crypto: ccp - Add support for displaying PSP firmware versions

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@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 64 insertions, 0 deletions

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@amd.com>
  */
 
+#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,
 };