Re: [PATCH v4 03/15] firmware: qcom_scm: Migrate to generic PAS service

[Sumit Garg <sumit.garg@kernel.org>]

On Wed, Apr 29, 2026 at 04:18:41PM +0530, Mukesh Ojha wrote:
> On Mon, Apr 27, 2026 at 03:25:51PM +0530, Sumit Garg wrote:
> > From: Sumit Garg <sumit.garg@oss.qualcomm.com>
> > 
> > With the availability of generic PAS service, let's add SCM calls as
> > a backend to keep supporting legacy QTEE interfaces. The exported
> > qcom_scm* wrappers will get dropped once all the client drivers get
> > migrated as part of future patches.
> > 
> > Signed-off-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
> > ---
> >  drivers/firmware/qcom/Kconfig    |   1 +
> >  drivers/firmware/qcom/qcom_scm.c | 335 ++++++++++++++-----------------
> >  2 files changed, 155 insertions(+), 181 deletions(-)
> > 
> > diff --git a/drivers/firmware/qcom/Kconfig b/drivers/firmware/qcom/Kconfig
> > index 8653639d06db..9a12ae2b639d 100644
> > --- a/drivers/firmware/qcom/Kconfig
> > +++ b/drivers/firmware/qcom/Kconfig
> > @@ -15,6 +15,7 @@ config QCOM_PAS
> >  	  TEE bus based PAS service implementation.
> >  
> >  config QCOM_SCM
> > +	select QCOM_PAS
> >  	select QCOM_TZMEM
> >  	tristate
> >  
> > diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
> > index 9b06a69d3a6d..d87a962e93da 100644
> > --- a/drivers/firmware/qcom/qcom_scm.c
> > +++ b/drivers/firmware/qcom/qcom_scm.c
> > @@ -13,6 +13,7 @@
> >  #include <linux/dma-mapping.h>
> >  #include <linux/err.h>
> >  #include <linux/export.h>
> > +#include <linux/firmware/qcom/qcom_pas.h>
> >  #include <linux/firmware/qcom/qcom_scm.h>
> >  #include <linux/firmware/qcom/qcom_tzmem.h>
> >  #include <linux/init.h>
> > @@ -33,6 +34,7 @@
> >  
> >  #include <dt-bindings/interrupt-controller/arm-gic.h>
> >  
> > +#include "qcom_pas.h"
> >  #include "qcom_scm.h"
> >  #include "qcom_tzmem.h"
> >  
> > @@ -479,25 +481,6 @@ void qcom_scm_cpu_power_down(u32 flags)
> >  }
> >  EXPORT_SYMBOL_GPL(qcom_scm_cpu_power_down);
> >  
> > -int qcom_scm_set_remote_state(u32 state, u32 id)
> > -{
> > -	struct qcom_scm_desc desc = {
> > -		.svc = QCOM_SCM_SVC_BOOT,
> > -		.cmd = QCOM_SCM_BOOT_SET_REMOTE_STATE,
> > -		.arginfo = QCOM_SCM_ARGS(2),
> > -		.args[0] = state,
> > -		.args[1] = id,
> > -		.owner = ARM_SMCCC_OWNER_SIP,
> > -	};
> > -	struct qcom_scm_res res;
> > -	int ret;
> > -
> > -	ret = qcom_scm_call(__scm->dev, &desc, &res);
> > -
> > -	return ret ? : res.result[0];
> > -}
> > -EXPORT_SYMBOL_GPL(qcom_scm_set_remote_state);
> > -
> >  static int qcom_scm_disable_sdi(void)
> >  {
> >  	int ret;
> > @@ -570,26 +553,12 @@ static void qcom_scm_set_download_mode(u32 dload_mode)
> >  		dev_err(__scm->dev, "failed to set download mode: %d\n", ret);
> >  }
> >  
> > -/**
> > - * devm_qcom_scm_pas_context_alloc() - Allocate peripheral authentication service
> > - *				       context for a given peripheral
> > - *
> > - * PAS context is device-resource managed, so the caller does not need
> > - * to worry about freeing the context memory.
