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Diffstat (limited to 'lib/librte_eal/common/eal_common_fbarray.c')
-rw-r--r--lib/librte_eal/common/eal_common_fbarray.c879
1 files changed, 879 insertions, 0 deletions
diff --git a/lib/librte_eal/common/eal_common_fbarray.c b/lib/librte_eal/common/eal_common_fbarray.c
new file mode 100644
index 00000000..019f84c1
--- /dev/null
+++ b/lib/librte_eal/common/eal_common_fbarray.c
@@ -0,0 +1,879 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2017-2018 Intel Corporation
+ */
+
+#include <inttypes.h>
+#include <limits.h>
+#include <sys/mman.h>
+#include <stdint.h>
+#include <errno.h>
+#include <sys/file.h>
+#include <string.h>
+
+#include <rte_common.h>
+#include <rte_log.h>
+#include <rte_errno.h>
+#include <rte_spinlock.h>
+#include <rte_tailq.h>
+
+#include "eal_filesystem.h"
+#include "eal_private.h"
+
+#include "rte_fbarray.h"
+
+#define MASK_SHIFT 6ULL
+#define MASK_ALIGN (1ULL << MASK_SHIFT)
+#define MASK_LEN_TO_IDX(x) ((x) >> MASK_SHIFT)
+#define MASK_LEN_TO_MOD(x) ((x) - RTE_ALIGN_FLOOR(x, MASK_ALIGN))
+#define MASK_GET_IDX(idx, mod) ((idx << MASK_SHIFT) + mod)
+
+/*
+ * This is a mask that is always stored at the end of array, to provide fast
+ * way of finding free/used spots without looping through each element.
+ */
+
+struct used_mask {
+ unsigned int n_masks;
+ uint64_t data[];
+};
+
+static size_t
+calc_mask_size(unsigned int len)
+{
+ /* mask must be multiple of MASK_ALIGN, even though length of array
+ * itself may not be aligned on that boundary.
+ */
+ len = RTE_ALIGN_CEIL(len, MASK_ALIGN);
+ return sizeof(struct used_mask) +
+ sizeof(uint64_t) * MASK_LEN_TO_IDX(len);
+}
+
+static size_t
+calc_data_size(size_t page_sz, unsigned int elt_sz, unsigned int len)
+{
+ size_t data_sz = elt_sz * len;
+ size_t msk_sz = calc_mask_size(len);
+ return RTE_ALIGN_CEIL(data_sz + msk_sz, page_sz);
+}
+
+static struct used_mask *
+get_used_mask(void *data, unsigned int elt_sz, unsigned int len)
+{
+ return (struct used_mask *) RTE_PTR_ADD(data, elt_sz * len);
+}
+
+static int
+resize_and_map(int fd, void *addr, size_t len)
+{
+ char path[PATH_MAX];
+ void *map_addr;
+
+ if (ftruncate(fd, len)) {
+ RTE_LOG(ERR, EAL, "Cannot truncate %s\n", path);
+ /* pass errno up the chain */
+ rte_errno = errno;
+ return -1;
+ }
+
+ map_addr = mmap(addr, len, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_FIXED, fd, 0);
+ if (map_addr != addr) {
+ RTE_LOG(ERR, EAL, "mmap() failed: %s\n", strerror(errno));
+ /* pass errno up the chain */
+ rte_errno = errno;
+ return -1;
+ }
+ return 0;
+}
+
+static int
+find_next_n(const struct rte_fbarray *arr, unsigned int start, unsigned int n,
+ bool used)
+{
+ const struct used_mask *msk = get_used_mask(arr->data, arr->elt_sz,
+ arr->len);
+ unsigned int msk_idx, lookahead_idx, first, first_mod;
+ unsigned int last, last_mod;
+ uint64_t last_msk, ignore_msk;
+
+ /*
+ * mask only has granularity of MASK_ALIGN, but start may not be aligned
+ * on that boundary, so construct a special mask to exclude anything we
+ * don't want to see to avoid confusing ctz.
