[PATCH v3 02/10] crypto: ccp: Add support for displaying PSP firmware versions

[Mario Limonciello]

As it's not always obvious what PSP bootloader or TEE version are
present in OEM systems, add the ability to get this information from
sysfs for supported platforms.

Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
v2->v3:
 * Pick up tag
v1->v2:
 * Move GENMASK declarations to top of the file
 * Add comment to support why checking for 0xffffffff
---
 Documentation/ABI/testing/sysfs-driver-ccp | 18 ++++++
 drivers/crypto/ccp/sp-dev.h                |  2 +
 drivers/crypto/ccp/sp-pci.c                | 64 ++++++++++++++++++++++
 3 files changed, 84 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-driver-ccp b/Documentation/ABI/testing/sysfs-driver-ccp
index 7aded9b75553..ee6b787eee7a 100644
--- a/Documentation/ABI/testing/sysfs-driver-ccp
+++ b/Documentation/ABI/testing/sysfs-driver-ccp
@@ -85,3 +85,21 @@ Description:
 		Possible values:
 		0: Not enforced
 		1: Enforced
+
+What:		/sys/bus/pci/devices/<BDF>/bootloader_version
+Date:		June 2023
+KernelVersion:	6.4
+Contact:	mario.limonciello@xxxxxxx
+Description:
+		The /sys/bus/pci/devices/<BDF>/bootloader_version
+		file reports the firmware version of the AMD AGESA
+		bootloader.
+
+What:		/sys/bus/pci/devices/<BDF>/tee_version
+Date:		June 2023
+KernelVersion:	6.4
+Contact:	mario.limonciello@xxxxxxx
+Description:
+		The /sys/bus/pci/devices/<BDF>/tee_version
+		file reports the firmware version of the AMD Trusted
+		Execution Environment (TEE).
diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h
index 1253a0217985..76c32ee6bd65 100644
--- a/drivers/crypto/ccp/sp-dev.h
+++ b/drivers/crypto/ccp/sp-dev.h
@@ -51,6 +51,7 @@ struct tee_vdata {
 	const unsigned int cmdbuff_addr_hi_reg;
 	const unsigned int ring_wptr_reg;
 	const unsigned int ring_rptr_reg;
+	const unsigned int info_reg;
 };
 
 struct platform_access_vdata {
@@ -69,6 +70,7 @@ struct psp_vdata {
 	const unsigned int feature_reg;
 	const unsigned int inten_reg;
 	const unsigned int intsts_reg;
+	const unsigned int bootloader_info_reg;
 };
 
 /* Structure to hold SP device data */
diff --git a/drivers/crypto/ccp/sp-pci.c b/drivers/crypto/ccp/sp-pci.c
index c8f075a7f49f..6c93577950c7 100644
--- a/drivers/crypto/ccp/sp-pci.c
+++ b/drivers/crypto/ccp/sp-pci.c
@@ -8,6 +8,7 @@
  * Author: Gary R Hook <gary.hook@xxxxxxx>
  */
 
+#include <linux/bitfield.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/device.h>
@@ -24,6 +25,12 @@
 #include "ccp-dev.h"
 #include "psp-dev.h"
 
+/* used for version string AA.BB.CC.DD */
+#define AA				GENMASK(31, 24)
+#define BB				GENMASK(23, 16)
+#define CC				GENMASK(15, 8)
+#define DD				GENMASK(7, 0)
+
 #define MSIX_VECTORS			2
 
 struct sp_pci {
@@ -88,8 +95,65 @@ static struct attribute_group psp_security_attr_group = {
 	.is_visible = psp_security_is_visible,
 };
 
+#define version_attribute_show(name, _offset)					\
+static ssize_t name##_show(struct device *d, struct device_attribute *attr,	\
+			   char *buf)						\
+{										\
+	struct sp_device *sp = dev_get_drvdata(d);				\
+	struct psp_device *psp = sp->psp_data;					\
+	unsigned int val = ioread32(psp->io_regs + _offset);			\
+	return sysfs_emit(buf, "%02lx.%02lx.%02lx.%02lx\n",			\
+			  FIELD_GET(AA, val),			\
+			  FIELD_GET(BB, val),			\
+			  FIELD_GET(CC, val),			\
+			  FIELD_GET(DD, val));			\
+}
+
+version_attribute_show(bootloader_version, psp->vdata->bootloader_info_reg)
+static DEVICE_ATTR_RO(bootloader_version);
+version_attribute_show(tee_version, psp->vdata->tee->info_reg)
+static DEVICE_ATTR_RO(tee_version);
+
+static struct attribute *psp_firmware_attrs[] = {
+	&dev_attr_bootloader_version.attr,
+	&dev_attr_tee_version.attr,
+	NULL,
+};
+
+static umode_t psp_firmware_is_visible(struct kobject *kobj, struct attribute *attr, int idx)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct sp_device *sp = dev_get_drvdata(dev);
+	struct psp_device *psp = sp->psp_data;
+	unsigned int val = 0xffffffff;
+
+	if (!psp)
+		return 0;
+
+	if (attr == &dev_attr_bootloader_version.attr &&
+	    psp->vdata->bootloader_info_reg)
+		val = ioread32(psp->io_regs + psp->vdata->bootloader_info_reg);
+
+	if (attr == &dev_attr_tee_version.attr &&
+	    psp->capability & PSP_CAPABILITY_TEE &&
+	    psp->vdata->tee->info_reg)
+		val = ioread32(psp->io_regs + psp->vdata->tee->info_reg);
+
+	/* If platform disallows accessing this register it will be all f's */
+	if (val != 0xffffffff)
+		return 0444;
+
+	return 0;
+}
+
+static struct attribute_group psp_firmware_attr_group = {
+	.attrs = psp_firmware_attrs,
+	.is_visible = psp_firmware_is_visible,
+};
+
 static const struct attribute_group *psp_groups[] = {
 	&psp_security_attr_group,
+	&psp_firmware_attr_group,
 	NULL,
 };
 
-- 
2.34.1