soc/amd/picasso: move smm_region to soc/amd/common/block/cpu/noncar

The same functionality is needed on Cezanne.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I40f9d2fe7d144e94369a417225bcca0a299d1f45
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50400
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

1 files changed, 54 insertions, 2 deletions

diff --git a/src/soc/amd/common/block/cpu/noncar/memmap.c b/src/soc/amd/common/block/cpu/noncar/memmap.c
index 9efe959d4d..470b51785e 100644
--- a/src/soc/amd/common/block/cpu/noncar/memmap.c
+++ b/src/soc/amd/common/block/cpu/noncar/memmap.c
@@ -1,9 +1,14 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
-#include <stdint.h>
+#include <amdblocks/memmap.h>
 #include <console/console.h>
 #include <cbmem.h>
-#include <amdblocks/memmap.h>
+#include <cpu/amd/msr.h>
+#include <cpu/x86/smm.h>
+#include <fsp/util.h>
+#include <FspGuids.h>
+#include <memrange.h>
+#include <stdint.h>
 
 void memmap_stash_early_dram_usage(void)
 {
@@ -27,3 +32,50 @@ const struct memmap_early_dram *memmap_get_early_dram_usage(void)
 
 	return e;
 }
+
+/*
+ * For data stored in TSEG, ensure TValid is clear so R/W access can reach
+ * the DRAM when not in SMM.
+ */
+static void clear_tvalid(void)
+{
+	msr_t hwcr = rdmsr(HWCR_MSR);
+	msr_t mask = rdmsr(SMM_MASK_MSR);
+	int tvalid = !!(mask.lo & SMM_TSEG_VALID);
+
+	if (hwcr.lo & SMM_LOCK) {
+		if (!tvalid) /* not valid but locked means still accessible */
+			return;
+
+		printk(BIOS_ERR, "Error: can't clear TValid, already locked\n");
+		return;
+	}
+
+	mask.lo &= ~SMM_TSEG_VALID;
+	wrmsr(SMM_MASK_MSR, mask);
+}
+
+void smm_region(uintptr_t *start, size_t *size)
+{
+	static int once;
+	struct range_entry tseg;
+	int status;
+
+	*start = 0;
+	*size = 0;
+
+	status = fsp_find_range_hob(&tseg, AMD_FSP_TSEG_HOB_GUID.b);
+
+	if (status < 0) {
+		printk(BIOS_ERR, "Error: unable to find TSEG HOB\n");
+		return;
+	}
+
+	*start = (uintptr_t)range_entry_base(&tseg);
+	*size = range_entry_size(&tseg);
+
+	if (!once) {
+		clear_tvalid();
+		once = 1;
+	}
+}