+ */
+ first = MASK_LEN_TO_IDX(start);
+ first_mod = MASK_LEN_TO_MOD(start);
+ ignore_msk = ~((1ULL << first_mod) - 1);
+
+ /* array length may not be aligned, so calculate ignore mask for last
+ * mask index.
+ */
+ last = MASK_LEN_TO_IDX(arr->len);
+ last_mod = MASK_LEN_TO_MOD(arr->len);
+ last_msk = ~(-1ULL << last_mod);
+
+ for (msk_idx = first; msk_idx < msk->n_masks; msk_idx++) {
+ uint64_t cur_msk, lookahead_msk;
+ unsigned int run_start, clz, left;
+ bool found = false;
+ /*
+ * The process of getting n consecutive bits for arbitrary n is
+ * a bit involved, but here it is in a nutshell:
+ *
+ * 1. let n be the number of consecutive bits we're looking for
+ * 2. check if n can fit in one mask, and if so, do n-1
+ * rshift-ands to see if there is an appropriate run inside
+ * our current mask
+ * 2a. if we found a run, bail out early
+ * 2b. if we didn't find a run, proceed
+ * 3. invert the mask and count leading zeroes (that is, count
+ * how many consecutive set bits we had starting from the
+ * end of current mask) as k
+ * 3a. if k is 0, continue to next mask
+ * 3b. if k is not 0, we have a potential run
+ * 4. to satisfy our requirements, next mask must have n-k
+ * consecutive set bits right at the start, so we will do
+ * (n-k-1) rshift-ands and check if first bit is set.
+ *
+ * Step 4 will need to be repeated if (n-k) > MASK_ALIGN until
+ * we either run out of masks, lose the run, or find what we
+ * were looking for.
+ */
+ cur_msk = msk->data[msk_idx];
+ left = n;
+
+ /* if we're looking for free spaces, invert the mask */
+ if (!used)
+ cur_msk = ~cur_msk;
+
+ /* combine current ignore mask with last index ignore mask */
+ if (msk_idx == last)
+ ignore_msk |= last_msk;
+
+ /* if we have an ignore mask, ignore once */
+ if (ignore_msk) {
+ cur_msk &= ignore_msk;
+ ignore_msk = 0;
+ }
+
+ /* if n can fit in within a single mask, do a search */
+ if (n <= MASK_ALIGN) {
+ uint64_t tmp_msk = cur_msk;
+ unsigned int s_idx;
+ for (s_idx = 0; s_idx < n - 1; s_idx++)
+ tmp_msk &= tmp_msk >> 1ULL;
+ /* we found what we were looking for */
+ if (tmp_msk != 0) {
+ run_start = __builtin_ctzll(tmp_msk);
+ return MASK_GET_IDX(msk_idx, run_start);
+ }
+ }
+
+ /*
+ * we didn't find our run within the mask, or n > MASK_ALIGN,
+ * so we're going for plan B.
+ */
+
+ /* count leading zeroes on inverted mask */
+ if (~cur_msk == 0)
+ clz = sizeof(cur_msk) * 8;
+ else
+ clz = __builtin_clzll(~cur_msk);
+
+ /* if there aren't any runs at the end either, just continue */
+ if (clz == 0)
+ continue;
+
+ /* we have a partial run at the end, so try looking ahead */
+ run_start = MASK_ALIGN - clz;
+ left -= clz;
+
+ for (lookahead_idx = msk_idx + 1; lookahead_idx < msk->n_masks;
+ lookahead_idx++) {
+ unsigned int s_idx, need;
+ lookahead_msk = msk->data[lookahead_idx];
+
+ /* if we're looking for free space, invert the mask */
+ if (!used)
+ lookahead_msk = ~lookahead_msk;
+
+ /* figure out how many consecutive bits we need here */
+ need = RTE_MIN(left, MASK_ALIGN);
+
+ for (s_idx = 0; s_idx < need - 1; s_idx++)
+ lookahead_msk &= lookahead_msk >> 1ULL;
+
+ /* if first bit is not set, we've lost the run */
+ if ((lookahead_msk & 1) == 0) {
+ /*
+ * we've scanned this far, so we know there are
+ * no runs in the space we've lookahead-scanned
+ * as well, so skip that on next iteration.