> > - *
> > - * @dev:	  PAS firmware device
> > - * @pas_id:	  peripheral authentication service id
> > - * @mem_phys:	  Subsystem reserve memory start address
> > - * @mem_size:	  Subsystem reserve memory size
> > - *
> > - * Returns: The new PAS context, or ERR_PTR() on failure.
> > - */
> >  struct qcom_scm_pas_context *devm_qcom_scm_pas_context_alloc(struct device *dev,
> >  							     u32 pas_id,
> >  							     phys_addr_t mem_phys,
> >  							     size_t mem_size)
> >  {
> > -	struct qcom_scm_pas_context *ctx;
> > +	struct qcom_pas_context *ctx;
> >  
> >  	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> >  	if (!ctx)
> > @@ -600,11 +569,12 @@ struct qcom_scm_pas_context *devm_qcom_scm_pas_context_alloc(struct device *dev,
> >  	ctx->mem_phys = mem_phys;
> >  	ctx->mem_size = mem_size;
> >  
> > -	return ctx;
> > +	return (struct qcom_scm_pas_context *)ctx;
> >  }
> >  EXPORT_SYMBOL_GPL(devm_qcom_scm_pas_context_alloc);
> >  
> > -static int __qcom_scm_pas_init_image(u32 pas_id, dma_addr_t mdata_phys,
> > +static int __qcom_scm_pas_init_image(struct device *dev, u32 pas_id,
> > +				     dma_addr_t mdata_phys,
> >  				     struct qcom_scm_res *res)
> >  {
> >  	struct qcom_scm_desc desc = {
> > @@ -626,7 +596,7 @@ static int __qcom_scm_pas_init_image(u32 pas_id, dma_addr_t mdata_phys,
> >  
> >  	desc.args[1] = mdata_phys;
> >  
> > -	ret = qcom_scm_call(__scm->dev, &desc, res);
> > +	ret = qcom_scm_call(dev, &desc, res);
> >  	qcom_scm_bw_disable();
> >  
> >  disable_clk:
> > @@ -635,7 +605,8 @@ static int __qcom_scm_pas_init_image(u32 pas_id, dma_addr_t mdata_phys,
> >  	return ret;
> >  }
> >  
> > -static int qcom_scm_pas_prep_and_init_image(struct qcom_scm_pas_context *ctx,
> > +static int qcom_scm_pas_prep_and_init_image(struct device *dev,
> > +					    struct qcom_pas_context *ctx,
> >  					    const void *metadata, size_t size)
> >  {
> >  	struct qcom_scm_res res;
> > @@ -650,7 +621,7 @@ static int qcom_scm_pas_prep_and_init_image(struct qcom_scm_pas_context *ctx,
> >  	memcpy(mdata_buf, metadata, size);
> >  	mdata_phys = qcom_tzmem_to_phys(mdata_buf);
> >  
> > -	ret = __qcom_scm_pas_init_image(ctx->pas_id, mdata_phys, &res);
> > +	ret = __qcom_scm_pas_init_image(dev, ctx->pas_id, mdata_phys, &res);
> >  	if (ret < 0)
> >  		qcom_tzmem_free(mdata_buf);
> >  	else
> > @@ -659,25 +630,9 @@ static int qcom_scm_pas_prep_and_init_image(struct qcom_scm_pas_context *ctx,
> >  	return ret ? : res.result[0];
> >  }
> >  
> > -/**
> > - * qcom_scm_pas_init_image() - Initialize peripheral authentication service
> > - *			       state machine for a given peripheral, using the
> > - *			       metadata
> > - * @pas_id:	peripheral authentication service id
> > - * @metadata:	pointer to memory containing ELF header, program header table
> > - *		and optional blob of data used for authenticating the metadata
> > - *		and the rest of the firmware
> > - * @size:	size of the metadata
> > - * @ctx:	optional pas context
> > - *
> > - * Return: 0 on success.
