diff mbox series

[v2] genirq/msi: Add the address and data that show MSI/MSIX

Message ID 20250301123953.291675-1-18255117159@163.com (mailing list archive)
State Superseded
Delegated to: Bjorn Helgaas
Headers show
Series [v2] genirq/msi: Add the address and data that show MSI/MSIX | expand

Commit Message

Hans Zhang March 1, 2025, 12:39 p.m. UTC
The debug_show() callback function is implemented in the MSI core code.
And assign it to the domain ops::debug_show() creation.

cat /sys/kernel/debug/irq/irqs/msi_irq_num, the address and data stored
in the MSI capability or the address and data stored in the MSIX vector
table will be displayed.

e.g.
root@root:/sys/kernel/debug/irq/irqs# cat /proc/interrupts | grep ITS
 85:          0          0          0          0          0          0          0          0          0          0          0          0   ITS-MSI 75497472 Edge      PCIe PME, aerdrv
 86:          0         30          0          0          0          0          0          0          0          0          0          0   ITS-MSI 76021760 Edge      nvme0q0
 87:        287          0          0          0          0          0          0          0          0          0          0          0   ITS-MSI 76021761 Edge      nvme0q1
 88:          0        265          0          0          0          0          0          0          0          0          0          0   ITS-MSI 76021762 Edge      nvme0q2
 89:          0          0        177          0          0          0          0          0          0          0          0          0   ITS-MSI 76021763 Edge      nvme0q3
 90:          0          0          0         76          0          0          0          0          0          0          0          0   ITS-MSI 76021764 Edge      nvme0q4
 91:          0          0          0          0        161          0          0          0          0          0          0          0   ITS-MSI 76021765 Edge      nvme0q5
 92:          0          0          0          0          0        991          0          0          0          0          0          0   ITS-MSI 76021766 Edge      nvme0q6
 93:          0          0          0          0          0          0        194          0          0          0          0          0   ITS-MSI 76021767 Edge      nvme0q7
 94:          0          0          0          0          0          0          0         94          0          0          0          0   ITS-MSI 76021768 Edge      nvme0q8
 95:          0          0          0          0          0          0          0          0        148          0          0          0   ITS-MSI 76021769 Edge      nvme0q9
 96:          0          0          0          0          0          0          0          0          0        261          0          0   ITS-MSI 76021770 Edge      nvme0q10
 97:          0          0          0          0          0          0          0          0          0          0        127          0   ITS-MSI 76021771 Edge      nvme0q11
 98:          0          0          0          0          0          0          0          0          0          0          0        317   ITS-MSI 76021772 Edge      nvme0q12
root@root:/sys/kernel/debug/irq/irqs#
root@root:/sys/kernel/debug/irq/irqs# cat 87
handler:  handle_fasteoi_irq
device:   0000:91:00.0
status:   0x00000000
istate:   0x00004000
ddepth:   0
wdepth:   0
dstate:   0x31600200
            IRQD_ACTIVATED
            IRQD_IRQ_STARTED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_MANAGED
            IRQD_AFFINITY_ON_ACTIVATE
            IRQD_HANDLE_ENFORCE_IRQCTX
node:     0
affinity: 0
effectiv: 0
domain:  :soc@0:interrupt-controller@0e001000:its@0e050000-3
 hwirq:   0x4880001
 chip:    ITS-MSI
  flags:   0x20
             IRQCHIP_ONESHOT_SAFE
 msix:
  address_hi: 0x00000000
  address_lo: 0x0e060040
  msg_data:   0x00000001
 parent:
    domain:  :soc@0:interrupt-controller@0e001000:its@0e050000-5
     hwirq:   0x2002
     chip:    ITS
      flags:   0x0
     parent:
        domain:  :soc@0:interrupt-controller@0e001000-1
         hwirq:   0x2002
         chip:    GICv3
          flags:   0x15
                     IRQCHIP_SET_TYPE_MASKED
                     IRQCHIP_MASK_ON_SUSPEND
                     IRQCHIP_SKIP_SET_WAKE

