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-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_fcoe.c2
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_txrx.c13
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_txrx.h35
-rw-r--r--drivers/net/ethernet/intel/i40evf/i40e_txrx.c13
-rw-r--r--drivers/net/ethernet/intel/i40evf/i40e_txrx.h35
5 files changed, 83 insertions, 15 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_fcoe.c b/drivers/net/ethernet/intel/i40e/i40e_fcoe.c
index 8ad162c16f61..92d2208d13c7 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_fcoe.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_fcoe.c
@@ -1371,7 +1371,7 @@ static netdev_tx_t i40e_fcoe_xmit_frame(struct sk_buff *skb,
if (i40e_chk_linearize(skb, count)) {
if (__skb_linearize(skb))
goto out_drop;
- count = TXD_USE_COUNT(skb->len);
+ count = i40e_txd_use_count(skb->len);
tx_ring->tx_stats.tx_linearize++;
}
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 084d0ab316b7..9af1411bd423 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2717,6 +2717,8 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
tx_bi = first;
for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
+ unsigned int max_data = I40E_MAX_DATA_PER_TXD_ALIGNED;
+
if (dma_mapping_error(tx_ring->dev, dma))
goto dma_error;
@@ -2724,12 +2726,14 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
dma_unmap_len_set(tx_bi, len, size);
dma_unmap_addr_set(tx_bi, dma, dma);
+ /* align size to end of page */
+ max_data += -dma & (I40E_MAX_READ_REQ_SIZE - 1);
tx_desc->buffer_addr = cpu_to_le64(dma);
while (unlikely(size > I40E_MAX_DATA_PER_TXD)) {
tx_desc->cmd_type_offset_bsz =
build_ctob(td_cmd, td_offset,
- I40E_MAX_DATA_PER_TXD, td_tag);
+ max_data, td_tag);
tx_desc++;
i++;
@@ -2740,9 +2744,10 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
i = 0;
}
- dma += I40E_MAX_DATA_PER_TXD;
- size -= I40E_MAX_DATA_PER_TXD;
+ dma += max_data;
+ size -= max_data;
+ max_data = I40E_MAX_DATA_PER_TXD_ALIGNED;
tx_desc->buffer_addr = cpu_to_le64(dma);
}
@@ -2892,7 +2897,7 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
if (i40e_chk_linearize(skb, count)) {
if (__skb_linearize(skb))
goto out_drop;
- count = TXD_USE_COUNT(skb->len);
+ count = i40e_txd_use_count(skb->len);
tx_ring->tx_stats.tx_linearize++;
}
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index cdd5dc00aec5..9e654e611642 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -146,10 +146,39 @@ enum i40e_dyn_idx_t {
#define I40E_MAX_BUFFER_TXD 8
#define I40E_MIN_TX_LEN 17
-#define I40E_MAX_DATA_PER_TXD 8192
+
+/* The size limit for a transmit buffer in a descriptor is (16K - 1).
+ * In order to align with the read requests we will align the value to
+ * the nearest 4K which represents our maximum read request size.
+ */
+#define I40E_MAX_READ_REQ_SIZE 4096
+#define I40E_MAX_DATA_PER_TXD (16 * 1024 - 1)
+#define I40E_MAX_DATA_PER_TXD_ALIGNED \
+ (I40E_MAX_DATA_PER_TXD & ~(I40E_MAX_READ_REQ_SIZE - 1))
+
+/* This ugly bit of math is equivalent to DIV_ROUNDUP(size, X) where X is
+ * the value I40E_MAX_DATA_PER_TXD_ALIGNED. It is needed due to the fact
+ * that 12K is not a power of 2 and division is expensive. It is used to
+ * approximate the number of descriptors used per linear buffer. Note
+ * that this will overestimate in some cases as it doesn't account for the
+ * fact that we will add up to 4K - 1 in aligning the 12K buffer, however
+ * the error should not impact things much as large buffers usually mean
+ * we will use fewer descriptors then there are frags in an skb.