> > - *
> > - * Upon successful return, the PAS metadata context (@ctx) will be used to
> > - * track the metadata allocation, this needs to be released by invoking
> > - * qcom_scm_pas_metadata_release() by the caller.
> > - */
> > -int qcom_scm_pas_init_image(u32 pas_id, const void *metadata, size_t size,
> > -			    struct qcom_scm_pas_context *ctx)
> > +static int __qcom_scm_pas_init_image2(struct device *dev, u32 pas_id,
> > +				      const void *metadata, size_t size,
> > +				      struct qcom_pas_context *ctx)
> >  {
> >  	struct qcom_scm_res res;
> >  	dma_addr_t mdata_phys;
> > @@ -685,7 +640,7 @@ int qcom_scm_pas_init_image(u32 pas_id, const void *metadata, size_t size,
> >  	int ret;
> >  
> >  	if (ctx && ctx->use_tzmem)
> > -		return qcom_scm_pas_prep_and_init_image(ctx, metadata, size);
> > +		return qcom_scm_pas_prep_and_init_image(dev, ctx, metadata, size);
> >  
> >  	/*
> >  	 * During the scm call memory protection will be enabled for the meta
> > @@ -699,16 +654,15 @@ int qcom_scm_pas_init_image(u32 pas_id, const void *metadata, size_t size,
> >  	 * If we pass a buffer that is already part of an SHM Bridge to this
> >  	 * call, it will fail.
> >  	 */
> > -	mdata_buf = dma_alloc_coherent(__scm->dev, size, &mdata_phys,
> > -				       GFP_KERNEL);
> > +	mdata_buf = dma_alloc_coherent(dev, size, &mdata_phys, GFP_KERNEL);
> >  	if (!mdata_buf)
> >  		return -ENOMEM;
> >  
> >  	memcpy(mdata_buf, metadata, size);
> >  
> > -	ret = __qcom_scm_pas_init_image(pas_id, mdata_phys, &res);
> > +	ret = __qcom_scm_pas_init_image(dev, pas_id, mdata_phys, &res);
> >  	if (ret < 0 || !ctx) {
> > -		dma_free_coherent(__scm->dev, size, mdata_buf, mdata_phys);
> > +		dma_free_coherent(dev, size, mdata_buf, mdata_phys);
> >  	} else if (ctx) {
> >  		ctx->ptr = mdata_buf;
> >  		ctx->phys = mdata_phys;
> > @@ -717,36 +671,35 @@ int qcom_scm_pas_init_image(u32 pas_id, const void *metadata, size_t size,
> >  
> >  	return ret ? : res.result[0];
> >  }
> > -EXPORT_SYMBOL_GPL(qcom_scm_pas_init_image);
> >  
> > -/**
> > - * qcom_scm_pas_metadata_release() - release metadata context
> > - * @ctx:	pas context
> > - */
> > -void qcom_scm_pas_metadata_release(struct qcom_scm_pas_context *ctx)
> > +int qcom_scm_pas_init_image(u32 pas_id, const void *metadata, size_t size,
> > +			    struct qcom_scm_pas_context *ctx)
> >  {
> > -	if (!ctx->ptr)
> > -		return;
> > +	return __qcom_scm_pas_init_image2(__scm->dev, pas_id, metadata, size,
> > +					  (struct qcom_pas_context *)ctx);
> > +}
> > +EXPORT_SYMBOL_GPL(qcom_scm_pas_init_image);
> >  
> > +static void __qcom_scm_pas_metadata_release(struct device *dev,
> > +					    struct qcom_pas_context *ctx)
> > +{
> >  	if (ctx->use_tzmem)
> >  		qcom_tzmem_free(ctx->ptr);
> >  	else
> > -		dma_free_coherent(__scm->dev, ctx->size, ctx->ptr, ctx->phys);
> > +		dma_free_coherent(dev, ctx->size, ctx->ptr, ctx->phys);
> >  
> >  	ctx->ptr = NULL;
> >  }
> > +
> > +void qcom_scm_pas_metadata_release(struct qcom_scm_pas_context *ctx)
> > +{
> > +	__qcom_scm_pas_metadata_release(__scm->dev,
> > +					(struct qcom_pas_context *)ctx);
> > +}
> >  EXPORT_SYMBOL_GPL(qcom_scm_pas_metadata_release);
> >  
> > -/**
> > - * qcom_scm_pas_mem_setup() - Prepare the memory related to a given peripheral
> > - *			      for firmware loading
> > - * @pas_id:	peripheral authentication service id
> > - * @addr:	start address of memory area to prepare
> > - * @size:	size of the memory area to prepare
> > - *
> > - * Returns 0 on success.
