155 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			155 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /* Copyright (C) 2012-2019 ARM Limited (or its affiliates). */
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| 
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| #include <linux/kernel.h>
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| #include <linux/fips.h>
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| #include <linux/notifier.h>
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| 
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| #include "cc_driver.h"
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| #include "cc_fips.h"
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| 
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| static void fips_dsr(unsigned long devarg);
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| 
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| struct cc_fips_handle {
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| 	struct tasklet_struct tasklet;
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| 	struct notifier_block nb;
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| 	struct cc_drvdata *drvdata;
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| };
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| 
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| /* The function called once at driver entry point to check
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|  * whether TEE FIPS error occurred.
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|  */
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| static bool cc_get_tee_fips_status(struct cc_drvdata *drvdata)
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| {
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| 	u32 reg;
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| 
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| 	reg = cc_ioread(drvdata, CC_REG(GPR_HOST));
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| 	/* Did the TEE report status? */
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| 	if (reg & CC_FIPS_SYNC_TEE_STATUS)
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| 		/* Yes. Is it OK? */
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| 		return (reg & CC_FIPS_SYNC_MODULE_OK);
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| 
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| 	/* No. It's either not in use or will be reported later */
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| 	return true;
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| }
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| 
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| /*
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|  * This function should push the FIPS REE library status towards the TEE library
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|  * by writing the error state to HOST_GPR0 register.
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|  */
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| void cc_set_ree_fips_status(struct cc_drvdata *drvdata, bool status)
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| {
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| 	int val = CC_FIPS_SYNC_REE_STATUS;
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| 
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| 	if (drvdata->hw_rev < CC_HW_REV_712)
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| 		return;
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| 
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| 	val |= (status ? CC_FIPS_SYNC_MODULE_OK : CC_FIPS_SYNC_MODULE_ERROR);
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| 
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| 	cc_iowrite(drvdata, CC_REG(HOST_GPR0), val);
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| }
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| 
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| /* Push REE side FIPS test failure to TEE side */
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| static int cc_ree_fips_failure(struct notifier_block *nb, unsigned long unused1,
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| 			       void *unused2)
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| {
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| 	struct cc_fips_handle *fips_h =
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| 				container_of(nb, struct cc_fips_handle, nb);
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| 	struct cc_drvdata *drvdata = fips_h->drvdata;
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| 	struct device *dev = drvdata_to_dev(drvdata);
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| 
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| 	cc_set_ree_fips_status(drvdata, false);
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| 	dev_info(dev, "Notifying TEE of FIPS test failure...\n");
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| 
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| 	return NOTIFY_OK;
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| }
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| 
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| void cc_fips_fini(struct cc_drvdata *drvdata)
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| {
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| 	struct cc_fips_handle *fips_h = drvdata->fips_handle;
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| 
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| 	if (drvdata->hw_rev < CC_HW_REV_712 || !fips_h)
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| 		return;
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| 
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| 	atomic_notifier_chain_unregister(&fips_fail_notif_chain, &fips_h->nb);
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| 
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| 	/* Kill tasklet */
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| 	tasklet_kill(&fips_h->tasklet);
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| 	drvdata->fips_handle = NULL;
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| }
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| 
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| void fips_handler(struct cc_drvdata *drvdata)
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| {
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| 	struct cc_fips_handle *fips_handle_ptr = drvdata->fips_handle;
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| 
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| 	if (drvdata->hw_rev < CC_HW_REV_712)
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| 		return;
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| 
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| 	tasklet_schedule(&fips_handle_ptr->tasklet);
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| }
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| 
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| static inline void tee_fips_error(struct device *dev)
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| {
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| 	if (fips_enabled)
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| 		panic("ccree: TEE reported cryptographic error in fips mode!\n");
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| 	else
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| 		dev_err(dev, "TEE reported error!\n");
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| }
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| 
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| /*
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|  * This function check if cryptocell tee fips error occurred
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|  * and in such case triggers system error
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|  */
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| void cc_tee_handle_fips_error(struct cc_drvdata *p_drvdata)
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| {
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| 	struct device *dev = drvdata_to_dev(p_drvdata);
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| 
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| 	if (!cc_get_tee_fips_status(p_drvdata))
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| 		tee_fips_error(dev);
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| }
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| 
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| /* Deferred service handler, run as interrupt-fired tasklet */
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| static void fips_dsr(unsigned long devarg)
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| {
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| 	struct cc_drvdata *drvdata = (struct cc_drvdata *)devarg;
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| 	u32 irq, val;
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| 
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| 	irq = (drvdata->irq & (CC_GPR0_IRQ_MASK));
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| 
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| 	if (irq) {
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| 		cc_tee_handle_fips_error(drvdata);
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| 	}
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| 
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| 	/* after verifying that there is nothing to do,
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| 	 * unmask AXI completion interrupt.
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| 	 */
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| 	val = (CC_REG(HOST_IMR) & ~irq);
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| 	cc_iowrite(drvdata, CC_REG(HOST_IMR), val);
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| }
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| 
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| /* The function called once at driver entry point .*/
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| int cc_fips_init(struct cc_drvdata *p_drvdata)
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| {
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| 	struct cc_fips_handle *fips_h;
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| 	struct device *dev = drvdata_to_dev(p_drvdata);
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| 
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| 	if (p_drvdata->hw_rev < CC_HW_REV_712)
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| 		return 0;
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| 
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| 	fips_h = devm_kzalloc(dev, sizeof(*fips_h), GFP_KERNEL);
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| 	if (!fips_h)
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| 		return -ENOMEM;
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| 
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| 	p_drvdata->fips_handle = fips_h;
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| 
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| 	dev_dbg(dev, "Initializing fips tasklet\n");
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| 	tasklet_init(&fips_h->tasklet, fips_dsr, (unsigned long)p_drvdata);
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| 	fips_h->drvdata = p_drvdata;
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| 	fips_h->nb.notifier_call = cc_ree_fips_failure;
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| 	atomic_notifier_chain_register(&fips_fail_notif_chain, &fips_h->nb);
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| 
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| 	cc_tee_handle_fips_error(p_drvdata);
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| 
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| 	return 0;
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| }
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