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authorYongseok Koh <yskoh@mellanox.com>2018-05-09 04:09:04 -0700
committerFerruh Yigit <ferruh.yigit@intel.com>2018-05-14 22:31:51 +0100
commit974f1e7ef146ffa112ab1a2afaf5db0360bc159f (patch)
treee1f9d27ede46a3fdc973eaa4f2890437d5bf9e14 /drivers/net/mlx5/mlx5_mr.c
parentd561b5dc133fd98ddfa2dde237b1aa1d73e4df76 (diff)
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net/mlx5: add new memory region support
This is the new design of Memory Region (MR) for mlx PMD, in order to: - Accommodate the new memory hotplug model. - Support non-contiguous Mempool. There are multiple layers for MR search. L0 is to look up the last-hit entry which is pointed by mr_ctrl->mru (Most Recently Used). If L0 misses, L1 is to look up the address in a fixed-sized array by linear search. L0/L1 is in an inline function - mlx5_mr_lookup_cache(). If L1 misses, the bottom-half function is called to look up the address from the bigger local cache of the queue. This is L2 - mlx5_mr_addr2mr_bh() and it is not an inline function. Data structure for L2 is the Binary Tree. If L2 misses, the search falls into the slowest path which takes locks in order to access global device cache (priv->mr.cache) which is also a B-tree and caches the original MR list (priv->mr.mr_list) of the device. Unless the global cache is overflowed, it is all-inclusive of the MR list. This is L3 - mlx5_mr_lookup_dev(). The size of the L3 cache table is limited and can't be expanded on the fly due to deadlock. Refer to the comments in the code for the details - mr_lookup_dev(). If L3 is overflowed, the list will have to be searched directly bypassing the cache although it is slower. If L3 misses, a new MR for the address should be created - mlx5_mr_create(). When it creates a new MR, it tries to register adjacent memsegs as much as possible which are virtually contiguous around the address. This must take two locks - memory_hotplug_lock and priv->mr.rwlock. Due to memory_hotplug_lock, there can't be any allocation/free of memory inside. In the free callback of the memory hotplug event, freed space is searched from the MR list and corresponding bits are cleared from the bitmap of MRs. This can fragment a MR and the MR will have multiple search entries in the caches. Once there's a change by the event, the global cache must be rebuilt and all the per-queue caches will be flushed as well. If memory is frequently freed in run-time, that may cause jitter on dataplane processing in the worst case by incurring MR cache flush and rebuild. But, it would be the least probable scenario. To guarantee the most optimal performance, it is highly recommended to use an EAL option - '--socket-mem'. Then, the reserved memory will be pinned and won't be freed dynamically. And it is also recommended to configure per-lcore cache of Mempool. Even though there're many MRs for a device or MRs are highly fragmented, the cache of Mempool will be much helpful to reduce misses on per-queue caches anyway. '--legacy-mem' is also supported. Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
Diffstat (limited to 'drivers/net/mlx5/mlx5_mr.c')
-rw-r--r--drivers/net/mlx5/mlx5_mr.c1174
1 files changed, 1174 insertions, 0 deletions
diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
index 736c40a..abb1f51 100644
--- a/drivers/net/mlx5/mlx5_mr.c
+++ b/drivers/net/mlx5/mlx5_mr.c
@@ -13,8 +13,1182 @@
#include <rte_mempool.h>
#include <rte_malloc.h>
+#include <rte_rwlock.h>
#include "mlx5.h"
+#include "mlx5_mr.h"
#include "mlx5_rxtx.h"
#include "mlx5_glue.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;
+};
+
+/**
+ * Expand B-tree table to a given size. Can't be called with holding
+ * memory_hotplug_lock or priv->mr.rwlock due to rte_realloc().
+ *
+ * @param bt
+ * Pointer to B-tree structure.
+ * @param n
+ * Number of entries for expansion.
+ *
+ * @return
+ * 0 on success, -1 on failure.
+ */
+static int
+mr_btree_expand(struct mlx5_mr_btree *bt, int n)
+{
+ void *mem;
+ int ret = 0;
+
+ if (n <= bt->size)
+ return ret;
+ /*
+ * Downside of directly using rte_realloc() is that SOCKET_ID_ANY is
+ * used inside if there's no room to expand. Because this is a quite
+ * rare case and a part of very slow path, it is very acceptable.
+ * Initially cache_bh[] will be given practically enough space and once
+ * it is expanded, expansion wouldn't be needed again ever.
+ */
+ mem = rte_realloc(bt->table, n * sizeof(struct mlx5_mr_cache), 0);
+ if (mem == NULL) {
+ /* Not an error, B-tree search will be skipped. */
+ DRV_LOG(WARNING, "failed to expand MR B-tree (%p) table",
+ (void *)bt);
+ ret = -1;
+ } else {
+ DRV_LOG(DEBUG, "expanded MR B-tree table (size=%u)", n);
+ bt->table = mem;
+ bt->size = n;
+ }
+ return ret;
+}
+
+/**
+ * Look up LKey from given B-tree lookup table, store the last index and return
+ * searched LKey.
+ *
+ * @param bt
+ * Pointer to B-tree structure.
+ * @param[out] idx
+ * Pointer to index. Even on search failure, returns index where it stops
+ * searching so that index can be used when inserting a new entry.
+ * @param addr
+ * Search key.
+ *
+ * @return
+ * Searched LKey on success, UINT32_MAX on no match.
