ahci: per-port msix support
Some AHCI controllers support per-port MSI-X vectors. At the same time
the Linux AHCI driver needs to support one-off architectures that
implement a single MSI-X vector for all ports. The heuristic for
enabling AHCI ports becomes, in order of preference:
1/ per-port multi-MSI-X
2/ per-port multi-MSI
3/ single MSI
4/ single MSI-X
5/ legacy INTX
This all depends on AHCI implementations with potentially broken MSI-X
requesting less vectors than the number of ports. If this assumption is
violated we will need to start explicitly white-listing AHCI-MSIX
implementations.
Reported-by: Ricardo Neri <ricardo.neri@intel.com>
[ricardo: fix struct msix_entry handling]
Reported-by: kernel test robot <ying.huang@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 45586c1..9e60c50 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -242,6 +242,7 @@
AHCI_HFLAG_NO_FBS = (1 << 18), /* no FBS */
AHCI_HFLAG_EDGE_IRQ = (1 << 19), /* HOST_IRQ_STAT behaves as
Edge Triggered */
+ AHCI_HFLAG_MULTI_MSIX = (1 << 20), /* per-port MSI-X */
/* ap->flags bits */
@@ -343,6 +344,7 @@
* the PHY position in this array.
*/
struct phy **phys;
+ struct msix_entry *msix; /* Optional MSI-X support */
unsigned nports; /* Number of ports */
void *plat_data; /* Other platform data */
unsigned int irq; /* interrupt line */