Signed-off-by: Hans Zhang <18255117159@163.com>
---
Changes since v1:
https://lore.kernel.org/linux-pci/20250227162821.253020-1-18255117159@163.com/

- According to Thomas(tglx), the debug_show() callback should be added
  to the MSI core code.
---
 kernel/irq/msi.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)


base-commit: 76544811c850a1f4c055aa182b513b7a843868ea

Comments

kernel test robot March 2, 2025, 1:12 a.m. UTC | #1
Hi Hans,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 76544811c850a1f4c055aa182b513b7a843868ea]

url:    https://github.com/intel-lab-lkp/linux/commits/Hans-Zhang/genirq-msi-Add-the-address-and-data-that-show-MSI-MSIX/20250301-204332
base:   76544811c850a1f4c055aa182b513b7a843868ea
patch link:    https://lore.kernel.org/r/20250301123953.291675-1-18255117159%40163.com
patch subject: [v2] genirq/msi: Add the address and data that show MSI/MSIX
config: arm-randconfig-001-20250302 (https://download.01.org/0day-ci/archive/20250302/202503020812.PKZf7JBa-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250302/202503020812.PKZf7JBa-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503020812.PKZf7JBa-lkp@intel.com/

All warnings (new ones prefixed by >>):

   kernel/irq/msi.c: In function 'msi_domain_debug_show':
   kernel/irq/msi.c:770:9: error: implicit declaration of function 'seq_printf'; did you mean 'bstr_printf'? [-Wimplicit-function-declaration]
     770 |         seq_printf(m, "%*s%s:", ind, "", is_msix ? "msix" : "msi");
         |         ^~~~~~~~~~
         |         bstr_printf
   kernel/irq/msi.c: At top level:
   kernel/irq/msi.c:782:10: error: 'const struct irq_domain_ops' has no member named 'debug_show'
     782 |         .debug_show     = msi_domain_debug_show,
         |          ^~~~~~~~~~
>> kernel/irq/msi.c:782:27: warning: excess elements in struct initializer
     782 |         .debug_show     = msi_domain_debug_show,
         |                           ^~~~~~~~~~~~~~~~~~~~~
   kernel/irq/msi.c:782:27: note: (near initialization for 'msi_domain_ops')


vim +782 kernel/irq/msi.c

   775	
   776	static const struct irq_domain_ops msi_domain_ops = {
   777		.alloc		= msi_domain_alloc,
   778		.free		= msi_domain_free,
   779		.activate	= msi_domain_activate,
   780		.deactivate	= msi_domain_deactivate,
   781		.translate	= msi_domain_translate,
 > 782		.debug_show     = msi_domain_debug_show,
   783	};
   784
kernel test robot March 2, 2025, 1:12 a.m. UTC | #2
Hi Hans,

kernel test robot noticed the following build errors:

[auto build test ERROR on 76544811c850a1f4c055aa182b513b7a843868ea]

url:    https://github.com/intel-lab-lkp/linux/commits/Hans-Zhang/genirq-msi-Add-the-address-and-data-that-show-MSI-MSIX/20250301-204332
base:   76544811c850a1f4c055aa182b513b7a843868ea
patch link:    https://lore.kernel.org/r/20250301123953.291675-1-18255117159%40163.com
patch subject: [v2] genirq/msi: Add the address and data that show MSI/MSIX
config: x86_64-buildonly-randconfig-003-20250302 (https://download.01.org/0day-ci/archive/20250302/202503020807.c3MhmbJh-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250302/202503020807.c3MhmbJh-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503020807.c3MhmbJh-lkp@intel.com/