> > - */
> > -int qcom_scm_pas_mem_setup(u32 pas_id, phys_addr_t addr, phys_addr_t size)
> > +static int __qcom_scm_pas_mem_setup(struct device *dev, u32 pas_id,
> > +				    phys_addr_t addr, phys_addr_t size)
> >  {
> >  	int ret;
> >  	struct qcom_scm_desc desc = {
> > @@ -768,7 +721,7 @@ int qcom_scm_pas_mem_setup(u32 pas_id, phys_addr_t addr, phys_addr_t size)
> >  	if (ret)
> >  		goto disable_clk;
> >  
> > -	ret = qcom_scm_call(__scm->dev, &desc, &res);
> > +	ret = qcom_scm_call(dev, &desc, &res);
> >  	qcom_scm_bw_disable();
> >  
> >  disable_clk:
> > @@ -776,9 +729,15 @@ int qcom_scm_pas_mem_setup(u32 pas_id, phys_addr_t addr, phys_addr_t size)
> >  
> >  	return ret ? : res.result[0];
> >  }
> > +
> > +int qcom_scm_pas_mem_setup(u32 pas_id, phys_addr_t addr, phys_addr_t size)
> > +{
> > +	return __qcom_scm_pas_mem_setup(__scm->dev, pas_id, addr, size);
> > +}
> >  EXPORT_SYMBOL_GPL(qcom_scm_pas_mem_setup);
> >  
> > -static void *__qcom_scm_pas_get_rsc_table(u32 pas_id, void *input_rt_tzm,
> > +static void *__qcom_scm_pas_get_rsc_table(struct device *dev, u32 pas_id,
> > +					  void *input_rt_tzm,
> >  					  size_t input_rt_size,
> >  					  size_t *output_rt_size)
> >  {
> > @@ -813,7 +772,7 @@ static void *__qcom_scm_pas_get_rsc_table(u32 pas_id, void *input_rt_tzm,
> >  	 * with output_rt_tzm buffer with res.result[2] size however, It should not
> >  	 * be of unresonable size.
> >  	 */
> > -	ret = qcom_scm_call(__scm->dev, &desc, &res);
> > +	ret = qcom_scm_call(dev, &desc, &res);
> >  	if (!ret && res.result[2] > SZ_1G) {
> >  		ret = -E2BIG;
> >  		goto free_output_rt;
> > @@ -830,51 +789,11 @@ static void *__qcom_scm_pas_get_rsc_table(u32 pas_id, void *input_rt_tzm,
> >  	return ret ? ERR_PTR(ret) : output_rt_tzm;
> >  }
> >  
> > -/**
> > - * qcom_scm_pas_get_rsc_table() - Retrieve the resource table in passed output buffer
> > - *				  for a given peripheral.
