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vmxnet3: allow variable length transmit data ring buffer
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vmxnet3 driver supports transmit data ring viz. a set of fixed size
buffers used by the driver to copy packet headers. Small packets that
fit these buffers are copied into these buffers entirely.

Currently this buffer size of fixed at 128 bytes. This patch extends
transmit data ring implementation to allow variable length transmit
data ring buffers. The length of the buffer is read from the emulation
during initialization.

Signed-off-by: Sriram Rangarajan <rangarajans@vmware.com>
Signed-off-by: Shrikrishna Khare <skhare@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Shrikrishna Khare authored and David S. Miller committed Jun 17, 2016
1 parent f35c748 commit 3c8b3ef
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Showing 4 changed files with 64 additions and 19 deletions.
12 changes: 11 additions & 1 deletion drivers/net/vmxnet3/vmxnet3_defs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -92,6 +92,7 @@ enum {
VMXNET3_CMD_GET_DEV_EXTRA_INFO,
VMXNET3_CMD_GET_CONF_INTR,
VMXNET3_CMD_GET_RESERVED1,
VMXNET3_CMD_GET_TXDATA_DESC_SIZE
};

/*
Expand Down Expand Up @@ -377,13 +378,20 @@ union Vmxnet3_GenericDesc {
#define VMXNET3_RING_SIZE_ALIGN 32
#define VMXNET3_RING_SIZE_MASK (VMXNET3_RING_SIZE_ALIGN - 1)

/* Tx Data Ring buffer size must be a multiple of 64 */
#define VMXNET3_TXDATA_DESC_SIZE_ALIGN 64
#define VMXNET3_TXDATA_DESC_SIZE_MASK (VMXNET3_TXDATA_DESC_SIZE_ALIGN - 1)

/* Max ring size */
#define VMXNET3_TX_RING_MAX_SIZE 4096
#define VMXNET3_TC_RING_MAX_SIZE 4096
#define VMXNET3_RX_RING_MAX_SIZE 4096
#define VMXNET3_RX_RING2_MAX_SIZE 4096
#define VMXNET3_RC_RING_MAX_SIZE 8192

#define VMXNET3_TXDATA_DESC_MIN_SIZE 128
#define VMXNET3_TXDATA_DESC_MAX_SIZE 2048

/* a list of reasons for queue stop */

enum {
Expand Down Expand Up @@ -470,7 +478,9 @@ struct Vmxnet3_TxQueueConf {
__le32 compRingSize; /* # of comp desc */
__le32 ddLen; /* size of driver data */
u8 intrIdx;
u8 _pad[7];
u8 _pad1[1];
__le16 txDataRingDescSize;
u8 _pad2[4];
};


Expand Down
55 changes: 42 additions & 13 deletions drivers/net/vmxnet3/vmxnet3_drv.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -435,8 +435,8 @@ vmxnet3_tq_destroy(struct vmxnet3_tx_queue *tq,
tq->tx_ring.base = NULL;
}
if (tq->data_ring.base) {
dma_free_coherent(&adapter->pdev->dev, tq->data_ring.size *
sizeof(struct Vmxnet3_TxDataDesc),
dma_free_coherent(&adapter->pdev->dev,
tq->data_ring.size * tq->txdata_desc_size,
tq->data_ring.base, tq->data_ring.basePA);
tq->data_ring.base = NULL;
}
Expand Down Expand Up @@ -478,8 +478,8 @@ vmxnet3_tq_init(struct vmxnet3_tx_queue *tq,
tq->tx_ring.next2fill = tq->tx_ring.next2comp = 0;
tq->tx_ring.gen = VMXNET3_INIT_GEN;

memset(tq->data_ring.base, 0, tq->data_ring.size *
sizeof(struct Vmxnet3_TxDataDesc));
memset(tq->data_ring.base, 0,
tq->data_ring.size * tq->txdata_desc_size);