+ */
+ ignore_msk = ~((1ULL << need) - 1);
+ msk_idx = lookahead_idx;
+ break;
+ }
+
+ left -= need;
+
+ /* check if we've found what we were looking for */
+ if (left == 0) {
+ found = true;
+ break;
+ }
+ }
+
+ /* we didn't find anything, so continue */
+ if (!found)
+ continue;
+
+ return MASK_GET_IDX(msk_idx, run_start);
+ }
+ /* we didn't find anything */
+ rte_errno = used ? -ENOENT : -ENOSPC;
+ return -1;
+}
+
+static int
+find_next(const struct rte_fbarray *arr, unsigned int start, bool used)
+{
+ const struct used_mask *msk = get_used_mask(arr->data, arr->elt_sz,
+ arr->len);
+ unsigned int idx, first, first_mod;
+ unsigned int last, last_mod;
+ uint64_t last_msk, ignore_msk;
+
+ /*
+ * mask only has granularity of MASK_ALIGN, but start may not be aligned
+ * on that boundary, so construct a special mask to exclude anything we
+ * don't want to see to avoid confusing ctz.
+ */
+ first = MASK_LEN_TO_IDX(start);
+ first_mod = MASK_LEN_TO_MOD(start);
+ ignore_msk = ~((1ULL << first_mod) - 1ULL);
+
+ /* array length may not be aligned, so calculate ignore mask for last
+ * mask index.
+ */
+ last = MASK_LEN_TO_IDX(arr->len);
+ last_mod = MASK_LEN_TO_MOD(arr->len);
+ last_msk = ~(-(1ULL) << last_mod);
+
+ for (idx = first; idx < msk->n_masks; idx++) {
+ uint64_t cur = msk->data[idx];
+ int found;
+
+ /* if we're looking for free entries, invert mask */
+ if (!used)
+ cur = ~cur;
+
+ if (idx == last)
+ cur &= last_msk;
+
+ /* ignore everything before start on first iteration */
+ if (idx == first)
+ cur &= ignore_msk;
+
+ /* check if we have any entries */
+ if (cur == 0)
+ continue;
+
+ /*
+ * find first set bit - that will correspond to whatever it is
+ * that we're looking for.
+ */
+ found = __builtin_ctzll(cur);
+ return MASK_GET_IDX(idx, found);
+ }
+ /* we didn't find anything */
+ rte_errno = used ? -ENOENT : -ENOSPC;
+ return -1;
+}
+
+static int
+find_contig(const struct rte_fbarray *arr, unsigned int start, bool used)
+{
+ const struct used_mask *msk = get_used_mask(arr->data, arr->elt_sz,
+ arr->len);
+ unsigned int idx, first, first_mod;
+ unsigned int last, last_mod;
+ uint64_t last_msk;
+ unsigned int need_len, result = 0;
+
+ /* array length may not be aligned, so calculate ignore mask for last
+ * mask index.
