General Memory Interfaces

Defined by enum wd_buff_type:

Buffer Type	Description	Type Value
WD_FLAT_BUF	General buffer type	0
WD_SGL_BUF	Parent and child hash linked list buffer	1

For details about the SGL format, see SGL Memory Format Interfaces.

Prototype	typedef void (wd_alloc)(void *usr, size_t size);
Function	Apply for memory of a specified size based on the user memory mechanism usr.
Input Description	usr: user memory mechanism handle size: memory size
Output Description	None
Return Value Description	A non-NULL value: success, the start address of the memory NULL: failure
Usage Instruction	Currently, this interface is used to support the no-IOMMU and IOMMU-passthrough scenarios. This interface is not required in the SVA scenario.
Precautions	Multiple threads need to be supported.

Prototype	typedef void (wd_free)(void usr, void *va);
Function	Release the memory of the start address va based on the user memory mechanism usr.
Input Description	usr: user memory mechanism va: start address of the memory to be released
Output Description	None
Return Value Description	None
Usage Instruction	Currently, this interface is used to support the no-IOMMU and IOMMU-passthrough scenarios. This interface is not required in the SVA scenario.
Precautions	Multiple threads need to be supported.

Prototype	typedef void ( wd_map)(void usr, void va, size_t sz);
Function	Perform iova map on the memory of the start address va and size sz based on the user memory mechanism usr.
Input Description	usr: user memory mechanism va: start address of the memory on which iova map is performed sz: memory size
Output Description	None
Return Value Description	IOVA of corresponding VA is returned.
Usage Instruction	Currently, this interface is used to support the no-IOMMU and IOMMU-passthrough scenarios. This interface is not required in the SVA scenario. Southbound API
Precautions	Multiple threads need to be supported.

Prototype	typedef void (wd_unmap)(void usr, void va, void iova, size_t sz);
Function	Perform iova unmap on the memory of the start address va or iova and size sz based on the user memory mechanism usr.
Input Description	usr: user memory mechanism va: start address of the memory on which iova unmap is performed iova: start IOVA address sz: memory size
Output Description	None
Return Value Description	None
Usage Instruction	Currently, this interface is used to support the no-IOMMU and IOMMU-passthrough scenarios. This interface is not required in the SVA scenario. Southbound API
Precautions	Multiple threads need to be supported.

/* Memory brigde from user, it is given at ctx. While SVA, this interface is in no need */
struct wd_mm_br {
wd_alloc alloc;/* Memory allocation */
wd_free free;/* Memory free */
wd_map iova_map;     /* get iova from user space VA */
wd_unmap iova_unmap;    /* destroy the mapping between the PA of VA and iova */
void *usr; /* data for the above operations */
};

/* Warpdrive data buffer */
struct wd_dtb {
char *data;/* data/buffer start address */
__u32 dsize;/* data size */
__u32 bsize;/* buffer size */
};

Prototype	void wd_iova_map(struct wd_queue q, void *va, size_t sz);
Function	Perform iova map on the user-mode memory of the start address va and size sz based on the WD queue.
Input Description	q: source queue va: user-mode virtual address sz: memory size starting from va
Output Description	None
Return Value Description	A non-NULL value: IOVA address NULL: failure
Usage Instruction	Southbound API
Precautions	This interface is used to support the no-IOMMU and IOMMU-passthrough scenarios. Only virtual and physical address conversion is performed in the no-IOMMU mode.

Prototype	void wd_iova_unmap(struct wd_queue q, void va, void *iova, size_t sz);
Function	Perform iova unmap on the user-mode memory of the start address va or iova and size sz based on the WD queue.
Input Description	q: source queue va: user-mode virtual address iova: user-mode IOVA address sz: memory size
Output Description	None
Return Value Description	None
Usage Instruction	Southbound API
Precautions	This interface is used to support the no-IOMMU and IOMMU-passthrough scenarios. No operation is performed in the no-IOMMU mode.

Parent topic: WD Data Storage Formats and Memory Interfaces