diff mbox series

[2/6] x86: remove memblock_find_dma_reserve()

Message ID 20240318142138.783350-3-bhe@redhat.com (mailing list archive)
State New
Headers show
Series mm/mm_init.c: refactor free_area_init_core() | expand

Commit Message

Baoquan He March 18, 2024, 2:21 p.m. UTC
This is not needed any more.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
 arch/x86/include/asm/pgtable.h |  1 -
 arch/x86/kernel/setup.c        |  2 --
 arch/x86/mm/init.c             | 45 ----------------------------------
 3 files changed, 48 deletions(-)

Comments

Mike Rapoport March 19, 2024, 3:49 p.m. UTC | #1
Hi Baoquan,

On Mon, Mar 18, 2024 at 10:21:34PM +0800, Baoquan He wrote:
> This is not needed any more.

I'd swap this and the first patch, so that the first patch would remove
memblock_find_dma_reserve() and it's changelog will explain why it's not
needed and then the second patch will simply drop unused set_dma_reserve()

> Signed-off-by: Baoquan He <bhe@redhat.com>
> ---
>  arch/x86/include/asm/pgtable.h |  1 -
>  arch/x86/kernel/setup.c        |  2 --
>  arch/x86/mm/init.c             | 45 ----------------------------------
>  3 files changed, 48 deletions(-)
> 
> diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
> index 315535ffb258..cefc7a84f7a4 100644
> --- a/arch/x86/include/asm/pgtable.h
> +++ b/arch/x86/include/asm/pgtable.h
> @@ -1200,7 +1200,6 @@ static inline int pgd_none(pgd_t pgd)
>  extern int direct_gbpages;
>  void init_mem_mapping(void);
>  void early_alloc_pgt_buf(void);
> -extern void memblock_find_dma_reserve(void);
>  void __init poking_init(void);
>  unsigned long init_memory_mapping(unsigned long start,
>  				  unsigned long end, pgprot_t prot);
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 3e1e96efadfe..5aa00938051f 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -1106,8 +1106,6 @@ void __init setup_arch(char **cmdline_p)
>  	 */
>  	arch_reserve_crashkernel();
>  
> -	memblock_find_dma_reserve();
> -
>  	if (!early_xdbc_setup_hardware())
>  		early_xdbc_register_console();
>  
> diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
> index 5209549e8192..615f0bf4bda6 100644
> --- a/arch/x86/mm/init.c
> +++ b/arch/x86/mm/init.c
> @@ -990,51 +990,6 @@ void __init free_initrd_mem(unsigned long start, unsigned long end)
>  }
>  #endif
>  
> -/*
> - * Calculate the precise size of the DMA zone (first 16 MB of RAM),
> - * and pass it to the MM layer - to help it set zone watermarks more
> - * accurately.
> - *
> - * Done on 64-bit systems only for the time being, although 32-bit systems
> - * might benefit from this as well.
> - */
> -void __init memblock_find_dma_reserve(void)
> -{
> -#ifdef CONFIG_X86_64
> -	u64 nr_pages = 0, nr_free_pages = 0;
> -	unsigned long start_pfn, end_pfn;
> -	phys_addr_t start_addr, end_addr;
> -	int i;
> -	u64 u;
> -
> -	/*
> -	 * Iterate over all memory ranges (free and reserved ones alike),
> -	 * to calculate the total number of pages in the first 16 MB of RAM:
> -	 */
> -	nr_pages = 0;
> -	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
> -		start_pfn = min(start_pfn, MAX_DMA_PFN);
> -		end_pfn   = min(end_pfn,   MAX_DMA_PFN);
> -
> -		nr_pages += end_pfn - start_pfn;
> -	}
> -
> -	/*
> -	 * Iterate over free memory ranges to calculate the number of free
> -	 * pages in the DMA zone, while not counting potential partial
> -	 * pages at the beginning or the end of the range:
> -	 */
> -	nr_free_pages = 0;
> -	for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start_addr, &end_addr, NULL) {
> -		start_pfn = min_t(unsigned long, PFN_UP(start_addr), MAX_DMA_PFN);
> -		end_pfn   = min_t(unsigned long, PFN_DOWN(end_addr), MAX_DMA_PFN);
> -
> -		if (start_pfn < end_pfn)
> -			nr_free_pages += end_pfn - start_pfn;
> -	}
> -#endif
> -}
> -
>  void __init zone_sizes_init(void)
>  {
>  	unsigned long max_zone_pfns[MAX_NR_ZONES];
> -- 
> 2.41.0
>
Baoquan He March 20, 2024, 7:52 a.m. UTC | #2
On 03/19/24 at 05:49pm, Mike Rapoport wrote:
> Hi Baoquan,
> 
> On Mon, Mar 18, 2024 at 10:21:34PM +0800, Baoquan He wrote:
> > This is not needed any more.
> 
> I'd swap this and the first patch, so that the first patch would remove
> memblock_find_dma_reserve() and it's changelog will explain why it's not
> needed and then the second patch will simply drop unused set_dma_reserve()

Thanks, Mike.

My thought on the patch 1/2 splitting is:
patch 1 is removing all relevant codes in mm, including the usage of
dma_reserve in free_area_init_core() and exporting set_dma_reserve()
to any ARCH which want to subtract the dma_reserve from DMA zone.

