numam-dpdk/drivers/net/mlx5/mlx5_mr.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright 2016 6WIND S.A.
 * Copyright 2016 Mellanox Technologies, Ltd
 */

#include <rte_eal_memconfig.h>
#include <rte_mempool.h>
#include <rte_malloc.h>
#include <rte_rwlock.h>
#include <rte_bus_pci.h>

#include <mlx5_common_mp.h>
#include <mlx5_common_mr.h>

#include "mlx5.h"
#include "mlx5_mr.h"
#include "mlx5_rxtx.h"

struct mr_find_contig_memsegs_data {
	uintptr_t addr;
	uintptr_t start;
	uintptr_t end;
	const struct rte_memseg_list *msl;
};

struct mr_update_mp_data {
	struct rte_eth_dev *dev;
	struct mlx5_mr_ctrl *mr_ctrl;
	int ret;
};

/**
 * Callback for memory free event. Iterate freed memsegs and check whether it
 * belongs to an existing MR. If found, clear the bit from bitmap of MR. As a
 * result, the MR would be fragmented. If it becomes empty, the MR will be freed
 * later by mlx5_mr_garbage_collect(). Even if this callback is called from a
 * secondary process, the garbage collector will be called in primary process
 * as the secondary process can't call mlx5_mr_create().
 *
 * The global cache must be rebuilt if there's any change and this event has to
 * be propagated to dataplane threads to flush the local caches.
 *
 * @param sh
 *   Pointer to the Ethernet device shared context.
 * @param addr
 *   Address of freed memory.
 * @param len
 *   Size of freed memory.
 */
static void
mlx5_mr_mem_event_free_cb(struct mlx5_dev_ctx_shared *sh,
			  const void *addr, size_t len)
{
	const struct rte_memseg_list *msl;
	struct mlx5_mr *mr;
	int ms_n;
	int i;
	int rebuild = 0;

	DEBUG("device %s free callback: addr=%p, len=%zu",
	      sh->ibdev_name, addr, len);
	msl = rte_mem_virt2memseg_list(addr);
	/* addr and len must be page-aligned. */
	MLX5_ASSERT((uintptr_t)addr ==
		    RTE_ALIGN((uintptr_t)addr, msl->page_sz));
	MLX5_ASSERT(len == RTE_ALIGN(len, msl->page_sz));
	ms_n = len / msl->page_sz;
	rte_rwlock_write_lock(&sh->share_cache.rwlock);
	/* Clear bits of freed memsegs from MR. */
	for (i = 0; i < ms_n; ++i) {
		const struct rte_memseg *ms;
		struct mr_cache_entry entry;
		uintptr_t start;
		int ms_idx;
		uint32_t pos;

		/* Find MR having this memseg. */
		start = (uintptr_t)addr + i * msl->page_sz;
		mr = mlx5_mr_lookup_list(&sh->share_cache, &entry, start);
		if (mr == NULL)
			continue;
		MLX5_ASSERT(mr->msl); /* Can't be external memory. */
		ms = rte_mem_virt2memseg((void *)start, msl);
		MLX5_ASSERT(ms != NULL);
		MLX5_ASSERT(msl->page_sz == ms->hugepage_sz);
		ms_idx = rte_fbarray_find_idx(&msl->memseg_arr, ms);
		pos = ms_idx - mr->ms_base_idx;
		MLX5_ASSERT(rte_bitmap_get(mr->ms_bmp, pos));
		MLX5_ASSERT(pos < mr->ms_bmp_n);
		DEBUG("device %s MR(%p): clear bitmap[%u] for addr %p",
		      sh->ibdev_name, (void *)mr, pos, (void *)start);
		rte_bitmap_clear(mr->ms_bmp, pos);
		if (--mr->ms_n == 0) {
			LIST_REMOVE(mr, mr);
			LIST_INSERT_HEAD(&sh->share_cache.mr_free_list, mr, mr);
			DEBUG("device %s remove MR(%p) from list",
			      sh->ibdev_name, (void *)mr);
		}
		/*
		 * MR is fragmented or will be freed. the global cache must be
		 * rebuilt.
		 */
		rebuild = 1;
	}
	if (rebuild) {
		mlx5_mr_rebuild_cache(&sh->share_cache);
		/*
		 * Flush local caches by propagating invalidation across cores.
		 * rte_smp_wmb() is enough to synchronize this event. If one of
		 * freed memsegs is seen by other core, that means the memseg
		 * has been allocated by allocator, which will come after this
		 * free call. Therefore, this store instruction (incrementing
		 * generation below) will be guaranteed to be seen by other core
		 * before the core sees the newly allocated memory.
		 */
		++sh->share_cache.dev_gen;
		DEBUG("broadcasting local cache flush, gen=%d",
		      sh->share_cache.dev_gen);
		rte_smp_wmb();
	}
	rte_rwlock_write_unlock(&sh->share_cache.rwlock);
}

