[PATCH net-next v2 2/5] mvpp2: use page_pool allocator

Matteo Croce
2020-07-02T14:14:21Z

Use the page_pool API for memory management.
This is a prerequisite for native XDP support.

Tested-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
---
drivers/net/ethernet/marvell/Kconfig | 1 +
drivers/net/ethernet/marvell/mvpp2/mvpp2.h | 8 +
.../net/ethernet/marvell/mvpp2/mvpp2_main.c | 156 +++++++++++++++---
3 files changed, 140 insertions(+), 25 deletions(-)

diff --git a/drivers/net/ethernet/marvell/Kconfig b/drivers/net/ethernet/marvell/Kconfig
index cd8ddd1ef6f2..ef4f35ba077d 100644
--- a/drivers/net/ethernet/marvell/Kconfig
+++ b/drivers/net/ethernet/marvell/Kconfig
@@ -87,6 +87,7 @@ config MVPP2
depends on ARCH_MVEBU || COMPILE_TEST
select MVMDIO
select PHYLINK
+ select PAGE_POOL
help
This driver supports the network interface units in the
Marvell ARMADA 375, 7K and 8K SoCs.
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
index 543a310ec102..4c16c9e9c1e5 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
@@ -15,6 +15,7 @@
#include <linux/phy.h>
#include <linux/phylink.h>
#include <net/flow_offload.h>
+#include <net/page_pool.h>

/* Fifo Registers */
#define MVPP2_RX_DATA_FIFO_SIZE_REG(port) (0x00 + 4 * (port))
@@ -820,6 +821,9 @@ struct mvpp2 {

/* RSS Indirection tables */
struct mvpp2_rss_table *rss_tables[MVPP22_N_RSS_TABLES];
+
+ /* page_pool allocator */
+ struct page_pool *page_pool[MVPP2_PORT_MAX_RXQ];
};

struct mvpp2_pcpu_stats {
@@ -1161,6 +1165,10 @@ struct mvpp2_rx_queue {

/* Port's logic RXQ number to which physical RXQ is mapped */
int logic_rxq;
+
+ /* XDP memory accounting */
+ struct xdp_rxq_info xdp_rxq_short;
+ struct xdp_rxq_info xdp_rxq_long;
};

struct mvpp2_bm_pool {
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 027de7291f92..5d0e02c161a6 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -95,6 +95,22 @@ static inline u32 mvpp2_cpu_to_thread(struct mvpp2 *priv, int cpu)
return cpu % priv->nthreads;
}

+static struct page_pool *
+mvpp2_create_page_pool(struct device *dev, int num, int len)
+{
+ struct page_pool_params pp_params = {
+ /* internal DMA mapping in page_pool */
+ .flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
+ .pool_size = num,
+ .nid = NUMA_NO_NODE,
+ .dev = dev,
+ .dma_dir = DMA_FROM_DEVICE,
+ .max_len = len,
+ };
+
+ return page_pool_create(&pp_params);
+}
+
/* These accessors should be used to access:
*
* - per-thread registers, where each thread has its own copy of the
@@ -327,17 +343,25 @@ static inline int mvpp2_txq_phys(int port, int txq)
return (MVPP2_MAX_TCONT + port) * MVPP2_MAX_TXQ + txq;
}

-static void *mvpp2_frag_alloc(const struct mvpp2_bm_pool *pool)
+/* Returns a struct page if page_pool is set, otherwise a buffer */
+static void *mvpp2_frag_alloc(const struct mvpp2_bm_pool *pool,
+ struct page_pool *page_pool)
{
+ if (page_pool)
+ return page_pool_dev_alloc_pages(page_pool);
+
if (likely(pool->frag_size <= PAGE_SIZE))
return netdev_alloc_frag(pool->frag_size);
- else
- return kmalloc(pool->frag_size, GFP_ATOMIC);
+
+ return kmalloc(pool->frag_size, GFP_ATOMIC);
}

-static void mvpp2_frag_free(const struct mvpp2_bm_pool *pool, void *data)
+static void mvpp2_frag_free(const struct mvpp2_bm_pool *pool,
+ struct page_pool *page_pool, void *data)
{
- if (likely(pool->frag_size <= PAGE_SIZE))
+ if (page_pool)
+ page_pool_put_full_page(page_pool, virt_to_head_page(data), false);
+ else if (likely(pool->frag_size <= PAGE_SIZE))
skb_free_frag(data);
else
kfree(data);
@@ -442,6 +466,7 @@ static void mvpp2_bm_bufs_get_addrs(struct device *dev, struct mvpp2 *priv,
static void mvpp2_bm_bufs_free(struct device *dev, struct mvpp2 *priv,
struct mvpp2_bm_pool *bm_pool, int buf_num)
{
+ struct page_pool *pp = NULL;
int i;

if (buf_num > bm_pool->buf_num) {
@@ -450,6 +475,9 @@ static void mvpp2_bm_bufs_free(struct device *dev, struct mvpp2 *priv,
buf_num = bm_pool->buf_num;
}