+ */
+static inline unsigned int i40e_txd_use_count(unsigned int size)
+{
+ const unsigned int max = I40E_MAX_DATA_PER_TXD_ALIGNED;
+ const unsigned int reciprocal = ((1ull << 32) - 1 + (max / 2)) / max;
+ unsigned int adjust = ~(u32)0;
+
+ /* if we rounded up on the reciprocal pull down the adjustment */
+ if ((max * reciprocal) > adjust)
+ adjust = ~(u32)(reciprocal - 1);
+
+ return (u32)((((u64)size * reciprocal) + adjust) >> 32);
+}
/* Tx Descriptors needed, worst case */
-#define TXD_USE_COUNT(S) DIV_ROUND_UP((S), I40E_MAX_DATA_PER_TXD)
#define DESC_NEEDED (MAX_SKB_FRAGS + 4)
#define I40E_MIN_DESC_PENDING 4
@@ -377,7 +406,7 @@ static inline int i40e_xmit_descriptor_count(struct sk_buff *skb)
int count = 0, size = skb_headlen(skb);
for (;;) {
- count += TXD_USE_COUNT(size);
+ count += i40e_txd_use_count(size);
if (!nr_frags--)
break;
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index ebcc25c05796..5f9c1bbab1fa 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -1936,6 +1936,8 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
tx_bi = first;
for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
+ unsigned int max_data = I40E_MAX_DATA_PER_TXD_ALIGNED;
+
if (dma_mapping_error(tx_ring->dev, dma))
goto dma_error;
@@ -1943,12 +1945,14 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
dma_unmap_len_set(tx_bi, len, size);
dma_unmap_addr_set(tx_bi, dma, dma);
+ /* align size to end of page */
+ max_data += -dma & (I40E_MAX_READ_REQ_SIZE - 1);
tx_desc->buffer_addr = cpu_to_le64(dma);
while (unlikely(size > I40E_MAX_DATA_PER_TXD)) {
tx_desc->cmd_type_offset_bsz =
build_ctob(td_cmd, td_offset,
- I40E_MAX_DATA_PER_TXD, td_tag);
+ max_data, td_tag);
tx_desc++;
i++;
@@ -1959,9 +1963,10 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
i = 0;
}
- dma += I40E_MAX_DATA_PER_TXD;
- size -= I40E_MAX_DATA_PER_TXD;
+ dma += max_data;
+ size -= max_data;
+ max_data = I40E_MAX_DATA_PER_TXD_ALIGNED;
tx_desc->buffer_addr = cpu_to_le64(dma);
}
@@ -2110,7 +2115,7 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
if (i40e_chk_linearize(skb, count)) {
if (__skb_linearize(skb))
goto out_drop;
- count = TXD_USE_COUNT(skb->len);
+ count = i40e_txd_use_count(skb->len);
tx_ring->tx_stats.tx_linearize++;
}
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
index c1dd8c5c9666..3ec0ea5ea3db 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
@@ -146,10 +146,39 @@ enum i40e_dyn_idx_t {
#define I40E_MAX_BUFFER_TXD 8
#define I40E_MIN_TX_LEN 17
-#define I40E_MAX_DATA_PER_TXD 8192
+
+/* The size limit for a transmit buffer in a descriptor is (16K - 1).
+ * In order to align with the read requests we will align the value to
+ * the nearest 4K which represents our maximum read request size.
+ */
+#define I40E_MAX_READ_REQ_SIZE 4096
+#define I40E_MAX_DATA_PER_TXD (16 * 1024 - 1)
+#define I40E_MAX_DATA_PER_TXD_ALIGNED \
+ (I40E_MAX_DATA_PER_TXD & ~(I40E_MAX_READ_REQ_SIZE - 1))
+
+/* This ugly bit of math is equivalent to DIV_ROUNDUP(size, X) where X is
+ * the value I40E_MAX_DATA_PER_TXD_ALIGNED. It is needed due to the fact
+ * that 12K is not a power of 2 and division is expensive. It is used to
+ * approximate the number of descriptors used per linear buffer. Note
+ * that this will overestimate in some cases as it doesn't account for the
+ * fact that we will add up to 4K - 1 in aligning the 12K buffer, however
+ * the error should not impact things much as large buffers usually mean
+ * we will use fewer descriptors then there are frags in an skb.
+ */
+static inline unsigned int i40e_txd_use_count(unsigned int size)
+{
+ const unsigned int max = I40E_MAX_DATA_PER_TXD_ALIGNED;
+ const unsigned int reciprocal = ((1ull << 32) - 1 + (max / 2)) / max;
+ unsigned int adjust = ~(u32)0;
+
+ /* if we rounded up on the reciprocal pull down the adjustment */
+ if ((max * reciprocal) > adjust)
+ adjust = ~(u32)(reciprocal - 1);
+
+ return (u32)((((u64)size * reciprocal) + adjust) >> 32);
+}
/* Tx Descriptors needed, worst case */
-#define TXD_USE_COUNT(S) DIV_ROUND_UP((S), I40E_MAX_DATA_PER_TXD)
#define DESC_NEEDED (MAX_SKB_FRAGS + 4)
#define I40E_MIN_DESC_PENDING 4
@@ -359,7 +388,7 @@ static inline int i40e_xmit_descriptor_count(struct sk_buff *skb)
int count = 0, size = skb_headlen(skb);
for (;;) {
- count += TXD_USE_COUNT(size);
+ count += i40e_txd_use_count(size);
if (!nr_frags--)
break;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.