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IB: Refactor umem to use linear SG table
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This patch refactors the IB core umem code and vendor drivers to use a
linear (chained) SG table instead of chunk list.  With this change the
relevant code becomes clearer—no need for nested loops to build and
use umem.

Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
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Yishai Hadas authored and Roland Dreier committed Mar 4, 2014
1 parent cfbf8d4 commit eeb8461
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Showing 16 changed files with 448 additions and 552 deletions.
120 changes: 56 additions & 64 deletions drivers/infiniband/core/umem.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -42,29 +42,29 @@

#include "uverbs.h"

#define IB_UMEM_MAX_PAGE_CHUNK \
((PAGE_SIZE - offsetof(struct ib_umem_chunk, page_list)) / \
((void *) &((struct ib_umem_chunk *) 0)->page_list[1] - \
(void *) &((struct ib_umem_chunk *) 0)->page_list[0]))

static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
{
struct ib_umem_chunk *chunk, *tmp;
struct scatterlist *sg;
struct page *page;
int i;

list_for_each_entry_safe(chunk, tmp, &umem->chunk_list, list) {
ib_dma_unmap_sg(dev, chunk->page_list,
chunk->nents, DMA_BIDIRECTIONAL);
for (i = 0; i < chunk->nents; ++i) {
struct page *page = sg_page(&chunk->page_list[i]);
if (umem->nmap > 0)
ib_dma_unmap_sg(dev, umem->sg_head.sgl,
umem->nmap,
DMA_BIDIRECTIONAL);

if (umem->writable && dirty)
set_page_dirty_lock(page);
put_page(page);
}
for_each_sg(umem->sg_head.sgl, sg, umem->npages, i) {

kfree(chunk);
page = sg_page(sg);
if (umem->writable && dirty)
set_page_dirty_lock(page);
put_page(page);
}

sg_free_table(&umem->sg_head);
return;

}

/**
Expand All @@ -81,23 +81,23 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
struct ib_umem *umem;
struct page **page_list;
struct vm_area_struct **vma_list;
struct ib_umem_chunk *chunk;
unsigned long locked;
unsigned long lock_limit;
unsigned long cur_base;
unsigned long npages;
int ret;
int off;
int i;
DEFINE_DMA_ATTRS(attrs);
struct scatterlist *sg, *sg_list_start;
int need_release = 0;

if (dmasync)
dma_set_attr(DMA_ATTR_WRITE_BARRIER, &attrs);

if (!can_do_mlock())
return ERR_PTR(-EPERM);

umem = kmalloc(sizeof *umem, GFP_KERNEL);
umem = kzalloc(sizeof *umem, GFP_KERNEL);
if (!umem)
return ERR_PTR(-ENOMEM);

Expand All @@ -117,8 +117,6 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
/* We assume the memory is from hugetlb until proved otherwise */
umem->hugetlb = 1;

INIT_LIST_HEAD(&umem->chunk_list);

page_list = (struct page **) __get_free_page(GFP_KERNEL);
if (!page_list) {
kfree(umem);
Expand Down Expand Up @@ -147,7 +145,18 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,

cur_base = addr & PAGE_MASK;

ret = 0;
if (npages == 0) {
ret = -EINVAL;
goto out;
}

ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL);
if (ret)
goto out;

need_release = 1;
sg_list_start = umem->sg_head.sgl;

while (npages) {
ret = get_user_pages(current, current->mm, cur_base,
min_t(unsigned long, npages,
Expand All @@ -157,54 +166,38 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
if (ret < 0)
goto out;

umem->npages += ret;
cur_base += ret * PAGE_SIZE;
npages -= ret;

off = 0;

while (ret) {
chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) *
min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK),
GFP_KERNEL);
if (!chunk) {
ret = -ENOMEM;
goto out;
}

chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
sg_init_table(chunk->page_list, chunk->nents);
for (i = 0; i < chunk->nents; ++i) {
if (vma_list &&
!is_vm_hugetlb_page(vma_list[i + off]))
umem->hugetlb = 0;
sg_set_page(&chunk->page_list[i], page_list[i + off], PAGE_SIZE, 0);
}

