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154 lines · 3.8 KiB

1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (C) 2012-2019 ARM Limited (or its affiliates). */
3
4#include <linux/kernel.h>
5#include <linux/fips.h>
6#include <linux/notifier.h>
7
8#include "cc_driver.h"
9#include "cc_fips.h"
10
11static void fips_dsr(unsigned long devarg);
12
13struct cc_fips_handle {
14 struct tasklet_struct tasklet;
15 struct notifier_block nb;
16 struct cc_drvdata *drvdata;
17};
18
19/* The function called once at driver entry point to check
20 * whether TEE FIPS error occurred.
21 */
22static bool cc_get_tee_fips_status(struct cc_drvdata *drvdata)
23{
24 u32 reg;
25
26 reg = cc_ioread(drvdata, CC_REG(GPR_HOST));
27 /* Did the TEE report status? */
28 if (reg & CC_FIPS_SYNC_TEE_STATUS)
29 /* Yes. Is it OK? */
30 return (reg & CC_FIPS_SYNC_MODULE_OK);
31
32 /* No. It's either not in use or will be reported later */
33 return true;
34}
35
36/*
37 * This function should push the FIPS REE library status towards the TEE library
38 * by writing the error state to HOST_GPR0 register.
39 */
40void cc_set_ree_fips_status(struct cc_drvdata *drvdata, bool status)
41{
42 int val = CC_FIPS_SYNC_REE_STATUS;
43
44 if (drvdata->hw_rev < CC_HW_REV_712)
45 return;
46
47 val |= (status ? CC_FIPS_SYNC_MODULE_OK : CC_FIPS_SYNC_MODULE_ERROR);
48
49 cc_iowrite(drvdata, CC_REG(HOST_GPR0), val);
50}
51
52/* Push REE side FIPS test failure to TEE side */
53static int cc_ree_fips_failure(struct notifier_block *nb, unsigned long unused1,
54 void *unused2)
55{
56 struct cc_fips_handle *fips_h =
57 container_of(nb, struct cc_fips_handle, nb);
58 struct cc_drvdata *drvdata = fips_h->drvdata;
59 struct device *dev = drvdata_to_dev(drvdata);
60
61 cc_set_ree_fips_status(drvdata, false);
62 dev_info(dev, "Notifying TEE of FIPS test failure...\n");
63
64 return NOTIFY_OK;
65}
66
67void cc_fips_fini(struct cc_drvdata *drvdata)
68{
69 struct cc_fips_handle *fips_h = drvdata->fips_handle;
70
71 if (drvdata->hw_rev < CC_HW_REV_712 || !fips_h)
72 return;
73
74 atomic_notifier_chain_unregister(&fips_fail_notif_chain, &fips_h->nb);
75
76 /* Kill tasklet */
77 tasklet_kill(&fips_h->tasklet);
78 drvdata->fips_handle = NULL;
79}
80
81void fips_handler(struct cc_drvdata *drvdata)
82{
83 struct cc_fips_handle *fips_handle_ptr = drvdata->fips_handle;
84
85 if (drvdata->hw_rev < CC_HW_REV_712)
86 return;
87
88 tasklet_schedule(&fips_handle_ptr->tasklet);
89}
90
91static inline void tee_fips_error(struct device *dev)
92{
93 if (fips_enabled)
94 panic("ccree: TEE reported cryptographic error in fips mode!\n");
95 else
96 dev_err(dev, "TEE reported error!\n");
97}
98
99/*
100 * This function check if cryptocell tee fips error occurred
101 * and in such case triggers system error
102 */
103void cc_tee_handle_fips_error(struct cc_drvdata *p_drvdata)
104{
105 struct device *dev = drvdata_to_dev(p_drvdata);
106
107 if (!cc_get_tee_fips_status(p_drvdata))
108 tee_fips_error(dev);
109}
110
111/* Deferred service handler, run as interrupt-fired tasklet */
112static void fips_dsr(unsigned long devarg)
113{
114 struct cc_drvdata *drvdata = (struct cc_drvdata *)devarg;
115 u32 irq, val;
116
117 irq = (drvdata->irq & (CC_GPR0_IRQ_MASK));
118
119 if (irq) {
120 cc_tee_handle_fips_error(drvdata);
121 }
122
123 /* after verifying that there is nothing to do,
124 * unmask AXI completion interrupt.
125 */
126 val = (CC_REG(HOST_IMR) & ~irq);
127 cc_iowrite(drvdata, CC_REG(HOST_IMR), val);
128}
129
130/* The function called once at driver entry point .*/
131int cc_fips_init(struct cc_drvdata *p_drvdata)
132{
133 struct cc_fips_handle *fips_h;
134 struct device *dev = drvdata_to_dev(p_drvdata);
135
136 if (p_drvdata->hw_rev < CC_HW_REV_712)
137 return 0;
138
139 fips_h = devm_kzalloc(dev, sizeof(*fips_h), GFP_KERNEL);
140 if (!fips_h)
141 return -ENOMEM;
142
143 p_drvdata->fips_handle = fips_h;
144
145 dev_dbg(dev, "Initializing fips tasklet\n");
146 tasklet_init(&fips_h->tasklet, fips_dsr, (unsigned long)p_drvdata);
147 fips_h->drvdata = p_drvdata;
148 fips_h->nb.notifier_call = cc_ree_fips_failure;
149 atomic_notifier_chain_register(&fips_fail_notif_chain, &fips_h->nb);
150
151 cc_tee_handle_fips_error(p_drvdata);
152
153 return 0;
154}