| /openbmc/linux/drivers/net/ethernet/sfc/ |
| H A D | rx_common.c | 458f5d92 Mon Apr 04 05:48:51 CDT 2022 Martin Habets <habetsm.xilinx@gmail.com> sfc: Do not free an empty page_ring
When the page_ring is not used page_ptr_mask is 0.
Do not dereference page_ring[0] in this case.
Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs")
Reported-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1d5a4742 Sun Jan 02 02:41:22 CST 2022 Martin Habets <habetsm.xilinx@gmail.com> sfc: The RX page_ring is optional
The RX page_ring is an optional feature that improves
performance. When allocation fails the driver can still
function, but possibly with a lower bandwidth.
Guard against dereferencing a NULL page_ring.
Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs")
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Reported-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/164111288276.5798.10330502993729113868.stgit@palantir17.mph.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
d1c87d36 Mon Apr 04 05:48:51 CDT 2022 Martin Habets <habetsm.xilinx@gmail.com> sfc: Do not free an empty page_ring
[ Upstream commit 458f5d92df4807e2a7c803ed928369129996bf96 ]
When the page_ring is not used page_ptr_mask is 0.
Do not dereference page_ring[0] in this case.
Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs")
Reported-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
8fbbc33c Sun Jan 02 02:41:22 CST 2022 Martin Habets <habetsm.xilinx@gmail.com> sfc: The RX page_ring is optional
commit 1d5a474240407c38ca8c7484a656ee39f585399c upstream.
The RX page_ring is an optional feature that improves
performance. When allocation fails the driver can still
function, but possibly with a lower bandwidth.
Guard against dereferencing a NULL page_ring.
Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs")
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Reported-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/164111288276.5798.10330502993729113868.stgit@palantir17.mph.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
| H A D | rx.c | 734d4e15 Thu Jul 04 17:48:46 CDT 2013 Ben Hutchings <bhutchings@solarflare.com> sfc: Fix memory leak when discarding scattered packets
Commit 2768935a4660 ('sfc: reuse pages to avoid DMA mapping/unmapping
costs') did not fully take account of DMA scattering which was
introduced immediately before. If a received packet is invalid and
must be discarded, we only drop a reference to the first buffer's
page, but we need to drop a reference for each buffer the packet
used.
I think this bug was missed partly because efx_recycle_rx_buffers()
was not renamed and so no longer does what its name says. It does not
change the state of buffers, but only prepares the underlying pages
for recycling. Rename it accordingly.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2768935a Wed Feb 13 04:54:41 CST 2013 Daniel Pieczko <dpieczko@solarflare.com> sfc: reuse pages to avoid DMA mapping/unmapping costs
On POWER systems, DMA mapping/unmapping operations are very expensive.
These changes reduce these costs by trying to reuse DMA mapped pages.
After all the buffers associated with a page have been processed and
passed up, the page is placed into a ring (if there is room). For
each page that is required for a refill operation, a page in the ring
is examined to determine if its page count has fallen to 1, ie. the
kernel has released its reference to these packets. If this is the
case, the page can be immediately added back into the RX descriptor
ring, without having to re-map it for DMA.
If the kernel is still holding a reference to this page, it is removed
from the ring and unmapped for DMA. Then a new page, which can
immediately be used by RX buffers in the descriptor ring, is allocated
and DMA mapped.
The time a page needs to spend in the recycle ring before the kernel
has released its page references is based on the number of buffers
that use this page. As large pages can hold more RX buffers, the RX
recycle ring can be shorter. This reduces memory usage on POWER
systems, while maintaining the performance gain achieved by recycling
pages, following the driver change to pack more than two RX buffers
into large pages.
When an IOMMU is not present, the recycle ring can be small to reduce
memory usage, since DMA mapping operations are inexpensive.
With a small recycle ring, attempting to refill the descriptor queue
with more buffers than the equivalent size of the recycle ring could
ultimately lead to memory leaks if page entries in the recycle ring
were overwritten. To prevent this, the check to see if the recycle
ring is full is changed to check if the next entry to be written is
NULL.
[bwh: Combine and rebase several commits so this is complete
before the following buffer-packing changes. Remove module
parameter.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
734d4e15 Thu Jul 04 17:48:46 CDT 2013 Ben Hutchings <bhutchings@solarflare.com> sfc: Fix memory leak when discarding scattered packets
Commit 2768935a4660 ('sfc: reuse pages to avoid DMA mapping/unmapping
costs') did not fully take account of DMA scattering which was
introduced immediately before. If a received packet is invalid and
must be discarded, we only drop a reference to the first buffer's
page, but we need to drop a reference for each buffer the packet
used.