+ */
+static uint32_t
+mr_btree_lookup(struct mlx5_mr_btree *bt, uint16_t *idx, uintptr_t addr)
+{
+ struct mlx5_mr_cache *lkp_tbl;
+ uint16_t n;
+ uint16_t base = 0;
+
+ assert(bt != NULL);
+ lkp_tbl = *bt->table;
+ n = bt->len;
+ /* First entry must be NULL for comparison. */
+ assert(bt->len > 0 || (lkp_tbl[0].start == 0 &&
+ lkp_tbl[0].lkey == UINT32_MAX));
+ /* Binary search. */
+ do {
+ register uint16_t delta = n >> 1;
+
+ if (addr < lkp_tbl[base + delta].start) {
+ n = delta;
+ } else {
+ base += delta;
+ n -= delta;
+ }
+ } while (n > 1);
+ assert(addr >= lkp_tbl[base].start);
+ *idx = base;
+ if (addr < lkp_tbl[base].end)
+ return lkp_tbl[base].lkey;
+ /* Not found. */
+ return UINT32_MAX;
+}
+
+/**
+ * Insert an entry to B-tree lookup table.
+ *
+ * @param bt
+ * Pointer to B-tree structure.
+ * @param entry
+ * Pointer to new entry to insert.
+ *
+ * @return
+ * 0 on success, -1 on failure.
+ */
+static int
+mr_btree_insert(struct mlx5_mr_btree *bt, struct mlx5_mr_cache *entry)
+{
+ struct mlx5_mr_cache *lkp_tbl;
+ uint16_t idx = 0;
+ size_t shift;
+
+ assert(bt != NULL);
+ assert(bt->len <= bt->size);
+ assert(bt->len > 0);
+ lkp_tbl = *bt->table;
+ /* Find out the slot for insertion. */
+ if (mr_btree_lookup(bt, &idx, entry->start) != UINT32_MAX) {
+ DRV_LOG(DEBUG,
+ "abort insertion to B-tree(%p): already exist at"
+ " idx=%u [0x%" PRIxPTR ", 0x%" PRIxPTR ") lkey=0x%x",
+ (void *)bt, idx, entry->start, entry->end, entry->lkey);
+ /* Already exist, return. */
+ return 0;
+ }
+ /* If table is full, return error. */
+ if (unlikely(bt->len == bt->size)) {
+ bt->overflow = 1;
+ return -1;
+ }
+ /* Insert entry. */
+ ++idx;
+ shift = (bt->len - idx) * sizeof(struct mlx5_mr_cache);
+ if (shift)
+ memmove(&lkp_tbl[idx + 1], &lkp_tbl[idx], shift);
+ lkp_tbl[idx] = *entry;
+ bt->len++;
+ DRV_LOG(DEBUG,
+ "inserted B-tree(%p)[%u],"
+ " [0x%" PRIxPTR ", 0x%" PRIxPTR ") lkey=0x%x",
+ (void *)bt, idx, entry->start, entry->end, entry->lkey);
+ return 0;
+}
+
+/**
+ * Initialize B-tree and allocate memory for lookup table.
+ *
+ * @param bt
+ * Pointer to B-tree structure.
+ * @param n
+ * Number of entries to allocate.
+ * @param socket
+ * NUMA socket on which memory must be allocated.
+ *
+ * @return
+ * 0 on success, a negative errno value otherwise and rte_errno is set.
+ */
+int
+mlx5_mr_btree_init(struct mlx5_mr_btree *bt, int n, int socket)
+{
+ if (bt == NULL) {
+ rte_errno = EINVAL;
+ return -rte_errno;
+ }
+ memset(bt, 0, sizeof(*bt));
+ bt->table = rte_calloc_socket("B-tree table",
+ n, sizeof(struct mlx5_mr_cache),
+ 0, socket);
+ if (bt->table == NULL) {
+ rte_errno = ENOMEM;
+ DRV_LOG(ERR,
+ "failed to allocate memory for btree cache on socket %d",
+ socket);
+ return -rte_errno;
+ }
+ bt->size = n;
+ /* First entry must be NULL for binary search. */
+ (*bt->table)[bt->len++] = (struct mlx5_mr_cache) {
+ .lkey = UINT32_MAX,
+ };
+ DRV_LOG(DEBUG, "initialized B-tree %p with table %p",
+ (void *)bt, (void *)bt->table);
+ return 0;
+}
+
+/**
+ * Free B-tree resources.
+ *
+ * @param bt
+ * Pointer to B-tree structure.
+ */
+void
+mlx5_mr_btree_free(struct mlx5_mr_btree *bt)
+{
+ if (bt == NULL)
+ return;
+ DRV_LOG(DEBUG, "freeing B-tree %p with table %p",
+ (void *)bt, (void *)bt->table);
+ rte_free(bt->table);
+ memset(bt, 0, sizeof(*bt));
+}
+
+/**
+ * Dump all the entries in a B-tree
+ *
+ * @param bt
+ * Pointer to B-tree structure.
+ */
+static void
+mlx5_mr_btree_dump(struct mlx5_mr_btree *bt)
+{
+ int idx;
+ struct mlx5_mr_cache *lkp_tbl;
+
+ if (bt == NULL)
+ return;
+ lkp_tbl = *bt->table;
+ for (idx = 0; idx < bt->len; ++idx) {
+ struct mlx5_mr_cache *entry = &lkp_tbl[idx];
+
+ DRV_LOG(DEBUG,
+ "B-tree(%p)[%u],"
+ " [0x%" PRIxPTR ", 0x%" PRIxPTR ") lkey=0x%x",
+ (void *)bt, idx, entry->start, entry->end, entry->lkey);
+ }
+}
+
+/**
+ * Find virtually contiguous memory chunk in a given MR.
