RE: [EXT] Re: [PATCH v2 12/12] bus: fsl-mc: Add ACPI support for fsl-mc

[Makarand Pawagi <makarand.pawagi@nxp.com>]

> -----Original Message-----
> From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Sent: Thursday, July 9, 2020 2:50 PM
> To: Laurentiu Tudor <laurentiu.tudor@nxp.com>
> Cc: linux-arm-kernel@lists.infradead.org; Makarand Pawagi
> <makarand.pawagi@nxp.com>; Diana Madalina Craciun (OSS)
> <diana.craciun@oss.nxp.com>; iommu@lists.linux-foundation.org; linux-
> acpi@vger.kernel.org; devicetree@vger.kernel.org; linux-pci@vger.kernel.org;
> Rob Herring <robh+dt@kernel.org>; Rafael J. Wysocki <rjw@rjwysocki.net>;
> Joerg Roedel <joro@8bytes.org>; Hanjun Guo <guohanjun@huawei.com>; Bjorn
> Helgaas <bhelgaas@google.com>; Sudeep Holla <sudeep.holla@arm.com>;
> Robin Murphy <robin.murphy@arm.com>; Catalin Marinas
> <catalin.marinas@arm.com>; Will Deacon <will@kernel.org>; Marc Zyngier
> <maz@kernel.org>
> Subject: [EXT] Re: [PATCH v2 12/12] bus: fsl-mc: Add ACPI support for fsl-mc
> 
> Caution: EXT Email
> 
> On Wed, Jul 01, 2020 at 07:55:28PM +0300, Laurentiu Tudor wrote:
> >
> >
> > On 6/19/2020 11:20 AM, Lorenzo Pieralisi wrote:
> > > From: Makarand Pawagi <makarand.pawagi@nxp.com>
> > >
> > > Add ACPI support in the fsl-mc driver. Driver parses MC DSDT table
> > > to extract memory and other resources.
> > >
> > > Interrupt (GIC ITS) information is extracted from the MADT table by
> > > drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c.
> > >
> > > IORT table is parsed to configure DMA.
> > >
> > > Signed-off-by: Makarand Pawagi <makarand.pawagi@nxp.com>
> > > Signed-off-by: Diana Craciun <diana.craciun@oss.nxp.com>
> > > Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
> > > ---
> > >  drivers/bus/fsl-mc/fsl-mc-bus.c             | 73 ++++++++++++----
> > >  drivers/bus/fsl-mc/fsl-mc-msi.c             | 37 +++++----
> > >  drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c | 92
> > > ++++++++++++++++-----
> > >  3 files changed, 150 insertions(+), 52 deletions(-)
> > >
> > > diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c
> > > b/drivers/bus/fsl-mc/fsl-mc-bus.c index 824ff77bbe86..324d49d6df89
> > > 100644
> > > --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
> > > +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
> > > @@ -18,6 +18,8 @@
> > >  #include <linux/bitops.h>
> > >  #include <linux/msi.h>
> > >  #include <linux/dma-mapping.h>
> > > +#include <linux/acpi.h>
> > > +#include <linux/iommu.h>
> > >
> > >  #include "fsl-mc-private.h"
> > >
> > > @@ -38,6 +40,7 @@ struct fsl_mc {
> > >     struct fsl_mc_device *root_mc_bus_dev;
> > >     u8 num_translation_ranges;
> > >     struct fsl_mc_addr_translation_range *translation_ranges;
> > > +   void *fsl_mc_regs;
> > >  };
> > >
> > >  /**
> > > @@ -56,6 +59,10 @@ struct fsl_mc_addr_translation_range {
> > >     phys_addr_t start_phys_addr;
> > >  };
> > >
> > > +#define FSL_MC_FAPR        0x28
> > > +#define MC_FAPR_PL BIT(18)
> > > +#define MC_FAPR_BMT        BIT(17)
> > > +
> > >  /**
> > >   * fsl_mc_bus_match - device to driver matching callback
> > >   * @dev: the fsl-mc device to match against @@ -124,7 +131,10 @@
> > > static int fsl_mc_dma_configure(struct device *dev)
> > >     while (dev_is_fsl_mc(dma_dev))
> > >             dma_dev = dma_dev->parent;
> > >
> > > -   return of_dma_configure_id(dev, dma_dev->of_node, 0, &input_id);
> > > +   if (dev_of_node(dma_dev))
> > > +           return of_dma_configure_id(dev, dma_dev->of_node, 0,
> > > + &input_id);
> > > +
> > > +   return acpi_dma_configure_id(dev, DEV_DMA_COHERENT, &input_id);
> > >  }
> > >
> > >  static ssize_t modalias_show(struct device *dev, struct
> > > device_attribute *attr, @@ -865,8 +875,11 @@ static int
> fsl_mc_bus_probe(struct platform_device *pdev)
> > >     struct fsl_mc_io *mc_io = NULL;
> > >     int container_id;
> > >     phys_addr_t mc_portal_phys_addr;
> > > -   u32 mc_portal_size;
