path: root/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c

// SPDX-License-Identifier: GPL-2.0+

#include <linux/bpf.h>
#include <linux/filter.h>
#include <net/page_pool/helpers.h>

#include "lan966x_main.h"

static int lan966x_fdma_channel_active(struct lan966x *lan966x)
{
	return lan_rd(lan966x, FDMA_CH_ACTIVE);
}

static struct page *lan966x_fdma_rx_alloc_page(struct lan966x_rx *rx,
					       struct lan966x_db *db)
{
	struct page *page;

	page = page_pool_dev_alloc_pages(rx->page_pool);
	if (unlikely(!page))
		return NULL;

	db->dataptr = page_pool_get_dma_addr(page) + XDP_PACKET_HEADROOM;

	return page;
}

static void lan966x_fdma_rx_free_pages(struct lan966x_rx *rx)
{
	int i, j;

	for (i = 0; i < FDMA_DCB_MAX; ++i) {
		for (j = 0; j < FDMA_RX_DCB_MAX_DBS; ++j)
			page_pool_put_full_page(rx->page_pool,
						rx->page[i][j], false);
	}
}

static void lan966x_fdma_rx_free_page(struct lan966x_rx *rx)
{
	struct page *page;

	page = rx->page[rx->dcb_index][rx->db_index];
	if (unlikely(!page))
		return;

	page_pool_recycle_direct(rx->page_pool, page);
}

static void lan966x_fdma_rx_add_dcb(struct lan966x_rx *rx,
				    struct lan966x_rx_dcb *dcb,
				    u64 nextptr)
{
	struct lan966x_db *db;
	int i;

	for (i = 0; i < FDMA_RX_DCB_MAX_DBS; ++i) {
		db = &dcb->db[i];
		db->status = FDMA_DCB_STATUS_INTR;
	}

	dcb->nextptr = FDMA_DCB_INVALID_DATA;
	dcb->info = FDMA_DCB_INFO_DATAL(PAGE_SIZE << rx->page_order);

	rx->last_entry->nextptr = nextptr;
	rx->last_entry = dcb;
}

static int lan966x_fdma_rx_alloc_page_pool(struct lan966x_rx *rx)
{
	struct lan966x *lan966x = rx->lan966x;
	struct page_pool_params pp_params = {
		.order = rx->page_order,
		.flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV,
		.pool_size = FDMA_DCB_MAX,
		.nid = NUMA_NO_NODE,
		.dev = lan966x->dev,
		.dma_dir = DMA_FROM_DEVICE,
		.offset = XDP_PACKET_HEADROOM,
		.max_len = rx->max_mtu -
			   SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
	};

	if (lan966x_xdp_present(lan966x))
		pp_params.dma_dir = DMA_BIDIRECTIONAL;

	rx->page_pool = page_pool_create(&pp_params);

	for (int i = 0; i < lan966x->num_phys_ports; ++i) {
		struct lan966x_port *port;

		if (!lan966x->ports[i])
			continue;

		port = lan966x->ports[i];
		xdp_rxq_info_unreg_mem_model(&port->xdp_rxq);
		xdp_rxq_info_reg_mem_model(&port->xdp_rxq, MEM_TYPE_PAGE_POOL,
					   rx->page_pool);
	}

	return PTR_ERR_OR_ZERO(rx->page_pool);
}

static int lan966x_fdma_rx_alloc(struct lan966x_rx *rx)
{
	struct lan966x *lan966x = rx->lan966x;
	struct lan966x_rx_dcb *dcb;
	struct lan966x_db *db;
	struct page *page;
	int i, j;
	int size;

	if (lan966x_fdma_rx_alloc_page_pool(rx))
		return PTR_ERR(rx->page_pool);

	/* calculate how many pages are needed to allocate the dcbs */
	size = sizeof(struct lan966x_rx_dcb) * FDMA_DCB_MAX;
	size = ALIGN(size, PAGE_SIZE);

	rx->dcbs = dma_alloc_coherent(lan966x->dev, size, &rx->dma, GFP_KERNEL);
	if (!rx->dcbs)
		return -ENOMEM;

	rx->last_entry = rx->dcbs;
	rx->db_index = 0;
	rx->dcb_index = 0;

	/* Now for each dcb allocate the dbs */
	for (i = 0; i < FDMA_DCB_MAX; ++i) {
		dcb = &rx->dcbs[i];
		dcb->info = 0;

		/* For each db allocate a page and map it to the DB dataptr. */
		for (j = 0; j < FDMA_RX_DCB_MAX_DBS; ++j) {
			db = &dcb->db[j];
			page = lan966x_fdma_rx_alloc_page(rx, db);
			if (!page)
				return -ENOMEM;

			db->status = 0;
			rx->page[i][j] = page;
		}

		lan966x_fdma_rx_add_dcb(rx, dcb, rx->dma + sizeof(*dcb) * i);
	}

	return 0;
}

static <