Re: [PATCH v3 6/8] x86/xen: Use __pa_symbol instead of __pa on C visible symbols

Konrad Rzeszutek Wilk
2012-11-06T15:59:58Z

On Mon, Nov 05, 2012 at 11:06:00AM -0800, Alexander Duyck wrote:
> This change updates a few of the functions to use __pa_symbol when
> translating C visible symbols instead of __pa. By using __pa_symbol we are
> able to drop a few extra lines of code as don't have to test to see if the
> virtual pointer is a part of the kernel text or just standard virtual memory.
>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Acked-by.

> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
> ---
>
> arch/x86/xen/mmu.c | 21 +++++++++++----------
> 1 files changed, 11 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
> index 4a05b39..a63e5f9 100644
> --- a/arch/x86/xen/mmu.c
> +++ b/arch/x86/xen/mmu.c
> @@ -1486,7 +1486,8 @@ static int xen_pgd_alloc(struct mm_struct *mm)
>
> if (user_pgd != NULL) {
> user_pgd[pgd_index(VSYSCALL_START)] =
> - __pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
> + __pgd(__pa_symbol(level3_user_vsyscall) |
> + _PAGE_TABLE);
> ret = 0;
> }
>
> @@ -1958,10 +1959,10 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
> * pgd.
> */
> if (xen_feature(XENFEAT_writable_page_tables)) {
> - native_write_cr3(__pa(init_level4_pgt));
> + native_write_cr3(__pa_symbol(init_level4_pgt));
> } else {
> xen_mc_batch();
> - __xen_write_cr3(true, __pa(init_level4_pgt));
> + __xen_write_cr3(true, __pa_symbol(init_level4_pgt));
> xen_mc_issue(PARAVIRT_LAZY_CPU);
> }
> /* We can't that easily rip out L3 and L2, as the Xen pagetables are
> @@ -1984,10 +1985,10 @@ static RESERVE_BRK_ARRAY(pmd_t, swapper_kernel_pmd, PTRS_PER_PMD);
>
> static void __init xen_write_cr3_init(unsigned long cr3)
> {
> - unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir));
> + unsigned long pfn = PFN_DOWN(__pa_symbol(swapper_pg_dir));
>
> - BUG_ON(read_cr3() != __pa(initial_page_table));
> - BUG_ON(cr3 != __pa(swapper_pg_dir));
> + BUG_ON(read_cr3() != __pa_symbol(initial_page_table));
> + BUG_ON(cr3 != __pa_symbol(swapper_pg_dir));
>
> /*
> * We are switching to swapper_pg_dir for the first time (from
> @@ -2011,7 +2012,7 @@ static void __init xen_write_cr3_init(unsigned long cr3)
> pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, pfn);
>
> pin_pagetable_pfn(MMUEXT_UNPIN_TABLE,
> - PFN_DOWN(__pa(initial_page_table)));
> + PFN_DOWN(__pa_symbol(initial_page_table)));
> set_page_prot(initial_page_table, PAGE_KERNEL);
> set_page_prot(initial_kernel_pmd, PAGE_KERNEL);
>
> @@ -2036,7 +2037,7 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
>
> copy_page(initial_page_table, pgd);
> initial_page_table[KERNEL_PGD_BOUNDARY] =
> - __pgd(__pa(initial_kernel_pmd) | _PAGE_PRESENT);
> + __pgd(__pa_symbol(initial_kernel_pmd) | _PAGE_PRESENT);
>
> set_page_prot(initial_kernel_pmd, PAGE_KERNEL_RO);
> set_page_prot(initial_page_table, PAGE_KERNEL_RO);
> @@ -2045,8 +2046,8 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
> pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
>
> pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE,
> - PFN_DOWN(__pa(initial_page_table)));
> - xen_write_cr3(__pa(initial_page_table));
> + PFN_DOWN(__pa_symbol(initial_page_table)));
> + xen_write_cr3(__pa_symbol(initial_page_table));
>
> memblock_reserve(__pa(xen_start_info->pt_base),
> xen_start_info->nr_pt_frames * PAGE_SIZE);