Re: [PATCH] PCI/MSI: pci-xgene-msi: Enable MSI support in ACPI boot for X-Gene v1

[Bjorn Helgaas]

On Sat, Feb 20, 2016 at 1:47 PM, Duc Dang <dhdang@xxxxxxx> wrote:
> On Tue, Feb 9, 2016 at 5:56 PM, Duc Dang <dhdang@xxxxxxx> wrote:
>> This patch makes pci-xgene-msi driver ACPI-aware and provides
>> MSI capability for X-Gene v1 PCIe controllers in ACPI boot mode.
>
> Hi Bjorn,
>
> Are you planning to take this patch into your tree?

Sorry, I haven't had a chance to look at this yet.  I had a sick
daughter last week, so I'm even farther behind than usual.

When I get to it, I'll be asking questions like:

  - Does this correspond to some analogous x86 code?
  - Is there something unique about arm64 or X-Gene that means it
needs special code?

I don't really understand the arm64/ACPI strategy yet, so I'll be
looking first for generic solutions that work across x86/ia64/arm64,
and justifications for the inevitable exceptions.

>> Signed-off-by: Duc Dang <dhdang@xxxxxxx>
>> ---
>>  drivers/pci/host/pci-xgene-msi.c | 35 ++++++++++++++++++++++++++++++++---
>>  1 file changed, 32 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/pci/host/pci-xgene-msi.c b/drivers/pci/host/pci-xgene-msi.c
>> index a6456b5..466aa93 100644
>> --- a/drivers/pci/host/pci-xgene-msi.c
>> +++ b/drivers/pci/host/pci-xgene-msi.c
>> @@ -24,6 +24,7 @@
>>  #include <linux/pci.h>
>>  #include <linux/platform_device.h>
>>  #include <linux/of_pci.h>
>> +#include <linux/acpi.h>
>>
>>  #define MSI_IR0                        0x000000
>>  #define MSI_INT0               0x800000
>> @@ -39,7 +40,7 @@ struct xgene_msi_group {
>>  };
>>
>>  struct xgene_msi {
>> -       struct device_node      *node;
>> +       struct fwnode_handle    *fwnode;
>>         struct irq_domain       *inner_domain;
>>         struct irq_domain       *msi_domain;
>>         u64                     msi_addr;
>> @@ -249,6 +250,13 @@ static const struct irq_domain_ops msi_domain_ops = {
>>         .free   = xgene_irq_domain_free,
>>  };
>>
>> +#ifdef CONFIG_ACPI
>> +static struct fwnode_handle *xgene_msi_get_fwnode(struct device *dev)
>> +{
>> +       return xgene_msi_ctrl.fwnode;
>> +}
>> +#endif
>> +
>>  static int xgene_allocate_domains(struct xgene_msi *msi)
>>  {
>>         msi->inner_domain = irq_domain_add_linear(NULL, NR_MSI_VEC,
>> @@ -256,7 +264,7 @@ static int xgene_allocate_domains(struct xgene_msi *msi)
>>         if (!msi->inner_domain)
>>                 return -ENOMEM;
>>
>> -       msi->msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(msi->node),
>> +       msi->msi_domain = pci_msi_create_irq_domain(msi->fwnode,
>>                                                     &xgene_msi_domain_info,
>>                                                     msi->inner_domain);
>>
>> @@ -265,6 +273,9 @@ static int xgene_allocate_domains(struct xgene_msi *msi)
>>                 return -ENOMEM;
>>         }
>>
>> +#ifdef CONFIG_ACPI
>> +       pci_msi_register_fwnode_provider(&xgene_msi_get_fwnode);
>> +#endif
>>         return 0;
>>  }
>>
>> @@ -473,6 +484,13 @@ static const struct of_device_id xgene_msi_match_table[] = {
>>         {},
>>  };
>>
>> +#ifdef CONFIG_ACPI
>> +static const struct acpi_device_id xgene_msi_acpi_ids[] = {
>> +       {"APMC0D0E", 0},
>> +       { },
>> +};
>> +#endif
>> +
>>  static int xgene_msi_probe(struct platform_device *pdev)
>>  {
>>         struct resource *res;
>> @@ -494,7 +512,17 @@ static int xgene_msi_probe(struct platform_device *pdev)
>>                 goto error;
>>         }
>>         xgene_msi->msi_addr = res->start;
>> -       xgene_msi->node = pdev->dev.of_node;
>> +
>> +       xgene_msi->fwnode = of_node_to_fwnode(pdev->dev.of_node);
>> +       if (!xgene_msi->fwnode) {
>> +               xgene_msi->fwnode = irq_domain_alloc_fwnode(NULL);
>> +               if (!xgene_msi->fwnode) {
>> +                       dev_err(&pdev->dev, "Failed to create fwnode\n");
>> +                       rc = ENOMEM;
>> +                       goto error;
>> +               }
>> +       }
>> +
>>         xgene_msi->num_cpus = num_possible_cpus();
>>
>>         rc = xgene_msi_init_allocator(xgene_msi);
>> @@ -571,6 +599,7 @@ static struct platform_driver xgene_msi_driver = {
>>         .driver = {
>>                 .name = "xgene-msi",
>>                 .of_match_table = xgene_msi_match_table,
>> +               .acpi_match_table = ACPI_PTR(xgene_msi_acpi_ids),
>>         },
>>         .probe = xgene_msi_probe,
>>         .remove = xgene_msi_remove,
>> --
>> 1.9.1
>>