[v8] tpm: Preserve TPM measurement log across kexec (ppc64)

[PATCH v8 2/4] tpm: of: Make of-tree specific function commonly available

Posted by Stefan Berger 3 years, 7 months ago

Simplify tpm_read_log_of() by moving reusable parts of the code into
an inline function that makes it commonly available so it can be
used also for kexec support. Call the new of_tpm_get_sml_parameters()
function from the TPM Open Firmware driver.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Coiby Xu <coxu@redhat.com>

---
v7:
 - Added original comment back into inlined function

v4:
 - converted to inline function
---
 drivers/char/tpm/eventlog/of.c | 31 +++++------------------------
 include/linux/tpm.h            | 36 ++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 26 deletions(-)

diff --git a/drivers/char/tpm/eventlog/of.c b/drivers/char/tpm/eventlog/of.c
index a9ce66d09a75..f9462d19632e 100644
--- a/drivers/char/tpm/eventlog/of.c
+++ b/drivers/char/tpm/eventlog/of.c
@@ -12,6 +12,7 @@
 
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/tpm.h>
 #include <linux/tpm_eventlog.h>
 
 #include "../tpm.h"
@@ -20,11 +21,10 @@
 int tpm_read_log_of(struct tpm_chip *chip)
 {
 	struct device_node *np;
-	const u32 *sizep;
-	const u64 *basep;
 	struct tpm_bios_log *log;
 	u32 size;
 	u64 base;
+	int ret;
 
 	log = &chip->log;
 	if (chip->dev.parent && chip->dev.parent->of_node)
@@ -35,30 +35,9 @@ int tpm_read_log_of(struct tpm_chip *chip)
 	if (of_property_read_bool(np, "powered-while-suspended"))
 		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
 
-	sizep = of_get_property(np, "linux,sml-size", NULL);
-	basep = of_get_property(np, "linux,sml-base", NULL);
-	if (sizep == NULL && basep == NULL)
-		return -ENODEV;
-	if (sizep == NULL || basep == NULL)
-		return -EIO;
-
-	/*
-	 * For both vtpm/tpm, firmware has log addr and log size in big
-	 * endian format. But in case of vtpm, there is a method called
-	 * sml-handover which is run during kernel init even before
-	 * device tree is setup. This sml-handover function takes care
-	 * of endianness and writes to sml-base and sml-size in little
-	 * endian format. For this reason, vtpm doesn't need conversion
-	 * but physical tpm needs the conversion.
-	 */
-	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
-	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
-		size = be32_to_cpup((__force __be32 *)sizep);
-		base = be64_to_cpup((__force __be64 *)basep);
-	} else {
-		size = *sizep;
-		base = *basep;
-	}
+	ret = of_tpm_get_sml_parameters(np, &base, &size);
+	if (ret < 0)
+		return ret;
 
 	if (size == 0) {
 		dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index dfeb25a0362d..6356baaa1393 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -460,4 +460,40 @@ static inline struct tpm_chip *tpm_default_chip(void)
 	return NULL;
 }
 #endif
+
+#ifdef CONFIG_OF
+static inline int of_tpm_get_sml_parameters(struct device_node *np,
+					    u64 *base, u32 *size)
+{
+	const u32 *sizep;
+	const u64 *basep;
+
+	sizep = of_get_property(np, "linux,sml-size", NULL);
+	basep = of_get_property(np, "linux,sml-base", NULL);
+	if (sizep == NULL && basep == NULL)
+		return -ENODEV;
+	if (sizep == NULL || basep == NULL)
+		return -EIO;
+
+	/*
+	 * For both vtpm/tpm, firmware has log addr and log size in big
+	 * endian format. But in case of vtpm, there is a method called
+	 * sml-handover which is run during kernel init even before
+	 * device tree is setup. This sml-handover function takes care
+	 * of endianness and writes to sml-base and sml-size in little
+	 * endian format. For this reason, vtpm doesn't need conversion
+	 * but physical tpm needs the conversion.
+	 */
+	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
+	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
+		*size = be32_to_cpup((__force __be32 *)sizep);
+		*base = be64_to_cpup((__force __be64 *)basep);
+	} else {
+		*size = *sizep;
+		*base = *basep;
+	}
+	return 0;
+}
+#endif
+
 #endif
-- 
2.35.1