+ */
+ last = MASK_LEN_TO_IDX(arr->len);
+ last_mod = MASK_LEN_TO_MOD(arr->len);
+ last_msk = ~(-(1ULL) << last_mod);
+
+ first = MASK_LEN_TO_IDX(start);
+ first_mod = MASK_LEN_TO_MOD(start);
+ for (idx = first; idx < msk->n_masks; idx++, result += need_len) {
+ uint64_t cur = msk->data[idx];
+ unsigned int run_len;
+
+ need_len = MASK_ALIGN;
+
+ /* if we're looking for free entries, invert mask */
+ if (!used)
+ cur = ~cur;
+
+ /* if this is last mask, ignore everything after last bit */
+ if (idx == last)
+ cur &= last_msk;
+
+ /* ignore everything before start on first iteration */
+ if (idx == first) {
+ cur >>= first_mod;
+ /* at the start, we don't need the full mask len */
+ need_len -= first_mod;
+ }
+
+ /* we will be looking for zeroes, so invert the mask */
+ cur = ~cur;
+
+ /* if mask is zero, we have a complete run */
+ if (cur == 0)
+ continue;
+
+ /*
+ * see if current run ends before mask end.
+ */
+ run_len = __builtin_ctzll(cur);
+
+ /* add however many zeroes we've had in the last run and quit */
+ if (run_len < need_len) {
+ result += run_len;
+ break;
+ }
+ }
+ return result;
+}
+
+static int
+set_used(struct rte_fbarray *arr, unsigned int idx, bool used)
+{
+ struct used_mask *msk;
+ uint64_t msk_bit = 1ULL << MASK_LEN_TO_MOD(idx);
+ unsigned int msk_idx = MASK_LEN_TO_IDX(idx);
+ bool already_used;
+ int ret = -1;
+
+ if (arr == NULL || idx >= arr->len) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+ msk = get_used_mask(arr->data, arr->elt_sz, arr->len);
+ ret = 0;
+
+ /* prevent array from changing under us */
+ rte_rwlock_write_lock(&arr->rwlock);
+
+ already_used = (msk->data[msk_idx] & msk_bit) != 0;
+
+ /* nothing to be done */
+ if (used == already_used)
+ goto out;
+
+ if (used) {
+ msk->data[msk_idx] |= msk_bit;
+ arr->count++;
+ } else {
+ msk->data[msk_idx] &= ~msk_bit;
+ arr->count--;
+ }
+out:
+ rte_rwlock_write_unlock(&arr->rwlock);
+
+ return ret;
+}
+
+static int
+fully_validate(const char *name, unsigned int elt_sz, unsigned int len)
+{
+ if (name == NULL || elt_sz == 0 || len == 0 || len > INT_MAX) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ if (strnlen(name, RTE_FBARRAY_NAME_LEN) == RTE_FBARRAY_NAME_LEN) {
+ rte_errno = ENAMETOOLONG;
+ return -1;
+ }
+ return 0;
+}
+
+int __rte_experimental
+rte_fbarray_init(struct rte_fbarray *arr, const char *name, unsigned int len,
+ unsigned int elt_sz)
+{
+ size_t page_sz, mmap_len;
+ char path[PATH_MAX];
+ struct used_mask *msk;
+ void *data = NULL;
+ int fd = -1;
+
+ if (arr == NULL) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ if (fully_validate(name, elt_sz, len))
+ return -1;
+
+ page_sz = sysconf(_SC_PAGESIZE);
+ if (page_sz == (size_t)-1)
+ goto fail;
+
+ /* calculate our memory limits */
+ mmap_len = calc_data_size(page_sz, elt_sz, len);
+
+ data = eal_get_virtual_area(NULL, &mmap_len, page_sz, 0, 0);
+ if (data == NULL)
+ goto fail;
+
+ eal_get_fbarray_path(path, sizeof(path), name);
+
+ /*
+ * Each fbarray is unique to process namespace, i.e. the filename
+ * depends on process prefix. Try to take out a lock and see if we
+ * succeed. If we don't, someone else is using it already.
+ */
+ fd = open(path, O_CREAT | O_RDWR, 0600);
+ if (fd < 0) {
+ RTE_LOG(DEBUG, EAL, "%s(): couldn't open %s: %s\n", __func__,
+ path, strerror(errno));
+ rte_errno = errno;
+ goto fail;
+ } else if (flock(fd, LOCK_EX | LOCK_NB)) {
+ RTE_LOG(DEBUG, EAL, "%s(): couldn't lock %s: %s\n", __func__,
+ path, strerror(errno));
+ rte_errno = EBUSY;
+ goto fail;
+ }
+
+ /* take out a non-exclusive lock, so that other processes could still
+ * attach to it, but no other process could reinitialize it.
