Commit fa5ab66e authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Jon Mason
Browse files

NTB: Add check and comment for link up to mw_count() and mw_get_align() 



Adds a comment and a check to ntb_mw_get_align() so that it always fails
if the function is called before the link is up.

Also adds a comment to ntb_mw_count() to note that it may return 0 if
it is called before the link is up.

This is to prevent accidental mis-use in clients that are testing
on hardware that this doesn't matter for.

Signed-off-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Acked-by: default avatarAllen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
parent 980c41c8

include/linux/ntb.h

+6 −2
Original line number Diff line number Diff line
@@ -730,7 +730,8 @@ static inline int ntb_link_disable(struct ntb_dev *ntb) 
 * Hardware and topology may support a different number of memory windows.

 * Moreover different peer devices can support different number of memory

 * windows. Simply speaking this method returns the number of possible inbound

 * memory windows to share with specified peer device.

 * memory windows to share with specified peer device. Note: this may return

 * zero if the link is not up yet.

 *

 * Return: the number of memory windows.

 */
@@ -751,7 +752,7 @@ static inline int ntb_mw_count(struct ntb_dev *ntb, int pidx) 
 * Get the alignments of an inbound memory window with specified index.

 * NULL may be given for any output parameter if the value is not needed.

 * The alignment and size parameters may be used for allocation of proper

 * shared memory.

 * shared memory. Note: this must only be called when the link is up.

 *

 * Return: Zero on success, otherwise a negative error number.

 */
@@ -760,6 +761,9 @@ static inline int ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int widx, 
				   resource_size_t *size_align,

				   resource_size_t *size_max)

{

	if (!(ntb_link_is_up(ntb, NULL, NULL) & (1 << pidx)))

		return -ENOTCONN;



	return ntb->ops->mw_get_align(ntb, pidx, widx, addr_align, size_align,

				      size_max);

}

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