/**
 * Callback for memory event. This can be called from both primary and secondary
 * process.
 *
 * @param event_type
 *   Memory event type.
 * @param addr
 *   Address of memory.
 * @param len
 *   Size of memory.
 */
void
mlx5_mr_mem_event_cb(enum rte_mem_event event_type, const void *addr,
		     size_t len, void *arg __rte_unused)
{
	struct mlx5_dev_ctx_shared *sh;
	struct mlx5_dev_list *dev_list = &mlx5_shared_data->mem_event_cb_list;

	/* Must be called from the primary process. */
	MLX5_ASSERT(rte_eal_process_type() == RTE_PROC_PRIMARY);
	switch (event_type) {
	case RTE_MEM_EVENT_FREE:
		rte_rwlock_write_lock(&mlx5_shared_data->mem_event_rwlock);
		/* Iterate all the existing mlx5 devices. */
		LIST_FOREACH(sh, dev_list, mem_event_cb)
			mlx5_mr_mem_event_free_cb(sh, addr, len);
		rte_rwlock_write_unlock(&mlx5_shared_data->mem_event_rwlock);
		break;
	case RTE_MEM_EVENT_ALLOC:
	default:
		break;
	}
}

/**
 * Bottom-half of LKey search on Rx.
 *
 * @param rxq
 *   Pointer to Rx queue structure.
 * @param addr
 *   Search key.
 *
 * @return
 *   Searched LKey on success, UINT32_MAX on no match.
 */
uint32_t
mlx5_rx_addr2mr_bh(struct mlx5_rxq_data *rxq, uintptr_t addr)
{
	struct mlx5_rxq_ctrl *rxq_ctrl =
		container_of(rxq, struct mlx5_rxq_ctrl, rxq);
	struct mlx5_mr_ctrl *mr_ctrl = &rxq->mr_ctrl;
	struct mlx5_priv *priv = rxq_ctrl->priv;

	return mlx5_mr_addr2mr_bh(priv->sh->pd, &priv->mp_id,
				  &priv->sh->share_cache, mr_ctrl, addr,
				  priv->config.mr_ext_memseg_en);
}

/**
 * Bottom-half of LKey search on Tx.
 *
 * @param txq
 *   Pointer to Tx queue structure.
 * @param addr
 *   Search key.
 *
 * @return
 *   Searched LKey on success, UINT32_MAX on no match.
 */
static uint32_t
mlx5_tx_addr2mr_bh(struct mlx5_txq_data *txq, uintptr_t addr)
{
	struct mlx5_txq_ctrl *txq_ctrl =
		container_of(txq, struct mlx5_txq_ctrl, txq);
	struct mlx5_mr_ctrl *mr_ctrl = &txq->mr_ctrl;
	struct mlx5_priv *priv = txq_ctrl->priv;

	return mlx5_mr_addr2mr_bh(priv->sh->pd, &priv->mp_id,
				  &priv->sh->share_cache, mr_ctrl, addr,
				  priv->config.mr_ext_memseg_en);
}

/**
 * Bottom-half of LKey search on Tx. If it can't be searched in the memseg
 * list, register the mempool of the mbuf as externally allocated memory.
 *
 * @param txq
 *   Pointer to Tx queue structure.
 * @param mb
 *   Pointer to mbuf.
 *
 * @return
 *   Searched LKey on success, UINT32_MAX on no match.
 */
uint32_t
mlx5_tx_mb2mr_bh(struct mlx5_txq_data *txq, struct rte_mbuf *mb)
{
	uintptr_t addr = (uintptr_t)mb->buf_addr;
	uint32_t lkey;

	lkey = mlx5_tx_addr2mr_bh(txq, addr);
	if (lkey == UINT32_MAX && rte_errno == ENXIO) {
		/* Mempool may have externally allocated memory. */
		return mlx5_tx_update_ext_mp(txq, addr, mlx5_mb2mp(mb));
	}
	return lkey;
}

