diff mbox series

[XEN,v3,1/2] x86/vmsi: rename variables to address MISRA C:2012 Rule 5.3

Message ID 605687eff99db7181ef6c05bce671e20f194b46b.1691488505.git.nicola.vetrini@bugseng.com (mailing list archive)
State New, archived
Headers show
Series x86: address MISRA C:2012 Rule 5.3 and 8.3 | expand

Commit Message

Nicola Vetrini Aug. 8, 2023, 12:22 p.m. UTC
The local variables 'irq_desc' shadow the homonymous global variable,
declared in 'xen/arch/x86/include/asm/irq.h', therefore they are renamed
'irqd' for consistency with ARM code. Other variables of the same type
in the file are also renamed 'irqd' for consistency.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
---
Changes in v2:
- Renamed the local variables instead of the global.
- Edited subject from x86/irq to x86/vmsi

Renaming everything to 'desc' would have been the most obvious choice,
but given that there's also 'msi_desc' used in the same functions, 'irqd'
is less error-prone in my opinion.
---
 xen/arch/x86/hvm/vmsi.c | 46 ++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 23 deletions(-)

Comments

Jan Beulich Aug. 8, 2023, 1:22 p.m. UTC | #1
On 08.08.2023 14:22, Nicola Vetrini wrote:
> The local variables 'irq_desc' shadow the homonymous global variable,
> declared in 'xen/arch/x86/include/asm/irq.h', therefore they are renamed
> 'irqd' for consistency with ARM code. Other variables of the same type
> in the file are also renamed 'irqd' for consistency.

I'm pretty sure I pointed out that Arm uses a mix of "desc" and "irqd".
So "consistency with ARM code" doesn't ...

> --- a/xen/arch/x86/hvm/vmsi.c
> +++ b/xen/arch/x86/hvm/vmsi.c
> @@ -281,7 +281,7 @@ static int msixtbl_write(struct vcpu *v, unsigned long address,
>      unsigned int nr_entry, index;
>      int r = X86EMUL_UNHANDLEABLE;
>      unsigned long flags;
> -    struct irq_desc *desc;
> +    struct irq_desc *irqd;

... require e.g. this rename. As mentioned before: Let's limit code
churn where possible, and where going beyond what's strictly necessary
isn't otherwise useful; there's already enough of it with all these not
really helpful Misra changes.

> @@ -462,7 +462,7 @@ static void del_msixtbl_entry(struct msixtbl_entry *entry)
>  
>  int msixtbl_pt_register(struct domain *d, struct pirq *pirq, uint64_t gtable)
>  {
> -    struct irq_desc *irq_desc;
> +    struct irq_desc *irqd;

This one indeed wants renaming, but then - consistent within the file -
to "desc". At least that's my view.

Jan
Nicola Vetrini Aug. 8, 2023, 1:38 p.m. UTC | #2
On 08/08/2023 15:22, Jan Beulich wrote:
> On 08.08.2023 14:22, Nicola Vetrini wrote:
>> The local variables 'irq_desc' shadow the homonymous global variable,
>> declared in 'xen/arch/x86/include/asm/irq.h', therefore they are 
>> renamed
>> 'irqd' for consistency with ARM code. Other variables of the same type
>> in the file are also renamed 'irqd' for consistency.
> 
> I'm pretty sure I pointed out that Arm uses a mix of "desc" and "irqd".
> So "consistency with ARM code" doesn't ...
> 
>> --- a/xen/arch/x86/hvm/vmsi.c
>> +++ b/xen/arch/x86/hvm/vmsi.c
>> @@ -281,7 +281,7 @@ static int msixtbl_write(struct vcpu *v, unsigned 
>> long address,
>>      unsigned int nr_entry, index;
>>      int r = X86EMUL_UNHANDLEABLE;
>>      unsigned long flags;
>> -    struct irq_desc *desc;
>> +    struct irq_desc *irqd;
> 
> ... require e.g. this rename. As mentioned before: Let's limit code
> churn where possible, and where going beyond what's strictly necessary
> isn't otherwise useful; there's already enough of it with all these not
> really helpful Misra changes.
> 
>> @@ -462,7 +462,7 @@ static void del_msixtbl_entry(struct msixtbl_entry 
>> *entry)
>> 
>>  int msixtbl_pt_register(struct domain *d, struct pirq *pirq, uint64_t 
>> gtable)
>>  {
>> -    struct irq_desc *irq_desc;
>> +    struct irq_desc *irqd;
> 
> This one indeed wants renaming, but then - consistent within the file -
> to "desc". At least that's my view.
> 
> Jan