I think this bug was missed partly because efx_recycle_rx_buffers()
was not renamed and so no longer does what its name says. It does not
change the state of buffers, but only prepares the underlying pages
for recycling. Rename it accordingly.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2768935a Wed Feb 13 04:54:41 CST 2013 Daniel Pieczko <dpieczko@solarflare.com> sfc: reuse pages to avoid DMA mapping/unmapping costs
On POWER systems, DMA mapping/unmapping operations are very expensive.
These changes reduce these costs by trying to reuse DMA mapped pages.
After all the buffers associated with a page have been processed and
passed up, the page is placed into a ring (if there is room). For
each page that is required for a refill operation, a page in the ring
is examined to determine if its page count has fallen to 1, ie. the
kernel has released its reference to these packets. If this is the
case, the page can be immediately added back into the RX descriptor
ring, without having to re-map it for DMA.
If the kernel is still holding a reference to this page, it is removed
from the ring and unmapped for DMA. Then a new page, which can
immediately be used by RX buffers in the descriptor ring, is allocated
and DMA mapped.
The time a page needs to spend in the recycle ring before the kernel
has released its page references is based on the number of buffers
that use this page. As large pages can hold more RX buffers, the RX
recycle ring can be shorter. This reduces memory usage on POWER
systems, while maintaining the performance gain achieved by recycling
pages, following the driver change to pack more than two RX buffers
into large pages.
When an IOMMU is not present, the recycle ring can be small to reduce
memory usage, since DMA mapping operations are inexpensive.
With a small recycle ring, attempting to refill the descriptor queue
with more buffers than the equivalent size of the recycle ring could
ultimately lead to memory leaks if page entries in the recycle ring
were overwritten. To prevent this, the check to see if the recycle
ring is full is changed to check if the next entry to be written is
NULL.
[bwh: Combine and rebase several commits so this is complete
before the following buffer-packing changes. Remove module
parameter.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
|
| H A D | net_driver.h | 2768935a Wed Feb 13 04:54:41 CST 2013 Daniel Pieczko <dpieczko@solarflare.com> sfc: reuse pages to avoid DMA mapping/unmapping costs
On POWER systems, DMA mapping/unmapping operations are very expensive.
These changes reduce these costs by trying to reuse DMA mapped pages.
After all the buffers associated with a page have been processed and
passed up, the page is placed into a ring (if there is room). For
each page that is required for a refill operation, a page in the ring
is examined to determine if its page count has fallen to 1, ie. the
kernel has released its reference to these packets. If this is the
case, the page can be immediately added back into the RX descriptor
ring, without having to re-map it for DMA.
If the kernel is still holding a reference to this page, it is removed
from the ring and unmapped for DMA. Then a new page, which can
immediately be used by RX buffers in the descriptor ring, is allocated
and DMA mapped.
The time a page needs to spend in the recycle ring before the kernel
has released its page references is based on the number of buffers
that use this page. As large pages can hold more RX buffers, the RX
recycle ring can be shorter. This reduces memory usage on POWER
systems, while maintaining the performance gain achieved by recycling
pages, following the driver change to pack more than two RX buffers
into large pages.
When an IOMMU is not present, the recycle ring can be small to reduce
memory usage, since DMA mapping operations are inexpensive.
With a small recycle ring, attempting to refill the descriptor queue
with more buffers than the equivalent size of the recycle ring could
ultimately lead to memory leaks if page entries in the recycle ring
were overwritten. To prevent this, the check to see if the recycle
ring is full is changed to check if the next entry to be written is
NULL.
[bwh: Combine and rebase several commits so this is complete
before the following buffer-packing changes. Remove module
parameter.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2768935a Wed Feb 13 04:54:41 CST 2013 Daniel Pieczko <dpieczko@solarflare.com> sfc: reuse pages to avoid DMA mapping/unmapping costs
On POWER systems, DMA mapping/unmapping operations are very expensive.
These changes reduce these costs by trying to reuse DMA mapped pages.
After all the buffers associated with a page have been processed and
passed up, the page is placed into a ring (if there is room). For
each page that is required for a refill operation, a page in the ring
is examined to determine if its page count has fallen to 1, ie. the
kernel has released its reference to these packets. If this is the
case, the page can be immediately added back into the RX descriptor
ring, without having to re-map it for DMA.
If the kernel is still holding a reference to this page, it is removed
from the ring and unmapped for DMA. Then a new page, which can
immediately be used by RX buffers in the descriptor ring, is allocated
and DMA mapped.
The time a page needs to spend in the recycle ring before the kernel
has released its page references is based on the number of buffers
that use this page. As large pages can hold more RX buffers, the RX
recycle ring can be shorter. This reduces memory usage on POWER
systems, while maintaining the performance gain achieved by recycling
pages, following the driver change to pack more than two RX buffers
into large pages.
When an IOMMU is not present, the recycle ring can be small to reduce
memory usage, since DMA mapping operations are inexpensive.
