[dpdk-dev] [PATCH v3 6/7] mempool: prevent objects from being across pages

[Olivier Matz <olivier.matz@6wind.com>]

When populating a mempool, ensure that objects are not located across
several pages, except if user did not request iova contiguous objects.

Signed-off-by: Vamsi Krishna Attunuru <vattunuru@marvell.com>
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Nipun Gupta <nipun.gupta@nxp.com>
---
 drivers/mempool/bucket/rte_mempool_bucket.c   |  2 +-
 drivers/mempool/dpaa/dpaa_mempool.c           |  4 +-
 drivers/mempool/dpaa2/dpaa2_hw_mempool.c      |  4 +-
 .../mempool/octeontx/rte_mempool_octeontx.c   | 21 +++---
 drivers/mempool/octeontx2/Makefile            |  3 +
 drivers/mempool/octeontx2/meson.build         |  3 +
 drivers/mempool/octeontx2/otx2_mempool_ops.c  | 21 +++---
 lib/librte_mempool/rte_mempool.c              | 23 ++-----
 lib/librte_mempool/rte_mempool.h              | 24 +++++--
 lib/librte_mempool/rte_mempool_ops_default.c  | 66 +++++++++++++++----
 10 files changed, 115 insertions(+), 56 deletions(-)

diff --git a/drivers/mempool/bucket/rte_mempool_bucket.c b/drivers/mempool/bucket/rte_mempool_bucket.c
index dfeaf4e45..b978fd220 100644
--- a/drivers/mempool/bucket/rte_mempool_bucket.c
+++ b/drivers/mempool/bucket/rte_mempool_bucket.c
@@ -585,7 +585,7 @@ bucket_populate(struct rte_mempool *mp, unsigned int max_objs,
 
 		hdr->fill_cnt = 0;
 		hdr->lcore_id = LCORE_ID_ANY;
-		rc = rte_mempool_op_populate_helper(mp,
+		rc = rte_mempool_op_populate_helper(mp, 0,
 						     RTE_MIN(bd->obj_per_bucket,
 							     max_objs - n_objs),
 						     iter + bucket_header_sz,
diff --git a/drivers/mempool/dpaa/dpaa_mempool.c b/drivers/mempool/dpaa/dpaa_mempool.c
index 27736e6c2..3a2528331 100644
--- a/drivers/mempool/dpaa/dpaa_mempool.c
+++ b/drivers/mempool/dpaa/dpaa_mempool.c
@@ -341,8 +341,8 @@ dpaa_populate(struct rte_mempool *mp, unsigned int max_objs,
 	 */
 	TAILQ_INSERT_HEAD(&rte_dpaa_memsegs, ms, next);
 
-	return rte_mempool_op_populate_helper(mp, max_objs, vaddr, paddr, len,
-					       obj_cb, obj_cb_arg);
+	return rte_mempool_op_populate_helper(mp, 0, max_objs, vaddr, paddr,
+					       len, obj_cb, obj_cb_arg);
 }
 
 static const struct rte_mempool_ops dpaa_mpool_ops = {
diff --git a/drivers/mempool/dpaa2/dpaa2_hw_mempool.c b/drivers/mempool/dpaa2/dpaa2_hw_mempool.c
index 8f8dbeada..36c93decf 100644
--- a/drivers/mempool/dpaa2/dpaa2_hw_mempool.c
+++ b/drivers/mempool/dpaa2/dpaa2_hw_mempool.c
@@ -421,8 +421,8 @@ dpaa2_populate(struct rte_mempool *mp, unsigned int max_objs,
 	/* Insert entry into the PA->VA Table */
 	dpaax_iova_table_update(paddr, vaddr, len);
 
-	return rte_mempool_op_populate_helper(mp, max_objs, vaddr, paddr, len,
-					       obj_cb, obj_cb_arg);
+	return rte_mempool_op_populate_helper(mp, 0, max_objs, vaddr, paddr,
+					       len, obj_cb, obj_cb_arg);
 }
 
 static const struct rte_mempool_ops dpaa2_mpool_ops = {
diff --git a/drivers/mempool/octeontx/rte_mempool_octeontx.c b/drivers/mempool/octeontx/rte_mempool_octeontx.c
index fff33e5c6..bd0070020 100644
--- a/drivers/mempool/octeontx/rte_mempool_octeontx.c
+++ b/drivers/mempool/octeontx/rte_mempool_octeontx.c
@@ -132,14 +132,15 @@ octeontx_fpavf_calc_mem_size(const struct rte_mempool *mp,
 			     size_t *min_chunk_size, size_t *align)
 {
 	ssize_t mem_size;
+	size_t total_elt_sz;
 
-	/*
-	 * Simply need space for one more object to be able to
-	 * fulfil alignment requirements.
+	/* Need space for one more obj on each chunk to fulfill
+	 * alignment requirements.
 	 */
-	mem_size = rte_mempool_op_calc_mem_size_helper(mp, obj_num + 1,
-							pg_shift,
-							min_chunk_size, align);
+	total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
+	mem_size = rte_mempool_op_calc_mem_size_helper(mp, obj_num, pg_shift,
+						total_elt_sz, min_chunk_size,
+						align);
 	if (mem_size >= 0) {
 		/*
 		 * Memory area which contains objects must be physically
@@ -168,7 +169,7 @@ octeontx_fpavf_populate(struct rte_mempool *mp, unsigned int max_objs,
 	total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
 
 	/* align object start address to a multiple of total_elt_sz */
-	off = total_elt_sz - ((uintptr_t)vaddr % total_elt_sz);
+	off = total_elt_sz - ((((uintptr_t)vaddr - 1) % total_elt_sz) + 1);
 
 	if (len < off)
 		return -EINVAL;
@@ -184,8 +185,10 @@ octeontx_fpavf_populate(struct rte_mempool *mp, unsigned int max_objs,
 	if (ret < 0)
 		return ret;
 
-	return rte_mempool_op_populate_helper(mp, max_objs, vaddr, iova, len,
-					       obj_cb, obj_cb_arg);
+	return rte_mempool_op_populate_helper(mp,
+					RTE_MEMPOOL_POPULATE_F_ALIGN_OBJ,
+					max_objs, vaddr, iova, len,
+					obj_cb, obj_cb_arg);
 }
 
 static struct rte_mempool_ops octeontx_fpavf_ops = {
diff --git a/drivers/mempool/octeontx2/Makefile b/drivers/mempool/octeontx2/Makefile
index 8f55305c5..62e90f277 100644
--- a/drivers/mempool/octeontx2/Makefile
+++ b/drivers/mempool/octeontx2/Makefile
@@ -30,6 +30,9 @@ EXPORT_MAP := rte_mempool_octeontx2_version.map
 
 LIBABIVER := 1
 
+# for rte_mempool_get_page_size
+CFLAGS += -DALLOW_EXPERIMENTAL_API
+
 #
 # all source are stored in SRCS-y
 #
diff --git a/drivers/mempool/octeontx2/meson.build b/drivers/mempool/octeontx2/meson.build
index 5f93bb495..883b643da 100644
--- a/drivers/mempool/octeontx2/meson.build
+++ b/drivers/mempool/octeontx2/meson.build
@@ -24,3 +24,6 @@ foreach flag: extra_flags
 endforeach
 
 deps += ['eal', 'mbuf', 'kvargs', 'bus_pci', 'common_octeontx2', 'mempool']
+
+# for rte_mempool_get_page_size
+allow_experimental_apis = true
diff --git a/drivers/mempool/octeontx2/otx2_mempool_ops.c b/drivers/mempool/octeontx2/otx2_mempool_ops.c
index 3aea92a01..ea4b1c45d 100644
--- a/drivers/mempool/octeontx2/otx2_mempool_ops.c
+++ b/drivers/mempool/octeontx2/otx2_mempool_ops.c
@@ -713,12 +713,15 @@ static ssize_t
 otx2_npa_calc_mem_size(const struct rte_mempool *mp, uint32_t obj_num,
 		       uint32_t pg_shift, size_t *min_chunk_size, size_t *align)
 {
-	/*
-	 * Simply need space for one more object to be able to
-	 * fulfill alignment requirements.
+	size_t total_elt_sz;
+
+	/* Need space for one more obj on each chunk to fulfill
+	 * alignment requirements.
 	 */
-	return rte_mempool_op_calc_mem_size_helper(mp, obj_num + 1, pg_shift,
-						    min_chunk_size, align);
+	total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
+	return rte_mempool_op_calc_mem_size_helper(mp, obj_num, pg_shift,
+						total_elt_sz, min_chunk_size,
+						align);
 }
 
 static int
@@ -735,7 +738,7 @@ otx2_npa_populate(struct rte_mempool *mp, unsigned int max_objs, void *vaddr,
 	total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
 
 	/* Align object start address to a multiple of total_elt_sz */
-	off = total_elt_sz - ((uintptr_t)vaddr % total_elt_sz);
+	off = total_elt_sz - ((((uintptr_t)vaddr - 1) % total_elt_sz) + 1);
 
 	if (len < off)
 		return -EINVAL;
@@ -749,8 +752,10 @@ otx2_npa_populate(struct rte_mempool *mp, unsigned int max_objs, void *vaddr,
 	if (npa_lf_aura_range_update_check(mp->pool_id) < 0)
 		return -EBUSY;
 
-	return rte_mempool_op_populate_helper(mp, max_objs, vaddr, iova, len,
-					       obj_cb, obj_cb_arg);
+	return rte_mempool_op_populate_helper(mp,
+					RTE_MEMPOOL_POPULATE_F_ALIGN_OBJ,
+					max_objs, vaddr, iova, len,
+					obj_cb, obj_cb_arg);
 }
 
 static struct rte_mempool_ops otx2_npa_ops = {
diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index 758c5410b..d3db9273d 100644
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -431,8 +431,6 @@ rte_mempool_get_page_size(struct rte_mempool *mp, size_t *pg_sz)
 
 	if (!need_iova_contig_obj)
 		*pg_sz = 0;
-	else if (!alloc_in_ext_mem && rte_eal_iova_mode() == RTE_IOVA_VA)
-		*pg_sz = 0;
 	else if (rte_eal_has_hugepages() || alloc_in_ext_mem)
 		*pg_sz = get_min_page_size(mp->socket_id);
 	else
@@ -481,17 +479,15 @@ rte_mempool_populate_default(struct rte_mempool *mp)
 	 * then just set page shift and page size to 0, because the user has
 	 * indicated that there's no need to care about anything.
 	 *
-	 * if we do need contiguous objects, there is also an option to reserve
-	 * the entire mempool memory as one contiguous block of memory, in
-	 * which case the page shift and alignment wouldn't matter as well.
+	 * if we do need contiguous objects (if a mempool driver has its
+	 * own calc_size() method returning min_chunk_size = mem_size),
+	 * there is also an option to reserve the entire mempool memory
+	 * as one contiguous block of memory.
 	 *
 	 * if we require contiguous objects, but not necessarily the entire
-	 * mempool reserved space to be contiguous, then there are two options.
-	 *
-	 * if our IO addresses are virtual, not actual physical (IOVA as VA
-	 * case), then no page shift needed - our memory allocation will give us
-	 * contiguous IO memory as far as the hardware is concerned, so
-	 * act as if we're getting contiguous memory.
+	 * mempool reserved space to be contiguous, pg_sz will be != 0,
+	 * and the default ops->populate() will take care of not placing
+	 * objects across pages.
 	 *
 	 * if our IO addresses are physical, we may get memory from bigger
 	 * pages, or we might get memory from smaller pages, and how much of it
@@ -504,11 +500,6 @@ rte_mempool_populate_default(struct rte_mempool *mp)
 	 *
 	 * If we fail to get enough contiguous memory, then we'll go and
 	 * reserve space in smaller chunks.
-	 *
-	 * We also have to take into account the fact that memory that we're
-	 * going to allocate from can belong to an externally allocated memory
-	 * area, in which case the assumption of IOVA as VA mode being
-	 * synonymous with IOVA contiguousness will not hold.
 	 */
 
 	need_iova_contig_obj = !(mp->flags & MEMPOOL_F_NO_IOVA_CONTIG);
diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
index 26a98af30..f1cba3521 100644
--- a/lib/librte_mempool/rte_mempool.h
+++ b/lib/librte_mempool/rte_mempool.h
@@ -473,6 +473,10 @@ typedef ssize_t (*rte_mempool_calc_mem_size_t)(const struct rte_mempool *mp,
  * Otherwise, it is a number of pages required to store given number of
  * objects without crossing page boundary.
  *
+ * The chunk_reserve argument is the amount of memory that must be
+ * reserved at the beginning of each page, or at the beginning of the
+ * memory area if pg_shift is 0.
+ *
  * Note that if object size is bigger than page size, then it assumes
  * that pages are grouped in subsets of physically continuous pages big
  * enough to store at least one object.
@@ -482,7 +486,7 @@ typedef ssize_t (*rte_mempool_calc_mem_size_t)(const struct rte_mempool *mp,
  */
 __rte_experimental
 ssize_t rte_mempool_op_calc_mem_size_helper(const struct rte_mempool *mp,
-		uint32_t obj_num, uint32_t pg_shift,
+		uint32_t obj_num, uint32_t pg_shift, size_t chunk_reserve,
 		size_t *min_chunk_size, size_t *align);
 
