From mboxrd@z Thu Jan 1 00:00:00 1970 From: Azhar Shaikh Subject: [PATCH v5] tpm: Enable CLKRUN protocol for Braswell systems Date: Sun, 18 Jun 2017 19:17:59 -0700 Message-ID: <1497838679-147957-1-git-send-email-azhar.shaikh@intel.com> References: <1496369044-38234-1-git-send-email-azhar.shaikh@intel.com> Return-path: In-Reply-To: <1496369044-38234-1-git-send-email-azhar.shaikh@intel.com> Sender: owner-linux-security-module@vger.kernel.org To: jarkko.sakkinen@linux.intel.com, jgunthorpe@obsidianresearch.com, tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Cc: linux-security-module@vger.kernel.org, azhar.shaikh@intel.com List-Id: tpmdd-devel@lists.sourceforge.net To overcome a hardware limitation on Intel Braswell systems, disable CLKRUN protocol during TPM transactions and re-enable once the transaction is completed. Signed-off-by: Azhar Shaikh --- Changes from v1: - Add CONFIG_X86 around disable_lpc_clk_run() and enable_lpc_clk_run() to avoid - build breakage on architectures which do not implement kmap_atomic_pfn() Changes from v2: - Use ioremap()/iounmap() instead of kmap_atomic_pfn()/kunmap_atomic() - Move is_bsw() and all macros from tpm.h to tpm_tis.c file. - Add the is_bsw() check in disable_lpc_clk_run() and enable_lpc_clk_run() - instead of adding it in each read/write API. Changes from v3: - Move the code under #ifdef CONFIG_X86 and create stub functions for everything else - Rename the functions disable_lpc_clk_run() -> tpm_platform_begin_xfer() and - enable_lpc_clk_run() -> tpm_platform_end_xfer() - Remove wmb() - Correct the parameters for outb() Changes from v4: - Rebased to apply on git://git.infradead.org/users/jjs/linux-tpmdd.git drivers/char/tpm/tpm.h | 4 ++ drivers/char/tpm/tpm_tis.c | 112 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 116 insertions(+) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 1df0521138d3..cdd261383dea 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -36,6 +36,10 @@ #include #include +#ifdef CONFIG_X86 +#include +#endif + enum tpm_const { TPM_MINOR = 224, /* officially assigned */ TPM_BUFSIZE = 4096, diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index b14d4aa97af8..506e62ca3576 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -132,13 +132,93 @@ static int check_acpi_tpm2(struct device *dev) } #endif +#ifdef CONFIG_X86 +#define INTEL_LEGACY_BLK_BASE_ADDR 0xFED08000 +#define ILB_REMAP_SIZE 0x100 +#define LPC_CNTRL_REG_OFFSET 0x84 +#define LPC_CLKRUN_EN (1 << 2) + +void __iomem *ilb_base_addr; + +static inline bool is_bsw(void) +{ + return ((boot_cpu_data.x86_model == INTEL_FAM6_ATOM_AIRMONT) ? 1 : 0); +} + +/** + * tpm_platform_begin_xfer() - clear LPC CLKRUN_EN i.e. clocks will be running + */ +static void tpm_platform_begin_xfer(void) +{ + u32 clkrun_val; + + if (!is_bsw()) + return; + + clkrun_val = ioread32(ilb_base_addr + LPC_CNTRL_REG_OFFSET); + + /* Disable LPC CLKRUN# */ + clkrun_val &= ~LPC_CLKRUN_EN; + iowrite32(clkrun_val, ilb_base_addr + LPC_CNTRL_REG_OFFSET); + + /* + * Write any random value on port 0x80 which is on LPC, to make + * sure LPC clock is running before sending any TPM command. + */ + outb(0xCC, 0x80); + +} + +/** + * tpm_platform_end_xfer() - set LPC CLKRUN_EN i.e. clocks can be turned off + */ +static void tpm_platform_end_xfer(void) +{ + u32 clkrun_val; + + if (!is_bsw()) + return; + + clkrun_val = ioread32(ilb_base_addr + LPC_CNTRL_REG_OFFSET); + + /* Enable LPC CLKRUN# */ + clkrun_val |= LPC_CLKRUN_EN; + iowrite32(clkrun_val, ilb_base_addr + LPC_CNTRL_REG_OFFSET); + + /* + * Write any random value on port 0x80 which is on LPC, to make + * sure LPC clock is running before sending any TPM command. + */ + outb(0xCC, 0x80); + +} +#else +static inline bool is_bsw(void) +{ + return false; +} + +static void tpm_platform_begin_xfer(void) +{ +} + +static void tpm_platform_end_xfer(void) +{ +} +#endif + static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len, u8 *result) { struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data); + tpm_platform_begin_xfer(); + while (len--) *result++ = ioread8(phy->iobase + addr); + + tpm_platform_end_xfer(); + return 0; } @@ -147,8 +227,13 @@ 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(); + while (len--) iowrite8(*value++, phy->iobase + addr); + + tpm_platform_end_xfer(); + return 0; } @@ -156,7 +241,12 @@ 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(); + *result = ioread16(phy->iobase + addr); + + tpm_platform_end_xfer(); + return 0; } @@ -164,7 +254,12 @@ 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(); + *result = ioread32(phy->iobase + addr); + + tpm_platform_end_xfer(); + return 0; } @@ -172,7 +267,12 @@ 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(); + iowrite32(value, phy->iobase + addr); + + tpm_platform_end_xfer(); + return 0; } @@ -230,6 +330,12 @@ static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev, else tpm_info.irq = -1; +#ifdef CONFIG_X86 + if (is_bsw()) + ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR, + ILB_REMAP_SIZE); +#endif + return tpm_tis_init(&pnp_dev->dev, &tpm_info); } @@ -253,6 +359,12 @@ static void tpm_tis_pnp_remove(struct pnp_dev *dev) tpm_chip_unregister(chip); tpm_tis_remove(chip); + +#ifdef CONFIG_X86 + if (is_bsw()) + iounmap(ilb_base_addr); +#endif + } static struct pnp_driver tis_pnp_driver = { -- 1.9.1