southbridge/amd/agesa/hudson: Add initial support for SMM

This sets up the infrastructure to handle SMIs generated by the Hudson
southbridge. An API for interfacing to mainboard handlers is not
defined at this point. A few functions are defined to allow mainboard
code to enable SMIs from GEVENT pins. These are the only functions which
I expect to be needed anytime in the foreseeable future.

SMIs are always acknowledged and cleared, as not clearing an SMI will
cause us to re-enter the SMI, effectively bricking the machine if a
southbridge-generated SMI without a handler occurs.

Change-Id: Ibceb21ac5423eb134d3eb7d24800280b183f7619
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/5494
Reviewed-by: Aaron Durbin <adurbin@gmail.com>
Tested-by: build bot (Jenkins)

1 files changed, 100 insertions, 0 deletions

diff --git a/src/southbridge/amd/agesa/hudson/smihandler.c b/src/southbridge/amd/agesa/hudson/smihandler.c
new file mode 100644
index 0000000000..0bf0cdd1d3
--- /dev/null
+++ b/src/southbridge/amd/agesa/hudson/smihandler.c
@@ -0,0 +1,100 @@
+/*
+ * SMI handler for Hudson southbridges
+ *
+ * Copyright (C) 2014 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ * Subject to the GNU GPL v2, or (at your option) any later version.
+ */
+
+#include "smi.h"
+
+#include <console/console.h>
+#include <cpu/x86/smm.h>
+#include <delay.h>
+
+
+enum smi_source {
+	SMI_SOURCE_SCI = (1 << 0),
+	SMI_SOURCE_GPE = (1 << 1),
+	SMI_SOURCE_0x84 = (1 << 2),
+	SMI_SOURCE_0x88 = (1 << 3),
+	SMI_SOURCE_IRQ_TRAP = (1 << 4),
+	SMI_SOURCE_0x90 = (1 << 5)
+};
+
+int southbridge_io_trap_handler(int smif)
+{
+	return 0;
+}
+
+static void process_smi_sci(void)
+{
+	const uint32_t status = smi_read32(0x10);
+
+	/* Clear events to prevent re-entering SMI if event isn't handled */
+	smi_write32(0x10, status);
+}
+
+static void process_gpe_smi(void)
+{
+	const uint32_t status = smi_read32(0x80);
+
+	/* Clear events to prevent re-entering SMI if event isn't handled */
+	smi_write32(0x80, status);
+}
+
+static void process_smi_0x84(void)
+{
+	const uint32_t status = smi_read32(0x84);
+
+	/* Clear events to prevent re-entering SMI if event isn't handled */
+	smi_write32(0x84, status);
+}
+
+static void process_smi_0x88(void)
+{
+	const uint32_t status = smi_read32(0x88);
+
+	/* Clear events to prevent re-entering SMI if event isn't handled */
+	smi_write32(0x88, status);
+}
+
+static void process_smi_0x8c(void)
+{
+	const uint32_t status = smi_read32(0x8c);
+
+	/* Clear events to prevent re-entering SMI if event isn't handled */
+	smi_write32(0x8c, status);
+}
+
+static void process_smi_0x90(void)
+{
+	const uint32_t status = smi_read32(0x90);
+
+	/* Clear events to prevent re-entering SMI if event isn't handled */
+	smi_write32(0x90, status);
+}
+
+void southbridge_smi_handler(unsigned int node, smm_state_save_area_t *state_save)
+{
+	const uint16_t smi_src = smi_read16(0x94);
+
+	if (smi_src & SMI_SOURCE_SCI)
+		process_smi_sci();
+	if (smi_src & SMI_SOURCE_GPE)
+		process_gpe_smi();
+	if (smi_src & SMI_SOURCE_0x84)
+		process_smi_0x84();
+	if (smi_src & SMI_SOURCE_0x88)
+		process_smi_0x88();
+	if (smi_src & SMI_SOURCE_IRQ_TRAP)
+		process_smi_0x8c();
+	if (smi_src & SMI_SOURCE_0x90)
+		process_smi_0x90();
+}
+
+void southbridge_smi_set_eos(void)
+{
+	uint32_t reg = smi_read32(SMI_REG_SMITRIG0);
+	reg |= SMITRG0_EOS;
+	smi_write32(SMI_REG_SMITRIG0, reg);
+}