+ *
+ * @param dev
+ * Pointer to MR structure.
+ * @param[out] entry
+ * Pointer to returning MR cache entry. If not found, this will not be
+ * updated.
+ * @param start_idx
+ * Start index of the memseg bitmap.
+ *
+ * @return
+ * Next index to go on lookup.
+ */
+static int
+mr_find_next_chunk(struct mlx5_mr *mr, struct mlx5_mr_cache *entry,
+ int base_idx)
+{
+ uintptr_t start = 0;
+ uintptr_t end = 0;
+ uint32_t idx = 0;
+
+ for (idx = base_idx; idx < mr->ms_bmp_n; ++idx) {
+ if (rte_bitmap_get(mr->ms_bmp, idx)) {
+ const struct rte_memseg_list *msl;
+ const struct rte_memseg *ms;
+
+ msl = mr->msl;
+ ms = rte_fbarray_get(&msl->memseg_arr,
+ mr->ms_base_idx + idx);
+ assert(msl->page_sz == ms->hugepage_sz);
+ if (!start)
+ start = ms->addr_64;
+ end = ms->addr_64 + ms->hugepage_sz;
+ } else if (start) {
+ /* Passed the end of a fragment. */
+ break;
+ }
+ }
+ if (start) {
+ /* Found one chunk. */
+ entry->start = start;
+ entry->end = end;
+ entry->lkey = rte_cpu_to_be_32(mr->ibv_mr->lkey);
+ }
+ return idx;
+}
+
+/**
+ * Insert a MR to the global B-tree cache. It may fail due to low-on-memory.
+ * Then, this entry will have to be searched by mr_lookup_dev_list() in
+ * mlx5_mr_create() on miss.
+ *
+ * @param dev
+ * Pointer to Ethernet device.
+ * @param mr
+ * Pointer to MR to insert.
+ *
+ * @return
+ * 0 on success, -1 on failure.
+ */
+static int
+mr_insert_dev_cache(struct rte_eth_dev *dev, struct mlx5_mr *mr)
+{
+ struct priv *priv = dev->data->dev_private;
+ unsigned int n;
+
+ DRV_LOG(DEBUG, "port %u inserting MR(%p) to global cache",
+ dev->data->port_id, (void *)mr);
+ for (n = 0; n < mr->ms_bmp_n; ) {
+ struct mlx5_mr_cache entry = { 0, };
+
+ /* Find a contiguous chunk and advance the index. */
+ n = mr_find_next_chunk(mr, &entry, n);
+ if (!entry.end)
+ break;
+ if (mr_btree_insert(&priv->mr.cache, &entry) < 0) {
+ /*
+ * Overflowed, but the global table cannot be expanded
+ * because of deadlock.
+ */
+ return -1;
+ }
+ }
+ return 0;
+}
+
+/**
+ * Look up address in the original global MR list.
+ *
+ * @param dev
+ * Pointer to Ethernet device.
+ * @param[out] entry
+ * Pointer to returning MR cache entry. If no match, this will not be updated.
+ * @param addr
+ * Search key.
+ *
+ * @return
+ * Found MR on match, NULL otherwise.
+ */
+static struct mlx5_mr *
+mr_lookup_dev_list(struct rte_eth_dev *dev, struct mlx5_mr_cache *entry,
+ uintptr_t addr)
+{
+ struct priv *priv = dev->data->dev_private;
+ struct mlx5_mr *mr;
+
+ /* Iterate all the existing MRs. */
+ LIST_FOREACH(mr, &priv->mr.mr_list, mr) {
+ unsigned int n;
+
+ if (mr->ms_n == 0)
+ continue;
+ for (n = 0; n < mr->ms_bmp_n; ) {
+ struct mlx5_mr_cache ret = { 0, };
+
+ n = mr_find_next_chunk(mr, &ret, n);
+ if (addr >= ret.start && addr < ret.end) {
+ /* Found. */
+ *entry = ret;
+ return mr;
+ }
+ }
+ }
+ return NULL;
+}
+
+/**
+ * Look up address on device.
+ *
+ * @param dev
+ * Pointer to Ethernet device.
+ * @param[out] entry
+ * Pointer to returning MR cache entry. If no match, this will not be updated.
+ * @param addr
+ * Search key.
+ *
+ * @return
+ * Searched LKey on success, UINT32_MAX on failure and rte_errno is set.
+ */
+static uint32_t
+mr_lookup_dev(struct rte_eth_dev *dev, struct mlx5_mr_cache *entry,
+ uintptr_t addr)
+{
+ struct priv *priv = dev->data->dev_private;
+ uint16_t idx;
+ uint32_t lkey = UINT32_MAX;
+ struct mlx5_mr *mr;
+
+ /*
+ * If the global cache has overflowed since it failed to expand the
+ * B-tree table, it can't have all the existing MRs. Then, the address
+ * has to be searched by traversing the original MR list instead, which
+ * is very slow path. Otherwise, the global cache is all inclusive.
+ */
+ if (!unlikely(priv->mr.cache.overflow)) {
+ lkey = mr_btree_lookup(&priv->mr.cache, &idx, addr);
+ if (lkey != UINT32_MAX)
+ *entry = (*priv->mr.cache.table)[idx];
+ } else {
+ /* Falling back to the slowest path. */
+ mr = mr_lookup_dev_list(dev, entry, addr);
+ if (mr != NULL)
+ lkey = entry->lkey;
+ }
+ assert(lkey == UINT32_MAX || (addr >= entry->start &&
+ addr < entry->end));
+ return lkey;
+}
+
+/**
+ * Free MR resources. MR lock must not be held to avoid a deadlock. rte_free()
+ * can raise memory free event and the callback function will spin on the lock.
