Change in coreboot[master]: drivers/wifi/generic: Add support for UntrustedDevice ACPI property

[Felix Held (Code Review)]

Felix Held has submitted this change. ( https://review.coreboot.org/c/coreboot/+/61384 )

Change subject: drivers/wifi/generic: Add support for UntrustedDevice ACPI property
......................................................................

drivers/wifi/generic: Add support for UntrustedDevice ACPI property

The Linux kernel has the idea of an "untrusted" PCI device, which may
have limited I/O and memory access permissions, depending on which IOMMU
domains it may be a part of.

https://crrev.com/c/3406512 is a backport to the ChromiumOS kernel which
checks for this property.

BUG=b:215424986
TEST=dump SSDT on google/redrix, verify it contains the expected
UntrustedDevice property

Change-Id: I1a02ca7c5f717097ec97cf6373b9e0b81a13e05d
Signed-off-by: Tim Wawrzynczak 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61384
Tested-by: build bot (Jenkins) 
Reviewed-by: Subrata Banik 
Reviewed-by: Kangheui Won 
---
M src/drivers/wifi/generic/acpi.c
M src/drivers/wifi/generic/chip.h
2 files changed, 20 insertions(+), 2 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Kangheui Won: Looks good to me, but someone else must approve
  Subrata Banik: Looks good to me, approved

diff --git a/src/drivers/wifi/generic/acpi.c b/src/drivers/wifi/generic/acpi.c
index 3cc1c63..f4ffa5e 100644
--- a/src/drivers/wifi/generic/acpi.c
+++ b/src/drivers/wifi/generic/acpi.c
@@ -26,6 +26,9 @@
 /* Unique ID for the WIFI _DSM */
 #define ACPI_DSM_OEM_WIFI_UUID    "F21202BF-8F78-4DC6-A5B3-1F738E285ADE"

+/* Unique ID for the Wifi _DSD */
+#define ACPI_DSD_UNTRUSTED_UUID	  "88566a92-1a61-466d-949a-6d12809d480c"
+
 __weak int get_wifi_sar_limits(union wifi_sar_limits *sar_limits)
 {
    return -1;
@@ -508,10 +511,22 @@
    /* Scope */
    acpigen_write_scope(scope);

-	/* Wake capabilities */
-	if (config)
+	if (config) {
+		/* Wake capabilities */
    	acpigen_write_PRW(config->wake, ACPI_S3);

+		/* Add _DSD for UntrustedDevice property. */
+		if (config->is_untrusted) {
+			struct acpi_dp *dsd, *pkg;
+
+			dsd = acpi_dp_new_table("_DSD");
+			pkg = acpi_dp_new_table(ACPI_DSD_UNTRUSTED_UUID);
+			acpi_dp_add_integer(pkg, "UntrustedDevice", 1);
+			acpi_dp_add_package(dsd, pkg);
+			acpi_dp_write(dsd);
+		}
+	}
+
    /* Fill regulatory domain structure */
    if (CONFIG(HAVE_REGULATORY_DOMAIN)) {
    	/*
diff --git a/src/drivers/wifi/generic/chip.h b/src/drivers/wifi/generic/chip.h
index e3b0ba5..35726f2 100644
--- a/src/drivers/wifi/generic/chip.h
+++ b/src/drivers/wifi/generic/chip.h
@@ -9,6 +9,9 @@
  */
 struct drivers_wifi_generic_config {
    unsigned int wake;
+	/* When set to true, this will add a _DSD which contains a single
+	   property, `UntrustedDevice`, set to 1, to the ACPI Device. */
+	bool is_untrusted;
 };

#endif /* _GENERIC_WIFI_H_ */