Provide interrupt mapping information in PCI config registers.

Use system-specific information to program the interrupt line register
with the interrupt mappings, which is what the SRM console does on real
hardware; some operating systems (e.g. NetBSD) use this information
rather than having interrupt mappings tables for every possible system
variation.

Signed-off-by: Jason Thorpe <thorpej@me.com>
Message-Id: <20210603035317.6814-7-thorpej@me.com>
[rth: Use inline not macro; fold -1 -> 0xff map into interface.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/pci.c b/pci.c
index e60af55..351e5aa 100644
--- a/pci.c
+++ b/pci.c
@@ -29,6 +29,7 @@
 #include "protos.h"
 #include "pci.h"
 #include "pci_regs.h"
+#include SYSTEM_H
 
 
 #define PCI_SLOT_MAX		32
@@ -131,7 +132,16 @@ pci_setup_device(int bdf, uint32_t *p_io_base, uint32_t *p_mem_base)
 
   pci_config_maskw(bdf, PCI_COMMAND, 0, PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
 
-  /* Map the interrupt.  */
+  /* Map the interrupt and program the IRQ into the line register.
+     Some operating systems rely on the Console providing this information
+     in order to avoid having mapping tables for every possible system
+     variation.  */
+
+  const uint8_t pin = pci_config_readb(bdf, PCI_INTERRUPT_PIN);
+  const uint8_t slot = PCI_SLOT(bdf);
+  const uint8_t irq = MAP_PCI_INTERRUPT(slot, pin, class_id);
+
+  pci_config_writeb(bdf, PCI_INTERRUPT_LINE, irq);
 }
 
 void