> > - *
> > - * Qualcomm remote processor may rely on both static and dynamic resources for
> > - * its functionality. Static resources typically refer to memory-mapped addresses
> > - * required by the subsystem and are often embedded within the firmware binary
> > - * and dynamic resources, such as shared memory in DDR etc., are determined at
> > - * runtime during the boot process.
> > - *
> > - * On Qualcomm Technologies devices, it's possible that static resources are not
> > - * embedded in the firmware binary and instead are provided by TrustZone However,
> > - * dynamic resources are always expected to come from TrustZone. This indicates
> > - * that for Qualcomm devices, all resources (static and dynamic) will be provided
> > - * by TrustZone via the SMC call.
> > - *
> > - * If the remote processor firmware binary does contain static resources, they
> > - * should be passed in input_rt. These will be forwarded to TrustZone for
> > - * authentication. TrustZone will then append the dynamic resources and return
> > - * the complete resource table in output_rt_tzm.
> > - *
> > - * If the remote processor firmware binary does not include a resource table,
> > - * the caller of this function should set input_rt as NULL and input_rt_size
> > - * as zero respectively.
> > - *
> > - * More about documentation on resource table data structures can be found in
> > - * include/linux/remoteproc.h
> > - *
> > - * @ctx:	    PAS context
> > - * @pas_id:	    peripheral authentication service id
> > - * @input_rt:       resource table buffer which is present in firmware binary
> > - * @input_rt_size:  size of the resource table present in firmware binary
> > - * @output_rt_size: TrustZone expects caller should pass worst case size for
> > - *		    the output_rt_tzm.
> > - *
> > - * Return:
> > - *  On success, returns a pointer to the allocated buffer containing the final
> > - *  resource table and output_rt_size will have actual resource table size from
> > - *  TrustZone. The caller is responsible for freeing the buffer. On failure,
> > - *  returns ERR_PTR(-errno).
> > - */
> > -struct resource_table *qcom_scm_pas_get_rsc_table(struct qcom_scm_pas_context *ctx,
> > -						  void *input_rt,
> > -						  size_t input_rt_size,
> > -						  size_t *output_rt_size)
> > +static void *__qcom_scm_pas_get_rsc_table2(struct device *dev,
> > +					   struct qcom_pas_context *ctx,
> > +					   void *input_rt,
> > +					   size_t input_rt_size,
> > +					   size_t *output_rt_size)
> >  {
> >  	struct resource_table empty_rsc = {};
> >  	size_t size = SZ_16K;
> > @@ -909,11 +828,12 @@ struct resource_table *qcom_scm_pas_get_rsc_table(struct qcom_scm_pas_context *c
> >  
> >  	memcpy(input_rt_tzm, input_rt, input_rt_size);
> >  
> > -	output_rt_tzm = __qcom_scm_pas_get_rsc_table(ctx->pas_id, input_rt_tzm,
> > +	output_rt_tzm = __qcom_scm_pas_get_rsc_table(dev, ctx->pas_id,
> > +						     input_rt_tzm,
> >  						     input_rt_size, &size);
> >  	if (PTR_ERR(output_rt_tzm) == -EOVERFLOW)
> >  		/* Try again with the size requested by the TZ */
> > -		output_rt_tzm = __qcom_scm_pas_get_rsc_table(ctx->pas_id,
> > +		output_rt_tzm = __qcom_scm_pas_get_rsc_table(dev, ctx->pas_id,
> >  							     input_rt_tzm,
> >  							     input_rt_size,
> >  							     &size);
> > @@ -943,16 +863,20 @@ struct resource_table *qcom_scm_pas_get_rsc_table(struct qcom_scm_pas_context *c
> >  
> >  	return ret ? ERR_PTR(ret) : tbl_ptr;
> >  }
> > +
> > +struct resource_table *qcom_scm_pas_get_rsc_table(struct qcom_scm_pas_context *ctx,
> > +						  void *input_rt,
> > +						  size_t input_rt_size,
> > +						  size_t *output_rt_size)
> > +{
> > +	return __qcom_scm_pas_get_rsc_table2(__scm->dev,
> > +					     (struct qcom_pas_context *)ctx,
> > +					     input_rt, input_rt_size,
> > +					     output_rt_size);
> > +}
> >  EXPORT_SYMBOL_GPL(qcom_scm_pas_get_rsc_table);
> >  
> > -/**
> > - * qcom_scm_pas_auth_and_reset() - Authenticate the given peripheral firmware
> > - *				   and reset the remote processor
> > - * @pas_id:	peripheral authentication service id
> > - *
> > - * Return 0 on success.
