tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (C) 2012-2018 ARM Limited or its affiliates. */
3
4#include <linux/kernel.h>
5#include <linux/fips.h>
6
7#include "cc_driver.h"
8#include "cc_fips.h"
9
10static void fips_dsr(unsigned long devarg);
11
12struct cc_fips_handle {
13 struct tasklet_struct tasklet;
14};
15
16/* The function called once at driver entry point to check
17 * whether TEE FIPS error occurred.
18 */
19static bool cc_get_tee_fips_status(struct cc_drvdata *drvdata)
20{
21 u32 reg;
22
23 reg = cc_ioread(drvdata, CC_REG(GPR_HOST));
24 return (reg == (CC_FIPS_SYNC_TEE_STATUS | CC_FIPS_SYNC_MODULE_OK));
25}
26
27/*
28 * This function should push the FIPS REE library status towards the TEE library
29 * by writing the error state to HOST_GPR0 register.
30 */
31void cc_set_ree_fips_status(struct cc_drvdata *drvdata, bool status)
32{
33 int val = CC_FIPS_SYNC_REE_STATUS;
34
35 if (drvdata->hw_rev < CC_HW_REV_712)
36 return;
37
38 val |= (status ? CC_FIPS_SYNC_MODULE_OK : CC_FIPS_SYNC_MODULE_ERROR);
39
40 cc_iowrite(drvdata, CC_REG(HOST_GPR0), val);
41}
42
43void cc_fips_fini(struct cc_drvdata *drvdata)
44{
45 struct cc_fips_handle *fips_h = drvdata->fips_handle;
46
47 if (drvdata->hw_rev < CC_HW_REV_712 || !fips_h)
48 return;
49
50 /* Kill tasklet */
51 tasklet_kill(&fips_h->tasklet);
52
53 kfree(fips_h);
54 drvdata->fips_handle = NULL;
55}
56
57void fips_handler(struct cc_drvdata *drvdata)
58{
59 struct cc_fips_handle *fips_handle_ptr = drvdata->fips_handle;
60
61 if (drvdata->hw_rev < CC_HW_REV_712)
62 return;
63
64 tasklet_schedule(&fips_handle_ptr->tasklet);
65}
66
67static inline void tee_fips_error(struct device *dev)
68{
69 if (fips_enabled)
70 panic("ccree: TEE reported cryptographic error in fips mode!\n");
71 else
72 dev_err(dev, "TEE reported error!\n");
73}
74
75/* Deferred service handler, run as interrupt-fired tasklet */
76static void fips_dsr(unsigned long devarg)
77{
78 struct cc_drvdata *drvdata = (struct cc_drvdata *)devarg;
79 struct device *dev = drvdata_to_dev(drvdata);
80 u32 irq, state, val;
81
82 irq = (drvdata->irq & (CC_GPR0_IRQ_MASK));
83
84 if (irq) {
85 state = cc_ioread(drvdata, CC_REG(GPR_HOST));
86
87 if (state != (CC_FIPS_SYNC_TEE_STATUS | CC_FIPS_SYNC_MODULE_OK))
88 tee_fips_error(dev);
89 }
90
91 /* after verifing that there is nothing to do,
92 * unmask AXI completion interrupt.
93 */
94 val = (CC_REG(HOST_IMR) & ~irq);
95 cc_iowrite(drvdata, CC_REG(HOST_IMR), val);
96}
97
98/* The function called once at driver entry point .*/
99int cc_fips_init(struct cc_drvdata *p_drvdata)
100{
101 struct cc_fips_handle *fips_h;
102 struct device *dev = drvdata_to_dev(p_drvdata);
103
104 if (p_drvdata->hw_rev < CC_HW_REV_712)
105 return 0;
106
107 fips_h = kzalloc(sizeof(*fips_h), GFP_KERNEL);
108 if (!fips_h)
109 return -ENOMEM;
110
111 p_drvdata->fips_handle = fips_h;
112
113 dev_dbg(dev, "Initializing fips tasklet\n");
114 tasklet_init(&fips_h->tasklet, fips_dsr, (unsigned long)p_drvdata);
115
116 if (!cc_get_tee_fips_status(p_drvdata))
117 tee_fips_error(dev);
118
119 return 0;
120}