/**
 * Called during rte_mempool_mem_iter() by mlx5_mr_update_ext_mp().
 *
 * Externally allocated chunk is registered and a MR is created for the chunk.
 * The MR object is added to the global list. If memseg list of a MR object
 * (mr->msl) is null, the MR object can be regarded as externally allocated
 * memory.
 *
 * Once external memory is registered, it should be static. If the memory is
 * freed and the virtual address range has different physical memory mapped
 * again, it may cause crash on device due to the wrong translation entry. PMD
 * can't track the free event of the external memory for now.
 */
static void
mlx5_mr_update_ext_mp_cb(struct rte_mempool *mp, void *opaque,
			 struct rte_mempool_memhdr *memhdr,
			 unsigned mem_idx __rte_unused)
{
	struct mr_update_mp_data *data = opaque;
	struct rte_eth_dev *dev = data->dev;
	struct mlx5_priv *priv = dev->data->dev_private;
	struct mlx5_dev_ctx_shared *sh = priv->sh;
	struct mlx5_mr_ctrl *mr_ctrl = data->mr_ctrl;
	struct mlx5_mr *mr = NULL;
	uintptr_t addr = (uintptr_t)memhdr->addr;
	size_t len = memhdr->len;
	struct mr_cache_entry entry;
	uint32_t lkey;

	MLX5_ASSERT(rte_eal_process_type() == RTE_PROC_PRIMARY);
	/* If already registered, it should return. */
	rte_rwlock_read_lock(&sh->share_cache.rwlock);
	lkey = mlx5_mr_lookup_cache(&sh->share_cache, &entry, addr);
	rte_rwlock_read_unlock(&sh->share_cache.rwlock);
	if (lkey != UINT32_MAX)
		return;
	DRV_LOG(DEBUG, "port %u register MR for chunk #%d of mempool (%s)",
		dev->data->port_id, mem_idx, mp->name);
	mr = mlx5_create_mr_ext(sh->pd, addr, len, mp->socket_id,
				sh->share_cache.reg_mr_cb);
	if (!mr) {
		DRV_LOG(WARNING,
			"port %u unable to allocate a new MR of"
			" mempool (%s).",
			dev->data->port_id, mp->name);
		data->ret = -1;
		return;
	}
	rte_rwlock_write_lock(&sh->share_cache.rwlock);
	LIST_INSERT_HEAD(&sh->share_cache.mr_list, mr, mr);
	/* Insert to the global cache table. */
	mlx5_mr_insert_cache(&sh->share_cache, mr);
	rte_rwlock_write_unlock(&sh->share_cache.rwlock);
	/* Insert to the local cache table */
	mlx5_mr_addr2mr_bh(sh->pd, &priv->mp_id, &sh->share_cache,
			   mr_ctrl, addr, priv->config.mr_ext_memseg_en);
}

/**
 * Finds the first ethdev that match the pci device.
 * The existence of multiple ethdev per pci device is only with representors.
 * On such case, it is enough to get only one of the ports as they all share
 * the same ibv context.
 *
 * @param pdev
 *   Pointer to the PCI device.
 *
 * @return
 *   Pointer to the ethdev if found, NULL otherwise.
 */
static struct rte_eth_dev *
pci_dev_to_eth_dev(struct rte_pci_device *pdev)
{
	uint16_t port_id;

	port_id = rte_eth_find_next_of(0, &pdev->device);
	if (port_id == RTE_MAX_ETHPORTS)
		return NULL;
	return &rte_eth_devices[port_id];
}