Patch 2 purely remove the code in x86 ARCH about how to get dma_reserve.

Your suggestion is also good to me, I can rearrange the order and
repost.
Mike Rapoport March 20, 2024, 9:36 a.m. UTC | #3
On Wed, Mar 20, 2024 at 03:52:52PM +0800, Baoquan He wrote:
> On 03/19/24 at 05:49pm, Mike Rapoport wrote:
> > Hi Baoquan,
> > 
> > On Mon, Mar 18, 2024 at 10:21:34PM +0800, Baoquan He wrote:
> > > This is not needed any more.
> > 
> > I'd swap this and the first patch, so that the first patch would remove
> > memblock_find_dma_reserve() and it's changelog will explain why it's not
> > needed and then the second patch will simply drop unused set_dma_reserve()
> 
> Thanks, Mike.
> 
> My thought on the patch 1/2 splitting is:
> patch 1 is removing all relevant codes in mm, including the usage of
> dma_reserve in free_area_init_core() and exporting set_dma_reserve()
> to any ARCH which want to subtract the dma_reserve from DMA zone.
>
> Patch 2 purely remove the code in x86 ARCH about how to get dma_reserve.
 
I think it's better first to remove the usage of set_dma_reserve() in x86
and then clean up the unused code.

> Your suggestion is also good to me, I can rearrange the order and
> repost.
Baoquan He March 20, 2024, 1:14 p.m. UTC | #4
On 03/20/24 at 11:36am, Mike Rapoport wrote:
> On Wed, Mar 20, 2024 at 03:52:52PM +0800, Baoquan He wrote:
> > On 03/19/24 at 05:49pm, Mike Rapoport wrote:
> > > Hi Baoquan,
> > > 
> > > On Mon, Mar 18, 2024 at 10:21:34PM +0800, Baoquan He wrote:
> > > > This is not needed any more.
> > > 
> > > I'd swap this and the first patch, so that the first patch would remove
> > > memblock_find_dma_reserve() and it's changelog will explain why it's not
> > > needed and then the second patch will simply drop unused set_dma_reserve()
> > 
> > Thanks, Mike.
> > 
> > My thought on the patch 1/2 splitting is:
> > patch 1 is removing all relevant codes in mm, including the usage of
> > dma_reserve in free_area_init_core() and exporting set_dma_reserve()
> > to any ARCH which want to subtract the dma_reserve from DMA zone.
> >
> > Patch 2 purely remove the code in x86 ARCH about how to get dma_reserve.
>  
> I think it's better first to remove the usage of set_dma_reserve() in x86
> and then clean up the unused code.

OK, firslty remove the only user, that sounds reasonable. Will change.
Thanks.
diff mbox series

Patch

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 315535ffb258..cefc7a84f7a4 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1200,7 +1200,6 @@  static inline int pgd_none(pgd_t pgd)
 extern int direct_gbpages;
 void init_mem_mapping(void);
 void early_alloc_pgt_buf(void);
-extern void memblock_find_dma_reserve(void);
 void __init poking_init(void);
 unsigned long init_memory_mapping(unsigned long start,
 				  unsigned long end, pgprot_t prot);
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 3e1e96efadfe..5aa00938051f 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1106,8 +1106,6 @@  void __init setup_arch(char **cmdline_p)
 	 */
 	arch_reserve_crashkernel();
 
-	memblock_find_dma_reserve();
-
 	if (!early_xdbc_setup_hardware())
 		early_xdbc_register_console();
 
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 5209549e8192..615f0bf4bda6 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -990,51 +990,6 @@  void __init free_initrd_mem(unsigned long start, unsigned long end)
 }
 #endif
 
-/*
- * Calculate the precise size of the DMA zone (first 16 MB of RAM),
- * and pass it to the MM layer - to help it set zone watermarks more
- * accurately.
- *
- * Done on 64-bit systems only for the time being, although 32-bit systems
- * might benefit from this as well.
- */
-void __init memblock_find_dma_reserve(void)
-{
-#ifdef CONFIG_X86_64
-	u64 nr_pages = 0, nr_free_pages = 0;
-	unsigned long start_pfn, end_pfn;
-	phys_addr_t start_addr, end_addr;
-	int i;
-	u64 u;
-
-	/*
-	 * Iterate over all memory ranges (free and reserved ones alike),
-	 * to calculate the total number of pages in the first 16 MB of RAM:
-	 */
-	nr_pages = 0;
-	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
-		start_pfn = min(start_pfn, MAX_DMA_PFN);
-		end_pfn   = min(end_pfn,   MAX_DMA_PFN);
-
-		nr_pages += end_pfn - start_pfn;
-	}
-
-	/*
-	 * Iterate over free memory ranges to calculate the number of free
-	 * pages in the DMA zone, while not counting potential partial
-	 * pages at the beginning or the end of the range:
-	 */
-	nr_free_pages = 0;
-	for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start_addr, &end_addr, NULL) {
-		start_pfn = min_t(unsigned long, PFN_UP(start_addr), MAX_DMA_PFN);
-		end_pfn   = min_t(unsigned long, PFN_DOWN(end_addr), MAX_DMA_PFN);
-
-		if (start_pfn < end_pfn)
-			nr_free_pages += end_pfn - start_pfn;
-	}
-#endif
-}
-
 void __init zone_sizes_init(void)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES];