RE: [PATCH v2 14/27] nvdimm/ocxl: Add support for near storage commands

["Alastair D'Silva" <alastair@au1.ibm.com>]

On Mon, 2020-02-03 at 14:22 +0000, Jonathan Cameron wrote:
> On Tue, 3 Dec 2019 14:46:42 +1100
> Alastair D'Silva <alastair@au1.ibm.com> wrote:
> 
> > From: Alastair D'Silva <alastair@d-silva.org>
> > 
> > Similar to the previous patch, this adds support for near storage
> > commands.
> > 
> > Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> > ---
> >  drivers/nvdimm/ocxl/scm.c          |  6 +++++
> >  drivers/nvdimm/ocxl/scm_internal.c | 41
> > ++++++++++++++++++++++++++++++
> >  drivers/nvdimm/ocxl/scm_internal.h | 38
> > +++++++++++++++++++++++++++
> >  3 files changed, 85 insertions(+)
> > 
> > diff --git a/drivers/nvdimm/ocxl/scm.c b/drivers/nvdimm/ocxl/scm.c
> > index 1e175f3c3cf2..6c16ca7fabfa 100644
> > --- a/drivers/nvdimm/ocxl/scm.c
> > +++ b/drivers/nvdimm/ocxl/scm.c
> > @@ -310,12 +310,18 @@ static int scm_setup_command_metadata(struct
> > scm_data *scm_data)
> >  	int rc;
> >  
> >  	mutex_init(&scm_data->admin_command.lock);
> > +	mutex_init(&scm_data->ns_command.lock);
> >  
> >  	rc = scm_extract_command_metadata(scm_data,
> > GLOBAL_MMIO_ACMA_CREQO,
> >  					  &scm_data->admin_command);
> >  	if (rc)
> >  		return rc;
> >  
> > +	rc = scm_extract_command_metadata(scm_data,
> > GLOBAL_MMIO_NSCMA_CREQO,
> > +					  &scm_data->ns_command);
> > +	if (rc)
> > +		return rc;
> > +
> 
> Ah. So much for my comment in previous patch.  Ignore that...
> 
> >  	return 0;
> >  }
> >  
> > diff --git a/drivers/nvdimm/ocxl/scm_internal.c
> > b/drivers/nvdimm/ocxl/scm_internal.c
> > index 7b11b56863fb..c405f1d8afb8 100644
> > --- a/drivers/nvdimm/ocxl/scm_internal.c
> > +++ b/drivers/nvdimm/ocxl/scm_internal.c
> > @@ -132,6 +132,47 @@ int scm_admin_response_handled(const struct
> > scm_data *scm_data)
> >  				      OCXL_LITTLE_ENDIAN,
> > GLOBAL_MMIO_CHI_ACRA);
> >  }
> >  
> > +int scm_ns_command_request(struct scm_data *scm_data, u8 op_code)
> > +{
> > +	u64 val;
> > +	int rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CHI,
> > +					 OCXL_LITTLE_ENDIAN, &val);
> > +	if (rc)
> > +		return rc;
> > +
> > +	if (!(val & GLOBAL_MMIO_CHI_NSCRA))
> > +		return -EBUSY;
> > +
> > +	return scm_command_request(scm_data, &scm_data->ns_command,
> > op_code);
> > +}
> > +
> > +int scm_ns_response(const struct scm_data *scm_data)
> > +{
> > +	return scm_command_response(scm_data, &scm_data->ns_command);
> > +}
> > +
> > +int scm_ns_command_execute(const struct scm_data *scm_data)
> > +{
> > +	return ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_HCI,
> > +				      OCXL_LITTLE_ENDIAN,
> > GLOBAL_MMIO_HCI_NSCRW);
> > +}
> > +
> > +bool scm_ns_command_complete(const struct scm_data *scm_data)
> > +{
> > +	u64 val = 0;
> > +	int rc = scm_chi(scm_data, &val);
> > +
> > +	WARN_ON(rc);
> > +
> > +	return (val & GLOBAL_MMIO_CHI_NSCRA) != 0;
> > +}
> > +
> > +int scm_ns_response_handled(const struct scm_data *scm_data)
> > +{
> > +	return ocxl_global_mmio_set64(scm_data->ocxl_afu,
> > GLOBAL_MMIO_CHIC,
> > +				      OCXL_LITTLE_ENDIAN,
> > GLOBAL_MMIO_CHI_NSCRA);
> > +}
> > +
> >  void scm_warn_status(const struct scm_data *scm_data, const char
> > *message,
> >  		     u8 status)
> >  {
> > diff --git a/drivers/nvdimm/ocxl/scm_internal.h
> > b/drivers/nvdimm/ocxl/scm_internal.h
> > index 9bff684cd069..9575996a89e7 100644
> > --- a/drivers/nvdimm/ocxl/scm_internal.h
> > +++ b/drivers/nvdimm/ocxl/scm_internal.h
> > @@ -108,6 +108,7 @@ struct scm_data {
> >  	struct ocxl_context *ocxl_context;
> >  	void *metadata_addr;
> >  	struct command_metadata admin_command;
> > +	struct command_metadata ns_command;
> >  	struct resource scm_res;
> >  	struct nd_region *nd_region;
> >  	char fw_version[8+1];
> > @@ -176,6 +177,42 @@ int scm_admin_command_complete_timeout(const
> > struct scm_data *scm_data,
> >   */
> >  int scm_admin_response_handled(const struct scm_data *scm_data);
> >  
> > +/**
> > + * scm_ns_command_request() - Issue a near storage command request
> > + * @scm_data: a pointer to the SCM device data
> > + * @op_code: The op-code for the command
> > + * Returns an identifier for the command, or negative on error
> > + */
> > +int scm_ns_command_request(struct scm_data *scm_data, u8 op_code);
> > +
> > +/**
> > + * scm_ns_response() - Validate a near storage response
> > + * @scm_data: a pointer to the SCM device data
> > + * Returns the status code of the command, or negative on error
> > + */
> > +int scm_ns_response(const struct scm_data *scm_data);
> > +
> > +/**
> > + * scm_ns_command_execute() - Notify the controller to start
> > processing a pending near storage command
> > + * @scm_data: a pointer to the SCM device data
> > + * Returns 0 on success, negative on error
> > + */
> > +int scm_ns_command_execute(const struct scm_data *scm_data);
> > +
> > +/**
> > + * scm_ns_command_complete() - Is a near storage command executing
> > + * scm_data: a pointer to the SCM device data
> > + * Returns true if the previous admin command has completed
> > + */
> > +bool scm_ns_command_complete(const struct scm_data *scm_data);
> > +
> > +/**
> > + * scm_ns_response_handled() - Notify the controller that the near
> > storage response has been handled
> > + * scm_data: a pointer to the SCM device data
> > + * Returns 0 on success, negative on failure
> > + */
> > +int scm_ns_response_handled(const struct scm_data *scm_data);
> > +
> >  /**
> >   * scm_warn_status() - Emit a kernel warning showing a command
> > status.
> >   * @scm_data: a pointer to the SCM device data
> > @@ -184,3 +221,4 @@ int scm_admin_response_handled(const struct
> > scm_data *scm_data);
> >   */
> >  void scm_warn_status(const struct scm_data *scm_data, const char
> > *message,
> >  		     u8 status);
> > +
> Stray blank line!
Ok

> 
> Now we are into the real nitpicks.  Not enough coffee.
> 
> Jonathan
> 
-- 
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819