chunk->nmap = ib_dma_map_sg_attrs(context->device,
&chunk->page_list[0],
chunk->nents,
DMA_BIDIRECTIONAL,
&attrs);
if (chunk->nmap <= 0) {
for (i = 0; i < chunk->nents; ++i)
put_page(sg_page(&chunk->page_list[i]));
kfree(chunk);

ret = -ENOMEM;
goto out;
}

ret -= chunk->nents;
off += chunk->nents;
list_add_tail(&chunk->list, &umem->chunk_list);
for_each_sg(sg_list_start, sg, ret, i) {
if (vma_list && !is_vm_hugetlb_page(vma_list[i]))
umem->hugetlb = 0;

sg_set_page(sg, page_list[i], PAGE_SIZE, 0);
}

ret = 0;
/* preparing for next loop */
sg_list_start = sg;
}

umem->nmap = ib_dma_map_sg_attrs(context->device,
umem->sg_head.sgl,
umem->npages,
DMA_BIDIRECTIONAL,
&attrs);

if (umem->nmap <= 0) {
ret = -ENOMEM;
goto out;
}

ret = 0;

out:
if (ret < 0) {
__ib_umem_release(context->device, umem, 0);
if (need_release)
__ib_umem_release(context->device, umem, 0);
kfree(umem);
} else
current->mm->pinned_vm = locked;
Expand Down Expand Up @@ -278,17 +271,16 @@ EXPORT_SYMBOL(ib_umem_release);

int ib_umem_page_count(struct ib_umem *umem)
{
struct ib_umem_chunk *chunk;
int shift;
int i;
int n;
struct scatterlist *sg;

shift = ilog2(umem->page_size);

n = 0;
list_for_each_entry(chunk, &umem->chunk_list, list)
for (i = 0; i < chunk->nmap; ++i)
n += sg_dma_len(&chunk->page_list[i]) >> shift;
for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i)
n += sg_dma_len(sg) >> shift;

return n;
}
Expand Down
23 changes: 9 additions & 14 deletions drivers/infiniband/hw/amso1100/c2_provider.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -431,9 +431,9 @@ static struct ib_mr *c2_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
u64 *pages;
u64 kva = 0;
int shift, n, len;
int i, j, k;
int i, k, entry;
int err = 0;
struct ib_umem_chunk *chunk;
struct scatterlist *sg;
struct c2_pd *c2pd = to_c2pd(pd);
struct c2_mr *c2mr;

Expand All @@ -452,10 +452,7 @@ static struct ib_mr *c2_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
}

shift = ffs(c2mr->umem->page_size) - 1;

n = 0;
list_for_each_entry(chunk, &c2mr->umem->chunk_list, list)
n += chunk->nents;
n = c2mr->umem->nmap;

pages = kmalloc(n * sizeof(u64), GFP_KERNEL);
if (!pages) {
Expand All @@ -464,14 +461,12 @@ static struct ib_mr *c2_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
}

i = 0;
list_for_each_entry(chunk, &c2mr->umem->chunk_list, list) {
for (j = 0; j < chunk->nmap; ++j) {
len = sg_dma_len(&chunk->page_list[j]) >> shift;
for (k = 0; k < len; ++k) {
pages[i++] =
sg_dma_address(&chunk->page_list[j]) +
(c2mr->umem->page_size * k);
}
for_each_sg(c2mr->umem->sg_head.sgl, sg, c2mr->umem->nmap, entry) {
len = sg_dma_len(sg) >> shift;
for (k = 0; k < len; ++k) {
pages[i++] =
sg_dma_address(sg) +
(c2mr->umem->page_size * k);
}
}

