[PATCH v6 03/17] misc/habana: Stop using frame_vector helpers

From: Daniel Vetter
Date: Thu Nov 19 2020 - 09:42:21 EST


All we need are a pages array, pin_user_pages_fast can give us that
directly. Plus this avoids the entire raw pfn side of get_vaddr_frames.

Note that pin_user_pages_fast is a safe replacement despite the
seeming lack of checking for vma->vm_flasg & (VM_IO | VM_PFNMAP). Such
ptes are marked with pte_mkspecial (which pup_fast rejects in the
fastpath), and only architectures supporting that support the
pin_user_pages_fast fastpath.

Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Jérôme Glisse <jglisse@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-samsung-soc@xxxxxxxxxxxxxxx
Cc: linux-media@xxxxxxxxxxxxxxx
Cc: Oded Gabbay <oded.gabbay@xxxxxxxxx>
Cc: Omer Shpigelman <oshpigelman@xxxxxxxxx>
Cc: Ofir Bitton <obitton@xxxxxxxxx>
Cc: Tomer Tayar <ttayar@xxxxxxxxx>
Cc: Moti Haimovski <mhaimovski@xxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Pawel Piskorski <ppiskorski@xxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
--
v2: Use unpin_user_pages_dirty_lock (John)
v3: Update kerneldoc (Oded)
v6: Explain why pup_fast is safe, after discussions with John and
Christoph.
---
drivers/misc/habanalabs/Kconfig | 1 -
drivers/misc/habanalabs/common/habanalabs.h | 6 ++-
drivers/misc/habanalabs/common/memory.c | 49 ++++++++-------------
3 files changed, 22 insertions(+), 34 deletions(-)

diff --git a/drivers/misc/habanalabs/Kconfig b/drivers/misc/habanalabs/Kconfig
index 1640340d3e62..293d79811372 100644
--- a/drivers/misc/habanalabs/Kconfig
+++ b/drivers/misc/habanalabs/Kconfig
@@ -6,7 +6,6 @@
config HABANA_AI
tristate "HabanaAI accelerators (habanalabs)"
depends on PCI && HAS_IOMEM
- select FRAME_VECTOR
select GENERIC_ALLOCATOR
select HWMON
help
diff --git a/drivers/misc/habanalabs/common/habanalabs.h b/drivers/misc/habanalabs/common/habanalabs.h
index 80d4d7385ffe..272aa3f29200 100644
--- a/drivers/misc/habanalabs/common/habanalabs.h
+++ b/drivers/misc/habanalabs/common/habanalabs.h
@@ -921,7 +921,8 @@ struct hl_ctx_mgr {
* struct hl_userptr - memory mapping chunk information
* @vm_type: type of the VM.
* @job_node: linked-list node for hanging the object on the Job's list.
- * @vec: pointer to the frame vector.
+ * @pages: pointer to struct page array
+ * @npages: size of @pages array
* @sgt: pointer to the scatter-gather table that holds the pages.
* @dir: for DMA unmapping, the direction must be supplied, so save it.
* @debugfs_list: node in debugfs list of command submissions.
@@ -932,7 +933,8 @@ struct hl_ctx_mgr {
struct hl_userptr {
enum vm_type_t vm_type; /* must be first */
struct list_head job_node;
- struct frame_vector *vec;
+ struct page **pages;
+ unsigned int npages;
struct sg_table *sgt;
enum dma_data_direction dir;
struct list_head debugfs_list;
diff --git a/drivers/misc/habanalabs/common/memory.c b/drivers/misc/habanalabs/common/memory.c
index 84227819e4d1..0b220221873d 100644
--- a/drivers/misc/habanalabs/common/memory.c
+++ b/drivers/misc/habanalabs/common/memory.c
@@ -1291,45 +1291,41 @@ static int get_user_memory(struct hl_device *hdev, u64 addr, u64 size,
return -EFAULT;
}

- userptr->vec = frame_vector_create(npages);
- if (!userptr->vec) {
+ userptr->pages = kvmalloc_array(npages, sizeof(*userptr->pages),
+ GFP_KERNEL);
+ if (!userptr->pages) {
dev_err(hdev->dev, "Failed to create frame vector\n");
return -ENOMEM;
}

- rc = get_vaddr_frames(start, npages, FOLL_FORCE | FOLL_WRITE,
- userptr->vec);
+ rc = pin_user_pages_fast(start, npages, FOLL_FORCE | FOLL_WRITE,
+ userptr->pages);

if (rc != npages) {
dev_err(hdev->dev,
"Failed to map host memory, user ptr probably wrong\n");
if (rc < 0)
- goto destroy_framevec;
+ goto destroy_pages;
+ npages = rc;
rc = -EFAULT;
- goto put_framevec;
- }
-
- if (frame_vector_to_pages(userptr->vec) < 0) {
- dev_err(hdev->dev,
- "Failed to translate frame vector to pages\n");
- rc = -EFAULT;
- goto put_framevec;
+ goto put_pages;
}
+ userptr->npages = npages;

rc = sg_alloc_table_from_pages(userptr->sgt,
- frame_vector_pages(userptr->vec),
- npages, offset, size, GFP_ATOMIC);
+ userptr->pages,
+ npages, offset, size, GFP_ATOMIC);
if (rc < 0) {
dev_err(hdev->dev, "failed to create SG table from pages\n");
- goto put_framevec;
+ goto put_pages;
}

return 0;

-put_framevec:
- put_vaddr_frames(userptr->vec);
-destroy_framevec:
- frame_vector_destroy(userptr->vec);
+put_pages:
+ unpin_user_pages(userptr->pages, npages);
+destroy_pages:
+ kvfree(userptr->pages);
return rc;
}

@@ -1415,8 +1411,6 @@ int hl_pin_host_memory(struct hl_device *hdev, u64 addr, u64 size,
*/
void hl_unpin_host_memory(struct hl_device *hdev, struct hl_userptr *userptr)
{
- struct page **pages;
-
hl_debugfs_remove_userptr(hdev, userptr);

if (userptr->dma_mapped)
@@ -1424,15 +1418,8 @@ void hl_unpin_host_memory(struct hl_device *hdev, struct hl_userptr *userptr)
userptr->sgt->nents,
userptr->dir);

- pages = frame_vector_pages(userptr->vec);
- if (!IS_ERR(pages)) {
- int i;
-
- for (i = 0; i < frame_vector_count(userptr->vec); i++)
- set_page_dirty_lock(pages[i]);
- }
- put_vaddr_frames(userptr->vec);
- frame_vector_destroy(userptr->vec);
+ unpin_user_pages_dirty_lock(userptr->pages, userptr->npages, true);
+ kvfree(userptr->pages);

list_del(&userptr->job_node);

--
2.29.2