_t algo, void *data) +{ + return gen_pool_alloc_algo_owner(pool, size, algo, data, NULL); +} + +/** + * gen_pool_alloc - allocate special memory from the pool + * @pool: pool to allocate from + * @size: number of bytes to allocate from the pool + * + * Allocate the requested number of bytes from the specified pool. + * Uses the pool allocation function (with first-fit algorithm by default). + * Can not be used in NMI handler on architectures without + * NMI-safe cmpxchg implementation. + */ +static inline unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size) +{ + return gen_pool_alloc_algo(pool, size, pool->algo, pool->data); +} + extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma); -extern void gen_pool_free(struct gen_pool *, unsigned long, size_t); +extern void gen_pool_free_owner(struct gen_pool *pool, unsigned long addr, + size_t size, void **owner); +static inline void gen_pool_free(struct gen_pool *pool, unsigned long addr, + size_t size) +{ + gen_pool_free_owner(pool, addr, size, NULL); +} + extern void gen_pool_for_each_chunk(struct gen_pool *, void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *); extern size_t gen_pool_avail(struct gen_pool *); |