On 12/4/19 12:19 AM, Rijo Thomas wrote:
Read PSP feature register to check for TEE (Trusted Execution Environment)
support.
If neither SEV nor TEE is supported by PSP, then skip PSP initialization.
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Co-developed-by: Devaraj Rangasamy <Devaraj.Rangasamy@xxxxxxx>
Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@xxxxxxx>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@xxxxxxx>
Acked-by: Gary R Hook <gary.hook@xxxxxxx>
---
drivers/crypto/ccp/psp-dev.c | 46 +++++++++++++++++++++++++++++++++++++++-----
1 file changed, 41 insertions(+), 5 deletions(-)
diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 2cd7a5e..3bedf72 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -53,7 +53,7 @@ static irqreturn_t psp_irq_handler(int irq, void *data)
return IRQ_HANDLED;
}
-static int psp_check_sev_support(struct psp_device *psp)
+static unsigned int psp_get_capability(struct psp_device *psp)
{
unsigned int val = ioread32(psp->io_regs + psp->vdata->feature_reg);
@@ -66,11 +66,17 @@ static int psp_check_sev_support(struct psp_device *psp)
*/
if (val == 0xffffffff) {
dev_notice(psp->dev, "psp: unable to access the device: you might be running a broken BIOS.\n");
- return -ENODEV;
+ return 0;
}
- if (!(val & 1)) {
- /* Device does not support the SEV feature */
+ return val;
+}
+
+static int psp_check_sev_support(struct psp_device *psp,
+ unsigned int capability)
+{
+ /* Check if device supports SEV feature */
+ if (!(capability & 1)) {
dev_dbg(psp->dev, "psp does not support SEV\n");
return -ENODEV;
}
@@ -78,10 +84,36 @@ static int psp_check_sev_support(struct psp_device *psp)
return 0;
}
+static int psp_check_tee_support(struct psp_device *psp,
+ unsigned int capability)
+{
+ /* Check if device supports TEE feature */
+ if (!(capability & 2)) {
+ dev_dbg(psp->dev, "psp does not support TEE\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int psp_check_support(struct psp_device *psp,
+ unsigned int capability)
+{
+ int sev_support = psp_check_sev_support(psp, capability);
+ int tee_support = psp_check_tee_support(psp, capability);
+
+ /* Return error if device neither supports SEV nor TEE */
+ if (sev_support && tee_support)
+ return -ENODEV;
+
+ return 0;
+}
+
int psp_dev_init(struct sp_device *sp)
{
struct device *dev = sp->dev;
struct psp_device *psp;
+ unsigned int capability;
int ret;
ret = -ENOMEM;
@@ -100,7 +132,11 @@ int psp_dev_init(struct sp_device *sp)
psp->io_regs = sp->io_map;
- ret = psp_check_sev_support(psp);
+ capability = psp_get_capability(psp);
+ if (!capability)
+ goto e_disable;
+
+ ret = psp_check_support(psp, capability);
if (ret)
goto e_disable;