Well, but having

struct irq_desc *desc;
struct msi_desc *msi_desc;

and then using them both within the function doesn't seem that readable, 
but if you
prefer "desc" I have no objection (just two local variables that need to 
be changed).
Jan Beulich Aug. 8, 2023, 1:52 p.m. UTC | #3
On 08.08.2023 15:38, Nicola Vetrini wrote:
> On 08/08/2023 15:22, Jan Beulich wrote:
>> On 08.08.2023 14:22, Nicola Vetrini wrote:
>>> The local variables 'irq_desc' shadow the homonymous global variable,
>>> declared in 'xen/arch/x86/include/asm/irq.h', therefore they are 
>>> renamed
>>> 'irqd' for consistency with ARM code. Other variables of the same type
>>> in the file are also renamed 'irqd' for consistency.
>>
>> I'm pretty sure I pointed out that Arm uses a mix of "desc" and "irqd".
>> So "consistency with ARM code" doesn't ...
>>
>>> --- a/xen/arch/x86/hvm/vmsi.c
>>> +++ b/xen/arch/x86/hvm/vmsi.c
>>> @@ -281,7 +281,7 @@ static int msixtbl_write(struct vcpu *v, unsigned 
>>> long address,
>>>      unsigned int nr_entry, index;
>>>      int r = X86EMUL_UNHANDLEABLE;
>>>      unsigned long flags;
>>> -    struct irq_desc *desc;
>>> +    struct irq_desc *irqd;
>>
>> ... require e.g. this rename. As mentioned before: Let's limit code
>> churn where possible, and where going beyond what's strictly necessary
>> isn't otherwise useful; there's already enough of it with all these not
>> really helpful Misra changes.
>>
>>> @@ -462,7 +462,7 @@ static void del_msixtbl_entry(struct msixtbl_entry 
>>> *entry)
>>>
>>>  int msixtbl_pt_register(struct domain *d, struct pirq *pirq, uint64_t 
>>> gtable)
>>>  {
>>> -    struct irq_desc *irq_desc;
>>> +    struct irq_desc *irqd;
>>
>> This one indeed wants renaming, but then - consistent within the file -
>> to "desc". At least that's my view.
> 
> Well, but having
> 
> struct irq_desc *desc;
> struct msi_desc *msi_desc;
> 
> and then using them both within the function doesn't seem that readable, 

You have a point there, yes. Still I'd then probably follow up with a
change to rename msi_desc -> msi (and I say this despite seeing that
farther down in the file "msi" is also used for another pointer type
variables/parameters). But with what you say in mind I'd also be okay
with you renaming to irqd where renaming is needed, but leaving "desc"
alone.

Jan
Nicola Vetrini Aug. 8, 2023, 1:55 p.m. UTC | #4
>>> 
>>>> @@ -462,7 +462,7 @@ static void del_msixtbl_entry(struct 
>>>> msixtbl_entry
>>>> *entry)
>>>> 
>>>>  int msixtbl_pt_register(struct domain *d, struct pirq *pirq, 
>>>> uint64_t
>>>> gtable)
>>>>  {
>>>> -    struct irq_desc *irq_desc;
>>>> +    struct irq_desc *irqd;
>>> 
>>> This one indeed wants renaming, but then - consistent within the file 
>>> -
>>> to "desc". At least that's my view.
>> 
>> Well, but having
>> 
>> struct irq_desc *desc;
>> struct msi_desc *msi_desc;
>> 
>> and then using them both within the function doesn't seem that 
>> readable,
> 
> You have a point there, yes. Still I'd then probably follow up with a
> change to rename msi_desc -> msi (and I say this despite seeing that
> farther down in the file "msi" is also used for another pointer type
> variables/parameters). But with what you say in mind I'd also be okay
> with you renaming to irqd where renaming is needed, but leaving "desc"
> alone.
> 
> Jan

I'll go for the latter (it's quicker) as a separate patch, since 
hopefully the other patch
in the series can go in unmodified.
diff mbox series

Patch

diff --git a/xen/arch/x86/hvm/vmsi.c b/xen/arch/x86/hvm/vmsi.c
index 3cd4923060..55d5e26a04 100644
--- a/xen/arch/x86/hvm/vmsi.c
+++ b/xen/arch/x86/hvm/vmsi.c
@@ -281,7 +281,7 @@  static int msixtbl_write(struct vcpu *v, unsigned long address,
     unsigned int nr_entry, index;
     int r = X86EMUL_UNHANDLEABLE;
     unsigned long flags;
-    struct irq_desc *desc;
+    struct irq_desc *irqd;
 
     if ( (len != 4 && len != 8) || (address & (len - 1)) )
         return r;
@@ -330,21 +330,21 @@  static int msixtbl_write(struct vcpu *v, unsigned long address,
     if ( !msi_desc || msi_desc->irq < 0 )
         goto out;
     
