[PATCH v1 1/3] gpudev: mem alloc aligned memory

[<eagostini@nvidia.com>]

From: Elena Agostini <eagostini@nvidia.com>

Similarly to rte_malloc, rte_gpu_mem_alloc accept as
input the memory alignment size.

GPU driver should return GPU memory address aligned
with the input value.

Signed-off-by: Elena Agostini <eagostini@nvidia.com>
---
 lib/gpudev/gpudev.c        | 10 ++++++++--
 lib/gpudev/gpudev_driver.h |  2 +-
 lib/gpudev/rte_gpudev.h    | 10 +++++++---
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/lib/gpudev/gpudev.c b/lib/gpudev/gpudev.c
index 9ae36dbae9..dc8c3baefa 100644
--- a/lib/gpudev/gpudev.c
+++ b/lib/gpudev/gpudev.c
@@ -527,7 +527,7 @@ rte_gpu_info_get(int16_t dev_id, struct rte_gpu_info *info)
 }
 
 void *
-rte_gpu_mem_alloc(int16_t dev_id, size_t size)
+rte_gpu_mem_alloc(int16_t dev_id, size_t size, unsigned int align)
 {
 	struct rte_gpu *dev;
 	void *ptr;
@@ -549,7 +549,13 @@ rte_gpu_mem_alloc(int16_t dev_id, size_t size)
 	if (size == 0) /* dry-run */
 		return NULL;
 
-	ret = dev->ops.mem_alloc(dev, size, &ptr);
+	if (align && !rte_is_power_of_2(align)) {
+		GPU_LOG(ERR, "requested alignment is not a power of two %u", align);
+		rte_errno = EINVAL;
+		return NULL;
+	}
+
+	ret = dev->ops.mem_alloc(dev, size, &ptr, align);
 
 	switch (ret) {
 	case 0:
diff --git a/lib/gpudev/gpudev_driver.h b/lib/gpudev/gpudev_driver.h
index cb7b101f2f..d06f465194 100644
--- a/lib/gpudev/gpudev_driver.h
+++ b/lib/gpudev/gpudev_driver.h
@@ -27,7 +27,7 @@ enum rte_gpu_state {
 struct rte_gpu;
 typedef int (rte_gpu_close_t)(struct rte_gpu *dev);
 typedef int (rte_gpu_info_get_t)(struct rte_gpu *dev, struct rte_gpu_info *info);
-typedef int (rte_gpu_mem_alloc_t)(struct rte_gpu *dev, size_t size, void **ptr);
+typedef int (rte_gpu_mem_alloc_t)(struct rte_gpu *dev, size_t size, void **ptr, unsigned int align);
 typedef int (rte_gpu_mem_free_t)(struct rte_gpu *dev, void *ptr);
 typedef int (rte_gpu_mem_register_t)(struct rte_gpu *dev, size_t size, void *ptr);
 typedef int (rte_gpu_mem_unregister_t)(struct rte_gpu *dev, void *ptr);
diff --git a/lib/gpudev/rte_gpudev.h b/lib/gpudev/rte_gpudev.h
index fa3f3aad4f..9e2e2c5dce 100644
--- a/lib/gpudev/rte_gpudev.h
+++ b/lib/gpudev/rte_gpudev.h
@@ -364,18 +364,22 @@ int rte_gpu_info_get(int16_t dev_id, struct rte_gpu_info *info);
  * @param size
  *   Number of bytes to allocate.
  *   Requesting 0 will do nothing.
- *
+ * @param align
+ *   If 0, the return is a pointer that is suitably aligned for any kind of
+ *   variable (in the same manner as malloc()).
+ *   Otherwise, the return is a pointer that is a multiple of *align*. In
+ *   this case, it must obviously be a power of two.
  * @return
  *   A pointer to the allocated memory, otherwise NULL and rte_errno is set:
  *   - ENODEV if invalid dev_id
- *   - EINVAL if reserved flags
+ *   - EINVAL if align is not a power of two
  *   - ENOTSUP if operation not supported by the driver
  *   - E2BIG if size is higher than limit
  *   - ENOMEM if out of space
  *   - EPERM if driver error
  */
 __rte_experimental
-void *rte_gpu_mem_alloc(int16_t dev_id, size_t size)
+void *rte_gpu_mem_alloc(int16_t dev_id, size_t size, unsigned int align)
 __rte_alloc_size(2);
 
 /**
-- 
2.17.1