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authorJohn Hubbard <jhubbard@nvidia.com>2020-05-17 18:52:37 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-05-19 16:46:12 +0200
commitddae1423bc2ddf87d1e51746ebfa9034c8e323f1 (patch)
tree5424c53a8b0ac514ac3850faf782c00d492345bd
parent5459ceedb3940df460a6048762cc49d549049d6f (diff)
downloadlinux-ddae1423bc2ddf87d1e51746ebfa9034c8e323f1.tar.bz2
genwqe: convert get_user_pages() --> pin_user_pages()
This code was using get_user_pages*(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Cc: Frank Haverkamp <haver@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Link: https://lore.kernel.org/r/20200518015237.1568940-1-jhubbard@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/misc/genwqe/card_utils.c42
1 files changed, 9 insertions, 33 deletions
diff --git a/drivers/misc/genwqe/card_utils.c b/drivers/misc/genwqe/card_utils.c
index 2e1c4d2905e8..60460a053b2d 100644
--- a/drivers/misc/genwqe/card_utils.c
+++ b/drivers/misc/genwqe/card_utils.c
@@ -515,30 +515,6 @@ int genwqe_free_sync_sgl(struct genwqe_dev *cd, struct genwqe_sgl *sgl)
}
/**
- * genwqe_free_user_pages() - Give pinned pages back
- *
- * Documentation of get_user_pages is in mm/gup.c:
- *
- * If the page is written to, set_page_dirty (or set_page_dirty_lock,
- * as appropriate) must be called after the page is finished with, and
- * before put_page is called.
- */
-static int genwqe_free_user_pages(struct page **page_list,
- unsigned int nr_pages, int dirty)
-{
- unsigned int i;
-
- for (i = 0; i < nr_pages; i++) {
- if (page_list[i] != NULL) {
- if (dirty)
- set_page_dirty_lock(page_list[i]);
- put_page(page_list[i]);
- }
- }
- return 0;
-}
-
-/**
* genwqe_user_vmap() - Map user-space memory to virtual kernel memory
* @cd: pointer to genwqe device
* @m: mapping params
@@ -597,18 +573,18 @@ int genwqe_user_vmap(struct genwqe_dev *cd, struct dma_mapping *m, void *uaddr,
m->dma_list = (dma_addr_t *)(m->page_list + m->nr_pages);
/* pin user pages in memory */
- rc = get_user_pages_fast(data & PAGE_MASK, /* page aligned addr */
+ rc = pin_user_pages_fast(data & PAGE_MASK, /* page aligned addr */
m->nr_pages,
m->write ? FOLL_WRITE : 0, /* readable/writable */
m->page_list); /* ptrs to pages */
if (rc < 0)
- goto fail_get_user_pages;
+ goto fail_pin_user_pages;
- /* assumption: get_user_pages can be killed by signals. */
+ /* assumption: pin_user_pages can be killed by signals. */
if (rc < m->nr_pages) {
- genwqe_free_user_pages(m->page_list, rc, m->write);
+ unpin_user_pages_dirty_lock(m->page_list, rc, m->write);
rc = -EFAULT;
- goto fail_get_user_pages;
+ goto fail_pin_user_pages;
}
rc = genwqe_map_pages(cd, m->page_list, m->nr_pages, m->dma_list);
@@ -618,9 +594,9 @@ int genwqe_user_vmap(struct genwqe_dev *cd, struct dma_mapping *m, void *uaddr,
return 0;
fail_free_user_pages:
- genwqe_free_user_pages(m->page_list, m->nr_pages, m->write);
+ unpin_user_pages_dirty_lock(m->page_list, m->nr_pages, m->write);
- fail_get_user_pages:
+ fail_pin_user_pages:
kfree(m->page_list);
m->page_list = NULL;
m->dma_list = NULL;
@@ -650,8 +626,8 @@ int genwqe_user_vunmap(struct genwqe_dev *cd, struct dma_mapping *m)
genwqe_unmap_pages(cd, m->dma_list, m->nr_pages);
if (m->page_list) {
- genwqe_free_user_pages(m->page_list, m->nr_pages, m->write);
-
+ unpin_user_pages_dirty_lock(m->page_list, m->nr_pages,
+ m->write);
kfree(m->page_list);
m->page_list = NULL;
m->dma_list = NULL;