[PATCH 4/4] crypto: ccree: notify TEE on FIPS tests errors

[Gilad Ben-Yossef]

Register a FIPS test failure notifier and use it to notify
TEE side of FIPS test failures on our side prior to panic.

Signed-off-by: Gilad Ben-Yossef <gi...@benyossef.com>
---
 drivers/crypto/ccree/cc_fips.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/crypto/ccree/cc_fips.c b/drivers/crypto/ccree/cc_fips.c
index 040e09c0e1af..4c8bce33abcf 100644
--- a/drivers/crypto/ccree/cc_fips.c
+++ b/drivers/crypto/ccree/cc_fips.c
@@ -3,6 +3,7 @@
 
 #include <linux/kernel.h>
 #include <linux/fips.h>
+#include <linux/notifier.h>
 
 #include "cc_driver.h"
 #include "cc_fips.h"
@@ -11,6 +12,8 @@ static void fips_dsr(unsigned long devarg);
 
 struct cc_fips_handle {
        struct tasklet_struct tasklet;
+       struct notifier_block nb;
+       struct cc_drvdata *drvdata;
 };
 
 /* The function called once at driver entry point to check
@@ -46,6 +49,21 @@ void cc_set_ree_fips_status(struct cc_drvdata *drvdata, bool 
status)
        cc_iowrite(drvdata, CC_REG(HOST_GPR0), val);
 }
 
+/* Push REE side FIPS test failure to TEE side */
+static int cc_ree_fips_failure(struct notifier_block *nb, unsigned long 
unused1,
+                              void *unused2)
+{
+       struct cc_fips_handle *fips_h =
+                               container_of(nb, struct cc_fips_handle, nb);
+       struct cc_drvdata *drvdata = fips_h->drvdata;
+       struct device *dev = drvdata_to_dev(drvdata);
+
+       cc_set_ree_fips_status(drvdata, false);
+       dev_info(dev, "Notifying TEE of FIPS test failure...\n");
+
+       return NOTIFY_OK;
+}
+
 void cc_fips_fini(struct cc_drvdata *drvdata)
 {
        struct cc_fips_handle *fips_h = drvdata->fips_handle;
@@ -53,6 +71,8 @@ void cc_fips_fini(struct cc_drvdata *drvdata)
        if (drvdata->hw_rev < CC_HW_REV_712 || !fips_h)
                return;
 
+       atomic_notifier_chain_unregister(&fips_fail_notif_chain, &fips_h->nb);
+
        /* Kill tasklet */
        tasklet_kill(&fips_h->tasklet);
        drvdata->fips_handle = NULL;
@@ -124,6 +144,9 @@ int cc_fips_init(struct cc_drvdata *p_drvdata)
 
        dev_dbg(dev, "Initializing fips tasklet\n");
        tasklet_init(&fips_h->tasklet, fips_dsr, (unsigned long)p_drvdata);
+       fips_h->drvdata = p_drvdata;
+       fips_h->nb.notifier_call = cc_ree_fips_failure;
+       atomic_notifier_chain_register(&fips_fail_notif_chain, &fips_h->nb);
 
        cc_tee_handle_fips_error(p_drvdata);
 
-- 
2.21.0