RE: [PATCH for-next 2/2] IB/hns: Add support of ACPI to the Hisilicon RoCE driver

[Salil Mehta <salil.mehta@huawei.com>]

> -----Original Message-----
> From: Leon Romanovsky [mailto:leon@kernel.org]
> Sent: Wednesday, August 24, 2016 2:59 PM
> To: Salil Mehta
> Cc: dledford@redhat.com; davem@davemloft.net; Huwei (Xavier); oulijun;
> Zhuangyuzeng (Yisen); mehta.salil.lnk@gmail.com; linux-
> rdma@vger.kernel.org; netdev@vger.kernel.org; linux-
> kernel@vger.kernel.org; Linuxarm
> Subject: Re: [PATCH for-next 2/2] IB/hns: Add support of ACPI to the
> Hisilicon RoCE driver
> 
> On Wed, Aug 24, 2016 at 04:44:50AM +0800, Salil Mehta wrote:
> > This patch is meant to add support of ACPI to the Hisilicon RoCE
> > driver.
> >
> > Changes done are primarily meant to detect the type and then either
> > use DT specific or ACPI spcific functions. Where ever possible,
> > this patch tries to make use of Unified Device Property Interface
> > APIs to support both DT and ACPI through single interface.
> >
> > This patch depends upon HNS ethernet driver to Reset RoCE. This
> > function within HNS ethernet driver has also been enhanced to
> > support ACPI and is part of other accompanying patch with this
> > patch-set.
> >
> > NOTE: The changes in this patch are done over below branch,
> > https://github.com/dledford/linux/tree/hns-roce
> >
> > Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
> > ---
> > Change Log
> >
> > PATCH V1: Initial version to support ACPI in HNS RoCE driver.
> > ---
> >  drivers/infiniband/hw/hns/hns_roce_device.h |    2 +-
> >  drivers/infiniband/hw/hns/hns_roce_eq.c     |    2 +-
> >  drivers/infiniband/hw/hns/hns_roce_hw_v1.c  |   37 ++++++--
> >  drivers/infiniband/hw/hns/hns_roce_hw_v1.h  |    2 +-
> >  drivers/infiniband/hw/hns/hns_roce_main.c   |  127
> ++++++++++++++++++++++-----
> >  5 files changed, 136 insertions(+), 34 deletions(-)
> >
> > diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h
> b/drivers/infiniband/hw/hns/hns_roce_device.h
> > index 00f01be..ea73580 100644
> > --- a/drivers/infiniband/hw/hns/hns_roce_device.h
> > +++ b/drivers/infiniband/hw/hns/hns_roce_device.h
> > @@ -531,7 +531,7 @@ struct hns_roce_dev {
> >  	struct ib_device	ib_dev;
> >  	struct platform_device  *pdev;
> >  	struct hns_roce_uar     priv_uar;
> > -	const char		*irq_names;
> > +	const char		*irq_names[HNS_ROCE_MAX_IRQ_NUM];
> >  	spinlock_t		sm_lock;
> >  	spinlock_t		cq_db_lock;
> >  	spinlock_t		bt_cmd_lock;
> > diff --git a/drivers/infiniband/hw/hns/hns_roce_eq.c
> b/drivers/infiniband/hw/hns/hns_roce_eq.c
> > index 5febbb4..98af7fe 100644
> > --- a/drivers/infiniband/hw/hns/hns_roce_eq.c
> > +++ b/drivers/infiniband/hw/hns/hns_roce_eq.c
> > @@ -713,7 +713,7 @@ int hns_roce_init_eq_table(struct hns_roce_dev
> *hr_dev)
> >
> >  	for (j = 0; j < eq_num; j++) {
> >  		ret = request_irq(eq_table->eq[j].irq,
> hns_roce_msi_x_interrupt,
> > -				  0, hr_dev->irq_names, eq_table->eq + j);
> > +				  0, hr_dev->irq_names[j], eq_table->eq + j);
> >  		if (ret) {
> >  			dev_err(dev, "request irq error!\n");
> >  			goto err_request_irq_fail;
> > diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> > index b52f3ba..399f5de 100644
> > --- a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> > +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
> > @@ -31,6 +31,7 @@
> >   */
> >
> >  #include <linux/platform_device.h>
> > +#include <linux/acpi.h>
> >  #include <rdma/ib_umem.h>
> >  #include "hns_roce_common.h"
> >  #include "hns_roce_device.h"
> > @@ -794,29 +795,47 @@ static void hns_roce_port_enable(struct
> hns_roce_dev *hr_dev, int enable_flag)
> >   * @enable: true -- drop reset, false -- reset
> >   * return 0 - success , negative --fail
> >   */
> > -int hns_roce_v1_reset(struct hns_roce_dev *hr_dev, bool enable)
> > +int hns_roce_v1_reset(struct hns_roce_dev *hr_dev, bool dereset)
> >  {
> >  	struct device_node *dsaf_node;
> >  	struct device *dev = &hr_dev->pdev->dev;
> >  	struct device_node *np = dev->of_node;
> > +	struct fwnode_handle *fwnode;
> >  	int ret;
> >