All errors (new ones prefixed by >>):

   kernel/irq/msi.c: In function 'msi_domain_debug_show':
>> kernel/irq/msi.c:770:9: error: implicit declaration of function 'seq_printf'; did you mean 'bstr_printf'? [-Werror=implicit-function-declaration]
     770 |         seq_printf(m, "%*s%s:", ind, "", is_msix ? "msix" : "msi");
         |         ^~~~~~~~~~
         |         bstr_printf
   kernel/irq/msi.c: At top level:
>> kernel/irq/msi.c:782:10: error: 'const struct irq_domain_ops' has no member named 'debug_show'
     782 |         .debug_show     = msi_domain_debug_show,
         |          ^~~~~~~~~~
>> kernel/irq/msi.c:782:27: error: positional initialization of field in 'struct' declared with 'designated_init' attribute [-Werror=designated-init]
     782 |         .debug_show     = msi_domain_debug_show,
         |                           ^~~~~~~~~~~~~~~~~~~~~
   kernel/irq/msi.c:782:27: note: (near initialization for 'msi_domain_ops')
   kernel/irq/msi.c:782:27: error: initialization of 'int (*)(struct irq_domain *, unsigned int,  unsigned int,  void *)' from incompatible pointer type 'void (*)(struct seq_file *, struct irq_domain *, struct irq_data *, int)' [-Werror=incompatible-pointer-types]
   kernel/irq/msi.c:782:27: note: (near initialization for 'msi_domain_ops.alloc')
   kernel/irq/msi.c:782:27: warning: initialized field overwritten [-Woverride-init]
   kernel/irq/msi.c:782:27: note: (near initialization for 'msi_domain_ops.alloc')
   cc1: some warnings being treated as errors


vim +770 kernel/irq/msi.c

   758	
   759	static void msi_domain_debug_show(struct seq_file *m, struct irq_domain *d,
   760					  struct irq_data *irqd, int ind)
   761	{
   762		struct msi_desc *desc;
   763		bool is_msix;
   764	
   765		desc = irq_get_msi_desc(irqd->irq);
   766		if (!desc)
   767			return;
   768	
   769		is_msix = desc->pci.msi_attrib.is_msix;
 > 770		seq_printf(m, "%*s%s:", ind, "", is_msix ? "msix" : "msi");
   771		seq_printf(m, "\n%*saddress_hi: 0x%08x", ind + 1, "", desc->msg.address_hi);
   772		seq_printf(m, "\n%*saddress_lo: 0x%08x", ind + 1, "", desc->msg.address_lo);
   773		seq_printf(m, "\n%*smsg_data:   0x%08x\n", ind + 1, "", desc->msg.data);
   774	}
   775	
   776	static const struct irq_domain_ops msi_domain_ops = {
   777		.alloc		= msi_domain_alloc,
   778		.free		= msi_domain_free,
   779		.activate	= msi_domain_activate,
   780		.deactivate	= msi_domain_deactivate,
   781		.translate	= msi_domain_translate,
 > 782		.debug_show     = msi_domain_debug_show,
   783	};
   784
Thomas Gleixner March 2, 2025, 9:01 a.m. UTC | #3
Hans!

On Sat, Mar 01 2025 at 20:39, Hans Zhang wrote:
> The debug_show() callback function is implemented in the MSI core code.
> And assign it to the domain ops::debug_show() creation.
>
> cat /sys/kernel/debug/irq/irqs/msi_irq_num, the address and data stored
> in the MSI capability or the address and data stored in the MSIX vector
> table will be displayed.

So this explains what the patch is doing and what the output is. But it
fails to explain the _why_. Documentation gives proper guidance:

 https://www.kernel.org/doc/html/latest/process/maintainer-tip.html#changelog
 https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-changes

> e.g.
> root@root:/sys/kernel/debug/irq/irqs# cat /proc/interrupts | grep ITS
>  85:          0          0          0          0          0          0          0          0          0          0          0          0   ITS-MSI 75497472 Edge      PCIe PME, aerdrv
>  86:          0         30          0          0          0          0          0          0          0          0          0          0   ITS-MSI 76021760 Edge      nvme0q0
>  87:        287          0          0          0          0          0          0          0          0          0          0          0   ITS-MSI 76021761 Edge      nvme0q1
>  88:          0        265          0          0          0          0          0          0          0          0          0          0   ITS-MSI 76021762 Edge      nvme0q2
>  89:          0          0        177          0          0          0          0          0          0          0          0          0   ITS-MSI 76021763 Edge      nvme0q3
>  90:          0          0          0         76          0          0          0          0          0          0          0          0   ITS-MSI 76021764 Edge      nvme0q4
>  91:          0          0          0          0        161          0          0          0          0          0          0          0   ITS-MSI 76021765 Edge      nvme0q5
>  92:          0          0          0          0          0        991          0          0          0          0          0          0   ITS-MSI 76021766 Edge      nvme0q6
>  93:          0          0          0          0          0          0        194          0          0          0          0          0   ITS-MSI 76021767 Edge      nvme0q7
>  94:          0          0          0          0          0          0          0         94          0          0          0          0   ITS-MSI 76021768 Edge      nvme0q8
>  95:          0          0          0          0          0          0          0          0        148          0          0          0   ITS-MSI 76021769 Edge      nvme0q9
>  96:          0          0          0          0          0          0          0          0          0        261          0          0   ITS-MSI 76021770 Edge      nvme0q10
>  97:          0          0          0          0          0          0          0          0          0          0        127          0   ITS-MSI 76021771 Edge      nvme0q11
>  98:          0          0          0          0          0          0          0          0          0          0          0        317   ITS-MSI 76021772 Edge      nvme0q12

How is this relevant to describe the patch?

> root@root:/sys/kernel/debug/irq/irqs#
> root@root:/sys/kernel/debug/irq/irqs# cat 87
> handler:  handle_fasteoi_irq
> device:   0000:91:00.0
> status:   0x00000000
> istate:   0x00004000
> ddepth:   0
> wdepth:   0
> dstate:   0x31600200
>             IRQD_ACTIVATED
>             IRQD_IRQ_STARTED
>             IRQD_SINGLE_TARGET
>             IRQD_AFFINITY_MANAGED
>             IRQD_AFFINITY_ON_ACTIVATE
>             IRQD_HANDLE_ENFORCE_IRQCTX
> node:     0
> affinity: 0
> effectiv: 0
> domain:  :soc@0:interrupt-controller@0e001000:its@0e050000-3
>  hwirq:   0x4880001
>  chip:    ITS-MSI

This output is from a pre 6.11 kernel...

>   flags:   0x20
>              IRQCHIP_ONESHOT_SAFE
>  msix:
>   address_hi: 0x00000000
>   address_lo: 0x0e060040
>   msg_data:   0x00000001

For demonstration it's enough to stop here, no?
  
> +static void msi_domain_debug_show(struct seq_file *m, struct irq_domain *d,
> +				  struct irq_data *irqd, int ind)
> +{
> +	struct msi_desc *desc;
> +	bool is_msix;
> +
> +	desc = irq_get_msi_desc(irqd->irq);

Move this up to the declaration.

> +	if (!desc)
> +		return;
> +
> +	is_msix = desc->pci.msi_attrib.is_msix;

That's not valid for non PCI MSI interrupts.

This function is used for all types of MSI interrupts. So for non PCI
MSI interrupts this will output random garbage. Just print the address
and be done with it. The MSI variant is visible from the chip name on
current kernels. It's either ITS-PCI-MSI or ITS-PCI-MSIX and not
ITS-MSI.

> +	seq_printf(m, "%*s%s:", ind, "", is_msix ? "msix" : "msi");
> +	seq_printf(m, "\n%*saddress_hi: 0x%08x", ind + 1, "", desc->msg.address_hi);
> +	seq_printf(m, "\n%*saddress_lo: 0x%08x", ind + 1, "", desc->msg.address_lo);
> +	seq_printf(m, "\n%*smsg_data:   0x%08x\n", ind + 1, "", desc->msg.data);
> +}
> +
>  static const struct irq_domain_ops msi_domain_ops = {
>  	.alloc		= msi_domain_alloc,
>  	.free		= msi_domain_free,
>  	.activate	= msi_domain_activate,
>  	.deactivate	= msi_domain_deactivate,
>  	.translate	= msi_domain_translate,
> +	.debug_show     = msi_domain_debug_show,

This does not build when CONFIG_GENERIC_IRQ_DEBUGFS=n.

