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

[Laurentiu Tudor <laurentiu.tudor@nxp.com>]

On 7/9/2020 12:26 PM, Makarand Pawagi wrote:
> 
> 
>> -----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?
> 

Yes. I remember that a while ago I tested without this fwnode assignment
and didn't encounter any issues. Maybe we can just drop it?

---
Best Regards, Laurentiu
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu