Re: [Xen-devel] [PATCH v3 24/27] IA64/MSI: Use MSI chip framework to configure MSI/MSI-X irq

[Yijing Wang <wangyijing@xxxxxxxxxx>]

On 2014/10/23 7:53, Bjorn Helgaas wrote:
> On Wed, Oct 15, 2014 at 11:07:12AM +0800, Yijing Wang wrote:
>> Use MSI chip framework instead of arch MSI functions to configure
>> MSI/MSI-X irq. So we can manage MSI/MSI-X irq in a unified framework.
> 
> This needs slightly more detail.  You're using the MSI chip framework
> "instead of arch MSI functions".  Well, there are still arch-specific
> functions, i.e., arch_ia64_setup_msi_irq() and
> arch_ia64_teardown_msi_irq().
> 
> We used to have arch_setup_msi_irq() which had a weak default
> implementation, and a strong arch-specific implementation here, and you're
> replacing that model with the new "msi-ops" model.  I don't know how you
> want to write that, but it's not that you're getting rid of the
> arch-specific code; you're keeping arch-specific code but structuring it
> differently.

Hm, I will rename the msi-ops functions.

> 
>> Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
>> ---
>>  arch/ia64/include/asm/pci.h |   10 ++++++++++
>>  arch/ia64/kernel/msi_ia64.c |   14 ++++++++++----
>>  arch/ia64/pci/pci.c         |    1 +
>>  3 files changed, 21 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/ia64/include/asm/pci.h b/arch/ia64/include/asm/pci.h
>> index 52af5ed..907dcba 100644
>> --- a/arch/ia64/include/asm/pci.h
>> +++ b/arch/ia64/include/asm/pci.h
>> @@ -94,6 +94,7 @@ struct pci_controller {
>>      int segment;
>>      int node;               /* nearest node with memory or NUMA_NO_NODE for 
>> global allocation */
>>  
>> +    struct msi_chip *msi_chip;
>>      void *platform_data;
>>  };
>>  
>> @@ -101,6 +102,15 @@ struct pci_controller {
>>  #define PCI_CONTROLLER(busdev) ((struct pci_controller *) busdev->sysdata)
>>  #define pci_domain_nr(busdev)    (PCI_CONTROLLER(busdev)->segment)
>>  
>> +extern struct msi_chip chip;
> 
> Please make this name more descriptive.  "chip" is way too generic for a
> global name.

OK, what about rename it to ia64_msi_chip, and rename the original static 
irq_chip ia64_msi_chip to
static irq_chip msi_chip like in x86.

> 
>> +static inline struct msi_chip *pci_msi_chip(struct pci_bus *bus)
>> +{
>> +    struct pci_controller *ctrl = bus->sysdata;
>> +
>> +    return ctrl->msi_chip;
>> +}
>> +
>>  extern struct pci_ops pci_root_ops;
>>  
>>  static inline int pci_proc_domain(struct pci_bus *bus)
>> diff --git a/arch/ia64/kernel/msi_ia64.c b/arch/ia64/kernel/msi_ia64.c
>> index 8c3730c..401fc98 100644
>> --- a/arch/ia64/kernel/msi_ia64.c
>> +++ b/arch/ia64/kernel/msi_ia64.c
>> @@ -112,15 +112,16 @@ static struct irq_chip ia64_msi_chip = {
>>  };
>>  
>>  
>> -int arch_setup_msi_irq(struct pci_dev *pdev, struct msi_desc *desc)
>> +static int arch_ia64_setup_msi_irq(struct msi_chip *chip,
>> +            struct pci_dev *dev, struct msi_desc *desc)
>>  {
>>      if (platform_setup_msi_irq)
>> -            return platform_setup_msi_irq(pdev, desc);
>> +            return platform_setup_msi_irq(dev, desc);
>>  
>> -    return ia64_setup_msi_irq(pdev, desc);
>> +    return ia64_setup_msi_irq(dev, desc);
> 
> Please don't make gratuitous changes ("pdev" -> "dev") at the same time,
> especially since the rest of the file still uses "pdev".

OK.

> 
>>  }
>>  
>> -void arch_teardown_msi_irq(unsigned int irq)
>> +static void arch_ia64_teardown_msi_irq(struct msi_chip *chip, unsigned int 
>> irq)
>>  {
>>      if (platform_teardown_msi_irq)
>>              return platform_teardown_msi_irq(irq);
>> @@ -128,6 +129,11 @@ void arch_teardown_msi_irq(unsigned int irq)
>>      return ia64_teardown_msi_irq(irq);
>>  }
>>  
>> +struct msi_chip chip = {
>> +    .setup_irq = arch_ia64_setup_msi_irq,
>> +    .teardown_irq = arch_ia64_teardown_msi_irq,
>> +};
>> +
>>  #ifdef CONFIG_INTEL_IOMMU
>>  #ifdef CONFIG_SMP
>>  static int dmar_msi_set_affinity(struct irq_data *data,
>> diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
>> index 291a582..299b67d 100644
>> --- a/arch/ia64/pci/pci.c
>> +++ b/arch/ia64/pci/pci.c
>> @@ -437,6 +437,7 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root 
>> *root)
>>  
>>      controller->companion = device;
>>      controller->node = acpi_get_node(device->handle);
>> +    controller->msi_chip = &chip;
>>  
>>      info = kzalloc(sizeof(*info), GFP_KERNEL);
>>      if (!info) {
>> -- 
>> 1.7.1
>>
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> 
> .
> 


-- 
Thanks!
Yijing


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