> > > -   struct resource res;
> > > +   u32 mc_portal_size, mc_stream_id;
> > > +   struct resource *plat_res;
> > > +
> > > +   if (!iommu_present(&fsl_mc_bus_type))
> > > +           return -EPROBE_DEFER;
> > >
> > >     mc = devm_kzalloc(&pdev->dev, sizeof(*mc), GFP_KERNEL);
> > >     if (!mc)
> > > @@ -874,19 +887,33 @@ static int fsl_mc_bus_probe(struct
> > > platform_device *pdev)
> > >
> > >     platform_set_drvdata(pdev, mc);
> > >
> > > +   plat_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> > > +   mc->fsl_mc_regs = devm_ioremap_resource(&pdev->dev, plat_res);
> > > +   if (IS_ERR(mc->fsl_mc_regs))
> > > +           return PTR_ERR(mc->fsl_mc_regs);
> > > +
> > > +   if (IS_ENABLED(CONFIG_ACPI) && !dev_of_node(&pdev->dev)) {
> > > +           mc_stream_id = readl(mc->fsl_mc_regs + FSL_MC_FAPR);
> > > +           /*
> > > +            * HW ORs the PL and BMT bit, places the result in bit 15 of
> > > +            * the StreamID and ORs in the ICID. Calculate it accordingly.
> > > +            */
> > > +           mc_stream_id = (mc_stream_id & 0xffff) |
> > > +                           ((mc_stream_id & (MC_FAPR_PL | MC_FAPR_BMT)) ?
> > > +                                   0x4000 : 0);
> > > +           error = acpi_dma_configure_id(&pdev->dev, DEV_DMA_COHERENT,
> > > +                                         &mc_stream_id);
> > > +           if (error)
> > > +                   dev_warn(&pdev->dev, "failed to configure dma: %d.\n",
> > > +                            error);
> > > +   }
> > > +
> > >     /*
> > >      * Get physical address of MC portal for the root DPRC:
> > >      */
> > > -   error = of_address_to_resource(pdev->dev.of_node, 0, &res);
> > > -   if (error < 0) {
> > > -           dev_err(&pdev->dev,
> > > -                   "of_address_to_resource() failed for %pOF\n",
> > > -                   pdev->dev.of_node);
> > > -           return error;
> > > -   }
> > > -
> > > -   mc_portal_phys_addr = res.start;
> > > -   mc_portal_size = resource_size(&res);
> > > +   plat_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > +   mc_portal_phys_addr = plat_res->start;
> > > +   mc_portal_size = resource_size(plat_res);
> > >     error = fsl_create_mc_io(&pdev->dev, mc_portal_phys_addr,
> > >                              mc_portal_size, NULL,
> > >                              FSL_MC_IO_ATOMIC_CONTEXT_PORTAL,
> > > &mc_io); @@ -903,11 +930,13 @@ static int fsl_mc_bus_probe(struct
> platform_device *pdev)
> > >     dev_info(&pdev->dev, "MC firmware version: %u.%u.%u\n",
> > >              mc_version.major, mc_version.minor,
> > > mc_version.revision);
> > >
> > > -   error = get_mc_addr_translation_ranges(&pdev->dev,
> > > -                                          &mc->translation_ranges,
> > > -                                          &mc->num_translation_ranges);
> > > -   if (error < 0)
> > > -           goto error_cleanup_mc_io;
> > > +   if (dev_of_node(&pdev->dev)) {
> > > +           error = get_mc_addr_translation_ranges(&pdev->dev,
> > > +                                           &mc->translation_ranges,
> > > +                                           &mc->num_translation_ranges);
> > > +           if (error < 0)
> > > +                   goto error_cleanup_mc_io;
> > > +   }
> > >
> > >     error = dprc_get_container_id(mc_io, 0, &container_id);
> > >     if (error < 0) {
> > > @@ -934,6 +963,7 @@ static int fsl_mc_bus_probe(struct platform_device
> *pdev)
> > >             goto error_cleanup_mc_io;
> > >
> > >     mc->root_mc_bus_dev = mc_bus_dev;
> > > +   mc_bus_dev->dev.fwnode = pdev->dev.fwnode;
> >
> > Makarand, this looks a bit weird. Is there really a reason for it?
> 
> Can you clarify please so that we can reach a conclusion on this matter ?
> 
Laurentiu, can you clarify what exactly is the doubt here? Are you asking about fwnode assignment from pdev to mc_bus_dev?

> Thanks,
> Lorenzo
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