Thanks,

        tglx
Hans Zhang March 2, 2025, 2:45 p.m. UTC | #4
Hi Thomas(tglx),

On 2025/3/2 17:01, Thomas Gleixner wrote:
> Hans!
> 
> On Sat, Mar 01 2025 at 20:39, Hans Zhang wrote:
>> The debug_show() callback function is implemented in the MSI core code.
>> And assign it to the domain ops::debug_show() creation.
>>
>> cat /sys/kernel/debug/irq/irqs/msi_irq_num, the address and data stored
>> in the MSI capability or the address and data stored in the MSIX vector
>> table will be displayed.
> 
> So this explains what the patch is doing and what the output is. But it
> fails to explain the _why_. Documentation gives proper guidance:
> 
>   https://www.kernel.org/doc/html/latest/process/maintainer-tip.html#changelog
>   https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-changes

Is the following explanation OK?

Displaying the address and data of the MSI/MSIX interrupt in the debugfs 
helps with debugging.

>> e.g.
>> root@root:/sys/kernel/debug/irq/irqs# cat /proc/interrupts | grep ITS
>>   85:          0          0          0          0          0          0          0          0          0          0          0          0   ITS-MSI 75497472 Edge      PCIe PME, aerdrv
>>   86:          0         30          0          0          0          0          0          0          0          0          0          0   ITS-MSI 76021760 Edge      nvme0q0
>>   87:        287          0          0          0          0          0          0          0          0          0          0          0   ITS-MSI 76021761 Edge      nvme0q1
>>   88:          0        265          0          0          0          0          0          0          0          0          0          0   ITS-MSI 76021762 Edge      nvme0q2
>>   89:          0          0        177          0          0          0          0          0          0          0          0          0   ITS-MSI 76021763 Edge      nvme0q3
>>   90:          0          0          0         76          0          0          0          0          0          0          0          0   ITS-MSI 76021764 Edge      nvme0q4
>>   91:          0          0          0          0        161          0          0          0          0          0          0          0   ITS-MSI 76021765 Edge      nvme0q5
>>   92:          0          0          0          0          0        991          0          0          0          0          0          0   ITS-MSI 76021766 Edge      nvme0q6
>>   93:          0          0          0          0          0          0        194          0          0          0          0          0   ITS-MSI 76021767 Edge      nvme0q7
>>   94:          0          0          0          0          0          0          0         94          0          0          0          0   ITS-MSI 76021768 Edge      nvme0q8
>>   95:          0          0          0          0          0          0          0          0        148          0          0          0   ITS-MSI 76021769 Edge      nvme0q9
>>   96:          0          0          0          0          0          0          0          0          0        261          0          0   ITS-MSI 76021770 Edge      nvme0q10
>>   97:          0          0          0          0          0          0          0          0          0          0        127          0   ITS-MSI 76021771 Edge      nvme0q11
>>   98:          0          0          0          0          0          0          0          0          0          0          0        317   ITS-MSI 76021772 Edge      nvme0q12
> 
> How is this relevant to describe the patch?

The preceding information will be deleted in v4 patch.

> 
>> root@root:/sys/kernel/debug/irq/irqs#
>> root@root:/sys/kernel/debug/irq/irqs# cat 87
>> handler:  handle_fasteoi_irq
>> device:   0000:91:00.0
>> status:   0x00000000
>> istate:   0x00004000
>> ddepth:   0
>> wdepth:   0
>> dstate:   0x31600200
>>              IRQD_ACTIVATED
>>              IRQD_IRQ_STARTED
>>              IRQD_SINGLE_TARGET
>>              IRQD_AFFINITY_MANAGED
>>              IRQD_AFFINITY_ON_ACTIVATE
>>              IRQD_HANDLE_ENFORCE_IRQCTX
>> node:     0
>> affinity: 0
>> effectiv: 0
>> domain:  :soc@0:interrupt-controller@0e001000:its@0e050000-3
>>   hwirq:   0x4880001
>>   chip:    ITS-MSI
> 
> This output is from a pre 6.11 kernel...

I will delete all other information except for what my patch will display.