> > - */
> > -int qcom_scm_pas_auth_and_reset(u32 pas_id)
> > +static int __qcom_scm_pas_auth_and_reset(struct device *dev, u32 pas_id)
> >  {
> >  	int ret;
> >  	struct qcom_scm_desc desc = {
> > @@ -972,7 +896,7 @@ int qcom_scm_pas_auth_and_reset(u32 pas_id)
> >  	if (ret)
> >  		goto disable_clk;
> >  
> > -	ret = qcom_scm_call(__scm->dev, &desc, &res);
> > +	ret = qcom_scm_call(dev, &desc, &res);
> >  	qcom_scm_bw_disable();
> >  
> >  disable_clk:
> > @@ -980,28 +904,15 @@ int qcom_scm_pas_auth_and_reset(u32 pas_id)
> >  
> >  	return ret ? : res.result[0];
> >  }
> > +
> > +int qcom_scm_pas_auth_and_reset(u32 pas_id)
> > +{
> > +	return __qcom_scm_pas_auth_and_reset(__scm->dev, pas_id);
> > +}
> >  EXPORT_SYMBOL_GPL(qcom_scm_pas_auth_and_reset);
> >  
> > -/**
> > - * qcom_scm_pas_prepare_and_auth_reset() - Prepare, authenticate, and reset the
> > - *					   remote processor
> > - *
> > - * @ctx:	Context saved during call to qcom_scm_pas_context_init()
> > - *
> > - * This function performs the necessary steps to prepare a PAS subsystem,
> > - * authenticate it using the provided metadata, and initiate a reset sequence.
> > - *
> > - * It should be used when Linux is in control setting up the IOMMU hardware
> > - * for remote subsystem during secure firmware loading processes. The preparation
> > - * step sets up a shmbridge over the firmware memory before TrustZone accesses the
> > - * firmware memory region for authentication. The authentication step verifies
> > - * the integrity and authenticity of the firmware or configuration using secure
> > - * metadata. Finally, the reset step ensures the subsystem starts in a clean and
> > - * sane state.
> > - *
> > - * Return: 0 on success, negative errno on failure.
> > - */
> > -int qcom_scm_pas_prepare_and_auth_reset(struct qcom_scm_pas_context *ctx)
> > +static int __qcom_scm_pas_prepare_and_auth_reset(struct device *dev,
> > +						 struct qcom_pas_context *ctx)
> >  {
> >  	u64 handle;
> >  	int ret;
> > @@ -1012,7 +923,7 @@ int qcom_scm_pas_prepare_and_auth_reset(struct qcom_scm_pas_context *ctx)
> >  	 * memory region and then invokes a call to TrustZone to authenticate.
