mb,sb,soc/intel: Drop useless IO trap handlers

There are four requirements for the SMI to hit a printk()
this commit now removes.

Build must have DEBUG_SMI=y, otherwise any printk() is a no-op
inside SMM.
ASL must have a TRAP() with argument 0x99 or 0x32 for SMIF value.
Platform needs to have IO Trap #3 enabled at IO 0x800.
The SMI monitor must call io_trap_handler for IO Trap #3.

At the moment, only getac/p470 would meet the above criteria
with TRAP(0x32) in its DSDT _INI method. The ASL ignores any
return value of TRAP() calls made.

A mainboard IO trap handler should have precedence over
a southbridge IO trap handler. At the moment we seem to have
no cases of the latter to support, so remove the latter.

Change-Id: I3a3298c8d9814db8464fbf7444c6e0e6ac6ac008
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70365
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

1 files changed, 0 insertions, 17 deletions

diff --git a/src/soc/intel/broadwell/pch/smihandler.c b/src/soc/intel/broadwell/pch/smihandler.c
index b9d5e5048201..14d08af7af86 100644
--- a/src/soc/intel/broadwell/pch/smihandler.c
+++ b/src/soc/intel/broadwell/pch/smihandler.c
@@ -23,23 +23,6 @@
 #include <drivers/intel/gma/i915_reg.h>
 #include <smmstore.h>
 
-int southbridge_io_trap_handler(int smif)
-{
-	switch (smif) {
-	case 0x32:
-		printk(BIOS_DEBUG, "OS Init\n");
-		/* gnvs->smif:
-		 *  On success, the IO Trap Handler returns 0
-		 *  On failure, the IO Trap Handler returns a value != 0
-		 */
-		gnvs->smif = 0;
-		return 1; /* IO trap handled */
-	}
-
-	/* Not handled */
-	return 0;
-}
-
 /**
  * @brief Set the EOS bit
  */