> 
>>    flags:   0x20
>>               IRQCHIP_ONESHOT_SAFE
>>   msix:
>>    address_hi: 0x00000000
>>    address_lo: 0x0e060040
>>    msg_data:   0x00000001
> 
> For demonstration it's enough to stop here, no?

Yes, I will change it to the following:

    msix:
     address_hi: 0x00000000
     address_lo: 0x0e060040
     msg_data:   0x00000001

>    
>> +static void msi_domain_debug_show(struct seq_file *m, struct irq_domain *d,
>> +				  struct irq_data *irqd, int ind)
>> +{
>> +	struct msi_desc *desc;
>> +	bool is_msix;
>> +
>> +	desc = irq_get_msi_desc(irqd->irq);
> 
> Move this up to the declaration.
> 
>> +	if (!desc)
>> +		return;
>> +
>> +	is_msix = desc->pci.msi_attrib.is_msix;
> 
> That's not valid for non PCI MSI interrupts.

Do you mean to remove the following two lines of code?

is_msix = desc->pci.msi_attrib.is_msix;
seq_printf(m, "%*s%s:", ind, "", is_msix ? "msix" : "msi");

> This function is used for all types of MSI interrupts. So for non PCI
> MSI interrupts this will output random garbage. Just print the address
> and be done with it. The MSI variant is visible from the chip name on
> current kernels. It's either ITS-PCI-MSI or ITS-PCI-MSIX and not
> ITS-MSI.
> 
>> +	seq_printf(m, "%*s%s:", ind, "", is_msix ? "msix" : "msi");
>> +	seq_printf(m, "\n%*saddress_hi: 0x%08x", ind + 1, "", desc->msg.address_hi);
>> +	seq_printf(m, "\n%*saddress_lo: 0x%08x", ind + 1, "", desc->msg.address_lo);
>> +	seq_printf(m, "\n%*smsg_data:   0x%08x\n", ind + 1, "", desc->msg.data);
>> +}
>> +
>>   static const struct irq_domain_ops msi_domain_ops = {
>>   	.alloc		= msi_domain_alloc,
>>   	.free		= msi_domain_free,
>>   	.activate	= msi_domain_activate,
>>   	.deactivate	= msi_domain_deactivate,
>>   	.translate	= msi_domain_translate,
>> +	.debug_show     = msi_domain_debug_show,
> 
> This does not build when CONFIG_GENERIC_IRQ_DEBUGFS=n.
>
Kernel test robot has reported a compilation error, and I have submitted 
v3 patch to solve this problem. I will fix all your questions in v4 patch.

Finally, thank you very much for all your comments.

Best regards
Hans
diff mbox series

Patch

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 396a067a8a56..7dc786360172 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -756,12 +756,30 @@  static int msi_domain_translate(struct irq_domain *domain, struct irq_fwspec *fw
 	return info->ops->msi_translate(domain, fwspec, hwirq, type);
 }
 
+static void msi_domain_debug_show(struct seq_file *m, struct irq_domain *d,
+				  struct irq_data *irqd, int ind)
+{
+	struct msi_desc *desc;
+	bool is_msix;
+
+	desc = irq_get_msi_desc(irqd->irq);
+	if (!desc)
+		return;
+
+	is_msix = desc->pci.msi_attrib.is_msix;
+	seq_printf(m, "%*s%s:", ind, "", is_msix ? "msix" : "msi");
+	seq_printf(m, "\n%*saddress_hi: 0x%08x", ind + 1, "", desc->msg.address_hi);
+	seq_printf(m, "\n%*saddress_lo: 0x%08x", ind + 1, "", desc->msg.address_lo);
+	seq_printf(m, "\n%*smsg_data:   0x%08x\n", ind + 1, "", desc->msg.data);
+}
+
 static const struct irq_domain_ops msi_domain_ops = {
 	.alloc		= msi_domain_alloc,
 	.free		= msi_domain_free,
 	.activate	= msi_domain_activate,
 	.deactivate	= msi_domain_deactivate,
 	.translate	= msi_domain_translate,
+	.debug_show     = msi_domain_debug_show,
 };
 
 static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info,