> >  	 */
> >  	if (!ctx->use_tzmem)
> > -		return qcom_scm_pas_auth_and_reset(ctx->pas_id);
> > +		return __qcom_scm_pas_auth_and_reset(dev, ctx->pas_id);
> >  
> >  	/*
> >  	 * When Linux runs @ EL2 Linux must create the shmbridge itself and then
> > @@ -1022,20 +933,45 @@ int qcom_scm_pas_prepare_and_auth_reset(struct qcom_scm_pas_context *ctx)
> >  	if (ret)
> >  		return ret;
> >  
> > -	ret = qcom_scm_pas_auth_and_reset(ctx->pas_id);
> > +	ret = __qcom_scm_pas_auth_and_reset(dev, ctx->pas_id);
> >  	qcom_tzmem_shm_bridge_delete(handle);
> >  
> >  	return ret;
> >  }
> > +
> > +int qcom_scm_pas_prepare_and_auth_reset(struct qcom_scm_pas_context *ctx)
> > +{
> > +	return __qcom_scm_pas_prepare_and_auth_reset(__scm->dev,
> > +						     (struct qcom_pas_context *)ctx);
> > +}
> >  EXPORT_SYMBOL_GPL(qcom_scm_pas_prepare_and_auth_reset);
> >  
> > -/**
> > - * qcom_scm_pas_shutdown() - Shut down the remote processor
> > - * @pas_id:	peripheral authentication service id
> > - *
> > - * Returns 0 on success.
> > - */
> > -int qcom_scm_pas_shutdown(u32 pas_id)
> > +static int __qcom_scm_pas_set_remote_state(struct device *dev, u32 state,
> > +					   u32 pas_id)
> > +{
> > +	struct qcom_scm_desc desc = {
> > +		.svc = QCOM_SCM_SVC_BOOT,
> > +		.cmd = QCOM_SCM_BOOT_SET_REMOTE_STATE,
> > +		.arginfo = QCOM_SCM_ARGS(2),
> > +		.args[0] = state,
> > +		.args[1] = pas_id,
> > +		.owner = ARM_SMCCC_OWNER_SIP,
> > +	};
> > +	struct qcom_scm_res res;
> > +	int ret;
> > +
> > +	ret = qcom_scm_call(dev, &desc, &res);
> > +
> > +	return ret ? : res.result[0];
> > +}
> > +
> > +int qcom_scm_set_remote_state(u32 state, u32 id)
> 
> s/id/pas_id

Ack.

> 
> > +{
> > +	return __qcom_scm_pas_set_remote_state(__scm->dev, state, id);
> > +}
> > +EXPORT_SYMBOL_GPL(qcom_scm_set_remote_state);
> > +
> > +static int __qcom_scm_pas_shutdown(struct device *dev, u32 pas_id)
> >  {
> >  	int ret;
> >  	struct qcom_scm_desc desc = {
> > @@ -1055,7 +991,7 @@ int qcom_scm_pas_shutdown(u32 pas_id)
> >  	if (ret)
> >  		goto disable_clk;
> >  
> > -	ret = qcom_scm_call(__scm->dev, &desc, &res);
> > +	ret = qcom_scm_call(dev, &desc, &res);
> >  	qcom_scm_bw_disable();
> >  
> >  disable_clk:
> > @@ -1063,16 +999,14 @@ int qcom_scm_pas_shutdown(u32 pas_id)
> >  
> >  	return ret ? : res.result[0];
> >  }
> > +
> > +int qcom_scm_pas_shutdown(u32 pas_id)
> > +{
> > +	return __qcom_scm_pas_shutdown(__scm->dev, pas_id);
> > +}
> >  EXPORT_SYMBOL_GPL(qcom_scm_pas_shutdown);
> >  
> > -/**
> > - * qcom_scm_pas_supported() - Check if the peripheral authentication service is
> > - *			      available for the given peripherial
> > - * @pas_id:	peripheral authentication service id
> > - *
> > - * Returns true if PAS is supported for this peripheral, otherwise false.
