[PATCH] crypto: ccp - Consolidate sev INIT logic

[Peter Gonda]

Adds new helper function sev_init_if_required() for use in sev_ioctl().
The function calls __sev_platform_init_locked() if the command requires
the PSP's internal state be at least SEV_STATE_INIT. This consolidates
many checks scattered through out the ioctl delegation functions.

Signed-off-by: Peter Gonda <pgonda@xxxxxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
Cc: Marc Orr <marcorr@xxxxxxxxxx>
Cc: Joerg Roedel <jroedel@xxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: John Allen <john.allen@xxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: linux-crypto@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
 drivers/crypto/ccp/sev-dev.c | 63 +++++++++++++++---------------------
 1 file changed, 26 insertions(+), 37 deletions(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index e09925d86bf3..071d57fec4c4 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -386,24 +386,14 @@ static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
 
 static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
 {
-	struct sev_device *sev = psp_master->sev_data;
-	int rc;
-
 	if (!writable)
 		return -EPERM;
 
-	if (sev->state == SEV_STATE_UNINIT) {
-		rc = __sev_platform_init_locked(&argp->error);
-		if (rc)
-			return rc;
-	}
-
 	return __sev_do_cmd_locked(cmd, NULL, &argp->error);
 }
 
 static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
 {
-	struct sev_device *sev = psp_master->sev_data;
 	struct sev_user_data_pek_csr input;
 	struct sev_data_pek_csr data;
 	void __user *input_address;
@@ -435,12 +425,6 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
 	data.len = input.length;
 
 cmd:
-	if (sev->state == SEV_STATE_UNINIT) {
-		ret = __sev_platform_init_locked(&argp->error);
-		if (ret)
-			goto e_free_blob;
-	}
-
 	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);
 
 	 /* If we query the CSR length, FW responded with expected data. */
@@ -586,7 +570,6 @@ static int sev_update_firmware(struct device *dev)
 
 static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
 {
-	struct sev_device *sev = psp_master->sev_data;
 	struct sev_user_data_pek_cert_import input;
 	struct sev_data_pek_cert_import data;
 	void *pek_blob, *oca_blob;
@@ -617,17 +600,10 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
 	data.oca_cert_address = __psp_pa(oca_blob);
 	data.oca_cert_len = input.oca_cert_len;
 
-	/* If platform is not in INIT state then transition it to INIT */
-	if (sev->state != SEV_STATE_INIT) {
-		ret = __sev_platform_init_locked(&argp->error);
-		if (ret)
-			goto e_free_oca;
-	}
-
 	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);
 
-e_free_oca:
 	kfree(oca_blob);
+
 e_free_pek:
 	kfree(pek_blob);
 	return ret;
@@ -730,7 +706,6 @@ static int sev_ioctl_do_get_id(struct sev_issue_cmd *argp)
 
 static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
 {
-	struct sev_device *sev = psp_master->sev_data;
 	struct sev_user_data_pdh_cert_export input;
 	void *pdh_blob = NULL, *cert_blob = NULL;
 	struct sev_data_pdh_cert_export data;
@@ -738,16 +713,6 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
 	void __user *input_pdh_cert_address;
 	int ret;
 
-	/* If platform is not in INIT state then transition it to INIT. */
-	if (sev->state != SEV_STATE_INIT) {
-		if (!writable)
-			return -EPERM;
-
-		ret = __sev_platform_init_locked(&argp->error);
-		if (ret)
-			return ret;
-	}
-
 	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
 		return -EFAULT;
 
@@ -819,6 +784,26 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
 	return ret;
 }
 
+static int sev_init_if_required(int cmd_id, bool writable,
+				struct sev_issue_cmd *argp)
+{
+	struct sev_device *sev = psp_master->sev_data;
+
+	lockdep_assert_held(&sev_cmd_mutex);
+
+	if (!writable)
+		return -EPERM;
+
+	if (cmd_id == SEV_FACTORY_RESET || cmd_id == SEV_PLATFORM_STATUS ||
+	    cmd_id == SEV_GET_ID || cmd_id == SEV_GET_ID2)
+		return 0;
+
+	if (sev->state == SEV_STATE_UNINIT)
+		return __sev_platform_init_locked(&argp->error);
+
+	return 0;
+}
+
 static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
@@ -840,8 +825,11 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 
 	mutex_lock(&sev_cmd_mutex);
 
-	switch (input.cmd) {
+	ret = sev_init_if_required(input.cmd, writable, &input);
+	if (ret)
+		goto copy_out;
 
+	switch (input.cmd) {
 	case SEV_FACTORY_RESET:
 		ret = sev_ioctl_do_reset(&input, writable);
 		break;
@@ -875,6 +863,7 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 		goto out;
 	}
 
+copy_out:
 	if (copy_to_user(argp, &input, sizeof(struct sev_issue_cmd)))
 		ret = -EFAULT;
 out:
-- 
2.33.0.800.g4c38ced690-goog