[RFC,v3,1/2] tpm: Keep CLKRUN enabled throughout the duration of transmit_cmd()

Message ID	1510783632-55866-2-git-send-email-azhar.shaikh@intel.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-integrity-owner@kernel.org> From: Azhar Shaikh <azhar.shaikh@intel.com> To: jarkko.sakkinen@linux.intel.com, jgunthorpe@obsidianresearch.com, peterhuewe@gmx.de, linux-integrity@vger.kernel.org Cc: azhar.shaikh@intel.com Subject: [PATCH RFC v3 1/2] tpm: Keep CLKRUN enabled throughout the duration of transmit_cmd() Date: Wed, 15 Nov 2017 14:07:11 -0800 Message-Id: <1510783632-55866-2-git-send-email-azhar.shaikh@intel.com> In-Reply-To: <1510783632-55866-1-git-send-email-azhar.shaikh@intel.com> References: <1510783632-55866-1-git-send-email-azhar.shaikh@intel.com> Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 1d6729be4cd6..17f0d468e3e4 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -413,6 +413,9 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, if (chip->dev.parent) pm_runtime_get_sync(chip->dev.parent); + if (chip->ops->clk_toggle != NULL) + chip->ops->clk_toggle(chip, true); + /* Store the decision as chip->locality will be changed. */ need_locality = chip->locality == -1; @@ -489,6 +492,9 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, chip->locality = -1; } out_no_locality: + if (chip->ops->clk_toggle != NULL) + chip->ops->clk_toggle(chip, false); + if (chip->dev.parent) pm_runtime_put_sync(chip->dev.parent); diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index e2d1055fb814..76a7b64195c8 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -46,6 +46,7 @@ struct tpm_info { struct tpm_tis_tcg_phy { struct tpm_tis_data priv; void __iomem *iobase; + bool begin_xfer_done; }; static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data) @@ -148,12 +149,15 @@ static inline bool is_bsw(void) /** * tpm_platform_begin_xfer() - clear LPC CLKRUN_EN i.e. clocks will be running + * @data: struct tpm_tis_data instance */ -static void tpm_platform_begin_xfer(void) +static void tpm_platform_begin_xfer(struct tpm_tis_data *data) { u32 clkrun_val; + struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - if (!is_bsw()) + if (!is_bsw() || ((data->flags & TPM_TIS_CLK_ENABLE) && + phy->begin_xfer_done)) return; clkrun_val = ioread32(ilb_base_addr + LPC_CNTRL_REG_OFFSET); @@ -168,16 +172,21 @@ static void tpm_platform_begin_xfer(void) */ outb(0xCC, 0x80); + if (!(data->flags & TPM_TIS_CLK_ENABLE)) + phy->begin_xfer_done = false; + else + phy->begin_xfer_done = true; } /** * tpm_platform_end_xfer() - set LPC CLKRUN_EN i.e. clocks can be turned off + * @data: struct tpm_tis_data instance */ -static void tpm_platform_end_xfer(void) +static void tpm_platform_end_xfer(struct tpm_tis_data *data) { u32 clkrun_val; - if (!is_bsw()) + if (!is_bsw() || (data->flags & TPM_TIS_CLK_ENABLE)) return; clkrun_val = ioread32(ilb_base_addr + LPC_CNTRL_REG_OFFSET); @@ -193,17 +202,16 @@ static void tpm_platform_end_xfer(void) outb(0xCC, 0x80); } + #else static inline bool is_bsw(void) { return false; } - -static void tpm_platform_begin_xfer(void) +static void tpm_platform_begin_xfer(struct tpm_tis_data *data) { } - -static void tpm_platform_end_xfer(void) +static void tpm_platform_end_xfer(struct tpm_tis_data *data) { } #endif @@ -213,12 +221,12 @@ static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len, { struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - tpm_platform_begin_xfer(); + tpm_platform_begin_xfer(data); while (len--) *result++ = ioread8(phy->iobase + addr); - tpm_platform_end_xfer(); + tpm_platform_end_xfer(data); return 0; } @@ -228,12 +236,12 @@ static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len, { struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - tpm_platform_begin_xfer(); + tpm_platform_begin_xfer(data); while (len--) iowrite8(*value++, phy->iobase + addr); - tpm_platform_end_xfer(); + tpm_platform_end_xfer(data); return 0; } @@ -242,11 +250,11 @@ static int tpm_tcg_read16(struct tpm_tis_data *data, u32 addr, u16 *result) { struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - tpm_platform_begin_xfer(); + tpm_platform_begin_xfer(data); *result = ioread16(phy->iobase + addr); - tpm_platform_end_xfer(); + tpm_platform_end_xfer(data); return 0; } @@ -255,11 +263,11 @@ static int tpm_tcg_read32(struct tpm_tis_data *data, u32 addr, u32 *result) { struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - tpm_platform_begin_xfer(); + tpm_platform_begin_xfer(data); *result = ioread32(phy->iobase + addr); - tpm_platform_end_xfer(); + tpm_platform_end_xfer(data); return 0; } @@ -268,11 +276,11 @@ static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value) { struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); - tpm_platform_begin_xfer(); + tpm_platform_begin_xfer(data); iowrite32(value, phy->iobase + addr); - tpm_platform_end_xfer(); + tpm_platform_end_xfer(data); return 0; } diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index fdde971bc810..673d4fe2e87e 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -661,6 +661,26 @@ void tpm_tis_remove(struct tpm_chip *chip) } EXPORT_SYMBOL_GPL(tpm_tis_remove); +/** + * tpm_tis_clkrun_toggle() - Keep clkrun protocol disabled for entire duration + * of a single TPM command + * @chip: TPM chip to use + * @value: 1 - Disable CLKRUN protocol, so that clocks are free running + * 0 - Enable CLKRUN protocol + */ +static void tpm_tis_clkrun_toggle(struct tpm_chip *chip, bool value) +{ + struct tpm_tis_data *data = dev_get_drvdata(&chip->dev); + + if (!IS_ENABLED(CONFIG_X86)) + return; + + if (value) + data->flags |= TPM_TIS_CLK_ENABLE; + else + data->flags &= ~TPM_TIS_CLK_ENABLE; +} + static const struct tpm_class_ops tpm_tis = { .flags = TPM_OPS_AUTO_STARTUP, .status = tpm_tis_status, @@ -673,6 +693,7 @@ void tpm_tis_remove(struct tpm_chip *chip) .req_canceled = tpm_tis_req_canceled, .request_locality = request_locality, .relinquish_locality = release_locality, + .clk_toggle = tpm_tis_clkrun_toggle, }; int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index 6bbac319ff3b..281f744a1a44 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -81,6 +81,7 @@ enum tis_defaults { enum tpm_tis_flags { TPM_TIS_ITPM_WORKAROUND = BIT(0), + TPM_TIS_CLK_ENABLE = BIT(1), }; struct tpm_tis_data { diff --git a/include/linux/tpm.h b/include/linux/tpm.h index 5a090f5ab335..10753ec56d0a 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -50,6 +50,7 @@ struct tpm_class_ops { unsigned long *timeout_cap); int (*request_locality)(struct tpm_chip *chip, int loc); void (*relinquish_locality)(struct tpm_chip *chip, int loc); + void (*clk_toggle)(struct tpm_chip *chip, bool value); }; #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)

[RFC,v3,1/2] tpm: Keep CLKRUN enabled throughout the duration of transmit_cmd()

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