/**
 * DPDK callback to DMA map external memory to a PCI device.
 *
 * @param pdev
 *   Pointer to the PCI device.
 * @param addr
 *   Starting virtual address of memory to be mapped.
 * @param iova
 *   Starting IOVA address of memory to be mapped.
 * @param len
 *   Length of memory segment being mapped.
 *
 * @return
 *   0 on success, negative value on error.
 */
int
mlx5_dma_map(struct rte_pci_device *pdev, void *addr,
	     uint64_t iova __rte_unused, size_t len)
{
	struct rte_eth_dev *dev;
	struct mlx5_mr *mr;
	struct mlx5_priv *priv;
	struct mlx5_dev_ctx_shared *sh;

	dev = pci_dev_to_eth_dev(pdev);
	if (!dev) {
		DRV_LOG(WARNING, "unable to find matching ethdev "
				 "to PCI device %p", (void *)pdev);
		rte_errno = ENODEV;
		return -1;
	}
	priv = dev->data->dev_private;
	sh = priv->sh;
	mr = mlx5_create_mr_ext(sh->pd, (uintptr_t)addr, len, SOCKET_ID_ANY,
				sh->share_cache.reg_mr_cb);
	if (!mr) {
		DRV_LOG(WARNING,
			"port %u unable to dma map", dev->data->port_id);
		rte_errno = EINVAL;
		return -1;
	}
	rte_rwlock_write_lock(&sh->share_cache.rwlock);
	LIST_INSERT_HEAD(&sh->share_cache.mr_list, mr, mr);
	/* Insert to the global cache table. */
	mlx5_mr_insert_cache(&sh->share_cache, mr);
	rte_rwlock_write_unlock(&sh->share_cache.rwlock);
	return 0;
}

/**
 * DPDK callback to DMA unmap external memory to a PCI device.
 *
 * @param pdev
 *   Pointer to the PCI device.
 * @param addr
 *   Starting virtual address of memory to be unmapped.
 * @param iova
 *   Starting IOVA address of memory to be unmapped.
 * @param len
 *   Length of memory segment being unmapped.
 *
 * @return
 *   0 on success, negative value on error.
 */
int
mlx5_dma_unmap(struct rte_pci_device *pdev, void *addr,
	       uint64_t iova __rte_unused, size_t len __rte_unused)
{
	struct rte_eth_dev *dev;
	struct mlx5_priv *priv;
	struct mlx5_dev_ctx_shared *sh;
	struct mlx5_mr *mr;
	struct mr_cache_entry entry;

	dev = pci_dev_to_eth_dev(pdev);
	if (!dev) {
		DRV_LOG(WARNING, "unable to find matching ethdev "
				 "to PCI device %p", (void *)pdev);
		rte_errno = ENODEV;
		return -1;
	}
	priv = dev->data->dev_private;
	sh = priv->sh;
	rte_rwlock_read_lock(&sh->share_cache.rwlock);
	mr = mlx5_mr_lookup_list(&sh->share_cache, &entry, (uintptr_t)addr);
	if (!mr) {
		rte_rwlock_read_unlock(&sh->share_cache.rwlock);
		DRV_LOG(WARNING, "address 0x%" PRIxPTR " wasn't registered "
				 "to PCI device %p", (uintptr_t)addr,
				 (void *)pdev);
		rte_errno = EINVAL;
		return -1;
	}
	LIST_REMOVE(mr, mr);
	mlx5_mr_free(mr, sh->share_cache.dereg_mr_cb);
	DEBUG("port %u remove MR(%p) from list", dev->data->port_id,
	      (void *)mr);
	mlx5_mr_rebuild_cache(&sh->share_cache);
	/*
	 * Flush local caches by propagating invalidation across cores.
	 * rte_smp_wmb() is enough to synchronize this event. If one of
	 * freed memsegs is seen by other core, that means the memseg
	 * has been allocated by allocator, which will come after this
	 * free call. Therefore, this store instruction (incrementing
	 * generation below) will be guaranteed to be seen by other core
	 * before the core sees the newly allocated memory.
	 */
	++sh->share_cache.dev_gen;
	DEBUG("broadcasting local cache flush, gen=%d",
	      sh->share_cache.dev_gen);
	rte_smp_wmb();
	rte_rwlock_read_unlock(&sh->share_cache.rwlock);
	return 0;
}