+ if (priv->percpu_pools)
+ pp = priv->page_pool[bm_pool->id];
+
for (i = 0; i < buf_num; i++) {
dma_addr_t buf_dma_addr;
phys_addr_t buf_phys_addr;
@@ -458,14 +486,15 @@ static void mvpp2_bm_bufs_free(struct device *dev, struct mvpp2 *priv,
mvpp2_bm_bufs_get_addrs(dev, priv, bm_pool,
&buf_dma_addr, &buf_phys_addr);

- dma_unmap_single(dev, buf_dma_addr,
- bm_pool->buf_size, DMA_FROM_DEVICE);
+ if (!pp)
+ dma_unmap_single(dev, buf_dma_addr,
+ bm_pool->buf_size, DMA_FROM_DEVICE);

data = (void *)phys_to_virt(buf_phys_addr);
if (!data)
break;

- mvpp2_frag_free(bm_pool, data);
+ mvpp2_frag_free(bm_pool, pp, data);
}

/* Update BM driver with number of buffers removed from pool */
@@ -496,6 +525,9 @@ static int mvpp2_bm_pool_destroy(struct device *dev, struct mvpp2 *priv,
int buf_num;
u32 val;

+ if (priv->percpu_pools)
+ page_pool_destroy(priv->page_pool[bm_pool->id]);
+
buf_num = mvpp2_check_hw_buf_num(priv, bm_pool);
mvpp2_bm_bufs_free(dev, priv, bm_pool, buf_num);

@@ -548,8 +580,20 @@ static int mvpp2_bm_init(struct device *dev, struct mvpp2 *priv)
{
int i, err, poolnum = MVPP2_BM_POOLS_NUM;

- if (priv->percpu_pools)
+ if (priv->percpu_pools) {
poolnum = mvpp2_get_nrxqs(priv) * 2;
+ for (i = 0; i < poolnum; i++) {
+ /* the pool in use */
+ int pn = i / (poolnum / 2);
+
+ priv->page_pool[i] =
+ mvpp2_create_page_pool(dev,
+ mvpp2_pools[pn].buf_num,
+ mvpp2_pools[pn].pkt_size);
+ if (IS_ERR(priv->page_pool[i]))
+ return PTR_ERR(priv->page_pool[i]);
+ }
+ }

dev_info(dev, "using %d %s buffers\n", poolnum,
priv->percpu_pools ? "per-cpu" : "shared");
@@ -632,23 +676,31 @@ static void mvpp2_rxq_short_pool_set(struct mvpp2_port *port,

static void *mvpp2_buf_alloc(struct mvpp2_port *port,
struct mvpp2_bm_pool *bm_pool,
+ struct page_pool *page_pool,
dma_addr_t *buf_dma_addr,
phys_addr_t *buf_phys_addr,
gfp_t gfp_mask)
{
dma_addr_t dma_addr;
+ struct page *page;
void *data;

- data = mvpp2_frag_alloc(bm_pool);
+ data = mvpp2_frag_alloc(bm_pool, page_pool);
if (!data)
return NULL;

- dma_addr = dma_map_single(port->dev->dev.parent, data,
- MVPP2_RX_BUF_SIZE(bm_pool->pkt_size),
- DMA_FROM_DEVICE);
- if (unlikely(dma_mapping_error(port->dev->dev.parent, dma_addr))) {
- mvpp2_frag_free(bm_pool, data);
- return NULL;
+ if (page_pool) {
+ page = (struct page *)data;
+ dma_addr = page_pool_get_dma_addr(page);
+ data = page_to_virt(page);
+ } else {
+ dma_addr = dma_map_single(port->dev->dev.parent, data,
+ MVPP2_RX_BUF_SIZE(bm_pool->pkt_size),
+ DMA_FROM_DEVICE);
+ if (unlikely(dma_mapping_error(port->dev->dev.parent, dma_addr))) {
+ mvpp2_frag_free(bm_pool, NULL, data);
+ return NULL;
+ }
}
*buf_dma_addr = dma_addr;
*buf_phys_addr = virt_to_phys(data);
@@ -706,6 +758,7 @@ static int mvpp2_bm_bufs_add(struct mvpp2_port *port,
int i, buf_size, total_size;
dma_addr_t dma_addr;
phys_addr_t phys_addr;
+ struct page_pool *pp = NULL;
void *buf;

if (port->priv->percpu_pools &&
@@ -726,8 +779,10 @@ static int mvpp2_bm_bufs_add(struct mvpp2_port *port,
return 0;
}

+ if (port->priv->percpu_pools)
+ pp = port->priv->page_pool[bm_pool->id];
for (i = 0; i < buf_num; i++) {
- buf = mvpp2_buf_alloc(port, bm_pool, &dma_addr,
+ buf = mvpp2_buf_alloc(port, bm_pool, pp, &dma_addr,
&phys_addr, GFP_KERNEL);
if (!buf)
break;
@@ -2374,10 +2429,11 @@ static int mvpp2_aggr_txq_init(struct platform_device *pdev,
/* Create a specified Rx queue */
static int mvpp2_rxq_init(struct mvpp2_port *port,
struct mvpp2_rx_queue *rxq)
-
{
+ struct mvpp2 *priv = port->priv;
unsigned int thread;
u32 rxq_dma;
+ int err;

rxq->size = port->rx_ring_size;