/* reset the tx comp ring contents to 0 and reset comp ring states */
memset(tq->comp_ring.base, 0, tq->comp_ring.size *
Expand Down Expand Up @@ -514,10 +514,10 @@ vmxnet3_tq_create(struct vmxnet3_tx_queue *tq,
}

tq->data_ring.base = dma_alloc_coherent(&adapter->pdev->dev,
tq->data_ring.size * sizeof(struct Vmxnet3_TxDataDesc),
tq->data_ring.size * tq->txdata_desc_size,
&tq->data_ring.basePA, GFP_KERNEL);
if (!tq->data_ring.base) {
netdev_err(adapter->netdev, "failed to allocate data ring\n");
netdev_err(adapter->netdev, "failed to allocate tx data ring\n");
goto err;
}

Expand Down Expand Up @@ -689,7 +689,7 @@ vmxnet3_map_pkt(struct sk_buff *skb, struct vmxnet3_tx_ctx *ctx,
if (ctx->copy_size) {
ctx->sop_txd->txd.addr = cpu_to_le64(tq->data_ring.basePA +
tq->tx_ring.next2fill *
sizeof(struct Vmxnet3_TxDataDesc));
tq->txdata_desc_size);
ctx->sop_txd->dword[2] = cpu_to_le32(dw2 | ctx->copy_size);
ctx->sop_txd->dword[3] = 0;

Expand Down Expand Up @@ -873,8 +873,9 @@ vmxnet3_parse_hdr(struct sk_buff *skb, struct vmxnet3_tx_queue *tq,
ctx->eth_ip_hdr_size = 0;
ctx->l4_hdr_size = 0;
/* copy as much as allowed */
ctx->copy_size = min((unsigned int)VMXNET3_HDR_COPY_SIZE
, skb_headlen(skb));
ctx->copy_size = min_t(unsigned int,
tq->txdata_desc_size,
skb_headlen(skb));
}

if (skb->len <= VMXNET3_HDR_COPY_SIZE)
Expand All @@ -885,7 +886,7 @@ vmxnet3_parse_hdr(struct sk_buff *skb, struct vmxnet3_tx_queue *tq,
goto err;
}

if (unlikely(ctx->copy_size > VMXNET3_HDR_COPY_SIZE)) {
if (unlikely(ctx->copy_size > tq->txdata_desc_size)) {
tq->stats.oversized_hdr++;
ctx->copy_size = 0;
return 0;
Expand Down Expand Up @@ -2336,6 +2337,7 @@ vmxnet3_setup_driver_shared(struct vmxnet3_adapter *adapter)
tqc->ddPA = cpu_to_le64(tq->buf_info_pa);
tqc->txRingSize = cpu_to_le32(tq->tx_ring.size);
tqc->dataRingSize = cpu_to_le32(tq->data_ring.size);
tqc->txDataRingDescSize = cpu_to_le32(tq->txdata_desc_size);
tqc->compRingSize = cpu_to_le32(tq->comp_ring.size);
tqc->ddLen = cpu_to_le32(
sizeof(struct vmxnet3_tx_buf_info) *
Expand Down Expand Up @@ -2689,7 +2691,8 @@ vmxnet3_adjust_rx_ring_size(struct vmxnet3_adapter *adapter)

int
vmxnet3_create_queues(struct vmxnet3_adapter *adapter, u32 tx_ring_size,
u32 rx_ring_size, u32 rx_ring2_size)
u32 rx_ring_size, u32 rx_ring2_size,
u16 txdata_desc_size)
{
int err = 0, i;

Expand All @@ -2698,6 +2701,7 @@ vmxnet3_create_queues(struct vmxnet3_adapter *adapter, u32 tx_ring_size,
tq->tx_ring.size = tx_ring_size;
tq->data_ring.size = tx_ring_size;
tq->comp_ring.size = tx_ring_size;
tq->txdata_desc_size = txdata_desc_size;
tq->shared = &adapter->tqd_start[i].ctrl;
tq->stopped = true;
tq->adapter = adapter;
Expand Down Expand Up @@ -2754,9 +2758,34 @@ vmxnet3_open(struct net_device *netdev)
for (i = 0; i < adapter->num_tx_queues; i++)
spin_lock_init(&adapter->tx_queue[i].tx_lock);

err = vmxnet3_create_queues(adapter, adapter->tx_ring_size,
if (VMXNET3_VERSION_GE_3(adapter)) {
unsigned long flags;
u16 txdata_desc_size;