+ */
+ if (flock(fd, LOCK_SH | LOCK_NB)) {
+ rte_errno = errno;
+ goto fail;
+ }
+
+ if (resize_and_map(fd, data, mmap_len))
+ goto fail;
+
+ /* we've mmap'ed the file, we can now close the fd */
+ close(fd);
+
+ /* initialize the data */
+ memset(data, 0, mmap_len);
+
+ /* populate data structure */
+ strlcpy(arr->name, name, sizeof(arr->name));
+ arr->data = data;
+ arr->len = len;
+ arr->elt_sz = elt_sz;
+ arr->count = 0;
+
+ msk = get_used_mask(data, elt_sz, len);
+ msk->n_masks = MASK_LEN_TO_IDX(RTE_ALIGN_CEIL(len, MASK_ALIGN));
+
+ rte_rwlock_init(&arr->rwlock);
+
+ return 0;
+fail:
+ if (data)
+ munmap(data, mmap_len);
+ if (fd >= 0)
+ close(fd);
+ return -1;
+}
+
+int __rte_experimental
+rte_fbarray_attach(struct rte_fbarray *arr)
+{
+ size_t page_sz, mmap_len;
+ char path[PATH_MAX];
+ void *data = NULL;
+ int fd = -1;
+
+ if (arr == NULL) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ /*
+ * we don't need to synchronize attach as two values we need (element
+ * size and array length) are constant for the duration of life of
+ * the array, so the parts we care about will not race.
+ */
+
+ if (fully_validate(arr->name, arr->elt_sz, arr->len))
+ return -1;
+
+ page_sz = sysconf(_SC_PAGESIZE);
+ if (page_sz == (size_t)-1)
+ goto fail;
+
+ mmap_len = calc_data_size(page_sz, arr->elt_sz, arr->len);
+
+ data = eal_get_virtual_area(arr->data, &mmap_len, page_sz, 0, 0);
+ if (data == NULL)
+ goto fail;
+
+ eal_get_fbarray_path(path, sizeof(path), arr->name);
+
+ fd = open(path, O_RDWR);
+ if (fd < 0) {
+ rte_errno = errno;
+ goto fail;
+ }
+
+ /* lock the file, to let others know we're using it */
+ if (flock(fd, LOCK_SH | LOCK_NB)) {
+ rte_errno = errno;
+ goto fail;
+ }
+
+ if (resize_and_map(fd, data, mmap_len))
+ goto fail;
+
+ close(fd);
+
+ /* we're done */
+
+ return 0;
+fail:
+ if (data)
+ munmap(data, mmap_len);
+ if (fd >= 0)
+ close(fd);
+ return -1;
+}
+
+int __rte_experimental
+rte_fbarray_detach(struct rte_fbarray *arr)
+{
+ if (arr == NULL) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ /*
+ * we don't need to synchronize detach as two values we need (element
+ * size and total capacity) are constant for the duration of life of
+ * the array, so the parts we care about will not race. if the user is
+ * detaching while doing something else in the same process, we can't
+ * really do anything about it, things will blow up either way.
+ */
+
+ size_t page_sz = sysconf(_SC_PAGESIZE);
+
+ if (page_sz == (size_t)-1)
+ return -1;
+
+ /* this may already be unmapped (e.g. repeated call from previously
+ * failed destroy(), but this is on user, we can't (easily) know if this
+ * is still mapped.
