diff options
Diffstat (limited to 'drivers/char/tpm/tpm_tis.c')
| -rw-r--r-- | drivers/char/tpm/tpm_tis.c | 51 |
1 files changed, 44 insertions, 7 deletions
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index ed5dabd3c72d..7af389806643 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -50,6 +50,45 @@ static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *da return container_of(data, struct tpm_tis_tcg_phy, priv); } +#ifdef CONFIG_PREEMPT_RT +/* + * Flush previous write operations with a dummy read operation to the + * TPM MMIO base address. + */ +static inline void tpm_tis_flush(void __iomem *iobase) +{ + ioread8(iobase + TPM_ACCESS(0)); +} +#else +#define tpm_tis_flush(iobase) do { } while (0) +#endif + +/* + * Write a byte word to the TPM MMIO address, and flush the write queue. + * The flush ensures that the data is sent immediately over the bus and not + * aggregated with further requests and transferred later in a batch. The large + * write requests can lead to unwanted latency spikes by blocking the CPU until + * the complete batch has been transferred. + */ +static inline void tpm_tis_iowrite8(u8 b, void __iomem *iobase, u32 addr) +{ + iowrite8(b, iobase + addr); + tpm_tis_flush(iobase); +} + +/* + * Write a 32-bit word to the TPM MMIO address, and flush the write queue. + * The flush ensures that the data is sent immediately over the bus and not + * aggregated with further requests and transferred later in a batch. The large + * write requests can lead to unwanted latency spikes by blocking the CPU until + * the complete batch has been transferred. + */ +static inline void tpm_tis_iowrite32(u32 b, void __iomem *iobase, u32 addr) +{ + iowrite32(b, iobase + addr); + tpm_tis_flush(iobase); +} + static int interrupts = -1; module_param(interrupts, int, 0444); MODULE_PARM_DESC(interrupts, "Enable interrupts"); @@ -186,12 +225,12 @@ static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len, switch (io_mode) { case TPM_TIS_PHYS_8: while (len--) - iowrite8(*value++, phy->iobase + addr); + tpm_tis_iowrite8(*value++, phy->iobase, addr); break; case TPM_TIS_PHYS_16: return -EINVAL; case TPM_TIS_PHYS_32: - iowrite32(le32_to_cpu(*((__le32 *)value)), phy->iobase + addr); + tpm_tis_iowrite32(le32_to_cpu(*((__le32 *)value)), phy->iobase, addr); break; } @@ -227,7 +266,7 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info) irq = tpm_info->irq; if (itpm || is_itpm(ACPI_COMPANION(dev))) - phy->priv.flags |= TPM_TIS_ITPM_WORKAROUND; + set_bit(TPM_TIS_ITPM_WORKAROUND, &phy->priv.flags); return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg, ACPI_HANDLE(dev)); @@ -324,14 +363,12 @@ static int tpm_tis_plat_probe(struct platform_device *pdev) return tpm_tis_init(&pdev->dev, &tpm_info); } -static int tpm_tis_plat_remove(struct platform_device *pdev) +static void tpm_tis_plat_remove(struct platform_device *pdev) { struct tpm_chip *chip = dev_get_drvdata(&pdev->dev); tpm_chip_unregister(chip); tpm_tis_remove(chip); - - return 0; } #ifdef CONFIG_OF @@ -344,7 +381,7 @@ MODULE_DEVICE_TABLE(of, tis_of_platform_match); static struct platform_driver tis_drv = { .probe = tpm_tis_plat_probe, - .remove = tpm_tis_plat_remove, + .remove_new = tpm_tis_plat_remove, .driver = { .name = "tpm_tis", .pm = &tpm_tis_pm, |