Re: [RFT/PATCH] x86: Unify kernel_physical_mapping_init() API

From: KAMEZAWA Hiroyuki
Date: Thu Feb 25 2010 - 19:50:21 EST


On Wed, 24 Feb 2010 17:04:47 +0200 (EET)
Pekka J Enberg <penberg@xxxxxxxxxxxxxx> wrote:

> From: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
>
> This patch changes the 32-bit version of kernel_physical_mapping_init() to
> return the last mapped address like the 64-bit one so that we can unify the
> call-site in init_memory_mapping().
>

I'm sorry if I can't track the logic correctly..


> Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
> ---
> Note: I have only tested this on VirtualBox which is why I tagged the patch as
> RFT.
>
> arch/x86/mm/init.c | 7 -------
> arch/x86/mm/init_32.c | 8 +++++---
> 2 files changed, 5 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
> index d406c52..e71c5cb 100644
> --- a/arch/x86/mm/init.c
> +++ b/arch/x86/mm/init.c
> @@ -266,16 +266,9 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
> if (!after_bootmem)
> find_early_table_space(end, use_pse, use_gbpages);
>
> -#ifdef CONFIG_X86_32
> - for (i = 0; i < nr_range; i++)
> - kernel_physical_mapping_init(mr[i].start, mr[i].end,
> - mr[i].page_size_mask);
> - ret = end;
> -#else /* CONFIG_X86_64 */
> for (i = 0; i < nr_range; i++)
> ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
> mr[i].page_size_mask);
> -#endif
>
> #ifdef CONFIG_X86_32
> early_ioremap_page_table_range_init();
> diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
> index 9a0c258..2226f2c 100644
> --- a/arch/x86/mm/init_32.c
> +++ b/arch/x86/mm/init_32.c
> @@ -241,6 +241,7 @@ kernel_physical_mapping_init(unsigned long start,
> unsigned long page_size_mask)
> {
> int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
> + unsigned long last_map_addr = end;
> unsigned long start_pfn, end_pfn;
> pgd_t *pgd_base = swapper_pg_dir;
> int pgd_idx, pmd_idx, pte_ofs;
> @@ -341,9 +342,10 @@ repeat:
> prot = PAGE_KERNEL_EXEC;
>
> pages_4k++;
> - if (mapping_iter == 1)
> + if (mapping_iter == 1) {
> set_pte(pte, pfn_pte(pfn, init_prot));
> - else
> + last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
> + } else
> set_pte(pte, pfn_pte(pfn, prot));
> }
> }

Don't we need to update last_map_addr after pages_2m++; ?

And...from the logic,
unsigned long last_map_addr = end;
seems to be always true.

So, just returning "end" is not good ?

Thanks,
-Kame

> @@ -368,7 +370,7 @@ repeat:
> mapping_iter = 2;
> goto repeat;
> }
> - return 0;
> + return last_map_addr;
> }
>
> pte_t *kmap_pte;
> --
> 1.5.6.4
>
>

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