linux-kernel - RE: [PATCH 2/4] tpm: delete the TPM_TIS_CLK

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Date:   Wed, 20 Dec 2017 15:19:19 +0000
From:   "Shaikh, Azhar" <azhar.shaikh@...el.com>
To:     Javier Martinez Canillas <javierm@...hat.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     James Ettle <james@...le.org.uk>,
        Hans de Goede <hdegoede@...hat.com>,
        Arnd Bergmann <arnd@...db.de>,
        Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>,
        Peter Huewe <peterhuewe@....de>,
        "Jason Gunthorpe" <jgg@...pe.ca>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "linux-integrity@...r.kernel.org" <linux-integrity@...r.kernel.org>
Subject: RE: [PATCH 2/4] tpm: delete the TPM_TIS_CLK_ENABLE flag



>-----Original Message-----
>From: Javier Martinez Canillas [mailto:javierm@...hat.com]
>Sent: Wednesday, December 20, 2017 3:36 AM
>To: linux-kernel@...r.kernel.org
>Cc: James Ettle <james@...le.org.uk>; Hans de Goede
><hdegoede@...hat.com>; Shaikh, Azhar <azhar.shaikh@...el.com>; Javier
>Martinez Canillas <javierm@...hat.com>; Arnd Bergmann <arnd@...db.de>;
>Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>; Peter Huewe
><peterhuewe@....de>; Jason Gunthorpe <jgg@...pe.ca>; Greg Kroah-
>Hartman <gregkh@...uxfoundation.org>; linux-integrity@...r.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@...ux.intel.com>
>Signed-off-by: Javier Martinez Canillas <javierm@...hat.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