From 980093ebf777f95459eabcf0ca7a29db7e9a10f7 Mon Sep 17 00:00:00 2001 From: Jesse Brandeburg Date: Sat, 10 May 2014 04:49:12 +0000 Subject: [PATCH] i40e/i40evf: fix TSO accounting The TSO logic in the transmit path had some assumptions that have been broken now that the kernel can send as much as 32kB in a single skb->frag[.] entry, even on a system with 4kB pages. This fixes the assumptions and allows the kernel to operate as efficiently as possible with both SENDFILE and SEND. In addition, the hardware limit of data contained in a descriptor is changed to the next power of two below where it currently is in order to align to a power of two value, preventing a single byte of data in a descriptor. Change-ID: I6af1f0b87c1458e10644dbd47541591075a52651 Signed-off-by: Jesse Brandeburg Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 7 +------ drivers/net/ethernet/intel/i40e/i40e_txrx.h | 4 ++-- drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 7 +------ drivers/net/ethernet/intel/i40evf/i40e_txrx.h | 4 ++-- 4 files changed, 6 insertions(+), 16 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 1fe28ca..d1a9a05 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -2170,9 +2170,7 @@ static int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size) static int i40e_xmit_descriptor_count(struct sk_buff *skb, struct i40e_ring *tx_ring) { -#if PAGE_SIZE > I40E_MAX_DATA_PER_TXD unsigned int f; -#endif int count = 0; /* need: 1 descriptor per page * PAGE_SIZE/I40E_MAX_DATA_PER_TXD, @@ -2181,12 +2179,9 @@ static int i40e_xmit_descriptor_count(struct sk_buff *skb, * + 1 desc for context descriptor, * otherwise try next time */ -#if PAGE_SIZE > I40E_MAX_DATA_PER_TXD for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) count += TXD_USE_COUNT(skb_shinfo(skb)->frags[f].size); -#else - count += skb_shinfo(skb)->nr_frags; -#endif + count += TXD_USE_COUNT(skb_headlen(skb)); if (i40e_maybe_stop_tx(tx_ring, count + 4 + 1)) { tx_ring->tx_stats.tx_busy++; diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h index 30e5fe3..0277894 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h @@ -117,11 +117,11 @@ enum i40e_dyn_idx_t { #define i40e_rx_desc i40e_32byte_rx_desc #define I40E_MIN_TX_LEN 17 -#define I40E_MAX_DATA_PER_TXD 16383 /* aka 16kB - 1 */ +#define I40E_MAX_DATA_PER_TXD 8192 /* 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 * TXD_USE_COUNT(PAGE_SIZE)) + 4) +#define DESC_NEEDED (MAX_SKB_FRAGS + 4) #define I40E_TX_FLAGS_CSUM (u32)(1) #define I40E_TX_FLAGS_HW_VLAN (u32)(1 << 1) diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c index 82d6844..ae089df 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c @@ -1511,9 +1511,7 @@ static int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size) static int i40e_xmit_descriptor_count(struct sk_buff *skb, struct i40e_ring *tx_ring) { -#if PAGE_SIZE > I40E_MAX_DATA_PER_TXD unsigned int f; -#endif int count = 0; /* need: 1 descriptor per page * PAGE_SIZE/I40E_MAX_DATA_PER_TXD, @@ -1522,12 +1520,9 @@ static int i40e_xmit_descriptor_count(struct sk_buff *skb, * + 1 desc for context descriptor, * otherwise try next time */ -#if PAGE_SIZE > I40E_MAX_DATA_PER_TXD for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) count += TXD_USE_COUNT(skb_shinfo(skb)->frags[f].size); -#else - count += skb_shinfo(skb)->nr_frags; -#endif + count += TXD_USE_COUNT(skb_headlen(skb)); if (i40e_maybe_stop_tx(tx_ring, count + 4 + 1)) { tx_ring->tx_stats.tx_busy++; diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h index e297a3a..30d248b 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h @@ -117,11 +117,11 @@ enum i40e_dyn_idx_t { #define i40e_rx_desc i40e_32byte_rx_desc #define I40E_MIN_TX_LEN 17 -#define I40E_MAX_DATA_PER_TXD 16383 /* aka 16kB - 1 */ +#define I40E_MAX_DATA_PER_TXD 8192 /* 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 * TXD_USE_COUNT(PAGE_SIZE)) + 4) +#define DESC_NEEDED (MAX_SKB_FRAGS + 4) #define I40E_TX_FLAGS_CSUM (u32)(1) #define I40E_TX_FLAGS_HW_VLAN (u32)(1 << 1) -- 2.7.4