 /**
@@ -490,7 +494,7 @@ ssize_t rte_mempool_op_calc_mem_size_helper(const struct rte_mempool *mp,
  * objects.
  *
  * Equivalent to rte_mempool_op_calc_mem_size_helper(mp, obj_num, pg_shift,
- * min_chunk_size, align).
+ * 0, min_chunk_size, align).
  */
 ssize_t rte_mempool_op_calc_mem_size_default(const struct rte_mempool *mp,
 		uint32_t obj_num, uint32_t pg_shift,
@@ -544,20 +548,30 @@ typedef int (*rte_mempool_populate_t)(struct rte_mempool *mp,
 		void *vaddr, rte_iova_t iova, size_t len,
 		rte_mempool_populate_obj_cb_t *obj_cb, void *obj_cb_arg);
 
+/**
+ * Align objects on addresses multiple of total_elt_sz.
+ */
+#define RTE_MEMPOOL_POPULATE_F_ALIGN_OBJ 0x0001
+
 /**
  * Helper to populate memory pool object using provided memory
- * chunk: just slice objects one by one.
+ * chunk: just slice objects one by one, taking care of not
+ * crossing page boundaries.
+ *
+ * If RTE_MEMPOOL_POPULATE_F_ALIGN_OBJ is set in flags, the addresses
+ * of object headers will be aligned on a multiple of total_elt_sz.
+ * This feature is used by octeontx hardware.
  */
 __rte_experimental
 int rte_mempool_op_populate_helper(struct rte_mempool *mp,
-		unsigned int max_objs,
+		unsigned int flags, unsigned int max_objs,
 		void *vaddr, rte_iova_t iova, size_t len,
 		rte_mempool_populate_obj_cb_t *obj_cb, void *obj_cb_arg);
 
 /**
  * Default way to populate memory pool object using provided memory chunk.
  *
- * Equivalent to rte_mempool_op_populate_helper(mp, max_objs, vaddr, iova,
+ * Equivalent to rte_mempool_op_populate_helper(mp, 0, max_objs, vaddr, iova,
  * len, obj_cb, obj_cb_arg).
  */
 int rte_mempool_op_populate_default(struct rte_mempool *mp,
diff --git a/lib/librte_mempool/rte_mempool_ops_default.c b/lib/librte_mempool/rte_mempool_ops_default.c
index 0bfc63497..e6be7152b 100644
--- a/lib/librte_mempool/rte_mempool_ops_default.c
+++ b/lib/librte_mempool/rte_mempool_ops_default.c
@@ -9,6 +9,7 @@
 ssize_t
 rte_mempool_op_calc_mem_size_helper(const struct rte_mempool *mp,
 				uint32_t obj_num, uint32_t pg_shift,
+				size_t chunk_reserve,
 				size_t *min_chunk_size, size_t *align)
 {
 	size_t total_elt_sz;
@@ -19,10 +20,12 @@ rte_mempool_op_calc_mem_size_helper(const struct rte_mempool *mp,
 	if (total_elt_sz == 0) {
 		mem_size = 0;
 	} else if (pg_shift == 0) {
-		mem_size = total_elt_sz * obj_num;
+		mem_size = total_elt_sz * obj_num + chunk_reserve;
 	} else {
 		pg_sz = (size_t)1 << pg_shift;
-		obj_per_page = pg_sz / total_elt_sz;
+		if (chunk_reserve >= pg_sz)
+			return -EINVAL;
+		obj_per_page = (pg_sz - chunk_reserve) / total_elt_sz;
 		if (obj_per_page == 0) {
 			/*
 			 * Note that if object size is bigger than page size,
@@ -30,8 +33,8 @@ rte_mempool_op_calc_mem_size_helper(const struct rte_mempool *mp,
 			 * of physically continuous pages big enough to store
 			 * at least one object.
 			 */
-			mem_size =
-				RTE_ALIGN_CEIL(total_elt_sz, pg_sz) * obj_num;
+			mem_size = RTE_ALIGN_CEIL(total_elt_sz + chunk_reserve,
+						pg_sz) * obj_num;
 		} else {
 			/* In the best case, the allocator will return a
 			 * page-aligned address. For example, with 5 objs,
@@ -42,7 +45,8 @@ rte_mempool_op_calc_mem_size_helper(const struct rte_mempool *mp,
 			 */
 			objs_in_last_page = ((obj_num - 1) % obj_per_page) + 1;
 			/* room required for the last page */
-			mem_size = objs_in_last_page * total_elt_sz;
+			mem_size = objs_in_last_page * total_elt_sz +
+				chunk_reserve;
 			/* room required for other pages */
 			mem_size += ((obj_num - objs_in_last_page) /
 				obj_per_page) << pg_shift;
@@ -67,24 +71,60 @@ rte_mempool_op_calc_mem_size_default(const struct rte_mempool *mp,
 				size_t *min_chunk_size, size_t *align)
 {
 	return rte_mempool_op_calc_mem_size_helper(mp, obj_num, pg_shift,
-						min_chunk_size, align);
+						0, min_chunk_size, align);
+}
+
+/* Returns -1 if object crosses a page boundary, else returns 0 */
+static int
+check_obj_bounds(char *obj, size_t pg_sz, size_t elt_sz)
+{
+	if (pg_sz == 0)
+		return 0;
+	if (elt_sz > pg_sz)
+		return 0;
+	if (RTE_PTR_ALIGN(obj, pg_sz) != RTE_PTR_ALIGN(obj + elt_sz - 1, pg_sz))
+		return -1;
+	return 0;
 }
 
