[dpdk-dev] [PATCH v6 6/9] eal: new rte_memzone_free

[Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>]

Implement rte_memzone_free which, as its name implies, would free a
memzone.

Currently memzone are tracked in an array and cannot be free.
To be able to reuse the same array to track memzones, we have to
change how we keep track of reserved memzones.

With this patch, any memzone with addr NULL is not used, so we also need
to change how we look for the next memzone entry free.

Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
---
 lib/librte_eal/bsdapp/eal/rte_eal_version.map     |  6 ++
 lib/librte_eal/common/eal_common_memzone.c        | 67 ++++++++++++++++++++++-
 lib/librte_eal/common/include/rte_eal_memconfig.h |  2 +-
 lib/librte_eal/common/include/rte_memzone.h       | 11 ++++
 lib/librte_eal/linuxapp/eal/eal_ivshmem.c         |  8 +--
 lib/librte_eal/linuxapp/eal/rte_eal_version.map   |  6 ++
 6 files changed, 92 insertions(+), 8 deletions(-)

diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
index 0401be2..7110816 100644
--- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
@@ -105,3 +105,9 @@ DPDK_2.0 {
 
 	local: *;
 };
+
+DPDK_2.1 {
+	global:
+
+	rte_memzone_free;
+} DPDK_2.0;
diff --git a/lib/librte_eal/common/eal_common_memzone.c b/lib/librte_eal/common/eal_common_memzone.c
index 943012b..5bc4ab4 100644
--- a/lib/librte_eal/common/eal_common_memzone.c
+++ b/lib/librte_eal/common/eal_common_memzone.c
@@ -77,6 +77,23 @@ memzone_lookup_thread_unsafe(const char *name)
 	return NULL;
 }
 
+static inline struct rte_memzone *
+get_next_free_memzone(void)
+{
+	struct rte_mem_config *mcfg;
+	unsigned i = 0;
+
+	/* get pointer to global configuration */
+	mcfg = rte_eal_get_configuration()->mem_config;
+
+	for (i = 0; i < RTE_MAX_MEMZONE; i++) {
+		if (mcfg->memzone[i].addr == NULL)
+			return &mcfg->memzone[i];
+	}
+
+	return NULL;
+}
+
 /*
  * Return a pointer to a correctly filled memzone descriptor. If the
  * allocation cannot be done, return NULL.
@@ -141,7 +158,7 @@ memzone_reserve_aligned_thread_unsafe(const char *name, size_t len,
 	mcfg = rte_eal_get_configuration()->mem_config;
 
 	/* no more room in config */
-	if (mcfg->memzone_idx >= RTE_MAX_MEMZONE) {
+	if (mcfg->memzone_cnt >= RTE_MAX_MEMZONE) {
 		RTE_LOG(ERR, EAL, "%s(): No more room in config\n", __func__);
 		rte_errno = ENOSPC;
 		return NULL;
@@ -215,7 +232,16 @@ memzone_reserve_aligned_thread_unsafe(const char *name, size_t len,
 	const struct malloc_elem *elem = malloc_elem_from_data(mz_addr);
 
 	/* fill the zone in config */
-	struct rte_memzone *mz = &mcfg->memzone[mcfg->memzone_idx++];
+	struct rte_memzone *mz = get_next_free_memzone();
+
+	if (mz == NULL) {
+		RTE_LOG(ERR, EAL, "%s(): Cannot find free memzone but there is room "
+				"in config!\n", __func__);
+		rte_errno = ENOSPC;
+		return NULL;
+	}
+
+	mcfg->memzone_cnt++;
 	snprintf(mz->name, sizeof(mz->name), "%s", name);
 	mz->phys_addr = rte_malloc_virt2phy(mz_addr);
 	mz->addr = mz_addr;
@@ -291,6 +317,41 @@ rte_memzone_reserve_bounded(const char *name, size_t len,
 	return mz;
 }
 
+int
+rte_memzone_free(const struct rte_memzone *mz)
+{
+	struct rte_mem_config *mcfg;
+	int ret = 0;
+	void *addr;
+	unsigned idx;
+
+	if (mz == NULL)
+		return -EINVAL;
+
+	mcfg = rte_eal_get_configuration()->mem_config;
+
+	rte_rwlock_write_lock(&mcfg->mlock);
+
+	idx = ((uintptr_t)mz - (uintptr_t)mcfg->memzone);
+	idx = idx / sizeof(struct rte_memzone);
+
+	addr = mcfg->memzone[idx].addr;
+	if (addr == NULL)
+		ret = -EINVAL;
+	else if (mcfg->memzone_cnt == 0) {
+		rte_panic("%s(): memzone address not NULL but memzone_cnt is 0!\n",
+				__func__);
+	} else {
+		memset(&mcfg->memzone[idx], 0, sizeof(mcfg->memzone[idx]));
+		mcfg->memzone_cnt--;
+	}
+
+	rte_rwlock_write_unlock(&mcfg->mlock);
+
+	rte_free(addr);
+
+	return ret;
+}
 
