[dpdk-dev] [PATCH v6 36/70] eal: add iova2virt function

[Anatoly Burakov]

This is reverse lookup of PA to VA. Using this will make
other code less dependent on internals of mem API.

Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
Tested-by: Santosh Shukla <santosh.shu...@caviumnetworks.com>
Tested-by: Hemant Agrawal <hemant.agra...@nxp.com>
Tested-by: Gowrishankar Muthukrishnan <gowrishanka...@linux.vnet.ibm.com>
---
 lib/librte_eal/common/eal_common_memory.c  | 30 ++++++++++++++++++++++++++++++
 lib/librte_eal/common/include/rte_memory.h | 12 ++++++++++++
 lib/librte_eal/rte_eal_version.map         |  1 +
 3 files changed, 43 insertions(+)

diff --git a/lib/librte_eal/common/eal_common_memory.c 
b/lib/librte_eal/common/eal_common_memory.c
index 4b528b0..ea3c5a7 100644
--- a/lib/librte_eal/common/eal_common_memory.c
+++ b/lib/librte_eal/common/eal_common_memory.c
@@ -131,6 +131,36 @@ rte_eal_get_physmem_layout(void)
        return rte_eal_get_configuration()->mem_config->memseg;
 }
 
+struct virtiova {
+       rte_iova_t iova;
+       void *virt;
+};
+static int
+find_virt(const struct rte_memseg *ms, void *arg)
+{
+       struct virtiova *vi = arg;
+       if (vi->iova >= ms->iova && vi->iova < (ms->iova + ms->len)) {
+               size_t offset = vi->iova - ms->iova;
+               vi->virt = RTE_PTR_ADD(ms->addr, offset);
+               /* stop the walk */
+               return 1;
+       }
+       return 0;
+}
+
+__rte_experimental void *
+rte_mem_iova2virt(rte_iova_t iova)
+{
+       struct virtiova vi;
+
+       memset(&vi, 0, sizeof(vi));
+
+       vi.iova = iova;
+       rte_memseg_walk(find_virt, &vi);
+
+       return vi.virt;
+}
+
 static int
 physmem_size(const struct rte_memseg *ms, void *arg)
 {
diff --git a/lib/librte_eal/common/include/rte_memory.h 
b/lib/librte_eal/common/include/rte_memory.h
index 45d067f..5c60b91 100644
--- a/lib/librte_eal/common/include/rte_memory.h
+++ b/lib/librte_eal/common/include/rte_memory.h
@@ -131,6 +131,18 @@ phys_addr_t rte_mem_virt2phy(const void *virt);
 rte_iova_t rte_mem_virt2iova(const void *virt);
 
 /**
+ * Get virtual memory address corresponding to iova address.
+ *
+ * @param iova
+ *   The iova address.
+ * @return
+ *   Virtual address corresponding to iova address (or NULL if address does not
+ *   exist within DPDK memory map).
+ */
+__rte_experimental void *
+rte_mem_iova2virt(rte_iova_t iova);
+
+/**
  * Memseg walk function prototype.
  *
  * Returning 0 will continue walk
diff --git a/lib/librte_eal/rte_eal_version.map 
b/lib/librte_eal/rte_eal_version.map
index 93033b5..dccfc35 100644
--- a/lib/librte_eal/rte_eal_version.map
+++ b/lib/librte_eal/rte_eal_version.map
@@ -223,6 +223,7 @@ EXPERIMENTAL {
        rte_eal_mbuf_user_pool_ops;
        rte_log_register_type_and_pick_level;
        rte_malloc_dump_heaps;
+       rte_mem_iova2virt;
        rte_memseg_contig_walk;
        rte_memseg_walk;
        rte_mp_action_register;
-- 
2.7.4