linux-kernel - Re: [PATCH 3/4] xen/mmu: The xen_setup_kernel_pagetable doesn't need to return anything.

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Date:	Fri, 27 Jul 2012 11:36:58 +0100
From:	Stefano Stabellini <stefano.stabellini@...citrix.com>
To:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"xen-devel@...ts.xensource.com" <xen-devel@...ts.xensource.com>
Subject: Re: [PATCH 3/4] xen/mmu: The xen_setup_kernel_pagetable doesn't need
 to return anything.

On Thu, 26 Jul 2012, Konrad Rzeszutek Wilk wrote:
> We don't need to return the new PGD - as we do not use it.
> 
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>


Acked-by: Stefano Stabellini <stefano.stabellini@...citrix.com>

>  arch/x86/xen/enlighten.c |    5 +----
>  arch/x86/xen/mmu.c       |   10 ++--------
>  arch/x86/xen/xen-ops.h   |    2 +-
>  3 files changed, 4 insertions(+), 13 deletions(-)
> 
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index 9b1afa4..2b67948 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -1295,7 +1295,6 @@ asmlinkage void __init xen_start_kernel(void)
>  {
>  	struct physdev_set_iopl set_iopl;
>  	int rc;
> -	pgd_t *pgd;
>  
>  	if (!xen_start_info)
>  		return;
> @@ -1387,8 +1386,6 @@ asmlinkage void __init xen_start_kernel(void)
>  	acpi_numa = -1;
>  #endif
>  
> -	pgd = (pgd_t *)xen_start_info->pt_base;
> -
>  	/* Don't do the full vcpu_info placement stuff until we have a
>  	   possible map and a non-dummy shared_info. */
>  	per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
> @@ -1397,7 +1394,7 @@ asmlinkage void __init xen_start_kernel(void)
>  	early_boot_irqs_disabled = true;
>  
>  	xen_raw_console_write("mapping kernel into physical memory\n");
> -	pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
> +	xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base, xen_start_info->nr_pages);
>  
>  	xen_reserve_internals();
>  	/* Allocate and initialize top and mid mfn levels for p2m structure */
> diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
> index 3a73785..4ac21a4 100644
> --- a/arch/x86/xen/mmu.c
> +++ b/arch/x86/xen/mmu.c
> @@ -1719,8 +1719,7 @@ static void convert_pfn_mfn(void *v)
>   * of the physical mapping once some sort of allocator has been set
>   * up.
>   */
> -pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
> -					 unsigned long max_pfn)
> +void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
>  {
>  	pud_t *l3;
>  	pmd_t *l2;
> @@ -1781,8 +1780,6 @@ pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
>  
>  	memblock_reserve(__pa(xen_start_info->pt_base),
>  			 xen_start_info->nr_pt_frames * PAGE_SIZE);
> -
> -	return pgd;
>  }
>  #else	/* !CONFIG_X86_64 */
>  static RESERVE_BRK_ARRAY(pmd_t, initial_kernel_pmd, PTRS_PER_PMD);
> @@ -1825,8 +1822,7 @@ static void __init xen_write_cr3_init(unsigned long cr3)
>  	pv_mmu_ops.write_cr3 = &xen_write_cr3;
>  }
>  
> -pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
> -					 unsigned long max_pfn)
> +void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
>  {
>  	pmd_t *kernel_pmd;
>  
> @@ -1858,8 +1854,6 @@ pgd_t * __init xen_setup_kernel_pagetable(pgd_t *pgd,
>  
>  	memblock_reserve(__pa(xen_start_info->pt_base),
>  			 xen_start_info->nr_pt_frames * PAGE_SIZE);
> -
> -	return initial_page_table;
>  }
>  #endif	/* CONFIG_X86_64 */
>  
> diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
> index 202d4c1..2230f57 100644
> --- a/arch/x86/xen/xen-ops.h
> +++ b/arch/x86/xen/xen-ops.h
> @@ -27,7 +27,7 @@ void xen_setup_mfn_list_list(void);
>  void xen_setup_shared_info(void);
>  void xen_build_mfn_list_list(void);
>  void xen_setup_machphys_mapping(void);
> -pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn);
> +void xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn);
>  void xen_reserve_top(void);
>  extern unsigned long xen_max_p2m_pfn;
>  
> -- 
> 1.7.7.6
> 
> --
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