> > -	dsaf_node = of_parse_phandle(np, "dsaf-handle", 0);
> > -	if (!dsaf_node) {
> > -		dev_err(dev, "Unable to get dsaf node by dsaf-handle!\n");
> > -		return -EINVAL;
> > +	/* check if this is DT/ACPI case */
> > +	if (dev_of_node(dev)) {
> > +		dsaf_node = of_parse_phandle(np, "dsaf-handle", 0);
> > +		if (!dsaf_node) {
> > +			dev_err(dev, "could not find dsaf-handle\n");
> > +			return -EINVAL;
> > +		}
> > +		fwnode = &dsaf_node->fwnode;
> > +	} else if (is_acpi_device_node(dev->fwnode)) {
> > +		struct acpi_reference_args args;
> > +
> > +		ret = acpi_node_get_property_reference(dev->fwnode,
> > +						       "dsaf-handle", 0, &args);
> > +		if (ret) {
> > +			dev_err(dev, "could not find dsaf-handle\n");
> > +			return ret;
> > +		}
> > +		fwnode = acpi_fwnode_handle(args.adev);
> > +	} else {
> > +		dev_err(dev, "cannot read data from DT or ACPI\n");
> > +		return -ENXIO;
> >  	}
> >
> > -	ret = hns_dsaf_roce_reset(&dsaf_node->fwnode, false);
> > +	ret = hns_dsaf_roce_reset(fwnode, false);
> >  	if (ret)
> >  		return ret;
> >
> > -	if (enable) {
> > +	if (dereset) {
> >  		msleep(SLEEP_TIME_INTERVAL);
> > -		return hns_dsaf_roce_reset(&dsaf_node->fwnode, true);
> > +		ret = hns_dsaf_roce_reset(fwnode, true);
> >  	}
> >
> > -	return 0;
> > +	return ret;
> >  }
> >
> >  void hns_roce_v1_profile(struct hns_roce_dev *hr_dev)
> > diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v1.h
> b/drivers/infiniband/hw/hns/hns_roce_hw_v1.h
> > index 2b3bf21..316b592 100644
> > --- a/drivers/infiniband/hw/hns/hns_roce_hw_v1.h
> > +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.h
> > @@ -976,6 +976,6 @@ struct hns_roce_v1_priv {
> >  	struct hns_roce_raq_table raq_table;
> >  };
> >
> > -int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool
> enable);
> > +int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool
> dereset);
> >
> >  #endif
> > diff --git a/drivers/infiniband/hw/hns/hns_roce_main.c
> b/drivers/infiniband/hw/hns/hns_roce_main.c
> > index 6ead671..f64f0dd 100644
> > --- a/drivers/infiniband/hw/hns/hns_roce_main.c
> > +++ b/drivers/infiniband/hw/hns/hns_roce_main.c
> > @@ -30,7 +30,7 @@
> >   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
> >   * SOFTWARE.
> >   */
> > -
> > +#include <linux/acpi.h>
> >  #include <linux/of_platform.h>
> >  #include <rdma/ib_addr.h>
> >  #include <rdma/ib_smi.h>
> > @@ -694,40 +694,122 @@ error_failed_setup_mtu_gids:
> >  	return ret;
> >  }
> >
> > +static const struct of_device_id hns_roce_of_match[] = {
> > +	{ .compatible = "hisilicon,hns-roce-v1", .data = &hns_roce_hw_v1,
> },
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(of, hns_roce_of_match);
> > +
> > +static const struct acpi_device_id hns_roce_acpi_match[] = {
> > +	{ "HISI00D1", (kernel_ulong_t)&hns_roce_hw_v1 },
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(acpi, hns_roce_acpi_match);
> > +
> > +static int hns_roce_node_match(struct device *dev, void *fwnode)
> > +{
> > +	return dev->fwnode == fwnode;
> > +}
> 
> It looks like this function should return bool and not int.

Hi Leon,
Thanks for reviewing. Yes, I think bool would have been much
better as a return value but if you see the prototype of the
"match" function in bus_find_device(), it returns int:

struct device *bus_find_device(struct bus_type *bus,
			       struct device *start, void *data,
			       int (*match)(struct device *dev, void *data))
{
	struct klist_iter i;
      ..........................
      ..........................
}

I also verified this in few other example code legs where it is being
used, like:

File: platform.c
static int of_dev_node_match(struct device *dev, void *data)
{
	return dev->of_node == data;
}

being used in below function 

struct platform_device *of_find_device_by_node(struct device_node *np)
{
	struct device *dev;

	dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
	return dev ? to_platform_device(dev) : NULL;
}


It looks like we should retain the int as a return type or if you have
some other opinion or if I have missed something here please share :)

Best regards
Salil