From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shannon Zhao Subject: Re: [PATCH v4 05/10] acpi: Refactor acpi_os_map_memory to be architecturally independent Date: Fri, 22 Jan 2016 17:37:39 +0800 Message-ID: <56A1F863.1000507@huawei.com> References: <1452920477-13916-1-git-send-email-zhaoshenglong@huawei.com> <1452920477-13916-6-git-send-email-zhaoshenglong@huawei.com> <569CF7AF02000078000C806A@prv-mh.provo.novell.com> <56A1EA87.5050404@huawei.com> <56A1FABA02000078000C9E74@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <56A1FABA02000078000C9E74@prv-mh.provo.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: ian.campbell@citrix.com, peter.huangpeng@huawei.com, xen-devel@lists.xen.org, julien.grall@citrix.com, stefano.stabellini@citrix.com, shannon.zhao@linaro.org List-Id: xen-devel@lists.xenproject.org On 2016/1/22 16:47, Jan Beulich wrote: >>>> On 22.01.16 at 09:38, wrote: >> > >> > On 2016/1/18 21:33, Jan Beulich wrote: >>>>>> >>>>> On 16.01.16 at 06:01, wrote: >>>>> >>> > --- a/xen/drivers/acpi/osl.c >>>>> >>> > +++ b/xen/drivers/acpi/osl.c >>>>> >>> > @@ -86,17 +86,7 @@ acpi_physical_address __init >> > acpi_os_get_root_pointer(void) >>>>> >>> > void __iomem * >>>>> >>> > acpi_os_map_memory(acpi_physical_address phys, acpi_size size) >>>>> >>> > { >>>>> >>> > - if (system_state >= SYS_STATE_active) { >>>>> >>> > - mfn_t mfn = _mfn(PFN_DOWN(phys)); >>>>> >>> > - unsigned int offs = phys & (PAGE_SIZE - 1); >>>>> >>> > - >>>>> >>> > - /* The low first Mb is always mapped. */ >>>>> >>> > - if ( !((phys + size - 1) >> 20) ) >>>>> >>> > - return __va(phys); >>>>> >>> > - return __vmap(&mfn, PFN_UP(offs + size), 1, 1, >>>>> >>> > - PAGE_HYPERVISOR_NOCACHE) + offs; >>>>> >>> > - } >>>>> >>> > - return __acpi_map_table(phys, size); >>>>> >>> > + return arch_acpi_os_map_memory(phys, size); >>>>> >>> > } >>> >> I'm quite sure I've said before that this goes too far: The __vmap() >>> >> part and likely also the early-boot __acpi_map_table() one already >>> >> are architecture independent and hence should stay. The factoring >>> >> hence should only concern the first Mb handling and maybe the >>> >> the mapping attributes passed to __vmap(). >> > >> > Yes, the first MB handling and __vmap() should refactor. So if it only >> > moves them to an architecture function, how about below patch? >> > >> > diff --git a/xen/arch/x86/acpi/lib.c b/xen/arch/x86/acpi/lib.c >> > index cc15ea3..5885a3a 100644 >> > --- a/xen/arch/x86/acpi/lib.c >> > +++ b/xen/arch/x86/acpi/lib.c >> > @@ -33,6 +33,19 @@ u8 __read_mostly acpi_disable_value; >> > u32 __read_mostly x86_acpiid_to_apicid[MAX_MADT_ENTRIES] = >> > {[0 ... MAX_MADT_ENTRIES - 1] = BAD_APICID }; >> > >> > +void __iomem * >> > +arch_acpi_os_map_memory(acpi_physical_address phys, acpi_size size) >> > +{ >> > + mfn_t mfn = _mfn(PFN_DOWN(phys)); >> > + unsigned int offs = phys & (PAGE_SIZE - 1); >> > + >> > + /* The low first Mb is always mapped. */ >> > + if ( !((phys + size - 1) >> 20) ) >> > + return __va(phys); >> > + return __vmap(&mfn, PFN_UP(offs + size), 1, 1, >> > + PAGE_HYPERVISOR_NOCACHE) + offs; >> > +} > Well, I had clearly said the vmap() part is generic; if there's > anything architecture dependent here, then the mapping > attributes (and hence only _those_ should be factored out, > not the entire function invocation). I know what you said. But how can we change the attribute for ARM in acpi_os_map_memory() without moving these codes out? Thanks, -- Shannon