From mboxrd@z Thu Jan 1 00:00:00 1970 From: Azhar Shaikh Subject: [PATCH] tpm: Enable CLKRUN protocol for Braswell systems Date: Thu, 1 Jun 2017 12:13:52 -0700 Message-ID: <1496344432-76640-1-git-send-email-azhar.shaikh@intel.com> Return-path: 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 --- drivers/char/tpm/tpm.h | 20 +++++++++++ drivers/char/tpm/tpm_tis.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 105 insertions(+) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 4b4c8dee3096..98032a22317e 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, @@ -436,6 +440,22 @@ struct tpm_buf { u8 *data; }; +#define INTEL_LEGACY_BLK_BASE_ADDR 0xFED08000 +#define LPC_CNTRL_REG_OFFSET 0x84 +#define LPC_CLKRUN_EN (1 << 2) + +#ifdef CONFIG_X86 +static inline bool is_bsw(void) +{ + return ((boot_cpu_data.x86_model == INTEL_FAM6_ATOM_AIRMONT) ? 1 : 0); +} +#else +static inline bool is_bsw(void) +{ + return false; +} +#endif + static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal) { struct tpm_input_header *head; diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index c7e1384f1b08..25ead56382c0 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -89,13 +89,70 @@ static inline int is_itpm(struct acpi_device *dev) } #endif +/** + * disable_lpc_clk_run() - clear LPC CLKRUN_EN i.e. clocks will be free running + */ +static void disable_lpc_clk_run(void) +{ + u32 clkrun_val; + void __iomem *ilb_base_addr = NULL; + + ilb_base_addr = (void __iomem *) + kmap_atomic_pfn(INTEL_LEGACY_BLK_BASE_ADDR >> PAGE_SHIFT); + + 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); + + kunmap_atomic(ilb_base_addr); + /* + * Write any random value on port 0x80 which is on LPC, to make + * sure LPC clock is running before sending any TPM command. + */ + outb(0x80, 0xCC); +} + +/** + * enable_lpc_clk_run() - set LPC CLKRUN_EN i.e. clocks can be turned off + */ +static void enable_lpc_clk_run(void) +{ + u32 clkrun_val; + void __iomem *ilb_base_addr = NULL; + + ilb_base_addr = (void __iomem *) + kmap_atomic_pfn(INTEL_LEGACY_BLK_BASE_ADDR >> PAGE_SHIFT); + + 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); + + kunmap_atomic(ilb_base_addr); + /* + * Write any random value on port 0x80 which is on LPC, to make + * sure LPC clock is running before sending any TPM command. + */ + outb(0x80, 0xCC); +} + 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); + if (is_bsw()) + disable_lpc_clk_run(); + while (len--) *result++ = ioread8(phy->iobase + addr); + + if (is_bsw()) + enable_lpc_clk_run(); + return 0; } @@ -104,8 +161,15 @@ 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); + if (is_bsw()) + disable_lpc_clk_run(); + while (len--) iowrite8(*value++, phy->iobase + addr); + + if (is_bsw()) + enable_lpc_clk_run(); + return 0; } @@ -113,7 +177,14 @@ 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); + if (is_bsw()) + disable_lpc_clk_run(); + *result = ioread16(phy->iobase + addr); + + if (is_bsw()) + enable_lpc_clk_run(); + return 0; } @@ -121,7 +192,14 @@ 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); + if (is_bsw()) + disable_lpc_clk_run(); + *result = ioread32(phy->iobase + addr); + + if (is_bsw()) + enable_lpc_clk_run(); + return 0; } @@ -129,7 +207,14 @@ 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); + if (is_bsw()) + disable_lpc_clk_run(); + iowrite32(value, phy->iobase + addr); + + if (is_bsw()) + enable_lpc_clk_run(); + return 0; } -- 1.9.1