Commit f100ab62 authored by Rijo Thomas's avatar Rijo Thomas Committed by Herbert Xu
Browse files

crypto: ccp - check whether PSP supports SEV or TEE before initialization 



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@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Co-developed-by: default avatarDevaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: default avatarDevaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: default avatarRijo Thomas <Rijo-john.Thomas@amd.com>
Acked-by: default avatarGary R Hook <gary.hook@amd.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 6eb0cc72

drivers/crypto/ccp/psp-dev.c

+41 −5
Original line number Diff line number Diff line
@@ -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;

	}



	return val;

}



	if (!(val & 1)) {

		/* Device does not support the SEV feature */

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;