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Commit 719b7d8

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Jarkko Sakkinen
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tpm: introduce tpm_chip_start() and tpm_chip_stop()
Encapsulate power gating and locality functionality to tpm_chip_start() and tpm_chip_stop() in order to clean up the branching mess in tpm_transmit(). Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Tested-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com> Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com>
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3 files changed

+116
-81
lines changed

3 files changed

+116
-81
lines changed

‎drivers/char/tpm/tpm-chip.c

Lines changed: 111 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -37,6 +37,117 @@ struct class *tpm_class;
3737
struct class *tpmrm_class;
3838
dev_t tpm_devt;
3939

40+
static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
41+
{
42+
int rc;
43+
44+
if (flags & TPM_TRANSMIT_NESTED)
45+
return 0;
46+
47+
if (!chip->ops->request_locality)
48+
return 0;
49+
50+
rc = chip->ops->request_locality(chip, 0);
51+
if (rc < 0)
52+
return rc;
53+
54+
chip->locality = rc;
55+
return 0;
56+
}
57+
58+
static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
59+
{
60+
int rc;
61+
62+
if (flags & TPM_TRANSMIT_NESTED)
63+
return;
64+
65+
if (!chip->ops->relinquish_locality)
66+
return;
67+
68+
rc = chip->ops->relinquish_locality(chip, chip->locality);
69+
if (rc)
70+
dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
71+
72+
chip->locality = -1;
73+
}
74+
75+
static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
76+
{
77+
if (flags & TPM_TRANSMIT_NESTED)
78+
return 0;
79+
80+
if (!chip->ops->cmd_ready)
81+
return 0;
82+
83+
return chip->ops->cmd_ready(chip);
84+
}
85+
86+
static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
87+
{
88+
if (flags & TPM_TRANSMIT_NESTED)
89+
return 0;
90+
91+
if (!chip->ops->go_idle)
92+
return 0;
93+
94+
return chip->ops->go_idle(chip);
95+
}
96+
97+
/**
98+
* tpm_chip_start() - power on the TPM
99+
* @chip: a TPM chip to use
100+
* @flags: TPM transmit flags
101+
*
102+
* Return:
103+
* * The response length - OK
104+
* * -errno - A system error
105+
*/
106+
int tpm_chip_start(struct tpm_chip *chip, unsigned int flags)
107+
{
108+
int ret;
109+
110+
if (chip->ops->clk_enable)
111+
chip->ops->clk_enable(chip, true);
112+
113+
if (chip->locality == -1) {
114+
ret = tpm_request_locality(chip, flags);
115+
if (ret) {
116+
chip->ops->clk_enable(chip, false);
117+
return ret;
118+
}
119+
}
120+
121+
ret = tpm_cmd_ready(chip, flags);
122+
if (ret) {
123+
tpm_relinquish_locality(chip, flags);
124+
if (chip->ops->clk_enable)
125+
chip->ops->clk_enable(chip, false);
126+
return ret;
127+
}
128+
129+
return 0;
130+
}
131+
EXPORT_SYMBOL_GPL(tpm_chip_start);
132+
133+
/**
134+
* tpm_chip_stop() - power off the TPM
135+
* @chip: a TPM chip to use
136+
* @flags: TPM transmit flags
137+
*
138+
* Return:
139+
* * The response length - OK
140+
* * -errno - A system error
141+
*/
142+
void tpm_chip_stop(struct tpm_chip *chip, unsigned int flags)
143+
{
144+
tpm_go_idle(chip, flags);
145+
tpm_relinquish_locality(chip, flags);
146+
if (chip->ops->clk_enable)
147+
chip->ops->clk_enable(chip, false);
148+
}
149+
EXPORT_SYMBOL_GPL(tpm_chip_stop);
150+
40151
/**
41152
* tpm_try_get_ops() - Get a ref to the tpm_chip
42153
* @chip: Chip to ref

‎drivers/char/tpm/tpm-interface.c

Lines changed: 3 additions & 81 deletions
Original file line numberDiff line numberDiff line change
@@ -62,64 +62,6 @@ unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
6262
}
6363
EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
6464

65-
static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
66-
{
67-
int rc;
68-
69-
if (flags & TPM_TRANSMIT_NESTED)
70-
return 0;
71-
72-
if (!chip->ops->request_locality)
73-
return 0;
74-
75-
rc = chip->ops->request_locality(chip, 0);
76-
if (rc < 0)
77-
return rc;
78-
79-
chip->locality = rc;
80-
81-
return 0;
82-
}
83-
84-
static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
85-
{
86-
int rc;
87-
88-
if (flags & TPM_TRANSMIT_NESTED)
89-
return;
90-
91-
if (!chip->ops->relinquish_locality)
92-
return;
93-
94-
rc = chip->ops->relinquish_locality(chip, chip->locality);
95-
if (rc)
96-
dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
97-
98-
chip->locality = -1;
99-
}
100-
101-
static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
102-
{
103-
if (flags & TPM_TRANSMIT_NESTED)
104-
return 0;
105-
106-
if (!chip->ops->cmd_ready)
107-
return 0;
108-
109-
return chip->ops->cmd_ready(chip);
110-
}
111-
112-
static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
113-
{
114-
if (flags & TPM_TRANSMIT_NESTED)
115-
return 0;
116-
117-
if (!chip->ops->go_idle)
118-
return 0;
119-
120-
return chip->ops->go_idle(chip);
121-
}
122-
12365
static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz,
12466
unsigned int flags)
12567
{
@@ -221,7 +163,6 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
221163
/* space for header and handles */
222164
u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
223165
unsigned int delay_msec = TPM2_DURATION_SHORT;
224-
bool has_locality = false;
225166
u32 rc = 0;
226167
ssize_t ret;
227168
const size_t save_size = min(sizeof(save), bufsiz);
@@ -236,32 +177,13 @@ ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
236177
memcpy(save, buf, save_size);
237178

238179
for (;;) {
239-
if (chip->ops->clk_enable != NULL)
240-
chip->ops->clk_enable(chip, true);
241-
242-
if (chip->locality == -1) {
243-
ret = tpm_request_locality(chip, flags);
244-
if (ret)
245-
goto out_locality;
246-
has_locality = true;
247-
}
248-
249-
ret = tpm_cmd_ready(chip, flags);
180+
ret = tpm_chip_start(chip, flags);
250181
if (ret)
251-
goto out_locality;
182+
return ret;
252183

253184
ret = tpm_try_transmit(chip, buf, bufsiz, flags);
254185

255-
/* This may fail but do not override ret. */
256-
tpm_go_idle(chip, flags);
257-
258-
out_locality:
259-
if (has_locality)
260-
tpm_relinquish_locality(chip, flags);
261-
262-
if (chip->ops->clk_enable != NULL)
263-
chip->ops->clk_enable(chip, false);
264-
186+
tpm_chip_stop(chip, flags);
265187
if (ret < 0)
266188
break;
267189
rc = be32_to_cpu(header->return_code);

‎drivers/char/tpm/tpm.h

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -523,6 +523,8 @@ static inline void tpm_msleep(unsigned int delay_msec)
523523
delay_msec * 1000);
524524
};
525525

526+
int tpm_chip_start(struct tpm_chip *chip, unsigned int flags);
527+
void tpm_chip_stop(struct tpm_chip *chip, unsigned int flags);
526528
struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip);
527529
__must_check int tpm_try_get_ops(struct tpm_chip *chip);
528530
void tpm_put_ops(struct tpm_chip *chip);

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