+ *
+ * @param mr
+ * Pointer to MR to free.
+ */
+static void
+mr_free(struct mlx5_mr *mr)
+{
+ if (mr == NULL)
+ return;
+ DRV_LOG(DEBUG, "freeing MR(%p):", (void *)mr);
+ if (mr->ibv_mr != NULL)
+ claim_zero(mlx5_glue->dereg_mr(mr->ibv_mr));
+ if (mr->ms_bmp != NULL)
+ rte_bitmap_free(mr->ms_bmp);
+ rte_free(mr);
+}
+
+/**
+ * Releass resources of detached MR having no online entry.
+ *
+ * @param dev
+ * Pointer to Ethernet device.
+ */
+static void
+mlx5_mr_garbage_collect(struct rte_eth_dev *dev)
+{
+ struct priv *priv = dev->data->dev_private;
+ struct mlx5_mr *mr_next;
+ struct mlx5_mr_list free_list = LIST_HEAD_INITIALIZER(free_list);
+
+ /* Must be called from the primary process. */
+ assert(rte_eal_process_type() == RTE_PROC_PRIMARY);
+ /*
+ * MR can't be freed with holding the lock because rte_free() could call
+ * memory free callback function. This will be a deadlock situation.
+ */
+ rte_rwlock_write_lock(&priv->mr.rwlock);
+ /* Detach the whole free list and release it after unlocking. */
+ free_list = priv->mr.mr_free_list;
+ LIST_INIT(&priv->mr.mr_free_list);
+ rte_rwlock_write_unlock(&priv->mr.rwlock);
+ /* Release resources. */
+ mr_next = LIST_FIRST(&free_list);
+ while (mr_next != NULL) {
+ struct mlx5_mr *mr = mr_next;
+
+ mr_next = LIST_NEXT(mr, mr);
+ mr_free(mr);
+ }
+}
+
+/* Called during rte_memseg_contig_walk() by mlx5_mr_create(). */
+static int
+mr_find_contig_memsegs_cb(const struct rte_memseg_list *msl,
+ const struct rte_memseg *ms, size_t len, void *arg)
+{
+ struct mr_find_contig_memsegs_data *data = arg;
+
+ if (data->addr < ms->addr_64 || data->addr >= ms->addr_64 + len)
+ return 0;
+ /* Found, save it and stop walking. */
+ data->start = ms->addr_64;
+ data->end = ms->addr_64 + len;
+ data->msl = msl;
+ return 1;
+}
+
+/**
+ * Create a new global Memroy Region (MR) for a missing virtual address.
+ * Register entire virtually contiguous memory chunk around the address.
+ *
+ * @param dev
+ * Pointer to Ethernet device.
+ * @param[out] entry
+ * Pointer to returning MR cache entry, found in the global cache or newly
+ * created. If failed to create one, this will not be updated.
+ * @param addr
+ * Target virtual address to register.
+ *
+ * @return
+ * Searched LKey on success, UINT32_MAX on failure and rte_errno is set.
+ */
+static uint32_t
+mlx5_mr_create(struct rte_eth_dev *dev, struct mlx5_mr_cache *entry,
+ uintptr_t addr)
+{
+ struct priv *priv = dev->data->dev_private;
+ struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
+ const struct rte_memseg_list *msl;
+ const struct rte_memseg *ms;
+ struct mlx5_mr *mr = NULL;
+ size_t len;
+ uint32_t ms_n;
+ uint32_t bmp_size;
+ void *bmp_mem;
+ int ms_idx_shift = -1;
+ unsigned int n;
+ struct mr_find_contig_memsegs_data data = {
+ .addr = addr,
+ };
+ struct mr_find_contig_memsegs_data data_re;
+
+ DRV_LOG(DEBUG, "port %u creating a MR using address (%p)",
+ dev->data->port_id, (void *)addr);
+ if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
+ DRV_LOG(WARNING,
+ "port %u using address (%p) of unregistered mempool"
+ " in secondary process, please create mempool"
+ " before rte_eth_dev_start()",
+ dev->data->port_id, (void *)addr);
+ rte_errno = EPERM;
+ goto err_nolock;
+ }
+ /*
+ * Release detached MRs if any. This can't be called with holding either
+ * memory_hotplug_lock or priv->mr.rwlock. MRs on the free list have
+ * been detached by the memory free event but it couldn't be released
+ * inside the callback due to deadlock. As a result, releasing resources
+ * is quite opportunistic.
+ */
+ mlx5_mr_garbage_collect(dev);
+ /*
+ * Find out a contiguous virtual address chunk in use, to which the
+ * given address belongs, in order to register maximum range. In the
+ * best case where mempools are not dynamically recreated and
+ * '--socket-mem' is speicified as an EAL option, it is very likely to
+ * have only one MR(LKey) per a socket and per a hugepage-size even
+ * though the system memory is highly fragmented.
+ */
+ if (!rte_memseg_contig_walk(mr_find_contig_memsegs_cb, &data)) {
+ DRV_LOG(WARNING,
+ "port %u unable to find virtually contiguous"
+ " chunk for address (%p)."
