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authorDavid Christensen <drc@linux.vnet.ibm.com>2023-09-15 00:02:52 +0200
committerDavid S. Miller <davem@davemloft.net>2023-09-16 12:42:11 +0200
commit8f6b846b0a86c3cbae8a25b772651cfc2270ad0a (patch)
tree53de141c4edd6a072cc85bf3955e7f4ea88ef4cd /drivers/net/ethernet/pensando
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf (diff)
downloadlinux-8f6b846b0a86c3cbae8a25b772651cfc2270ad0a.tar.xz
linux-8f6b846b0a86c3cbae8a25b772651cfc2270ad0a.zip
ionic: fix 16bit math issue when PAGE_SIZE >= 64KB
The ionic device supports a maximum buffer length of 16 bits (see ionic_rxq_desc or ionic_rxq_sg_elem). When adding new buffers to the receive rings, the function ionic_rx_fill() uses 16bit math when calculating the number of pages to allocate for an RX descriptor, given the interface's MTU setting. If the system PAGE_SIZE >= 64KB, and the buf_info->page_offset is 0, the remain_len value will never decrement from the original MTU value and the frag_len value will always be 0, causing additional pages to be allocated as scatter- gather elements unnecessarily. A similar math issue exists in ionic_rx_frags(), but no failures have been observed here since a 64KB page should not normally require any scatter-gather elements at any legal Ethernet MTU size. Fixes: 4b0a7539a372 ("ionic: implement Rx page reuse") Signed-off-by: David Christensen <drc@linux.vnet.ibm.com> Reviewed-by: Shannon Nelson <shannon.nelson@amd.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/pensando')
-rw-r--r--drivers/net/ethernet/pensando/ionic/ionic_dev.h1
-rw-r--r--drivers/net/ethernet/pensando/ionic/ionic_txrx.c10
2 files changed, 8 insertions, 3 deletions
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
index 6aac98bcb9f4..aae4131f146a 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
@@ -187,6 +187,7 @@ typedef void (*ionic_desc_cb)(struct ionic_queue *q,
struct ionic_desc_info *desc_info,
struct ionic_cq_info *cq_info, void *cb_arg);
+#define IONIC_MAX_BUF_LEN ((u16)-1)
#define IONIC_PAGE_SIZE PAGE_SIZE
#define IONIC_PAGE_SPLIT_SZ (PAGE_SIZE / 2)
#define IONIC_PAGE_GFP_MASK (GFP_ATOMIC | __GFP_NOWARN |\
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
index 26798fc635db..44466e8c5d77 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
@@ -207,7 +207,8 @@ static struct sk_buff *ionic_rx_frags(struct ionic_queue *q,
return NULL;
}
- frag_len = min_t(u16, len, IONIC_PAGE_SIZE - buf_info->page_offset);
+ frag_len = min_t(u16, len, min_t(u32, IONIC_MAX_BUF_LEN,
+ IONIC_PAGE_SIZE - buf_info->page_offset));
len -= frag_len;
dma_sync_single_for_cpu(dev,
@@ -452,7 +453,8 @@ void ionic_rx_fill(struct ionic_queue *q)
/* fill main descriptor - buf[0] */
desc->addr = cpu_to_le64(buf_info->dma_addr + buf_info->page_offset);
- frag_len = min_t(u16, len, IONIC_PAGE_SIZE - buf_info->page_offset);
+ frag_len = min_t(u16, len, min_t(u32, IONIC_MAX_BUF_LEN,
+ IONIC_PAGE_SIZE - buf_info->page_offset));
desc->len = cpu_to_le16(frag_len);
remain_len -= frag_len;
buf_info++;
@@ -471,7 +473,9 @@ void ionic_rx_fill(struct ionic_queue *q)
}
sg_elem->addr = cpu_to_le64(buf_info->dma_addr + buf_info->page_offset);
- frag_len = min_t(u16, remain_len, IONIC_PAGE_SIZE - buf_info->page_offset);
+ frag_len = min_t(u16, remain_len, min_t(u32, IONIC_MAX_BUF_LEN,
+ IONIC_PAGE_SIZE -
+ buf_info->page_offset));
sg_elem->len = cpu_to_le16(frag_len);
remain_len -= frag_len;
buf_info++;