With a small recycle ring, attempting to refill the descriptor queue
with more buffers than the equivalent size of the recycle ring could
ultimately lead to memory leaks if page entries in the recycle ring
were overwritten. To prevent this, the check to see if the recycle
ring is full is changed to check if the next entry to be written is
NULL.
[bwh: Combine and rebase several commits so this is complete
before the following buffer-packing changes. Remove module
parameter.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
|
| H A D | efx.c | 2768935a Wed Feb 13 04:54:41 CST 2013 Daniel Pieczko <dpieczko@solarflare.com> sfc: reuse pages to avoid DMA mapping/unmapping costs
On POWER systems, DMA mapping/unmapping operations are very expensive.
These changes reduce these costs by trying to reuse DMA mapped pages.
After all the buffers associated with a page have been processed and
passed up, the page is placed into a ring (if there is room). For
each page that is required for a refill operation, a page in the ring
is examined to determine if its page count has fallen to 1, ie. the
kernel has released its reference to these packets. If this is the
case, the page can be immediately added back into the RX descriptor
ring, without having to re-map it for DMA.
If the kernel is still holding a reference to this page, it is removed
from the ring and unmapped for DMA. Then a new page, which can
immediately be used by RX buffers in the descriptor ring, is allocated
and DMA mapped.
The time a page needs to spend in the recycle ring before the kernel
has released its page references is based on the number of buffers
that use this page. As large pages can hold more RX buffers, the RX
recycle ring can be shorter. This reduces memory usage on POWER
systems, while maintaining the performance gain achieved by recycling
pages, following the driver change to pack more than two RX buffers
into large pages.
When an IOMMU is not present, the recycle ring can be small to reduce
memory usage, since DMA mapping operations are inexpensive.
With a small recycle ring, attempting to refill the descriptor queue
with more buffers than the equivalent size of the recycle ring could
ultimately lead to memory leaks if page entries in the recycle ring
were overwritten. To prevent this, the check to see if the recycle
ring is full is changed to check if the next entry to be written is
NULL.
[bwh: Combine and rebase several commits so this is complete
before the following buffer-packing changes. Remove module
parameter.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2768935a Wed Feb 13 04:54:41 CST 2013 Daniel Pieczko <dpieczko@solarflare.com> sfc: reuse pages to avoid DMA mapping/unmapping costs
On POWER systems, DMA mapping/unmapping operations are very expensive.
These changes reduce these costs by trying to reuse DMA mapped pages.
After all the buffers associated with a page have been processed and
passed up, the page is placed into a ring (if there is room). For
each page that is required for a refill operation, a page in the ring
is examined to determine if its page count has fallen to 1, ie. the
kernel has released its reference to these packets. If this is the
case, the page can be immediately added back into the RX descriptor
ring, without having to re-map it for DMA.
If the kernel is still holding a reference to this page, it is removed
from the ring and unmapped for DMA. Then a new page, which can
immediately be used by RX buffers in the descriptor ring, is allocated
and DMA mapped.
The time a page needs to spend in the recycle ring before the kernel
has released its page references is based on the number of buffers
that use this page. As large pages can hold more RX buffers, the RX
recycle ring can be shorter. This reduces memory usage on POWER
systems, while maintaining the performance gain achieved by recycling
pages, following the driver change to pack more than two RX buffers
into large pages.
When an IOMMU is not present, the recycle ring can be small to reduce
memory usage, since DMA mapping operations are inexpensive.
With a small recycle ring, attempting to refill the descriptor queue
with more buffers than the equivalent size of the recycle ring could
ultimately lead to memory leaks if page entries in the recycle ring
were overwritten. To prevent this, the check to see if the recycle
ring is full is changed to check if the next entry to be written is
NULL.
[bwh: Combine and rebase several commits so this is complete
before the following buffer-packing changes. Remove module
parameter.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
|
| /openbmc/linux/drivers/net/ethernet/sfc/falcon/ |
| H A D | rx.c | 1d5a4742 Sun Jan 02 02:41:22 CST 2022 Martin Habets <habetsm.xilinx@gmail.com> sfc: The RX page_ring is optional
The RX page_ring is an optional feature that improves
performance. When allocation fails the driver can still
function, but possibly with a lower bandwidth.
Guard against dereferencing a NULL page_ring.
Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs")
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Reported-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/164111288276.5798.10330502993729113868.stgit@palantir17.mph.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
8fbbc33c Sun Jan 02 02:41:22 CST 2022 Martin Habets <habetsm.xilinx@gmail.com> sfc: The RX page_ring is optional
commit 1d5a474240407c38ca8c7484a656ee39f585399c upstream.
The RX page_ring is an optional feature that improves
performance. When allocation fails the driver can still
function, but possibly with a lower bandwidth.
Guard against dereferencing a NULL page_ring.
Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs")
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Reported-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/164111288276.5798.10330502993729113868.stgit@palantir17.mph.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|