hw/phb5: Add support for 'Address-Based Interrupt Trigger' mode

The PHB5 introduces a new Address-Based Interrupt mode which extends
the notification offloading to the ESB pages. When ABT is activated,
the PHB maps the interrupt source number into the interrupt command
address. The PHB triggers the interrupt using directly the IC ESB page
of the interrupt number and does not use the notify page of the IC
anymore.

The PHB interrrupt configuration under ABT is a little different. The
'Interrupt Notify Base Address' register points to the base address of
the IC ESB pages and not to the notify page of the IC anymore as on
P9. The 'Interrupt Notify Base Index' register is unused.

This should improve overall performance. The P10 IC can handle higher
interrupt rates compared to P9 and the PHB latency should be improved
under ABT. Debug is easier as the interrupt number is now exposed on
the PowerBUS.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[FB: port to phb4.c]
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/hw/xive2.c b/hw/xive2.c
index 49c9467..125e3fb 100644
--- a/hw/xive2.c
+++ b/hw/xive2.c
@@ -2140,12 +2140,6 @@ uint64_t xive2_get_notify_port(uint32_t chip_id, uint32_t ent)
 	 *
 	 * P10 might now be randomizing the cache line bits in HW to
 	 * balance snoop bus usage
-	 *
-	 * TODO (phb5) : implement "address based triggers" (DD2.0?)
-	 *
-	 * The PHBs would no longer target the notify port page but
-	 * the "base ESB MMIO address" of the ESB/EAS range they are
-	 * allocated. Needs a XIVE API change for the PHBs.
 	 */
 	switch(ent) {
 	case XIVE_HW_SRC_PHBn(0):