@@ -2415,7 +2471,43 @@ static int mvpp2_rxq_init(struct mvpp2_port *port,
/* Add number of descriptors ready for receiving packets */
mvpp2_rxq_status_update(port, rxq->id, 0, rxq->size);

+ if (priv->percpu_pools) {
+ err = xdp_rxq_info_reg(&rxq->xdp_rxq_short, port->dev, rxq->id);
+ if (err < 0)
+ goto err_free_dma;
+
+ err = xdp_rxq_info_reg(&rxq->xdp_rxq_long, port->dev, rxq->id);
+ if (err < 0)
+ goto err_unregister_rxq_short;
+
+ /* Every RXQ has a pool for short and another for long packets */
+ err = xdp_rxq_info_reg_mem_model(&rxq->xdp_rxq_short,
+ MEM_TYPE_PAGE_POOL,
+ priv->page_pool[rxq->logic_rxq]);
+ if (err < 0)
+ goto err_unregister_rxq_long;
+
+ err = xdp_rxq_info_reg_mem_model(&rxq->xdp_rxq_long,
+ MEM_TYPE_PAGE_POOL,
+ priv->page_pool[rxq->logic_rxq +
+ port->nrxqs]);
+ if (err < 0)
+ goto err_unregister_mem_rxq_short;
+ }
+
return 0;
+
+err_unregister_mem_rxq_short:
+ xdp_rxq_info_unreg_mem_model(&rxq->xdp_rxq_short);
+err_unregister_rxq_long:
+ xdp_rxq_info_unreg(&rxq->xdp_rxq_long);
+err_unregister_rxq_short:
+ xdp_rxq_info_unreg(&rxq->xdp_rxq_short);
+err_free_dma:
+ dma_free_coherent(port->dev->dev.parent,
+ rxq->size * MVPP2_DESC_ALIGNED_SIZE,
+ rxq->descs, rxq->descs_dma);
+ return err;
}

/* Push packets received by the RXQ to BM pool */
@@ -2449,6 +2541,12 @@ static void mvpp2_rxq_deinit(struct mvpp2_port *port,
{
unsigned int thread;

+ if (xdp_rxq_info_is_reg(&rxq->xdp_rxq_short))
+ xdp_rxq_info_unreg(&rxq->xdp_rxq_short);
+
+ if (xdp_rxq_info_is_reg(&rxq->xdp_rxq_long))
+ xdp_rxq_info_unreg(&rxq->xdp_rxq_long);
+
mvpp2_rxq_drop_pkts(port, rxq);

if (rxq->descs)
@@ -2890,14 +2988,15 @@ static void mvpp2_rx_csum(struct mvpp2_port *port, u32 status,

/* Allocate a new skb and add it to BM pool */
static int mvpp2_rx_refill(struct mvpp2_port *port,
- struct mvpp2_bm_pool *bm_pool, int pool)
+ struct mvpp2_bm_pool *bm_pool,
+ struct page_pool *page_pool, int pool)
{
dma_addr_t dma_addr;
phys_addr_t phys_addr;
void *buf;

- buf = mvpp2_buf_alloc(port, bm_pool, &dma_addr, &phys_addr,
- GFP_ATOMIC);
+ buf = mvpp2_buf_alloc(port, bm_pool, page_pool,
+ &dma_addr, &phys_addr, GFP_ATOMIC);
if (!buf)
return -ENOMEM;

@@ -2956,6 +3055,7 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
while (rx_done < rx_todo) {
struct mvpp2_rx_desc *rx_desc = mvpp2_rxq_next_desc_get(rxq);
struct mvpp2_bm_pool *bm_pool;
+ struct page_pool *pp = NULL;
struct sk_buff *skb;
unsigned int frag_size;
dma_addr_t dma_addr;
@@ -2989,6 +3089,9 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
DMA_FROM_DEVICE);
prefetch(data);

+ if (port->priv->percpu_pools)
+ pp = port->priv->page_pool[pool];
+
if (bm_pool->frag_size > PAGE_SIZE)
frag_size = 0;
else
@@ -3000,15 +3103,18 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi,
goto err_drop_frame;
}

- err = mvpp2_rx_refill(port, bm_pool, pool);
+ err = mvpp2_rx_refill(port, bm_pool, pp, pool);
if (err) {
netdev_err(port->dev, "failed to refill BM pools\n");
goto err_drop_frame;
}

- dma_unmap_single_attrs(dev->dev.parent, dma_addr,
- bm_pool->buf_size, DMA_FROM_DEVICE,
- DMA_ATTR_SKIP_CPU_SYNC);
+ if (pp)
+ page_pool_release_page(pp, virt_to_page(data));
+ else
+ dma_unmap_single_attrs(dev->dev.parent, dma_addr,
+ bm_pool->buf_size, DMA_FROM_DEVICE,
+ DMA_ATTR_SKIP_CPU_SYNC);

rcvd_pkts++;
rcvd_bytes += rx_bytes;
--
2.26.2