+ " rte_memseg_contig_walk() failed.",
+ dev->data->port_id, (void *)addr);
+ rte_errno = ENXIO;
+ goto err_nolock;
+ }
+alloc_resources:
+ /* Addresses must be page-aligned. */
+ assert(rte_is_aligned((void *)data.start, data.msl->page_sz));
+ assert(rte_is_aligned((void *)data.end, data.msl->page_sz));
+ msl = data.msl;
+ ms = rte_mem_virt2memseg((void *)data.start, msl);
+ len = data.end - data.start;
+ assert(msl->page_sz == ms->hugepage_sz);
+ /* Number of memsegs in the range. */
+ ms_n = len / msl->page_sz;
+ DRV_LOG(DEBUG,
+ "port %u extending %p to [0x%" PRIxPTR ", 0x%" PRIxPTR "),"
+ " page_sz=0x%" PRIx64 ", ms_n=%u",
+ dev->data->port_id, (void *)addr,
+ data.start, data.end, msl->page_sz, ms_n);
+ /* Size of memory for bitmap. */
+ bmp_size = rte_bitmap_get_memory_footprint(ms_n);
+ mr = rte_zmalloc_socket(NULL,
+ RTE_ALIGN_CEIL(sizeof(*mr),
+ RTE_CACHE_LINE_SIZE) +
+ bmp_size,
+ RTE_CACHE_LINE_SIZE, msl->socket_id);
+ if (mr == NULL) {
+ DRV_LOG(WARNING,
+ "port %u unable to allocate memory for a new MR of"
+ " address (%p).",
+ dev->data->port_id, (void *)addr);
+ rte_errno = ENOMEM;
+ goto err_nolock;
+ }
+ mr->msl = msl;
+ /*
+ * Save the index of the first memseg and initialize memseg bitmap. To
+ * see if a memseg of ms_idx in the memseg-list is still valid, check:
+ * rte_bitmap_get(mr->bmp, ms_idx - mr->ms_base_idx)
+ */
+ mr->ms_base_idx = rte_fbarray_find_idx(&msl->memseg_arr, ms);
+ bmp_mem = RTE_PTR_ALIGN_CEIL(mr + 1, RTE_CACHE_LINE_SIZE);
+ mr->ms_bmp = rte_bitmap_init(ms_n, bmp_mem, bmp_size);
+ if (mr->ms_bmp == NULL) {
+ DRV_LOG(WARNING,
+ "port %u unable to initialize bitamp for a new MR of"
+ " address (%p).",
+ dev->data->port_id, (void *)addr);
+ rte_errno = EINVAL;
+ goto err_nolock;
+ }
+ /*
+ * Should recheck whether the extended contiguous chunk is still valid.
+ * Because memory_hotplug_lock can't be held if there's any memory
+ * related calls in a critical path, resource allocation above can't be
+ * locked. If the memory has been changed at this point, try again with
+ * just single page. If not, go on with the big chunk atomically from
+ * here.
+ */
+ rte_rwlock_read_lock(&mcfg->memory_hotplug_lock);
+ data_re = data;
+ if (len > msl->page_sz &&
+ !rte_memseg_contig_walk(mr_find_contig_memsegs_cb, &data_re)) {
+ DRV_LOG(WARNING,
+ "port %u unable to find virtually contiguous"
+ " chunk for address (%p)."
+ " rte_memseg_contig_walk() failed.",
+ dev->data->port_id, (void *)addr);
+ rte_errno = ENXIO;
+ goto err_memlock;
+ }
+ if (data.start != data_re.start || data.end != data_re.end) {
+ /*
+ * The extended contiguous chunk has been changed. Try again
+ * with single memseg instead.
+ */
+ data.start = RTE_ALIGN_FLOOR(addr, msl->page_sz);
+ data.end = data.start + msl->page_sz;
+ rte_rwlock_read_unlock(&mcfg->memory_hotplug_lock);
+ mr_free(mr);
+ goto alloc_resources;
+ }
+ assert(data.msl == data_re.msl);
+ rte_rwlock_write_lock(&priv->mr.rwlock);
+ /*
+ * Check the address is really missing. If other thread already created
+ * one or it is not found due to overflow, abort and return.
+ */
+ if (mr_lookup_dev(dev, entry, addr) != UINT32_MAX) {
+ /*
+ * Insert to the global cache table. It may fail due to
+ * low-on-memory. Then, this entry will have to be searched
+ * here again.
+ */
+ mr_btree_insert(&priv->mr.cache, entry);
+ DRV_LOG(DEBUG,
+ "port %u found MR for %p on final lookup, abort",
+ dev->data->port_id, (void *)addr);
+ rte_rwlock_write_unlock(&priv->mr.rwlock);
+ rte_rwlock_read_unlock(&mcfg->memory_hotplug_lock);
+ /*
+ * Must be unlocked before calling rte_free() because
+ * mlx5_mr_mem_event_free_cb() can be called inside.
+ */
+ mr_free(mr);
+ return entry->lkey;
+ }
+ /*
+ * Trim start and end addresses for verbs MR. Set bits for registering
+ * memsegs but exclude already registered ones. Bitmap can be
+ * fragmented.
+ */
+ for (n = 0; n < ms_n; ++n) {
+ uintptr_t start;
+ struct mlx5_mr_cache ret = { 0, };
+
+ start = data_re.start + n * msl->page_sz;
+ /* Exclude memsegs already registered by other MRs. */
+ if (mr_lookup_dev(dev, &ret, start) == UINT32_MAX) {
+ /*
+ * Start from the first unregistered memseg in the
+ * extended range.
+ */
+ if (ms_idx_shift == -1) {
+ mr->ms_base_idx += n;
+ data.start = start;
+ ms_idx_shift = n;
+ }
+ data.end = start + msl->page_sz;
+ rte_bitmap_set(mr->ms_bmp, n - ms_idx_shift);
+ ++mr->ms_n;
+ }
+ }
+ len = data.end - data.start;
+ mr->ms_bmp_n = len / msl->page_sz;
+ assert(ms_idx_shift + mr->ms_bmp_n <= ms_n);
+ /*
+ * Finally create a verbs MR for the memory chunk. ibv_reg_mr() can be
+ * called with holding the memory lock because it doesn't use
+ * mlx5_alloc_buf_extern() which eventually calls rte_malloc_socket()
+ * through mlx5_alloc_verbs_buf().
