[dpdk-dev] [PATCH 3/4] mempool: introduce block size align flag

[Santosh Shukla <santosh.shukla@caviumnetworks.com>]

Some mempool hw like octeontx/fpa block, demands block size aligned
buffer address.

Introducing an MEMPOOL_F_POOL_BLK_SZ_ALIGNED flag.
If this flag is set:
1) adjust 'off' value to block size aligned value.
2) Allocate one additional buffer. This buffer is used to make sure that
requested 'n' buffers get correctly populated to mempool.
Example:
	elem_sz = 2432 // total element size.
	n = 2111 // requested number of buffer.
	off = 2304 // new buf_offset value after step 1)
	vaddr = 0x0 // actual start address of pool
	pool_len = 5133952 // total pool length i.e.. (elem_sz * n)

Since 'off' is a non-zero value so below condition would fail for the
block size align case.

(((vaddr + off) + (elem_sz * n)) <= (vaddr + pool_len))

Which is incorrect behavior. Additional buffer will solve this
problem and correctly populate 'n' buffer to mempool for the aligned
mode.

Signed-off-by: Santosh Shukla <santosh.shukla@caviumnetworks.com>
Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
---
 lib/librte_mempool/rte_mempool.c | 19 ++++++++++++++++---
 lib/librte_mempool/rte_mempool.h |  1 +
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index 7dec2f51d..2010857f0 100644
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -350,7 +350,7 @@ rte_mempool_populate_phys(struct rte_mempool *mp, char *vaddr,
 {
 	unsigned total_elt_sz;
 	unsigned i = 0;
-	size_t off;
+	size_t off, delta;
 	struct rte_mempool_memhdr *memhdr;
 	int ret;
 
@@ -387,7 +387,15 @@ rte_mempool_populate_phys(struct rte_mempool *mp, char *vaddr,
 	memhdr->free_cb = free_cb;
 	memhdr->opaque = opaque;
 
-	if (mp->flags & MEMPOOL_F_NO_CACHE_ALIGN)
+	if (mp->flags & MEMPOOL_F_POOL_BLK_SZ_ALIGNED) {
+		delta = (uintptr_t)vaddr % total_elt_sz;
+		off = total_elt_sz - delta;
+		/* Validate alignment */
+		if (((uintptr_t)vaddr + off) % total_elt_sz) {
+			RTE_LOG(ERR, MEMPOOL, "vaddr(%p) not aligned to total_elt_sz(%u)\n", (vaddr + off), total_elt_sz);
+			return -EINVAL;
+		}
+	} else if (mp->flags & MEMPOOL_F_NO_CACHE_ALIGN)
 		off = RTE_PTR_ALIGN_CEIL(vaddr, 8) - vaddr;
 	else
 		off = RTE_PTR_ALIGN_CEIL(vaddr, RTE_CACHE_LINE_SIZE) - vaddr;
@@ -555,8 +563,13 @@ rte_mempool_populate_default(struct rte_mempool *mp)
 	}
 
 	total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
+
 	for (mz_id = 0, n = mp->size; n > 0; mz_id++, n -= ret) {
-		size = rte_mempool_xmem_size(n, total_elt_sz, pg_shift);
+		if (mp->flags & MEMPOOL_F_POOL_BLK_SZ_ALIGNED)
+			size = rte_mempool_xmem_size(n + 1, total_elt_sz,
+							pg_shift);
+		else
+			size = rte_mempool_xmem_size(n, total_elt_sz, pg_shift);
 
 		ret = snprintf(mz_name, sizeof(mz_name),
 			RTE_MEMPOOL_MZ_FORMAT "_%d", mp->name, mz_id);
diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
index fd8722e69..99a20263d 100644
--- a/lib/librte_mempool/rte_mempool.h
+++ b/lib/librte_mempool/rte_mempool.h
@@ -267,6 +267,7 @@ struct rte_mempool {
 #define MEMPOOL_F_POOL_CREATED   0x0010 /**< Internal: pool is created. */
 #define MEMPOOL_F_NO_PHYS_CONTIG 0x0020 /**< Don't need physically contiguous objs. */
 #define MEMPOOL_F_POOL_CONTIG    0x0040 /**< Detect physcially contiguous objs */
+#define MEMPOOL_F_POOL_BLK_SZ_ALIGNED 0x0080 /**< Align buffer address to block size*/
 
 /**
  * @internal When debug is enabled, store some statistics.
-- 
2.13.0