> > - */
> > -bool qcom_scm_pas_supported(u32 pas_id)
> > +static bool __qcom_scm_pas_supported(struct device *dev, u32 pas_id)
> >  {
> >  	int ret;
> >  	struct qcom_scm_desc desc = {
> > @@ -1084,16 +1018,49 @@ bool qcom_scm_pas_supported(u32 pas_id)
> >  	};
> >  	struct qcom_scm_res res;
> >  
> > -	if (!__qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_PIL,
> > +	if (!__qcom_scm_is_call_available(dev, QCOM_SCM_SVC_PIL,
> >  					  QCOM_SCM_PIL_PAS_IS_SUPPORTED))
> >  		return false;
> >  
> > -	ret = qcom_scm_call(__scm->dev, &desc, &res);
> > +	ret = qcom_scm_call(dev, &desc, &res);
> >  
> >  	return ret ? false : !!res.result[0];
> >  }
> > +
> > +bool qcom_scm_pas_supported(u32 pas_id)
> > +{
> > +	return __qcom_scm_pas_supported(__scm->dev, pas_id);
> > +}
> >  EXPORT_SYMBOL_GPL(qcom_scm_pas_supported);
> >  
> > +static struct qcom_pas_ops qcom_pas_ops_scm = {
> > +	.drv_name		= "qcom_scm",
> > +	.supported		= __qcom_scm_pas_supported,
> > +	.init_image		= __qcom_scm_pas_init_image2,
> > +	.mem_setup		= __qcom_scm_pas_mem_setup,
> > +	.get_rsc_table		= __qcom_scm_pas_get_rsc_table2,
> > +	.auth_and_reset		= __qcom_scm_pas_auth_and_reset,
> > +	.prepare_and_auth_reset	= __qcom_scm_pas_prepare_and_auth_reset,
> > +	.set_remote_state	= __qcom_scm_pas_set_remote_state,
> > +	.shutdown		= __qcom_scm_pas_shutdown,
> > +	.metadata_release	= __qcom_scm_pas_metadata_release,
> > +};
> > +
> > +/**
> > + * qcom_scm_is_pas_available() - Check if the peripheral authentication service
> > + *				 is available via SCM or not
> > + *
> > + * Returns true if PAS is available, otherwise false.
> > + */
> > +static bool qcom_scm_is_pas_available(void)
> > +{
> > +	if (!__qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_PIL,
> > +					  QCOM_SCM_PIL_PAS_AUTH_AND_RESET))
> 
> QCOM_SCM_PIL_PAS_IS_SUPPORTED ?

This SCM call is there to rather check if PAS is supported for a
particular co-processor ID but not the overall SCM PAS functionality.
And this API isn't used by every client driver for status check.

The PAS auth and reset SCM call is surely supported on every QTEE/TZ
implementation, that's why I used it as a reference for checking SCM PAS
support.

-Sumit

> 
> 
> > +		return false;
> > +
> > +	return true;
> > +}
> > +
> >  static int __qcom_scm_pas_mss_reset(struct device *dev, bool reset)
> >  {
> >  	struct qcom_scm_desc desc = {
> > @@ -2836,6 +2803,11 @@ static int qcom_scm_probe(struct platform_device *pdev)
> >  
> >  	__get_convention();
> >  
> > +	if (qcom_scm_is_pas_available()) {
> 
> Use qcom_scm_pas_supported() and remove qcom_scm_is_pas_available()..
> 
> > +		qcom_pas_ops_scm.dev = scm->dev;
> > +		qcom_pas_ops_register(&qcom_pas_ops_scm);
> > +	}
> > +
> >  	/*
> >  	 * If "download mode" is requested, from this point on warmboot
> >  	 * will cause the boot stages to enter download mode, unless
> > @@ -2875,6 +2847,7 @@ static void qcom_scm_shutdown(struct platform_device *pdev)
> >  {
> >  	/* Clean shutdown, disable download mode to allow normal restart */
> >  	qcom_scm_set_download_mode(QCOM_DLOAD_NODUMP);
> > +	qcom_pas_ops_unregister();
> >  }
> >  
> >  static const struct of_device_id qcom_scm_dt_match[] = {
> > -- 
> > 2.51.0
> > 
> 
> With above changes,
> 
> Reviewed-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com> 
> 
> -- 
> -Mukesh Ojha
>