Re: [PATCH v8 2/4] tpm: of: Make of-tree specific function commonly available

Posted by Jarkko Sakkinen 3 years, 7 months ago

On Thu, Sep 01, 2022 at 05:46:08PM -0400, Stefan Berger wrote:
> Simplify tpm_read_log_of() by moving reusable parts of the code into
> an inline function that makes it commonly available so it can be
> used also for kexec support. Call the new of_tpm_get_sml_parameters()
> function from the TPM Open Firmware driver.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> Cc: Jarkko Sakkinen <jarkko@kernel.org>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
> Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> Tested-by: Coiby Xu <coxu@redhat.com>
> 
> ---
> v7:
>  - Added original comment back into inlined function
> 
> v4:
>  - converted to inline function
> ---
>  drivers/char/tpm/eventlog/of.c | 31 +++++------------------------
>  include/linux/tpm.h            | 36 ++++++++++++++++++++++++++++++++++
>  2 files changed, 41 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/char/tpm/eventlog/of.c b/drivers/char/tpm/eventlog/of.c
> index a9ce66d09a75..f9462d19632e 100644
> --- a/drivers/char/tpm/eventlog/of.c
> +++ b/drivers/char/tpm/eventlog/of.c
> @@ -12,6 +12,7 @@
>  
>  #include <linux/slab.h>
>  #include <linux/of.h>
> +#include <linux/tpm.h>
>  #include <linux/tpm_eventlog.h>
>  
>  #include "../tpm.h"
> @@ -20,11 +21,10 @@
>  int tpm_read_log_of(struct tpm_chip *chip)
>  {
>  	struct device_node *np;
> -	const u32 *sizep;
> -	const u64 *basep;
>  	struct tpm_bios_log *log;
>  	u32 size;
>  	u64 base;
> +	int ret;
>  
>  	log = &chip->log;
>  	if (chip->dev.parent && chip->dev.parent->of_node)
> @@ -35,30 +35,9 @@ int tpm_read_log_of(struct tpm_chip *chip)
>  	if (of_property_read_bool(np, "powered-while-suspended"))
>  		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
>  
> -	sizep = of_get_property(np, "linux,sml-size", NULL);
> -	basep = of_get_property(np, "linux,sml-base", NULL);
> -	if (sizep == NULL && basep == NULL)
> -		return -ENODEV;
> -	if (sizep == NULL || basep == NULL)
> -		return -EIO;
> -
> -	/*
> -	 * For both vtpm/tpm, firmware has log addr and log size in big
> -	 * endian format. But in case of vtpm, there is a method called
> -	 * sml-handover which is run during kernel init even before
> -	 * device tree is setup. This sml-handover function takes care
> -	 * of endianness and writes to sml-base and sml-size in little
> -	 * endian format. For this reason, vtpm doesn't need conversion
> -	 * but physical tpm needs the conversion.
> -	 */
> -	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
> -	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
> -		size = be32_to_cpup((__force __be32 *)sizep);
> -		base = be64_to_cpup((__force __be64 *)basep);
> -	} else {
> -		size = *sizep;
> -		base = *basep;
> -	}
> +	ret = of_tpm_get_sml_parameters(np, &base, &size);
> +	if (ret < 0)
> +		return ret;
>  
>  	if (size == 0) {
>  		dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> index dfeb25a0362d..6356baaa1393 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -460,4 +460,40 @@ static inline struct tpm_chip *tpm_default_chip(void)
>  	return NULL;
>  }
>  #endif
> +
> +#ifdef CONFIG_OF
> +static inline int of_tpm_get_sml_parameters(struct device_node *np,
> +					    u64 *base, u32 *size)
> +{
> +	const u32 *sizep;
> +	const u64 *basep;
> +
> +	sizep = of_get_property(np, "linux,sml-size", NULL);
> +	basep = of_get_property(np, "linux,sml-base", NULL);
> +	if (sizep == NULL && basep == NULL)
> +		return -ENODEV;
> +	if (sizep == NULL || basep == NULL)
> +		return -EIO;
> +
> +	/*
> +	 * For both vtpm/tpm, firmware has log addr and log size in big
> +	 * endian format. But in case of vtpm, there is a method called
> +	 * sml-handover which is run during kernel init even before
> +	 * device tree is setup. This sml-handover function takes care
> +	 * of endianness and writes to sml-base and sml-size in little
> +	 * endian format. For this reason, vtpm doesn't need conversion
> +	 * but physical tpm needs the conversion.
> +	 */
> +	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
> +	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
> +		*size = be32_to_cpup((__force __be32 *)sizep);
> +		*base = be64_to_cpup((__force __be64 *)basep);
> +	} else {
> +		*size = *sizep;
> +		*base = *basep;
> +	}
> +	return 0;
> +}
> +#endif
> +
>  #endif
> -- 
> 2.35.1
> 

Acked-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko

[PATCH v8 1/4] drivers: of: kexec ima: Support 32-bit platforms
[PATCH v8 2/4] tpm: of: Make of-tree specific function commonly available
[PATCH v8 3/4] of: kexec: Refactor IMA buffer related functions to make them reusable
[PATCH v8 4/4] tpm/kexec: Duplicate TPM measurement log in of-tree for kexec