[Re-sending with cc to the current stable address. I still had the old
address in contacts, though I've definitely sent to the current address
previously...]
This bug fix is only for stable branches older than 3.10. The bug was
fixed upstream by commit 2768935a4660 ('sfc: reuse pages to avoid DMA
mapping/unmapping costs'), but that change is totally unsuitable for
stable.
Commit b590ace09d51 ('sfc: Fix efx_rx_buf_offset() in the presence of
swiotlb') added an explicit page_offset member to struct
efx_rx_buffer, which must be set consistently with the u.page and
dma_addr fields. However, it failed to add the necessary assignment
in efx_resurrect_rx_buffer(). It also did not correct the calculation
of efx_rx_buffer::dma_addr in efx_resurrect_rx_buffer(), which assumes
that DMA-mapping a page will result in a page-aligned DMA address
(exactly what swiotlb violates).
Add the assignment of efx_rx_buffer::page_offset and change the
calculation of dma_addr to make use of it.
I'm attaching the patches for 3.0.y, 3.2.y and 3.4.y (the last of which
should also be applicable to the later unofficial stable branches).
Ben.
--
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
>From d4e70d42eff6938c12d7d0b12f657b10d06a156d Mon Sep 17 00:00:00 2001
From: Ben Hutchings <bhutchings@xxxxxxxxxxxxxx>
Date: Fri, 6 Sep 2013 22:39:20 +0100
Subject: sfc: Fix efx_rx_buf_offset() for recycled pages
This bug fix is only for stable branches older than 3.10. The bug was
fixed upstream by commit 2768935a4660 ('sfc: reuse pages to avoid DMA
mapping/unmapping costs'), but that change is totally unsuitable for
stable.
Commit b590ace09d51 ('sfc: Fix efx_rx_buf_offset() in the presence of
swiotlb') added an explicit page_offset member to struct
efx_rx_buffer, which must be set consistently with the u.page and
dma_addr fields. However, it failed to add the necessary assignment
in efx_resurrect_rx_buffer(). It also did not correct the calculation
of efx_rx_buffer::dma_addr in efx_resurrect_rx_buffer(), which assumes
that DMA-mapping a page will result in a page-aligned DMA address
(exactly what swiotlb violates).
Add the assignment of efx_rx_buffer::page_offset and change the
calculation of dma_addr to make use of it.
Signed-off-by: Ben Hutchings <bhutchings@xxxxxxxxxxxxxx>
---
drivers/net/sfc/rx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c
index d429f0a..26e4cca 100644
--- a/drivers/net/sfc/rx.c
+++ b/drivers/net/sfc/rx.c
@@ -311,8 +311,9 @@ static void efx_resurrect_rx_buffer(struct efx_rx_queue *rx_queue,
index = rx_queue->added_count & rx_queue->ptr_mask;
new_buf = efx_rx_buffer(rx_queue, index);
- new_buf->dma_addr = rx_buf->dma_addr ^ (PAGE_SIZE >> 1);
new_buf->u.page = rx_buf->u.page;
+ new_buf->page_offset = rx_buf->page_offset ^ (PAGE_SIZE >> 1);
+ new_buf->dma_addr = state->dma_addr + new_buf->page_offset;
new_buf->len = rx_buf->len;
new_buf->is_page = true;
++rx_queue->added_count;
--
1.8.1.4
>From 43587737635de32882d9f69df36562e0d5b0e0bd Mon Sep 17 00:00:00 2001
From: Ben Hutchings <bhutchings@xxxxxxxxxxxxxx>
Date: Fri, 6 Sep 2013 22:39:20 +0100
Subject: sfc: Fix efx_rx_buf_offset() for recycled pages
This bug fix is only for stable branches older than 3.10. The bug was
fixed upstream by commit 2768935a4660 ('sfc: reuse pages to avoid DMA
mapping/unmapping costs'), but that change is totally unsuitable for
stable.
Commit b590ace09d51 ('sfc: Fix efx_rx_buf_offset() in the presence of
swiotlb') added an explicit page_offset member to struct
efx_rx_buffer, which must be set consistently with the u.page and
dma_addr fields. However, it failed to add the necessary assignment
in efx_resurrect_rx_buffer(). It also did not correct the calculation
of efx_rx_buffer::dma_addr in efx_resurrect_rx_buffer(), which assumes
that DMA-mapping a page will result in a page-aligned DMA address
(exactly what swiotlb violates).
Add the assignment of efx_rx_buffer::page_offset and change the
calculation of dma_addr to make use of it.
Signed-off-by: Ben Hutchings <bhutchings@xxxxxxxxxxxxxx>
---
drivers/net/ethernet/sfc/rx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index 9ce8665..c231b3f 100644
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -312,8 +312,9 @@ static void efx_resurrect_rx_buffer(struct efx_rx_queue *rx_queue,
index = rx_queue->added_count & rx_queue->ptr_mask;
new_buf = efx_rx_buffer(rx_queue, index);
- new_buf->dma_addr = rx_buf->dma_addr ^ (PAGE_SIZE >> 1);
new_buf->u.page = rx_buf->u.page;
+ new_buf->page_offset = rx_buf->page_offset ^ (PAGE_SIZE >> 1);
+ new_buf->dma_addr = state->dma_addr + new_buf->page_offset;
new_buf->len = rx_buf->len;
new_buf->is_page = true;
++rx_queue->added_count;
--
1.8.1.4
>From 55961f9a914e637f143da275da42154a49c9743a Mon Sep 17 00:00:00 2001
From: Ben Hutchings <bhutchings@xxxxxxxxxxxxxx>
Date: Fri, 6 Sep 2013 22:39:20 +0100
Subject: sfc: Fix efx_rx_buf_offset() for recycled pages
This bug fix is only for stable branches older than 3.10. The bug was
fixed upstream by commit 2768935a4660 ('sfc: reuse pages to avoid DMA
mapping/unmapping costs'), but that change is totally unsuitable for
stable.
Commit b590ace09d51 ('sfc: Fix efx_rx_buf_offset() in the presence of
swiotlb') added an explicit page_offset member to struct
efx_rx_buffer, which must be set consistently with the u.page and
dma_addr fields. However, it failed to add the necessary assignment
in efx_resurrect_rx_buffer(). It also did not correct the calculation
of efx_rx_buffer::dma_addr in efx_resurrect_rx_buffer(), which assumes
that DMA-mapping a page will result in a page-aligned DMA address
(exactly what swiotlb violates).
Add the assignment of efx_rx_buffer::page_offset and change the
calculation of dma_addr to make use of it.
Signed-off-by: Ben Hutchings <bhutchings@xxxxxxxxxxxxxx>
---
drivers/net/ethernet/sfc/rx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index 7b3c068..62311ad3 100644
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -311,8 +311,9 @@ static void efx_resurrect_rx_buffer(struct efx_rx_queue *rx_queue,
index = rx_queue->added_count & rx_queue->ptr_mask;
new_buf = efx_rx_buffer(rx_queue, index);
- new_buf->dma_addr = rx_buf->dma_addr ^ (PAGE_SIZE >> 1);
new_buf->u.page = rx_buf->u.page;
+ new_buf->page_offset = rx_buf->page_offset ^ (PAGE_SIZE >> 1);
+ new_buf->dma_addr = state->dma_addr + new_buf->page_offset;
new_buf->len = rx_buf->len;
new_buf->flags = EFX_RX_BUF_PAGE;
++rx_queue->added_count;
--
1.8.1.4