spin_lock_irqsave(&adapter->cmd_lock, flags);
VMXNET3_WRITE_BAR1_REG(adapter, VMXNET3_REG_CMD,
VMXNET3_CMD_GET_TXDATA_DESC_SIZE);
txdata_desc_size = VMXNET3_READ_BAR1_REG(adapter,
VMXNET3_REG_CMD);
spin_unlock_irqrestore(&adapter->cmd_lock, flags);

if ((txdata_desc_size < VMXNET3_TXDATA_DESC_MIN_SIZE) ||
(txdata_desc_size > VMXNET3_TXDATA_DESC_MAX_SIZE) ||
(txdata_desc_size & VMXNET3_TXDATA_DESC_SIZE_MASK)) {
adapter->txdata_desc_size =
sizeof(struct Vmxnet3_TxDataDesc);
} else {
adapter->txdata_desc_size = txdata_desc_size;
}
} else {
adapter->txdata_desc_size = sizeof(struct Vmxnet3_TxDataDesc);
}

err = vmxnet3_create_queues(adapter,
adapter->tx_ring_size,
adapter->rx_ring_size,
adapter->rx_ring2_size);
adapter->rx_ring2_size,
adapter->txdata_desc_size);
if (err)
goto queue_err;

Expand Down
9 changes: 5 additions & 4 deletions drivers/net/vmxnet3/vmxnet3_ethtool.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -396,8 +396,7 @@ vmxnet3_get_regs(struct net_device *netdev, struct ethtool_regs *regs, void *p)
buf[j++] = VMXNET3_GET_ADDR_LO(tq->data_ring.basePA);
buf[j++] = VMXNET3_GET_ADDR_HI(tq->data_ring.basePA);
buf[j++] = tq->data_ring.size;
/* transmit data ring buffer size */
buf[j++] = VMXNET3_HDR_COPY_SIZE;
buf[j++] = tq->txdata_desc_size;

buf[j++] = VMXNET3_GET_ADDR_LO(tq->comp_ring.basePA);
buf[j++] = VMXNET3_GET_ADDR_HI(tq->comp_ring.basePA);
Expand Down Expand Up @@ -591,7 +590,8 @@ vmxnet3_set_ringparam(struct net_device *netdev,
vmxnet3_rq_destroy_all(adapter);

err = vmxnet3_create_queues(adapter, new_tx_ring_size,
new_rx_ring_size, new_rx_ring2_size);
new_rx_ring_size, new_rx_ring2_size,
adapter->txdata_desc_size);

if (err) {
/* failed, most likely because of OOM, try default
Expand All @@ -604,7 +604,8 @@ vmxnet3_set_ringparam(struct net_device *netdev,
err = vmxnet3_create_queues(adapter,
new_tx_ring_size,
new_rx_ring_size,
new_rx_ring2_size);
new_rx_ring2_size,
adapter->txdata_desc_size);
if (err) {
netdev_err(netdev, "failed to create queues "
"with default sizes. Closing it\n");
Expand Down
7 changes: 6 additions & 1 deletion drivers/net/vmxnet3/vmxnet3_int.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -241,6 +241,7 @@ struct vmxnet3_tx_queue {
int num_stop; /* # of times the queue is
* stopped */
int qid;
u16 txdata_desc_size;
} __attribute__((__aligned__(SMP_CACHE_BYTES)));

enum vmxnet3_rx_buf_type {
Expand Down Expand Up @@ -363,6 +364,9 @@ struct vmxnet3_adapter {
u32 rx_ring_size;
u32 rx_ring2_size;

/* Size of buffer in the data ring */
u16 txdata_desc_size;

struct work_struct work;

unsigned long state; /* VMXNET3_STATE_BIT_xxx */
Expand Down Expand Up @@ -427,7 +431,8 @@ vmxnet3_set_features(struct net_device *netdev, netdev_features_t features);

int
vmxnet3_create_queues(struct vmxnet3_adapter *adapter,
u32 tx_ring_size, u32 rx_ring_size, u32 rx_ring2_size);
u32 tx_ring_size, u32 rx_ring_size, u32 rx_ring2_size,
u16 txdata_desc_size);

void vmxnet3_set_ethtool_ops(struct net_device *netdev);

Expand Down

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