diff options
author | Christophe Ricard <christophe.ricard@gmail.com> | 2014-12-01 18:32:58 (GMT) |
---|---|---|
committer | Peter Huewe <peterhuewe@gmx.de> | 2015-01-17 13:00:08 (GMT) |
commit | c3804b8cdbd2abb50cf87318b13660dff46b7fe8 (patch) | |
tree | 46d42a57c7b6b7e1a9590ddc5241ba56649a92ce /drivers/char/tpm | |
parent | 8dcd19874f31b7a806a2a2b129e94882918c3aaf (diff) | |
download | linux-c3804b8cdbd2abb50cf87318b13660dff46b7fe8.tar.xz |
tpm/tpm_i2c_stm_st33: Interrupt management improvement
Improve the irq management by using a new function wait_for_stat.
Instead of using a completion struct, we rely on the waitqueue read_queue
and int_queue from chip->vendor field.
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Diffstat (limited to 'drivers/char/tpm')
-rw-r--r-- | drivers/char/tpm/tpm_i2c_stm_st33.c | 197 |
1 files changed, 109 insertions, 88 deletions
diff --git a/drivers/char/tpm/tpm_i2c_stm_st33.c b/drivers/char/tpm/tpm_i2c_stm_st33.c index a444cd3..eb0244a 100644 --- a/drivers/char/tpm/tpm_i2c_stm_st33.c +++ b/drivers/char/tpm/tpm_i2c_stm_st33.c @@ -38,6 +38,7 @@ #include <linux/kernel.h> #include <linux/delay.h> #include <linux/wait.h> +#include <linux/freezer.h> #include <linux/string.h> #include <linux/interrupt.h> #include <linux/sysfs.h> @@ -102,9 +103,9 @@ enum tis_defaults { struct tpm_stm_dev { struct i2c_client *client; - struct completion irq_detection; struct tpm_chip *chip; u8 buf[TPM_BUFSIZE + 1]; + u32 intrs; int io_lpcpd; }; @@ -174,61 +175,18 @@ static int read8_reg(struct tpm_stm_dev *tpm_dev, u8 tpm_register, * clear_interruption * clear the TPM interrupt register. * @param: tpm, the chip description + * @return: the TPM_INT_STATUS value */ -static void clear_interruption(struct tpm_stm_dev *tpm_dev) +static u8 clear_interruption(struct tpm_stm_dev *tpm_dev) { u8 interrupt; I2C_READ_DATA(tpm_dev, TPM_INT_STATUS, &interrupt, 1); I2C_WRITE_DATA(tpm_dev, TPM_INT_STATUS, &interrupt, 1); - I2C_READ_DATA(tpm_dev, TPM_INT_STATUS, &interrupt, 1); + return interrupt; } /* clear_interruption() */ /* - * _wait_for_interrupt_serirq_timeout - * @param: tpm, the chip description - * @param: timeout, the timeout of the interrupt - * @return: the status of the interruption. - */ -static long _wait_for_interrupt_serirq_timeout(struct tpm_chip *chip, - unsigned long timeout) -{ - long status; - struct i2c_client *client; - struct tpm_stm_dev *tpm_dev; - - tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip); - client = tpm_dev->client; - - status = wait_for_completion_interruptible_timeout( - &tpm_dev->irq_detection, - timeout); - if (status > 0) - enable_irq(client->irq); - - return status; -} /* wait_for_interrupt_serirq_timeout() */ - -static int wait_for_serirq_timeout(struct tpm_chip *chip, bool condition, - unsigned long timeout) -{ - int status = 2; - struct tpm_stm_dev *tpm_dev; - - tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip); - - status = _wait_for_interrupt_serirq_timeout(chip, timeout); - if (!status) { - status = -EBUSY; - } else { - clear_interruption(tpm_dev); - if (condition) - status = 1; - } - return status; -} /* wait_for_serirq_timeout() */ - -/* * tpm_stm_i2c_cancel, cancel is not implemented. * @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h */ @@ -241,8 +199,6 @@ static void tpm_stm_i2c_cancel(struct tpm_chip *chip) data = TPM_STS_COMMAND_READY; I2C_WRITE_DATA(tpm_dev, TPM_STS, &data, 1); - if (chip->vendor.irq) - wait_for_serirq_timeout(chip, 1, chip->vendor.timeout_a); } /* tpm_stm_i2c_cancel() */ /* @@ -297,30 +253,24 @@ static int request_locality(struct tpm_chip *chip) struct tpm_stm_dev *tpm_dev; u8 data; - tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip); - if (check_locality(chip) == chip->vendor.locality) return chip->vendor.locality; + tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip); + data = TPM_ACCESS_REQUEST_USE; ret = I2C_WRITE_DATA(tpm_dev, TPM_ACCESS, &data, 1); if (ret < 0) goto end; - if (chip->vendor.irq) { - ret = wait_for_serirq_timeout(chip, (check_locality - (chip) >= 0), - chip->vendor.timeout_a); - if (ret > 0) + stop = jiffies + chip->vendor.timeout_a; + + /* Request locality is usually effective after the request */ + do { + if (check_locality(chip) >= 0) return chip->vendor.locality; - } else { - stop = jiffies + chip->vendor.timeout_a; - do { - if (check_locality(chip) >= 0) - return chip->vendor.locality; - msleep(TPM_TIMEOUT); - } while (time_before(jiffies, stop)); - } + msleep(TPM_TIMEOUT); + } while (time_before(jiffies, stop)); ret = -EACCES; end: return ret; @@ -378,36 +328,107 @@ end: return -EBUSY; } /* get_burstcount() */ +static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, + bool check_cancel, bool *canceled) +{ + u8 status = chip->ops->status(chip); + + *canceled = false; + if ((status & mask) == mask) + return true; + if (check_cancel && chip->ops->req_canceled(chip, status)) { + *canceled = true; + return true; + } + return false; +} + +/* + * interrupt_to_status + * @param: irq_mask, the irq mask value to wait + * @return: the corresponding tpm_sts value + */ +static u8 interrupt_to_status(u8 irq_mask) +{ + u8 status = 0; + + if ((irq_mask & TPM_INTF_STS_VALID_INT) == TPM_INTF_STS_VALID_INT) + status |= TPM_STS_VALID; + if ((irq_mask & TPM_INTF_DATA_AVAIL_INT) == TPM_INTF_DATA_AVAIL_INT) + status |= TPM_STS_DATA_AVAIL; + if ((irq_mask & TPM_INTF_CMD_READY_INT) == TPM_INTF_CMD_READY_INT) + status |= TPM_STS_COMMAND_READY; + + return status; +} /* status_to_interrupt() */ + /* * wait_for_stat wait for a TPM_STS value * @param: chip, the tpm chip description * @param: mask, the value mask to wait * @param: timeout, the timeout * @param: queue, the wait queue. + * @param: check_cancel, does the command can be cancelled ? * @return: the tpm status, 0 if success, -ETIME if timeout is reached. */ static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout, - wait_queue_head_t *queue) + wait_queue_head_t *queue, bool check_cancel) { unsigned long stop; - long ret; - u8 status; + int r; + bool canceled = false; + bool condition; + u32 cur_intrs; + u8 interrupt, status; + struct tpm_stm_dev *tpm_dev; + + tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip); + + /* check current status */ + status = tpm_stm_i2c_status(chip); + if ((status & mask) == mask) + return 0; + + stop = jiffies + timeout; if (chip->vendor.irq) { - ret = wait_for_serirq_timeout(chip, ((tpm_stm_i2c_status - (chip) & mask) == - mask), timeout); - if (ret > 0) + cur_intrs = tpm_dev->intrs; + interrupt = clear_interruption(tpm_dev); + enable_irq(chip->vendor.irq); + +again: + timeout = stop - jiffies; + if ((long) timeout <= 0) + return -1; + + r = wait_event_interruptible_timeout(*queue, + cur_intrs != tpm_dev->intrs, timeout); + + interrupt |= clear_interruption(tpm_dev); + status = interrupt_to_status(interrupt); + condition = wait_for_tpm_stat_cond(chip, mask, + check_cancel, &canceled); + + if (r >= 0 && condition) { + if (canceled) + return -ECANCELED; return 0; + } + if (r == -ERESTARTSYS && freezing(current)) { + clear_thread_flag(TIF_SIGPENDING); + goto again; + } + disable_irq_nosync(chip->vendor.irq); + } else { - stop = jiffies + timeout; do { msleep(TPM_TIMEOUT); - status = tpm_stm_i2c_status(chip); + status = chip->ops->status(chip); if ((status & mask) == mask) return 0; } while (time_before(jiffies, stop)); } + return -ETIME; } /* wait_for_stat() */ @@ -429,7 +450,7 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) wait_for_stat(chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, chip->vendor.timeout_c, - &chip->vendor.read_queue) == 0) { + &chip->vendor.read_queue, true) == 0) { burstcnt = get_burstcount(chip); if (burstcnt < 0) return burstcnt; @@ -449,15 +470,14 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id) { struct tpm_chip *chip = dev_id; - struct i2c_client *client; struct tpm_stm_dev *tpm_dev; - disable_irq_nosync(irq); - tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip); - client = tpm_dev->client; - complete(&tpm_dev->irq_detection); + tpm_dev->intrs++; + wake_up_interruptible(&chip->vendor.read_queue); + disable_irq_nosync(chip->vendor.irq); + return IRQ_HANDLED; } /* tpm_ioserirq_handler() */ @@ -500,7 +520,7 @@ static int tpm_stm_i2c_send(struct tpm_chip *chip, unsigned char *buf, tpm_stm_i2c_cancel(chip); if (wait_for_stat (chip, TPM_STS_COMMAND_READY, chip->vendor.timeout_b, - &chip->vendor.int_queue) < 0) { + &chip->vendor.read_queue, false) < 0) { ret = -ETIME; goto out_err; } @@ -743,7 +763,10 @@ tpm_stm_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) chip->vendor.locality = LOCALITY0; if (client->irq) { - init_completion(&tpm_dev->irq_detection); + /* INTERRUPT Setup */ + init_waitqueue_head(&chip->vendor.read_queue); + tpm_dev->intrs = 0; + if (request_locality(chip) != LOCALITY0) { ret = -ENODEV; goto _tpm_clean_answer; @@ -765,9 +788,6 @@ tpm_stm_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) goto _tpm_clean_answer; intmask |= TPM_INTF_CMD_READY_INT - | TPM_INTF_FIFO_AVALAIBLE_INT - | TPM_INTF_WAKE_UP_READY_INT - | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT | TPM_INTF_DATA_AVAIL_INT; @@ -787,6 +807,8 @@ tpm_stm_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) chip->vendor.irq = client->irq; + disable_irq_nosync(chip->vendor.irq); + tpm_gen_interrupt(chip); } @@ -852,10 +874,9 @@ static int tpm_stm_i2c_pm_resume(struct device *dev) if (gpio_is_valid(pin_infos->io_lpcpd)) { gpio_set_value(pin_infos->io_lpcpd, 1); - ret = wait_for_serirq_timeout(chip, - (chip->ops->status(chip) & - TPM_STS_VALID) == TPM_STS_VALID, - chip->vendor.timeout_b); + ret = wait_for_stat(chip, + TPM_STS_VALID, chip->vendor.timeout_b, + &chip->vendor.read_queue, false); } else { ret = tpm_pm_resume(dev); if (!ret) |