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// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2012-2019 ARM Limited (or its affiliates). */
#include <linux/kernel.h>
#include <linux/fips.h>
#include <linux/notifier.h>
#include "cc_driver.h"
#include "cc_fips.h"
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
* whether TEE FIPS error occurred.
*/
static bool cc_get_tee_fips_status(struct cc_drvdata *drvdata)
{
u32 reg;
reg = cc_ioread(drvdata, CC_REG(GPR_HOST));
/* Did the TEE report status? */
if (reg & CC_FIPS_SYNC_TEE_STATUS)
/* Yes. Is it OK? */
return (reg & CC_FIPS_SYNC_MODULE_OK);
/* No. It's either not in use or will be reported later */
return true;
}
/*
* This function should push the FIPS REE library status towards the TEE library
* by writing the error state to HOST_GPR0 register.
*/
void cc_set_ree_fips_status(struct cc_drvdata *drvdata, bool status)
{
int val = CC_FIPS_SYNC_REE_STATUS;
if (drvdata->hw_rev < CC_HW_REV_712)
return;
val |= (status ? CC_FIPS_SYNC_MODULE_OK : CC_FIPS_SYNC_MODULE_ERROR);
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;
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;
}
void fips_handler(struct cc_drvdata *drvdata)
{
struct cc_fips_handle *fips_handle_ptr = drvdata->fips_handle;
if (drvdata->hw_rev < CC_HW_REV_712)
return;
tasklet_schedule(&fips_handle_ptr->tasklet);
}
static inline void tee_fips_error(struct device *dev)
{
if (fips_enabled)
panic("ccree: TEE reported cryptographic error in fips mode!\n");
else
dev_err(dev, "TEE reported error!\n");
}
/*
* This function check if cryptocell tee fips error occurred
* and in such case triggers system error
*/
void cc_tee_handle_fips_error(struct cc_drvdata *p_drvdata)
{
struct device *dev = drvdata_to_dev(p_drvdata);
if (!cc_get_tee_fips_status(p_drvdata))
tee_fips_error(dev);
}
/* Deferred service handler, run as interrupt-fired tasklet */
static void fips_dsr(unsigned long devarg)
{
struct cc_drvdata *drvdata = (struct cc_drvdata *)devarg;
u32 irq, val;
irq = (drvdata->irq & (CC_GPR0_IRQ_MASK));
if (irq) {
cc_tee_handle_fips_error(drvdata);
}
/* after verifing that there is nothing to do,
* unmask AXI completion interrupt.
*/
val = (CC_REG(HOST_IMR) & ~irq);
cc_iowrite(drvdata, CC_REG(HOST_IMR), val);
}
/* The function called once at driver entry point .*/
int cc_fips_init(struct cc_drvdata *p_drvdata)
{
struct cc_fips_handle *fips_h;
struct device *dev = drvdata_to_dev(p_drvdata);
if (p_drvdata->hw_rev < CC_HW_REV_712)
return 0;
fips_h = devm_kzalloc(dev, sizeof(*fips_h), GFP_KERNEL);
if (!fips_h)
return -ENOMEM;
p_drvdata->fips_handle = fips_h;
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);
return 0;
}
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