Re: [PATCH RESEND 1/4] x86/mm: pgtable: Fix W=1 build kernel-doc warnings

[Shivank Garg <shivankg@amd.com>]

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On 5/15/2025 12:24 PM, Ingo Molnar wrote:
> 
> * Shivank Garg <shivankg@amd.com> wrote:
> 
>>
>>
>> On 5/14/2025 2:50 PM, Ingo Molnar wrote:
>>>
>>> * Shivank Garg <shivankg@amd.com> wrote:
>>>
>>>>>> @@ -665,6 +665,9 @@ void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
>>>>>>  #ifdef CONFIG_X86_5LEVEL
>>>>>>  /**
>>>>>>   * p4d_set_huge - setup kernel P4D mapping
>>>>>> + * @p4d: Pointer to a p4d entry.
>>>>>> + * @addr: Virtual Address associated with p4d.
>>>>>> + * @prot: Protection bits to use.
>>>>>
>>>>> How about using the same capitalization you already see in this 
>>>>> description?
>>>
>>>> Please review the revised patch with suggested changes.
>>>
>>> I think you misunderstood: why are you using 'p4d', while a line before 
>>> it's 'P4D'? It's an acronym, and only used lowercase when it's a local 
>>> variable. 'p4d is a pointer to a p4d entry' is doubly confusing in that 
>>> regard ...
>>>
>>> Same for PMD/PUD etc.
>>>
>>
>> Thank you for the clarification. I understand it now.
>> I hope the attached patch looks good now.
> 
> No. Please re-read your patches and see whether you caught everything, 
> not just the things I pointed out ...
> 
>>  /**
>>   * reserve_top_address - reserves a hole in the top of kernel address space
>> - * @reserve - size of hole to reserve
>> + * @reserve: size of hole to reserve.
> 
> And here the original capitalization in your -v1 patch was better.
> 
>>   * p4d_set_huge - setup kernel P4D mapping
>> + * @p4d: pointer to a P4D entry.
>> + * @addr: virtual Address associated with p4d.
>> + * @prot: protection bits to use.
> 
> Why is 'address' capitalized here?
> 
>>  /**
>>   * pud_set_huge - setup kernel PUD mapping
>> + * @pud: pointer to a PUD entry.
>> + * @addr: virtual Address associated with pud.
>> + * @prot: protection bits to use.
> 
> s/pud
>  /the PUD entry
> 
> Also, similar errors are elsewhere as well.

I'm sorry for missing these details in the previous revision.
I'm changing the first letter of variable description to capital.

https://docs.kernel.org/doc-guide/kernel-doc.html
/**
 * function_name() - Brief description of function.
 * @arg1: Describe the first argument.
 * @arg2: Describe the second argument.
 *        One can provide multiple line descriptions
 *        for arguments.

Function description also starts with capital letter in the doc-guide
and other kernel places so this should make it consistent.

Thanks,
Shivank






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From c76dd45d2cc8221412d69cede4fd713ce775ee64 Mon Sep 17 00:00:00 2001
From: Shivank Garg <shivankg@amd.com>
Date: Wed, 30 Apr 2025 11:29:59 +0000
Subject: [PATCH] x86/mm: pgtable: Fix W=1 build kernel-doc warnings

Sample warnings generated with 'make W=1':
arch/x86/mm/pgtable.c:623: warning: Function parameter or struct member 'reserve' not described in 'reserve_top_address'
arch/x86/mm/pgtable.c:672: warning: Function parameter or struct member 'p4d' not described in 'p4d_set_huge'
arch/x86/mm/pgtable.c:672: warning: Function parameter or struct member 'addr' not described in 'p4d_set_huge'
... so on

Add missing parameter documentation in page table functions to
fix kernel-doc warnings.

Signed-off-by: Shivank Garg <shivankg@amd.com>
---
 arch/x86/mm/pgtable.c | 30 +++++++++++++++++++++---------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index f7ae44d3dd9e..dc55e4d4c226 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -613,8 +613,8 @@ pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
 #endif
 
 /**
- * reserve_top_address - reserves a hole in the top of kernel address space
- * @reserve - size of hole to reserve
+ * reserve_top_address - Reserves a hole in the top of kernel address space
+ * @reserve: Size of hole to reserve.
  *
  * Can be used to relocate the fixmap area and poke a hole in the top
  * of kernel address space to make room for a hypervisor.
@@ -664,7 +664,10 @@ void native_set_fixmap(unsigned /* enum fixed_addresses */ idx,
 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
 #ifdef CONFIG_X86_5LEVEL
 /**
- * p4d_set_huge - setup kernel P4D mapping
+ * p4d_set_huge - Setup kernel P4D mapping
+ * @p4d: Pointer to the P4D entry.
+ * @addr: Virtual address associated with the P4D entry.
+ * @prot: Protection bits to use.
  *
  * No 512GB pages yet -- always return 0
  */
@@ -674,9 +677,10 @@ int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
 }
 
 /**
- * p4d_clear_huge - clear kernel P4D mapping when it is set
+ * p4d_clear_huge - Clear kernel P4D mapping when it is set
+ * @p4d: Pointer to the P4D entry to clear.
  *
- * No 512GB pages yet -- always return 0
+ * No 512GB pages yet -- do nothing
  */
 void p4d_clear_huge(p4d_t *p4d)
 {
@@ -684,7 +688,10 @@ void p4d_clear_huge(p4d_t *p4d)
 #endif
 
 /**
- * pud_set_huge - setup kernel PUD mapping
+ * pud_set_huge - Setup kernel PUD mapping
+ * @pud: Pointer to the PUD entry.
+ * @addr: Virtual address associated with the PUD entry.
+ * @prot: Protection bits to use.
  *
  * MTRRs can override PAT memory types with 4KiB granularity. Therefore, this
  * function sets up a huge page only if the complete range has the same MTRR
@@ -715,7 +722,10 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
 }
 
 /**
- * pmd_set_huge - setup kernel PMD mapping
+ * pmd_set_huge - Setup kernel PMD mapping
+ * @pmd: Pointer to the PMD entry.
+ * @addr: Virtual address associated with the PMD entry.
+ * @prot: Protection bits to use.
  *
  * See text over pud_set_huge() above.
  *
@@ -744,7 +754,8 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
 }
 
 /**
- * pud_clear_huge - clear kernel PUD mapping when it is set
+ * pud_clear_huge - Clear kernel PUD mapping when it is set
+ * @pud: Pointer to the PUD entry to clear.
  *
  * Returns 1 on success and 0 on failure (no PUD map is found).
  */
@@ -759,7 +770,8 @@ int pud_clear_huge(pud_t *pud)
 }
 
 /**
- * pmd_clear_huge - clear kernel PMD mapping when it is set
+ * pmd_clear_huge - Clear kernel PMD mapping when it is set
+ * @pmd: Pointer to the PMD entry to clear.
  *
  * Returns 1 on success and 0 on failure (no PMD map is found).
  */
-- 
2.34.1