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Commit 1569a4c4 authored by Jiang Liu's avatar Jiang Liu Committed by Rafael J. Wysocki
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ACPI / TPM: detect PPI features by checking availability of _DSM functions 



Detecting physical presence interface features by checking availbility
of corresponding ACPI _DSM functions, it should be more accurate than
checking TPM version number.

Signed-off-by: default avatarJiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 84b1667d

drivers/char/tpm/tpm_ppi.c

+19 −26
Original line number Diff line number Diff line
@@ -23,23 +23,18 @@ static const u8 tpm_ppi_uuid[] = { 
	0x8D, 0x10, 0x08, 0x9D, 0x16, 0x53

};



static char *tpm_device_name = "TPM";

static char tpm_ppi_version[PPI_VERSION_LEN + 1];

static acpi_handle tpm_ppi_handle;



static acpi_status ppi_callback(acpi_handle handle, u32 level, void *context,

				void **return_value)

{

	acpi_status status = AE_OK;

	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	union acpi_object *obj;



	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);

	if (ACPI_FAILURE(status))

	if (!acpi_check_dsm(handle, tpm_ppi_uuid, TPM_PPI_REVISION_ID,

			    1 << TPM_PPI_FN_VERSION))

		return AE_OK;



	if (strstr(buffer.pointer, context) != NULL) {

		union acpi_object *obj;



	/* Cache version string */

	obj = acpi_evaluate_dsm_typed(handle, tpm_ppi_uuid,

				      TPM_PPI_REVISION_ID, TPM_PPI_FN_VERSION,
@@ -51,11 +46,8 @@ static acpi_status ppi_callback(acpi_handle handle, u32 level, void *context, 
	}



	*return_value = handle;

		status = AE_CTRL_TERMINATE;

	}

	kfree(buffer.pointer);



	return status;

	return AE_CTRL_TERMINATE;

}



static inline union acpi_object *
@@ -118,7 +110,8 @@ static ssize_t tpm_store_ppi_request(struct device *dev, 
	 * is updated with function index from SUBREQ to SUBREQ2 since PPI

	 * version 1.1

	 */

	if (strcmp(tpm_ppi_version, "1.1") >= 0)

	if (acpi_check_dsm(tpm_ppi_handle, tpm_ppi_uuid, TPM_PPI_REVISION_ID,

			   1 << TPM_PPI_FN_SUBREQ2))

		func = TPM_PPI_FN_SUBREQ2;



	/*
@@ -272,7 +265,8 @@ static ssize_t show_ppi_operations(char *buf, u32 start, u32 end) 
		"User not required",

	};



	if (strcmp(tpm_ppi_version, "1.2") < 0)

	if (!acpi_check_dsm(tpm_ppi_handle, tpm_ppi_uuid, TPM_PPI_REVISION_ID,

			    1 << TPM_PPI_FN_GETOPR))

		return -EPERM;



	tmp.integer.type = ACPI_TYPE_INTEGER;
@@ -334,8 +328,7 @@ int tpm_add_ppi(struct kobject *parent) 
{

	/* Cache TPM ACPI handle and version string */

	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX,

			    ppi_callback, NULL,

			    tpm_device_name, &tpm_ppi_handle);

			    ppi_callback, NULL, NULL, &tpm_ppi_handle);

	if (tpm_ppi_handle == NULL)

		return -ENODEV;