 int
-rte_mempool_op_populate_helper(struct rte_mempool *mp, unsigned int max_objs,
-			void *vaddr, rte_iova_t iova, size_t len,
-			rte_mempool_populate_obj_cb_t *obj_cb, void *obj_cb_arg)
+rte_mempool_op_populate_helper(struct rte_mempool *mp, unsigned int flags,
+			unsigned int max_objs, void *vaddr, rte_iova_t iova,
+			size_t len, rte_mempool_populate_obj_cb_t *obj_cb,
+			void *obj_cb_arg)
 {
-	size_t total_elt_sz;
+	char *va = vaddr;
+	size_t total_elt_sz, pg_sz;
 	size_t off;
 	unsigned int i;
 	void *obj;
+	int ret;
+
+	ret = rte_mempool_get_page_size(mp, &pg_sz);
+	if (ret < 0)
+		return ret;
 
 	total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
 
-	for (off = 0, i = 0; off + total_elt_sz <= len && i < max_objs; i++) {
+	if (flags & RTE_MEMPOOL_POPULATE_F_ALIGN_OBJ)
+		off = total_elt_sz - (((uintptr_t)(va - 1) % total_elt_sz) + 1);
+	else
+		off = 0;
+	for (i = 0; i < max_objs; i++) {
+		/* avoid objects to cross page boundaries */
+		if (check_obj_bounds(va + off, pg_sz, total_elt_sz) < 0) {
+			off += RTE_PTR_ALIGN_CEIL(va + off, pg_sz) - (va + off);
+			if (flags & RTE_MEMPOOL_POPULATE_F_ALIGN_OBJ)
+				off += total_elt_sz -
+					(((uintptr_t)(va + off - 1) %
+						total_elt_sz) + 1);
+		}
+
+		if (off + total_elt_sz > len)
+			break;
+
 		off += mp->header_size;
-		obj = (char *)vaddr + off;
+		obj = va + off;
 		obj_cb(mp, obj_cb_arg, obj,
 		       (iova == RTE_BAD_IOVA) ? RTE_BAD_IOVA : (iova + off));
 		rte_mempool_ops_enqueue_bulk(mp, &obj, 1);
@@ -100,6 +140,6 @@ rte_mempool_op_populate_default(struct rte_mempool *mp, unsigned int max_objs,
 				rte_mempool_populate_obj_cb_t *obj_cb,
 				void *obj_cb_arg)
 {
-	return rte_mempool_op_populate_helper(mp, max_objs, vaddr, iova,
+	return rte_mempool_op_populate_helper(mp, 0, max_objs, vaddr, iova,
 					len, obj_cb, obj_cb_arg);
 }
-- 
2.20.1