 /*
  * Lookup for the memzone identified by the given name
@@ -364,7 +425,7 @@ rte_eal_memzone_init(void)
 	rte_rwlock_write_lock(&mcfg->mlock);
 
 	/* delete all zones */
-	mcfg->memzone_idx = 0;
+	mcfg->memzone_cnt = 0;
 	memset(mcfg->memzone, 0, sizeof(mcfg->memzone));
 
 	rte_rwlock_write_unlock(&mcfg->mlock);
diff --git a/lib/librte_eal/common/include/rte_eal_memconfig.h b/lib/librte_eal/common/include/rte_eal_memconfig.h
index 7de906b..2b5e0b1 100644
--- a/lib/librte_eal/common/include/rte_eal_memconfig.h
+++ b/lib/librte_eal/common/include/rte_eal_memconfig.h
@@ -67,7 +67,7 @@ struct rte_mem_config {
 	rte_rwlock_t qlock;   /**< used for tailq operation for thread safe. */
 	rte_rwlock_t mplock;  /**< only used by mempool LIB for thread-safe. */
 
-	uint32_t memzone_idx; /**< Index of memzone */
+	uint32_t memzone_cnt; /**< Number of allocated memzones */
 
 	/* memory segments and zones */
 	struct rte_memseg memseg[RTE_MAX_MEMSEG];    /**< Physmem descriptors. */
diff --git a/lib/librte_eal/common/include/rte_memzone.h b/lib/librte_eal/common/include/rte_memzone.h
index ee62680..5223b1e 100644
--- a/lib/librte_eal/common/include/rte_memzone.h
+++ b/lib/librte_eal/common/include/rte_memzone.h
@@ -240,6 +240,17 @@ const struct rte_memzone *rte_memzone_reserve_bounded(const char *name,
 			unsigned flags, unsigned align, unsigned bound);
 
 /**
+ * Free a memzone.
+ *
+ * @param mz
+ *   A pointer to the memzone
+ * @return
+ *  -EINVAL - invalid parameter
+ *  0 - success
+ */
+int rte_memzone_free(const struct rte_memzone *mz);
+
+/**
  * Lookup for a memzone.
  *
  * Get a pointer to a descriptor of an already reserved memory
diff --git a/lib/librte_eal/linuxapp/eal/eal_ivshmem.c b/lib/librte_eal/linuxapp/eal/eal_ivshmem.c
index facfb80..589019b 100644
--- a/lib/librte_eal/linuxapp/eal/eal_ivshmem.c
+++ b/lib/librte_eal/linuxapp/eal/eal_ivshmem.c
@@ -768,12 +768,12 @@ rte_eal_ivshmem_obj_init(void)
 		seg = &ivshmem_config->segment[i];
 
 		/* add memzone */
-		if (mcfg->memzone_idx == RTE_MAX_MEMZONE) {
+		if (mcfg->memzone_cnt == RTE_MAX_MEMZONE) {
 			RTE_LOG(ERR, EAL, "No more memory zones available!\n");
 			return -1;
 		}
 
-		idx = mcfg->memzone_idx;
+		idx = mcfg->memzone_cnt;
 
 		RTE_LOG(DEBUG, EAL, "Found memzone: '%s' at %p (len 0x%" PRIx64 ")\n",
 				seg->entry.mz.name, seg->entry.mz.addr, seg->entry.mz.len);
@@ -796,13 +796,13 @@ rte_eal_ivshmem_obj_init(void)
 			}
 		}
 
-		mcfg->memzone_idx++;
+		mcfg->memzone_cnt++;
 	}
 
 	rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);
 
 	/* find rings */
-	for (i = 0; i < mcfg->memzone_idx; i++) {
+	for (i = 0; i < mcfg->memzone_cnt; i++) {
 		mz = &mcfg->memzone[i];
 
 		/* check if memzone has a ring prefix */
diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
index c107b05..e537b42 100644
--- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
@@ -111,3 +111,9 @@ DPDK_2.0 {
 
 	local: *;
 };
+
+DPDK_2.1 {
+	global:
+
+	rte_memzone_free;
+} DPDK_2.0;
-- 
1.9.3