+ */
+ mr->ibv_mr = mlx5_glue->reg_mr(priv->pd, (void *)data.start, len,
+ IBV_ACCESS_LOCAL_WRITE);
+ if (mr->ibv_mr == NULL) {
+ DRV_LOG(WARNING,
+ "port %u fail to create a verbs MR for address (%p)",
+ dev->data->port_id, (void *)addr);
+ rte_errno = EINVAL;
+ goto err_mrlock;
+ }
+ assert((uintptr_t)mr->ibv_mr->addr == data.start);
+ assert(mr->ibv_mr->length == len);
+ LIST_INSERT_HEAD(&priv->mr.mr_list, mr, mr);
+ DRV_LOG(DEBUG,
+ "port %u MR CREATED (%p) for %p:\n"
+ " [0x%" PRIxPTR ", 0x%" PRIxPTR "),"
+ " lkey=0x%x base_idx=%u ms_n=%u, ms_bmp_n=%u",
+ dev->data->port_id, (void *)mr, (void *)addr,
+ data.start, data.end, rte_cpu_to_be_32(mr->ibv_mr->lkey),
+ mr->ms_base_idx, mr->ms_n, mr->ms_bmp_n);
+ /* Insert to the global cache table. */
+ mr_insert_dev_cache(dev, mr);
+ /* Fill in output data. */
+ mr_lookup_dev(dev, entry, addr);
+ /* Lookup can't fail. */
+ assert(entry->lkey != UINT32_MAX);
+ rte_rwlock_write_unlock(&priv->mr.rwlock);
+ rte_rwlock_read_unlock(&mcfg->memory_hotplug_lock);
+ return entry->lkey;
+err_mrlock:
+ rte_rwlock_write_unlock(&priv->mr.rwlock);
+err_memlock:
+ rte_rwlock_read_unlock(&mcfg->memory_hotplug_lock);
+err_nolock:
+ /*
+ * In case of error, as this can be called in a datapath, a warning
+ * message per an error is preferable instead. Must be unlocked before
+ * calling rte_free() because mlx5_mr_mem_event_free_cb() can be called
+ * inside.
+ */
+ mr_free(mr);
+ return UINT32_MAX;
+}
+
+/**
+ * Rebuild the global B-tree cache of device from the original MR list.
+ *
+ * @param dev
+ * Pointer to Ethernet device.
+ */
+static void
+mr_rebuild_dev_cache(struct rte_eth_dev *dev)
+{
+ struct priv *priv = dev->data->dev_private;
+ struct mlx5_mr *mr;
+
+ DRV_LOG(DEBUG, "port %u rebuild dev cache[]", dev->data->port_id);
+ /* Flush cache to rebuild. */
+ priv->mr.cache.len = 1;
+ priv->mr.cache.overflow = 0;
+ /* Iterate all the existing MRs. */
+ LIST_FOREACH(mr, &priv->mr.mr_list, mr)
+ if (mr_insert_dev_cache(dev, mr) < 0)
+ return;
+}
+
+/**
+ * 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 dev
+ * Pointer to Ethernet device.
+ * @param addr
+ * Address of freed memory.
+ * @param len
+ * Size of freed memory.
+ */
+static void
+mlx5_mr_mem_event_free_cb(struct rte_eth_dev *dev, const void *addr, size_t len)
+{
+ struct priv *priv = dev->data->dev_private;
+ const struct rte_memseg_list *msl;
+ struct mlx5_mr *mr;
+ int ms_n;
+ int i;
+ int rebuild = 0;
+
+ DRV_LOG(DEBUG, "port %u free callback: addr=%p, len=%zu",
+ dev->data->port_id, addr, len);
+ msl = rte_mem_virt2memseg_list(addr);
+ /* addr and len must be page-aligned. */
+ assert((uintptr_t)addr == RTE_ALIGN((uintptr_t)addr, msl->page_sz));
+ assert(len == RTE_ALIGN(len, msl->page_sz));
+ ms_n = len / msl->page_sz;
+ rte_rwlock_write_lock(&priv->mr.rwlock);
+ /* Clear bits of freed memsegs from MR. */
+ for (i = 0; i < ms_n; ++i) {
+ const struct rte_memseg *ms;
+ struct mlx5_mr_cache entry;
+ uintptr_t start;
+ int ms_idx;
+ uint32_t pos;
+
+ /* Find MR having this memseg. */
+ start = (uintptr_t)addr + i * msl->page_sz;
+ mr = mr_lookup_dev_list(dev, &entry, start);
+ if (mr == NULL)
+ continue;
+ ms = rte_mem_virt2memseg((void *)start, msl);
+ assert(ms != NULL);
+ assert(msl->page_sz == ms->hugepage_sz);
+ ms_idx = rte_fbarray_find_idx(&msl->memseg_arr, ms);
+ pos = ms_idx - mr->ms_base_idx;
+ assert(rte_bitmap_get(mr->ms_bmp, pos));
+ assert(pos < mr->ms_bmp_n);
+ DRV_LOG(DEBUG, "port %u MR(%p): clear bitmap[%u] for addr %p",
+ dev->data->port_id, (void *)mr, pos, (void *)start);
+ rte_bitmap_clear(mr->ms_bmp, pos);
+ if (--mr->ms_n == 0) {
+ LIST_REMOVE(mr, mr);
+ LIST_INSERT_HEAD(&priv->mr.mr_free_list, mr, mr);
+ DRV_LOG(DEBUG, "port %u remove MR(%p) from list",
+ dev->data->port_id, (void *)mr);
+ }
+ /*
+ * MR is fragmented or will be freed. the global cache must be
+ * rebuilt.