-    desc = irq_to_desc(msi_desc->irq);
-    if ( !desc )
+    irqd = irq_to_desc(msi_desc->irq);
+    if ( !irqd )
         goto out;
 
-    spin_lock_irqsave(&desc->lock, flags);
+    spin_lock_irqsave(&irqd->lock, flags);
 
-    if ( !desc->msi_desc )
+    if ( !irqd->msi_desc )
         goto unlock;
 
-    ASSERT(msi_desc == desc->msi_desc);
+    ASSERT(msi_desc == irqd->msi_desc);
    
-    guest_mask_msi_irq(desc, !!(val & PCI_MSIX_VECTOR_BITMASK));
+    guest_mask_msi_irq(irqd, !!(val & PCI_MSIX_VECTOR_BITMASK));
 
 unlock:
-    spin_unlock_irqrestore(&desc->lock, flags);
+    spin_unlock_irqrestore(&irqd->lock, flags);
     if ( len == 4 )
         r = X86EMUL_OKAY;
 
@@ -462,7 +462,7 @@  static void del_msixtbl_entry(struct msixtbl_entry *entry)
 
 int msixtbl_pt_register(struct domain *d, struct pirq *pirq, uint64_t gtable)
 {
-    struct irq_desc *irq_desc;
+    struct irq_desc *irqd;
     struct msi_desc *msi_desc;
     struct pci_dev *pdev;
     struct msixtbl_entry *entry, *new_entry;
@@ -482,14 +482,14 @@  int msixtbl_pt_register(struct domain *d, struct pirq *pirq, uint64_t gtable)
     if ( !new_entry )
         return -ENOMEM;
 
-    irq_desc = pirq_spin_lock_irq_desc(pirq, NULL);
-    if ( !irq_desc )
+    irqd = pirq_spin_lock_irq_desc(pirq, NULL);
+    if ( !irqd )
     {
         xfree(new_entry);
         return r;
     }
 
-    msi_desc = irq_desc->msi_desc;
+    msi_desc = irqd->msi_desc;
     if ( !msi_desc )
         goto out;
 
@@ -508,7 +508,7 @@  found:
     r = 0;
 
 out:
-    spin_unlock_irq(&irq_desc->lock);
+    spin_unlock_irq(&irqd->lock);
     xfree(new_entry);
 
     if ( !r )
@@ -533,7 +533,7 @@  out:
 
 void msixtbl_pt_unregister(struct domain *d, struct pirq *pirq)
 {
-    struct irq_desc *irq_desc;
+    struct irq_desc *irqd;
     struct msi_desc *msi_desc;
     struct pci_dev *pdev;
     struct msixtbl_entry *entry;
@@ -544,11 +544,11 @@  void msixtbl_pt_unregister(struct domain *d, struct pirq *pirq)
     if ( !msixtbl_initialised(d) )
         return;
 
-    irq_desc = pirq_spin_lock_irq_desc(pirq, NULL);
-    if ( !irq_desc )
+    irqd = pirq_spin_lock_irq_desc(pirq, NULL);
+    if ( !irqd )
         return;
 
-    msi_desc = irq_desc->msi_desc;
+    msi_desc = irqd->msi_desc;
     if ( !msi_desc )
         goto out;
 
@@ -559,14 +559,14 @@  void msixtbl_pt_unregister(struct domain *d, struct pirq *pirq)
             goto found;
 
 out:
-    spin_unlock_irq(&irq_desc->lock);
+    spin_unlock_irq(&irqd->lock);
     return;
 
 found:
     if ( !atomic_dec_and_test(&entry->refcnt) )
         del_msixtbl_entry(entry);
 
-    spin_unlock_irq(&irq_desc->lock);
+    spin_unlock_irq(&irqd->lock);
 }
 
 void msixtbl_init(struct domain *d)
@@ -664,12 +664,12 @@  static unsigned int msi_gflags(uint16_t data, uint64_t addr, bool masked)
 static void vpci_mask_pirq(struct domain *d, int pirq, bool mask)
 {
     unsigned long flags;
-    struct irq_desc *desc = domain_spin_lock_irq_desc(d, pirq, &flags);
+    struct irq_desc *irqd = domain_spin_lock_irq_desc(d, pirq, &flags);
 
-    if ( !desc )
+    if ( !irqd )
         return;
-    guest_mask_msi_irq(desc, mask);
-    spin_unlock_irqrestore(&desc->lock, flags);
+    guest_mask_msi_irq(irqd, mask);
+    spin_unlock_irqrestore(&irqd->lock, flags);
 }
 
 void vpci_msi_arch_mask(struct vpci_msi *msi, const struct pci_dev *pdev,