Expand Down
19 changes: 7 additions & 12 deletions drivers/infiniband/hw/cxgb3/iwch_provider.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -618,14 +618,13 @@ static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
{
__be64 *pages;
int shift, n, len;
int i, j, k;
int i, k, entry;
int err = 0;
struct ib_umem_chunk *chunk;
struct iwch_dev *rhp;
struct iwch_pd *php;
struct iwch_mr *mhp;
struct iwch_reg_user_mr_resp uresp;

struct scatterlist *sg;
PDBG("%s ib_pd %p\n", __func__, pd);

php = to_iwch_pd(pd);
Expand All @@ -645,9 +644,7 @@ static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,

shift = ffs(mhp->umem->page_size) - 1;

n = 0;
list_for_each_entry(chunk, &mhp->umem->chunk_list, list)
n += chunk->nents;
n = mhp->umem->nmap;

err = iwch_alloc_pbl(mhp, n);
if (err)
Expand All @@ -661,12 +658,10 @@ static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,

i = n = 0;

list_for_each_entry(chunk, &mhp->umem->chunk_list, list)
for (j = 0; j < chunk->nmap; ++j) {
len = sg_dma_len(&chunk->page_list[j]) >> shift;
for_each_sg(mhp->umem->sg_head.sgl, sg, mhp->umem->nmap, entry) {
len = sg_dma_len(sg) >> shift;
for (k = 0; k < len; ++k) {
pages[i++] = cpu_to_be64(sg_dma_address(
&chunk->page_list[j]) +
pages[i++] = cpu_to_be64(sg_dma_address(sg) +
mhp->umem->page_size * k);
if (i == PAGE_SIZE / sizeof *pages) {
err = iwch_write_pbl(mhp, pages, i, n);
Expand All @@ -676,7 +671,7 @@ static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
i = 0;
}
}
}
}

if (i)
err = iwch_write_pbl(mhp, pages, i, n);
Expand Down
39 changes: 17 additions & 22 deletions drivers/infiniband/hw/cxgb4/mem.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -678,9 +678,9 @@ struct ib_mr *c4iw_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
{
__be64 *pages;
int shift, n, len;
int i, j, k;
int i, k, entry;
int err = 0;
struct ib_umem_chunk *chunk;
struct scatterlist *sg;
struct c4iw_dev *rhp;
struct c4iw_pd *php;
struct c4iw_mr *mhp;
Expand Down Expand Up @@ -710,10 +710,7 @@ struct ib_mr *c4iw_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,

shift = ffs(mhp->umem->page_size) - 1;

n = 0;
list_for_each_entry(chunk, &mhp->umem->chunk_list, list)
n += chunk->nents;

n = mhp->umem->nmap;
err = alloc_pbl(mhp, n);
if (err)
goto err;
Expand All @@ -726,24 +723,22 @@ struct ib_mr *c4iw_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,

i = n = 0;

list_for_each_entry(chunk, &mhp->umem->chunk_list, list)
for (j = 0; j < chunk->nmap; ++j) {
len = sg_dma_len(&chunk->page_list[j]) >> shift;
for (k = 0; k < len; ++k) {
pages[i++] = cpu_to_be64(sg_dma_address(
&chunk->page_list[j]) +
mhp->umem->page_size * k);
if (i == PAGE_SIZE / sizeof *pages) {
err = write_pbl(&mhp->rhp->rdev,
pages,
mhp->attr.pbl_addr + (n << 3), i);
if (err)
goto pbl_done;
n += i;
i = 0;
}
for_each_sg(mhp->umem->sg_head.sgl, sg, mhp->umem->nmap, entry) {
len = sg_dma_len(sg) >> shift;
for (k = 0; k < len; ++k) {
pages[i++] = cpu_to_be64(sg_dma_address(sg) +
mhp->umem->page_size * k);
if (i == PAGE_SIZE / sizeof *pages) {
err = write_pbl(&mhp->rhp->rdev,
pages,
mhp->attr.pbl_addr + (n << 3), i);
if (err)
goto pbl_done;
n += i;
i = 0;
}
}
}

if (i)
err = write_pbl(&mhp->rhp->rdev, pages,
Expand Down
2 changes: 1 addition & 1 deletion drivers/infiniband/hw/ehca/ehca_classes.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -322,7 +322,7 @@ struct ehca_mr_pginfo {
} phy;
struct { /* type EHCA_MR_PGI_USER section */
struct ib_umem *region;
struct ib_umem_chunk *next_chunk;
struct scatterlist *next_sg;
u64 next_nmap;
} usr;
struct { /* type EHCA_MR_PGI_FMR section */
Expand Down
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