+ */
+ rebuild = 1;
+ }
+ if (rebuild) {
+ mr_rebuild_dev_cache(dev);
+ /*
+ * 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.
+ */
+ ++priv->mr.dev_gen;
+ DRV_LOG(DEBUG, "broadcasting local cache flush, gen=%d",
+ priv->mr.dev_gen);
+ rte_smp_wmb();
+ }
+ rte_rwlock_write_unlock(&priv->mr.rwlock);
+ if (rebuild && rte_log_get_level(mlx5_logtype) == RTE_LOG_DEBUG)
+ mlx5_mr_dump_dev(dev);
+}
+
+/**
+ * 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 priv *priv;
+ struct mlx5_dev_list *dev_list = &mlx5_shared_data->mem_event_cb_list;
+
+ 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(priv, dev_list, mem_event_cb)
+ mlx5_mr_mem_event_free_cb(ETH_DEV(priv), addr, len);
+ rte_rwlock_write_unlock(&mlx5_shared_data->mem_event_rwlock);
+ break;
+ case RTE_MEM_EVENT_ALLOC:
+ default:
+ break;
+ }
+}
+
+/**
+ * Look up address in the global MR cache table. If not found, create a new MR.
+ * Insert the found/created entry to local bottom-half cache table.
+ *
+ * @param dev
+ * Pointer to Ethernet device.
+ * @param mr_ctrl
+ * Pointer to per-queue MR control structure.
+ * @param[out] entry
+ * Pointer to returning MR cache entry, found in the global cache or newly
+ * created. If failed to create one, this is not written.
+ * @param addr
+ * Search key.
+ *
+ * @return
+ * Searched LKey on success, UINT32_MAX on no match.
+ */
+static uint32_t
+mlx5_mr_lookup_dev(struct rte_eth_dev *dev, struct mlx5_mr_ctrl *mr_ctrl,
+ struct mlx5_mr_cache *entry, uintptr_t addr)
+{
+ struct priv *priv = dev->data->dev_private;
+ struct mlx5_mr_btree *bt = &mr_ctrl->cache_bh;
+ uint16_t idx;
+ uint32_t lkey;
+
+ /* If local cache table is full, try to double it. */
+ if (unlikely(bt->len == bt->size))
+ mr_btree_expand(bt, bt->size << 1);
+ /* Look up in the global cache. */
+ rte_rwlock_read_lock(&priv->mr.rwlock);
+ lkey = mr_btree_lookup(&priv->mr.cache, &idx, addr);
+ if (lkey != UINT32_MAX) {
+ /* Found. */
+ *entry = (*priv->mr.cache.table)[idx];
+ rte_rwlock_read_unlock(&priv->mr.rwlock);
+ /*
+ * Update local cache. Even if it fails, return the found entry
+ * to update top-half cache. Next time, this entry will be found
+ * in the global cache.
+ */
+ mr_btree_insert(bt, entry);
+ return lkey;
+ }
+ rte_rwlock_read_unlock(&priv->mr.rwlock);
+ /* First time to see the address? Create a new MR. */
+ lkey = mlx5_mr_create(dev, entry, addr);
+ /*
+ * Update the local cache if successfully created a new global MR. Even
+ * if failed to create one, there's no action to take in this datapath
+ * code. As returning LKey is invalid, this will eventually make HW
+ * fail.
+ */
+ if (lkey != UINT32_MAX)
+ mr_btree_insert(bt, entry);
+ return lkey;
+}
+
+/**
+ * Bottom-half of LKey search on datapath. Firstly search in cache_bh[] and if
+ * misses, search in the global MR cache table and update the new entry to
+ * per-queue local caches.
+ *
+ * @param dev
+ * Pointer to Ethernet device.
+ * @param mr_ctrl
+ * Pointer to per-queue MR control structure.
+ * @param addr
+ * Search key.
+ *
+ * @return
+ * Searched LKey on success, UINT32_MAX on no match.
+ */
+static uint32_t
+mlx5_mr_addr2mr_bh(struct rte_eth_dev *dev, struct mlx5_mr_ctrl *mr_ctrl,
+ uintptr_t addr)
+{
+ uint32_t lkey;
+ uint16_t bh_idx = 0;
+ /* Victim in top-half cache to replace with new entry. */
+ struct mlx5_mr_cache *repl = &mr_ctrl->cache[mr_ctrl->head];
+
+ /* Binary-search MR translation table. */
+ lkey = mr_btree_lookup(&mr_ctrl->cache_bh, &bh_idx, addr);
+ /* Update top-half cache. */
+ if (likely(lkey != UINT32_MAX)) {
+ *repl = (*mr_ctrl->cache_bh.table)[bh_idx];
+ } else {
+ /*
+ * If missed in local lookup table, search in the global cache
+ * and local cache_bh[] will be updated inside if possible.
+ * Top-half cache entry will also be updated.
