lkml.org 
[lkml]   [2021]   [Jun]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH V3] RDMA/siw: Convert siw_tx_hdt() to kmap_local_page()
Date
From: Ira Weiny <ira.weiny@intel.com>

kmap() is being deprecated and will break uses of device dax after PKS
protection is introduced.[1]

The use of kmap() in siw_tx_hdt() is all thread local therefore
kmap_local_page() is a sufficient replacement and will work with pgmap
protected pages when those are implemented.

siw_tx_hdt() tracks pages used in a page_array. It uses that array to
unmap pages which were mapped on function exit. Not all entries in the
array are mapped and this is tracked in kmap_mask.

kunmap_local() takes a mapped address rather than a page. Alter
siw_unmap_pages() to take the iov array to reuse the iov_base address of
each mapping. Use PAGE_MASK to get the proper address for
kunmap_local().

kmap_local_page() mappings are tracked in a stack and must be unmapped
in the opposite order they were mapped in. Because segments are mapped
into the page array in increasing index order, modify siw_unmap_pages()
to unmap pages in decreasing order.

Use kmap_local_page() instead of kmap() to map pages in the page_array.

[1] https://lore.kernel.org/lkml/20201009195033.3208459-59-ira.weiny@intel.com/

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Jason, I went ahead and left this a separate patch. Let me know if you really
want this and the other siw squashed.

Changes for V3:
From Bernard
Use 'p' in kmap_local_page()
Use seg as length to siw_unmap_pages()

Changes for V2:
From Bernard
Reuse iov[].iov_base rather than declaring another array
of pointers and preserve the use of kmap_mask to know
which iov's were kmapped.
---
drivers/infiniband/sw/siw/siw_qp_tx.c | 30 +++++++++++++++++----------
1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/drivers/infiniband/sw/siw/siw_qp_tx.c b/drivers/infiniband/sw/siw/siw_qp_tx.c
index db68a10d12cd..89a5b75f7254 100644
--- a/drivers/infiniband/sw/siw/siw_qp_tx.c
+++ b/drivers/infiniband/sw/siw/siw_qp_tx.c
@@ -396,13 +396,20 @@ static int siw_0copy_tx(struct socket *s, struct page **page,

#define MAX_TRAILER (MPA_CRC_SIZE + 4)

-static void siw_unmap_pages(struct page **pp, unsigned long kmap_mask)
+static void siw_unmap_pages(struct kvec *iov, unsigned long kmap_mask, int len)
{
- while (kmap_mask) {
- if (kmap_mask & BIT(0))
- kunmap(*pp);
- pp++;
- kmap_mask >>= 1;
+ int i;
+
+ /*
+ * Work backwards through the array to honor the kmap_local_page()
+ * ordering requirements.
+ */
+ for (i = (len-1); i >= 0; i--) {
+ if (kmap_mask & BIT(i)) {
+ unsigned long addr = (unsigned long)iov[i].iov_base;
+
+ kunmap_local((void *)(addr & PAGE_MASK));
+ }
}
}

@@ -498,7 +505,7 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
p = siw_get_upage(mem->umem,
sge->laddr + sge_off);
if (unlikely(!p)) {
- siw_unmap_pages(page_array, kmap_mask);
+ siw_unmap_pages(iov, kmap_mask, seg);
wqe->processed -= c_tx->bytes_unsent;
rv = -EFAULT;
goto done_crc;
@@ -506,11 +513,12 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
page_array[seg] = p;

if (!c_tx->use_sendpage) {
- iov[seg].iov_base = kmap(p) + fp_off;
- iov[seg].iov_len = plen;
+ void *kaddr = kmap_local_page(p);

/* Remember for later kunmap() */
kmap_mask |= BIT(seg);
+ iov[seg].iov_base = kaddr + fp_off;
+ iov[seg].iov_len = plen;

if (do_crc)
crypto_shash_update(
@@ -542,7 +550,7 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)

if (++seg > (int)MAX_ARRAY) {
siw_dbg_qp(tx_qp(c_tx), "to many fragments\n");
- siw_unmap_pages(page_array, kmap_mask);
+ siw_unmap_pages(iov, kmap_mask, seg-1);
wqe->processed -= c_tx->bytes_unsent;
rv = -EMSGSIZE;
goto done_crc;
@@ -593,7 +601,7 @@ static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
} else {
rv = kernel_sendmsg(s, &msg, iov, seg + 1,
hdr_len + data_len + trl_len);
- siw_unmap_pages(page_array, kmap_mask);
+ siw_unmap_pages(iov, kmap_mask, seg+1);
}
if (rv < (int)hdr_len) {
/* Not even complete hdr pushed or negative rv */
--
2.28.0.rc0.12.gb6a658bd00c9
\
 
 \ /
  Last update: 2021-06-24 00:17    [W:0.145 / U:0.348 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site