Messages in this thread Patch in this message | | | From | Azhar Shaikh <> | Subject | [PATCH v3] tpm: Enable CLKRUN protocol for Braswell systems | Date | Wed, 7 Jun 2017 14:23:30 -0700 |
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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 <azhar.shaikh@intel.com> --- 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.
drivers/char/tpm/tpm.h | 4 ++ drivers/char/tpm/tpm_tis.c | 103 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 107 insertions(+)
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 4b4c8dee3096..6b769fbc4407 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -36,6 +36,10 @@ #include <linux/highmem.h> #include <crypto/hash_info.h> +#ifdef CONFIG_X86 +#include <asm/intel-family.h> +#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 c7e1384f1b08..6e32b4c7c70d 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -89,13 +89,89 @@ static inline int is_itpm(struct acpi_device *dev) } #endif +#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 + +#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; + +/** + * 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; + + 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(0x80, 0xCC); + + /* Make sure the above write is completed */ + wmb(); +} + +/** + * 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; + + 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(0x80, 0xCC); + + /* Make sure the above write is completed */ + wmb(); +} + 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); + disable_lpc_clk_run(); + while (len--) *result++ = ioread8(phy->iobase + addr); + + enable_lpc_clk_run(); + return 0; } @@ -104,8 +180,13 @@ 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); + disable_lpc_clk_run(); + while (len--) iowrite8(*value++, phy->iobase + addr); + + enable_lpc_clk_run(); + return 0; } @@ -113,7 +194,12 @@ 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); + disable_lpc_clk_run(); + *result = ioread16(phy->iobase + addr); + + enable_lpc_clk_run(); + return 0; } @@ -121,7 +207,12 @@ 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); + disable_lpc_clk_run(); + *result = ioread32(phy->iobase + addr); + + enable_lpc_clk_run(); + return 0; } @@ -129,7 +220,12 @@ 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); + disable_lpc_clk_run(); + iowrite32(value, phy->iobase + addr); + + enable_lpc_clk_run(); + return 0; } @@ -191,6 +287,10 @@ static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev, acpi_dev_handle = ACPI_HANDLE(&pnp_dev->dev); } + if (is_bsw()) + ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR, + ILB_REMAP_SIZE); + return tpm_tis_init(&pnp_dev->dev, &tpm_info, acpi_dev_handle); } @@ -214,6 +314,9 @@ static void tpm_tis_pnp_remove(struct pnp_dev *dev) tpm_chip_unregister(chip); tpm_tis_remove(chip); + + if (is_bsw()) + iounmap(ilb_base_addr); } static struct pnp_driver tis_pnp_driver = { -- 1.9.1
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