+ */
+ lkey = mlx5_mr_lookup_dev(dev, mr_ctrl, repl, addr);
+ if (unlikely(lkey == UINT32_MAX))
+ return UINT32_MAX;
+ }
+ /* Update the most recently used entry. */
+ mr_ctrl->mru = mr_ctrl->head;
+ /* Point to the next victim, the oldest. */
+ mr_ctrl->head = (mr_ctrl->head + 1) % MLX5_MR_CACHE_N;
+ return lkey;
+}
+
+/**
+ * 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 priv *priv = rxq_ctrl->priv;
+
+ DRV_LOG(DEBUG,
+ "Rx queue %u: miss on top-half, mru=%u, head=%u, addr=%p",
+ rxq_ctrl->idx, mr_ctrl->mru, mr_ctrl->head, (void *)addr);
+ return mlx5_mr_addr2mr_bh(ETH_DEV(priv), mr_ctrl, addr);
+}
+
+/**
+ * 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.
+ */
+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 priv *priv = txq_ctrl->priv;
+
+ DRV_LOG(DEBUG,
+ "Tx queue %u: miss on top-half, mru=%u, head=%u, addr=%p",
+ txq_ctrl->idx, mr_ctrl->mru, mr_ctrl->head, (void *)addr);
+ return mlx5_mr_addr2mr_bh(ETH_DEV(priv), mr_ctrl, addr);
+}
+
+/**
+ * Flush all of the local cache entries.
+ *
+ * @param mr_ctrl
+ * Pointer to per-queue MR control structure.
+ */
+void
+mlx5_mr_flush_local_cache(struct mlx5_mr_ctrl *mr_ctrl)
+{
+ /* Reset the most-recently-used index. */
+ mr_ctrl->mru = 0;
+ /* Reset the linear search array. */
+ mr_ctrl->head = 0;
+ memset(mr_ctrl->cache, 0, sizeof(mr_ctrl->cache));
+ /* Reset the B-tree table. */
+ mr_ctrl->cache_bh.len = 1;
+ mr_ctrl->cache_bh.overflow = 0;
+ /* Update the generation number. */
+ mr_ctrl->cur_gen = *mr_ctrl->dev_gen_ptr;
+ DRV_LOG(DEBUG, "mr_ctrl(%p): flushed, cur_gen=%d",
+ (void *)mr_ctrl, mr_ctrl->cur_gen);
+}
+
+/* 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;
+ 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(data->dev, data->mr_ctrl,
+ (uintptr_t)memhdr->addr);
+ 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,
+ };
+
+ rte_mempool_mem_iter(mp, mlx5_mr_update_mp_cb, &data);
+ return data.ret;
+}
+
+/**
+ * Dump all the created MRs and the global cache entries.
+ *
+ * @param dev
+ * Pointer to Ethernet device.
+ */
+void
+mlx5_mr_dump_dev(struct rte_eth_dev *dev)
+{
+ struct priv *priv = dev->data->dev_private;
+ struct mlx5_mr *mr;
+ int mr_n = 0;
+ int chunk_n = 0;
+
+ rte_rwlock_read_lock(&priv->mr.rwlock);
+ /* Iterate all the existing MRs. */
+ LIST_FOREACH(mr, &priv->mr.mr_list, mr) {
+ unsigned int n;
+
+ DRV_LOG(DEBUG,
+ "port %u MR[%u], LKey = 0x%x, ms_n = %u, ms_bmp_n = %u",
+ dev->data->port_id, mr_n++,
+ rte_cpu_to_be_32(mr->ibv_mr->lkey),
+ mr->ms_n, mr->ms_bmp_n);
+ if (mr->ms_n == 0)
+ continue;
+ for (n = 0; n < mr->ms_bmp_n; ) {
+ struct mlx5_mr_cache ret = { 0, };
+
+ n = mr_find_next_chunk(mr, &ret, n);
+ if (!ret.end)
+ break;
+ DRV_LOG(DEBUG,
+ " chunk[%u], [0x%" PRIxPTR ", 0x%" PRIxPTR ")",
+ chunk_n++, ret.start, ret.end);
+ }
+ }
+ DRV_LOG(DEBUG, "port %u dumping global cache", dev->data->port_id);
+ mlx5_mr_btree_dump(&priv->mr.cache);
+ rte_rwlock_read_unlock(&priv->mr.rwlock);
+}
+
+/**
+ * Release all the created MRs and resources. Remove device from memory callback
+ * list.
+ *
+ * @param dev
+ * Pointer to Ethernet device.
+ */
+void
+mlx5_mr_release(struct rte_eth_dev *dev)
+{
+ struct priv *priv = dev->data->dev_private;
+ struct mlx5_mr *mr_next = LIST_FIRST(&priv->mr.mr_list);
+
+ /* Remove from memory callback device list. */
+ rte_rwlock_write_lock(&mlx5_shared_data->mem_event_rwlock);
+ LIST_REMOVE(priv, mem_event_cb);
+ rte_rwlock_write_unlock(&mlx5_shared_data->mem_event_rwlock);
+ if (rte_log_get_level(mlx5_logtype) == RTE_LOG_DEBUG)
+ mlx5_mr_dump_dev(dev);
+ rte_rwlock_write_lock(&priv->mr.rwlock);
+ /* Detach from MR list and move to free list. */
+ while (mr_next != NULL) {
+ struct mlx5_mr *mr = mr_next;
+
+ mr_next = LIST_NEXT(mr, mr);
+ LIST_REMOVE(mr, mr);
+ LIST_INSERT_HEAD(&priv->mr.mr_free_list, mr, mr);
+ }
+ LIST_INIT(&priv->mr.mr_list);
+ /* Free global cache. */
+ mlx5_mr_btree_free(&priv->mr.cache);
+ rte_rwlock_write_unlock(&priv->mr.rwlock);
+ /* Free all remaining MRs. */
+ mlx5_mr_garbage_collect(dev);
+}