/**
 * Register MR for entire memory chunks in a Mempool having externally allocated
 * memory and fill in local cache.
 *
 * @param dev
 *   Pointer to Ethernet device.
 * @param mr_ctrl
 *   Pointer to per-queue MR control structure.
 * @param mp
 *   Pointer to registering Mempool.
 *
 * @return
 *   0 on success, -1 on failure.
 */
static uint32_t
mlx5_mr_update_ext_mp(struct rte_eth_dev *dev, struct mlx5_mr_ctrl *mr_ctrl,
		      struct rte_mempool *mp)
{
	struct mr_update_mp_data data = {
		.dev = dev,
		.mr_ctrl = mr_ctrl,
		.ret = 0,
	};

	rte_mempool_mem_iter(mp, mlx5_mr_update_ext_mp_cb, &data);
	return data.ret;
}

/**
 * Register MR entire memory chunks in a Mempool having externally allocated
 * memory and search LKey of the address to return.
 *
 * @param dev
 *   Pointer to Ethernet device.
 * @param addr
 *   Search key.
 * @param mp
 *   Pointer to registering Mempool where addr belongs.
 *
 * @return
 *   LKey for address on success, UINT32_MAX on failure.
 */
uint32_t
mlx5_tx_update_ext_mp(struct mlx5_txq_data *txq, uintptr_t addr,
		      struct rte_mempool *mp)
{
	struct mlx5_txq_ctrl *txq_ctrl =
		container_of(txq, struct mlx5_txq_ctrl, txq);
	struct mlx5_mr_ctrl *mr_ctrl = &txq->mr_ctrl;
	struct mlx5_priv *priv = txq_ctrl->priv;

	if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
		DRV_LOG(WARNING,
			"port %u using address (%p) from unregistered mempool"
			" having externally allocated memory"
			" in secondary process, please create mempool"
			" prior to rte_eth_dev_start()",
			PORT_ID(priv), (void *)addr);
		return UINT32_MAX;
	}
	mlx5_mr_update_ext_mp(ETH_DEV(priv), mr_ctrl, mp);
	return mlx5_tx_addr2mr_bh(txq, addr);
}

/* Called during rte_mempool_mem_iter() by mlx5_mr_update_mp(). */
static void
mlx5_mr_update_mp_cb(struct rte_mempool *mp __rte_unused, void *opaque,
		     struct rte_mempool_memhdr *memhdr,
		     unsigned mem_idx __rte_unused)
{
	struct mr_update_mp_data *data = opaque;
	struct rte_eth_dev *dev = data->dev;
	struct mlx5_priv *priv = dev->data->dev_private;

	uint32_t lkey;

	/* Stop iteration if failed in the previous walk. */
	if (data->ret < 0)
		return;
	/* Register address of the chunk and update local caches. */
	lkey = mlx5_mr_addr2mr_bh(priv->sh->pd, &priv->mp_id,
				  &priv->sh->share_cache, data->mr_ctrl,
				  (uintptr_t)memhdr->addr,
				  priv->config.mr_ext_memseg_en);
	if (lkey == UINT32_MAX)
		data->ret = -1;
}

/**
 * Register entire memory chunks in a Mempool.
 *
 * @param dev
 *   Pointer to Ethernet device.
 * @param mr_ctrl
 *   Pointer to per-queue MR control structure.
 * @param mp
 *   Pointer to registering Mempool.
 *
 * @return
 *   0 on success, -1 on failure.
 */
int
mlx5_mr_update_mp(struct rte_eth_dev *dev, struct mlx5_mr_ctrl *mr_ctrl,
		  struct rte_mempool *mp)
{
	struct mr_update_mp_data data = {
		.dev = dev,
		.mr_ctrl = mr_ctrl,
		.ret = 0,
	};

	DRV_LOG(DEBUG, "Port %u Rx queue registering mp %s "
		       "having %u chunks.", dev->data->port_id,
		       mp->name, mp->nb_mem_chunks);
	rte_mempool_mem_iter(mp, mlx5_mr_update_mp_cb, &data);
	if (data.ret < 0 && rte_errno == ENXIO) {
		/* Mempool may have externally allocated memory. */
		return mlx5_mr_update_ext_mp(dev, mr_ctrl, mp);
	}
	return data.ret;
}