+ */
+ munmap(arr->data, calc_data_size(page_sz, arr->elt_sz, arr->len));
+
+ return 0;
+}
+
+int __rte_experimental
+rte_fbarray_destroy(struct rte_fbarray *arr)
+{
+ int fd, ret;
+ char path[PATH_MAX];
+
+ ret = rte_fbarray_detach(arr);
+ if (ret)
+ return ret;
+
+ /* try deleting the file */
+ eal_get_fbarray_path(path, sizeof(path), arr->name);
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0) {
+ RTE_LOG(ERR, EAL, "Could not open fbarray file: %s\n",
+ strerror(errno));
+ return -1;
+ }
+ if (flock(fd, LOCK_EX | LOCK_NB)) {
+ RTE_LOG(DEBUG, EAL, "Cannot destroy fbarray - another process is using it\n");
+ rte_errno = EBUSY;
+ ret = -1;
+ } else {
+ ret = 0;
+ unlink(path);
+ memset(arr, 0, sizeof(*arr));
+ }
+ close(fd);
+
+ return ret;
+}
+
+void * __rte_experimental
+rte_fbarray_get(const struct rte_fbarray *arr, unsigned int idx)
+{
+ void *ret = NULL;
+ if (arr == NULL) {
+ rte_errno = EINVAL;
+ return NULL;
+ }
+
+ if (idx >= arr->len) {
+ rte_errno = EINVAL;
+ return NULL;
+ }
+
+ ret = RTE_PTR_ADD(arr->data, idx * arr->elt_sz);
+
+ return ret;
+}
+
+int __rte_experimental
+rte_fbarray_set_used(struct rte_fbarray *arr, unsigned int idx)
+{
+ return set_used(arr, idx, true);
+}
+
+int __rte_experimental
+rte_fbarray_set_free(struct rte_fbarray *arr, unsigned int idx)
+{
+ return set_used(arr, idx, false);
+}
+
+int __rte_experimental
+rte_fbarray_is_used(struct rte_fbarray *arr, unsigned int idx)
+{
+ struct used_mask *msk;
+ int msk_idx;
+ uint64_t msk_bit;
+ int ret = -1;
+
+ if (arr == NULL || idx >= arr->len) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ /* prevent array from changing under us */
+ rte_rwlock_read_lock(&arr->rwlock);
+
+ msk = get_used_mask(arr->data, arr->elt_sz, arr->len);
+ msk_idx = MASK_LEN_TO_IDX(idx);
+ msk_bit = 1ULL << MASK_LEN_TO_MOD(idx);
+
+ ret = (msk->data[msk_idx] & msk_bit) != 0;
+
+ rte_rwlock_read_unlock(&arr->rwlock);
+
+ return ret;
+}
+
+int __rte_experimental
+rte_fbarray_find_next_free(struct rte_fbarray *arr, unsigned int start)
+{
+ int ret = -1;
+
+ if (arr == NULL || start >= arr->len) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ /* prevent array from changing under us */
+ rte_rwlock_read_lock(&arr->rwlock);
+
+ if (arr->len == arr->count) {
+ rte_errno = ENOSPC;
+ goto out;
+ }
+
+ ret = find_next(arr, start, false);
+out:
+ rte_rwlock_read_unlock(&arr->rwlock);
+ return ret;
+}
+
+int __rte_experimental
+rte_fbarray_find_next_used(struct rte_fbarray *arr, unsigned int start)
+{
+ int ret = -1;
+
+ if (arr == NULL || start >= arr->len) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ /* prevent array from changing under us */
+ rte_rwlock_read_lock(&arr->rwlock);
+
+ if (arr->count == 0) {
+ rte_errno = ENOENT;
+ goto out;
+ }
+
+ ret = find_next(arr, start, true);
+out:
+ rte_rwlock_read_unlock(&arr->rwlock);
+ return ret;
+}
+
+int __rte_experimental
+rte_fbarray_find_next_n_free(struct rte_fbarray *arr, unsigned int start,
+ unsigned int n)
+{
+ int ret = -1;
+
+ if (arr == NULL || start >= arr->len || n > arr->len) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ /* prevent array from changing under us */
