RE: [PATCH 2/4] tpm: delete the TPM_TIS_CLK_ENABLE flag

Shaikh, Azhar
2017-12-20T15:19:25Z

>-----Original Message-----
>From: Javier Martinez Canillas [mailto:javierm@redhat.com]
>Sent: Wednesday, December 20, 2017 3:36 AM
>To: linux-kernel@vger.kernel.org
>Cc: James Ettle <james@ettle.org.uk>; Hans de Goede
><hdegoede@redhat.com>; Shaikh, Azhar <azhar.shaikh@intel.com>; Javier
>Martinez Canillas <javierm@redhat.com>; Arnd Bergmann <arnd@arndb.de>;
>Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>; Peter Huewe
><peterhuewe@gmx.de>; Jason Gunthorpe <jgg@ziepe.ca>; Greg Kroah-
>Hartman <gregkh@linuxfoundation.org>; linux-integrity@vger.kernel.org
>Subject: [PATCH 2/4] tpm: delete the TPM_TIS_CLK_ENABLE flag
>
>This flag is only used to warn if CLKRUN_EN wasn't disabled on Braswell
>systems, but the only way this can happen is if the code is not correct.
>
>So it's an unnecessary check that just makes the code harder to read.
>

Hi Javier,

This code was implemented as a suggestion from Jason on the previous patches.
https://www.spinics.net/lists/linux-integrity/msg00827.html

>Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
>Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
>---
>
> drivers/char/tpm/tpm_tis.c | 15 ---------------
> drivers/char/tpm/tpm_tis_core.c | 2 -- drivers/char/tpm/tpm_tis_core.h | 1
>-
> 3 files changed, 18 deletions(-)
>
>diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index
>d29add49b033..d0ad9a89b02b 100644
>--- a/drivers/char/tpm/tpm_tis.c
>+++ b/drivers/char/tpm/tpm_tis.c
>@@ -138,9 +138,6 @@ 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);
>
>- if (is_bsw() && !(data->flags & TPM_TIS_CLK_ENABLE))
>- WARN(1, "CLKRUN not enabled!\n");
>-
> while (len--)
> *result++ = ioread8(phy->iobase + addr);
>
>@@ -152,9 +149,6 @@ 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() && !(data->flags & TPM_TIS_CLK_ENABLE))
>- WARN(1, "CLKRUN not enabled!\n");
>-
> while (len--)
> iowrite8(*value++, phy->iobase + addr);
>
>@@ -165,9 +159,6 @@ 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() && !(data->flags & TPM_TIS_CLK_ENABLE))
>- WARN(1, "CLKRUN not enabled!\n");
>-
> *result = ioread16(phy->iobase + addr);
>
> return 0;
>@@ -177,9 +168,6 @@ 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() && !(data->flags & TPM_TIS_CLK_ENABLE))
>- WARN(1, "CLKRUN not enabled!\n");
>-
> *result = ioread32(phy->iobase + addr);
>
> return 0;
>@@ -189,9 +177,6 @@ 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() && !(data->flags & TPM_TIS_CLK_ENABLE))
>- WARN(1, "CLKRUN not enabled!\n");
>-
> iowrite32(value, phy->iobase + addr);
>
> return 0;
>diff --git a/drivers/char/tpm/tpm_tis_core.c
>b/drivers/char/tpm/tpm_tis_core.c index 3455abbb2035..09da1e1adc40
>100644
>--- a/drivers/char/tpm/tpm_tis_core.c
>+++ b/drivers/char/tpm/tpm_tis_core.c
>@@ -746,7 +746,6 @@ static void tpm_tis_clkrun_enable(struct tpm_chip
>*chip, bool value)
> return;
>
> if (value) {
>- data->flags |= TPM_TIS_CLK_ENABLE;
> data->clkrun_enabled++;
> if (data->clkrun_enabled > 1)
> return;
>@@ -777,7 +776,6 @@ static void tpm_tis_clkrun_enable(struct tpm_chip
>*chip, bool value)
> * sure LPC clock is running before sending any TPM
>command.
> */
> outb(0xCC, 0x80);
>- data->flags &= ~TPM_TIS_CLK_ENABLE;
> }
> }
>
>diff --git a/drivers/char/tpm/tpm_tis_core.h
>b/drivers/char/tpm/tpm_tis_core.h index afc50cde1ba6..d5c6a2e952b3
>100644
>--- a/drivers/char/tpm/tpm_tis_core.h
>+++ b/drivers/char/tpm/tpm_tis_core.h
>@@ -86,7 +86,6 @@ enum tis_defaults {
>
> enum tpm_tis_flags {
> TPM_TIS_ITPM_WORKAROUND = BIT(0),
>- TPM_TIS_CLK_ENABLE = BIT(1),
> };
>
> struct tpm_tis_data {
>--
>2.14.3