Commit e6ab1944 authored by Peiyang Wang's avatar Peiyang Wang Committed by Paolo Abeni
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net: hns3: default enable tx bounce buffer when smmu enabled



The SMMU engine on HIP09 chip has a hardware issue.
SMMU pagetable prefetch features may prefetch and use a invalid PTE
even the PTE is valid at that time. This will cause the device trigger
fake pagefaults. The solution is to avoid prefetching by adding a
SYNC command when smmu mapping a iova. But the performance of nic has a
sharp drop. Then we do this workaround, always enable tx bounce buffer,
avoid mapping/unmapping on TX path.

This issue only affects HNS3, so we always enable
tx bounce buffer when smmu enabled to improve performance.

Fixes: 295ba232 ("net: hns3: add device version to replace pci revision")
Signed-off-by: default avatarPeiyang Wang <wangpeiyang1@huawei.com>
Signed-off-by: default avatarJian Shen <shenjian15@huawei.com>
Signed-off-by: default avatarJijie Shao <shaojijie@huawei.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 637f4147
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+31 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@
#include <linux/irq.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/skbuff.h>
@@ -1032,6 +1033,8 @@ static bool hns3_can_use_tx_sgl(struct hns3_enet_ring *ring,
static void hns3_init_tx_spare_buffer(struct hns3_enet_ring *ring)
{
	u32 alloc_size = ring->tqp->handle->kinfo.tx_spare_buf_size;
	struct net_device *netdev = ring_to_netdev(ring);
	struct hns3_nic_priv *priv = netdev_priv(netdev);
	struct hns3_tx_spare *tx_spare;
	struct page *page;
	dma_addr_t dma;
@@ -1073,6 +1076,7 @@ static void hns3_init_tx_spare_buffer(struct hns3_enet_ring *ring)
	tx_spare->buf = page_address(page);
	tx_spare->len = PAGE_SIZE << order;
	ring->tx_spare = tx_spare;
	ring->tx_copybreak = priv->tx_copybreak;
	return;

dma_mapping_error:
@@ -4868,6 +4872,30 @@ static void hns3_nic_dealloc_vector_data(struct hns3_nic_priv *priv)
	devm_kfree(&pdev->dev, priv->tqp_vector);
}

static void hns3_update_tx_spare_buf_config(struct hns3_nic_priv *priv)
{
#define HNS3_MIN_SPARE_BUF_SIZE (2 * 1024 * 1024)
#define HNS3_MAX_PACKET_SIZE (64 * 1024)

	struct iommu_domain *domain = iommu_get_domain_for_dev(priv->dev);
	struct hnae3_ae_dev *ae_dev = hns3_get_ae_dev(priv->ae_handle);
	struct hnae3_handle *handle = priv->ae_handle;

	if (ae_dev->dev_version < HNAE3_DEVICE_VERSION_V3)
		return;

	if (!(domain && iommu_is_dma_domain(domain)))
		return;

	priv->min_tx_copybreak = HNS3_MAX_PACKET_SIZE;
	priv->min_tx_spare_buf_size = HNS3_MIN_SPARE_BUF_SIZE;

	if (priv->tx_copybreak < priv->min_tx_copybreak)
		priv->tx_copybreak = priv->min_tx_copybreak;
	if (handle->kinfo.tx_spare_buf_size < priv->min_tx_spare_buf_size)
		handle->kinfo.tx_spare_buf_size = priv->min_tx_spare_buf_size;
}

static void hns3_ring_get_cfg(struct hnae3_queue *q, struct hns3_nic_priv *priv,
			      unsigned int ring_type)
{
@@ -5101,6 +5129,7 @@ int hns3_init_all_ring(struct hns3_nic_priv *priv)
	int i, j;
	int ret;

	hns3_update_tx_spare_buf_config(priv);
	for (i = 0; i < ring_num; i++) {
		ret = hns3_alloc_ring_memory(&priv->ring[i]);
		if (ret) {
@@ -5305,6 +5334,8 @@ static int hns3_client_init(struct hnae3_handle *handle)
	priv->ae_handle = handle;
	priv->tx_timeout_count = 0;
	priv->max_non_tso_bd_num = ae_dev->dev_specs.max_non_tso_bd_num;
	priv->min_tx_copybreak = 0;
	priv->min_tx_spare_buf_size = 0;
	set_bit(HNS3_NIC_STATE_DOWN, &priv->state);

	handle->msg_enable = netif_msg_init(debug, DEFAULT_MSG_LEVEL);
+2 −0
Original line number Diff line number Diff line
@@ -596,6 +596,8 @@ struct hns3_nic_priv {
	struct hns3_enet_coalesce rx_coal;
	u32 tx_copybreak;
	u32 rx_copybreak;
	u32 min_tx_copybreak;
	u32 min_tx_spare_buf_size;
};

union l3_hdr_info {
+33 −0
Original line number Diff line number Diff line
@@ -1933,6 +1933,31 @@ static int hns3_set_tx_spare_buf_size(struct net_device *netdev,
	return ret;
}

static int hns3_check_tx_copybreak(struct net_device *netdev, u32 copybreak)
{
	struct hns3_nic_priv *priv = netdev_priv(netdev);

	if (copybreak < priv->min_tx_copybreak) {
		netdev_err(netdev, "tx copybreak %u should be no less than %u!\n",
			   copybreak, priv->min_tx_copybreak);
		return -EINVAL;
	}
	return 0;
}

static int hns3_check_tx_spare_buf_size(struct net_device *netdev, u32 buf_size)
{
	struct hns3_nic_priv *priv = netdev_priv(netdev);

	if (buf_size < priv->min_tx_spare_buf_size) {
		netdev_err(netdev,
			   "tx spare buf size %u should be no less than %u!\n",
			   buf_size, priv->min_tx_spare_buf_size);
		return -EINVAL;
	}
	return 0;
}

static int hns3_set_tunable(struct net_device *netdev,
			    const struct ethtool_tunable *tuna,
			    const void *data)
@@ -1949,6 +1974,10 @@ static int hns3_set_tunable(struct net_device *netdev,

	switch (tuna->id) {
	case ETHTOOL_TX_COPYBREAK:
		ret = hns3_check_tx_copybreak(netdev, *(u32 *)data);
		if (ret)
			return ret;

		priv->tx_copybreak = *(u32 *)data;

		for (i = 0; i < h->kinfo.num_tqps; i++)
@@ -1963,6 +1992,10 @@ static int hns3_set_tunable(struct net_device *netdev,

		break;
	case ETHTOOL_TX_COPYBREAK_BUF_SIZE:
		ret = hns3_check_tx_spare_buf_size(netdev, *(u32 *)data);
		if (ret)
			return ret;

		old_tx_spare_buf_size = h->kinfo.tx_spare_buf_size;
		new_tx_spare_buf_size = *(u32 *)data;
		netdev_info(netdev, "request to set tx spare buf size from %u to %u\n",