+ rte_rwlock_read_lock(&arr->rwlock);
+
+ if (arr->len == arr->count || arr->len - arr->count < n) {
+ rte_errno = ENOSPC;
+ goto out;
+ }
+
+ ret = find_next_n(arr, start, n, false);
+out:
+ rte_rwlock_read_unlock(&arr->rwlock);
+ return ret;
+}
+
+int __rte_experimental
+rte_fbarray_find_next_n_used(struct rte_fbarray *arr, unsigned int start,
+ unsigned int n)
+{
+ int ret = -1;
+
+ if (arr == NULL || start >= arr->len || n > arr->len) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ /* prevent array from changing under us */
+ rte_rwlock_read_lock(&arr->rwlock);
+
+ if (arr->count < n) {
+ rte_errno = ENOENT;
+ goto out;
+ }
+
+ ret = find_next_n(arr, start, n, true);
+out:
+ rte_rwlock_read_unlock(&arr->rwlock);
+ return ret;
+}
+
+int __rte_experimental
+rte_fbarray_find_contig_free(struct rte_fbarray *arr, unsigned int start)
+{
+ int ret = -1;
+
+ if (arr == NULL || start >= arr->len) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ /* prevent array from changing under us */
+ rte_rwlock_read_lock(&arr->rwlock);
+
+ if (arr->len == arr->count) {
+ rte_errno = ENOSPC;
+ goto out;
+ }
+
+ if (arr->count == 0) {
+ ret = arr->len - start;
+ goto out;
+ }
+
+ ret = find_contig(arr, start, false);
+out:
+ rte_rwlock_read_unlock(&arr->rwlock);
+ return ret;
+}
+
+int __rte_experimental
+rte_fbarray_find_contig_used(struct rte_fbarray *arr, unsigned int start)
+{
+ int ret = -1;
+
+ if (arr == NULL || start >= arr->len) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ /* prevent array from changing under us */
+ rte_rwlock_read_lock(&arr->rwlock);
+
+ ret = find_contig(arr, start, true);
+
+ rte_rwlock_read_unlock(&arr->rwlock);
+ return ret;
+}
+
+int __rte_experimental
+rte_fbarray_find_idx(const struct rte_fbarray *arr, const void *elt)
+{
+ void *end;
+ int ret = -1;
+
+ /*
+ * no need to synchronize as it doesn't matter if underlying data
+ * changes - we're doing pointer arithmetic here.
+ */
+
+ if (arr == NULL || elt == NULL) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+ end = RTE_PTR_ADD(arr->data, arr->elt_sz * arr->len);
+ if (elt < arr->data || elt >= end) {
+ rte_errno = EINVAL;
+ return -1;
+ }
+
+ ret = RTE_PTR_DIFF(elt, arr->data) / arr->elt_sz;
+
+ return ret;
+}
+
+void __rte_experimental
+rte_fbarray_dump_metadata(struct rte_fbarray *arr, FILE *f)
+{
+ struct used_mask *msk;
+ unsigned int i;
+
+ if (arr == NULL || f == NULL) {
+ rte_errno = EINVAL;
+ return;
+ }
+
+ if (fully_validate(arr->name, arr->elt_sz, arr->len)) {
+ fprintf(f, "Invalid file-backed array\n");
+ goto out;
+ }
+
+ /* prevent array from changing under us */
+ rte_rwlock_read_lock(&arr->rwlock);
+
+ fprintf(f, "File-backed array: %s\n", arr->name);
+ fprintf(f, "size: %i occupied: %i elt_sz: %i\n",
+ arr->len, arr->count, arr->elt_sz);
+
+ msk = get_used_mask(arr->data, arr->elt_sz, arr->len);
+
+ for (i = 0; i < msk->n_masks; i++)
+ fprintf(f, "msk idx %i: 0x%016" PRIx64 "\n", i, msk->data[i]);
+out:
+ rte_rwlock_read_unlock(&arr->rwlock);
+}