On Fri, Jul 24, 2015 at 12:47:47PM +0100, David Vrabel wrote:
> Rename alloc_p2m() to xen_alloc_p2m_entry() and export it.
>
> This is useful for ensuring that a p2m entry is allocated (i.e., not a
> shared missing or identity entry) so that subsequent set_phys_to_machine()
> calls will require no further allocations.
>
> Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> ---
> arch/x86/include/asm/xen/page.h | 2 ++
> arch/x86/xen/p2m.c | 16 ++++++++++------
> 2 files changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
> index c44a5d5..960b380 100644
> --- a/arch/x86/include/asm/xen/page.h
> +++ b/arch/x86/include/asm/xen/page.h
> @@ -45,6 +45,8 @@ extern unsigned long *xen_p2m_addr;
> extern unsigned long xen_p2m_size;
> extern unsigned long xen_max_p2m_pfn;
>
> +extern int xen_alloc_p2m_entry(unsigned long pfn);
> +
> extern unsigned long get_phys_to_machine(unsigned long pfn);
> extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
> extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
> diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
> index 8b7f18e..ef93ccf 100644
> --- a/arch/x86/xen/p2m.c
> +++ b/arch/x86/xen/p2m.c
> @@ -503,7 +503,7 @@ static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *pte_pg)
> * the new pages are installed with cmpxchg; if we lose the race then
> * simply free the page we allocated and use the one that's there.
> */
> -static bool alloc_p2m(unsigned long pfn)
> +int xen_alloc_p2m_entry(unsigned long pfn)
> {
> unsigned topidx, mididx;
> unsigned long *top_mfn_p, *mid_mfn;
> @@ -524,7 +524,7 @@ static bool alloc_p2m(unsigned long pfn)
> /* PMD level is missing, allocate a new one */
> ptep = alloc_p2m_pmd(addr, pte_pg);
> if (!ptep)
> - return false;
> + return -ENOMEM;
> }
>
> if (p2m_top_mfn) {
> @@ -541,7 +541,7 @@ static bool alloc_p2m(unsigned long pfn)
>
> mid_mfn = alloc_p2m_page();
> if (!mid_mfn)
> - return false;
> + return -ENOMEM;
>
> p2m_mid_mfn_init(mid_mfn, p2m_missing);
>
> @@ -567,7 +567,7 @@ static bool alloc_p2m(unsigned long pfn)
>
> p2m = alloc_p2m_page();
> if (!p2m)
> - return false;
> + return -ENOMEM;
>
> if (p2m_pfn == PFN_DOWN(__pa(p2m_missing)))
> p2m_init(p2m);
> @@ -590,8 +590,9 @@ static bool alloc_p2m(unsigned long pfn)
> free_p2m_page(p2m);
> }
>
> - return true;
> + return 0;
> }
> +EXPORT_SYMBOL(xen_alloc_p2m);
>
> unsigned long __init set_phys_range_identity(unsigned long pfn_s,
> unsigned long pfn_e)
> @@ -648,7 +649,10 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
> bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
> {
> if (unlikely(!__set_phys_to_machine(pfn, mfn))) {
> - if (!alloc_p2m(pfn))
> + int ret;
> +
> + ret = xen_alloc_p2m_entry(pfn);
> + if (ret < 0)
> return false;
>
> return __set_phys_to_machine(pfn, mfn);
> --
> 2.1.4
>
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