linux/drivers/crypto/ccree/cc_fips.c
Ofir Drang 897ab23169 crypto: ccree - add function to handle cryptocell tee fips error
Adds function that checks if cryptocell tee fips error occurred
and in such case triggers system error through kernel panic.
Change fips function to use this new routine.

Signed-off-by: Ofir Drang <ofir.drang@arm.com>
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-04-25 15:38:16 +08:00

126 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2012-2019 ARM Limited (or its affiliates). */
#include <linux/kernel.h>
#include <linux/fips.h>
#include "cc_driver.h"
#include "cc_fips.h"
static void fips_dsr(unsigned long devarg);
struct cc_fips_handle {
struct tasklet_struct tasklet;
};
/* 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));
return (reg == (CC_FIPS_SYNC_TEE_STATUS | CC_FIPS_SYNC_MODULE_OK));
}
/*
* 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);
}
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;
/* 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);
cc_tee_handle_fips_error(p_drvdata);
return 0;
}