| Message ID | 1458830676-27075-13-git-send-email-shannon.zhao@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Tue, Mar 29, 2016 at 05:18:38PM +0100, Will Deacon wrote: > On Thu, Mar 24, 2016 at 10:44:31PM +0800, Shannon Zhao wrote: > > When it's a Xen domain0 booting with ACPI, it will supply a /chosen and > > a /hypervisor node in DT. So check if it needs to enable ACPI. > > > > Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> > > Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > Acked-by: Hanjun Guo <hanjun.guo@linaro.org> > > --- > > arch/arm64/kernel/acpi.c | 12 ++++++++---- > > 1 file changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > > index d1ce8e2..4e92be0 100644 > > --- a/arch/arm64/kernel/acpi.c > > +++ b/arch/arm64/kernel/acpi.c > > @@ -67,10 +67,13 @@ static int __init dt_scan_depth1_nodes(unsigned long node, > > { > > /* > > * Return 1 as soon as we encounter a node at depth 1 that is > > - * not the /chosen node. > > + * not the /chosen node, or /hypervisor node when running on Xen. > > */ > > - if (depth == 1 && (strcmp(uname, "chosen") != 0)) > > - return 1; > > + if (depth == 1 && (strcmp(uname, "chosen") != 0)) { > > + if (!xen_initial_domain() || (strcmp(uname, "hypervisor") != 0)) > > + return 1; > > + } > > Hmm, but xen_initial_domain() is false when xen isn't being used at all, > so it feels to me like this is a bit too far-reaching and is basically > claiming the "/hypervisor" namespace for Xen. Couldn't it be renamed to > "xen,hypervisor" or something? > > Mark, got any thoughts on this? The node has a compatible string, "xen,xen" per [1], which would tell us absolutely that xen is present. I'd be happy checking for that explicitly. In patch 11 fdt_find_hyper_node checks the compatible string. We could factor that out into a helper like is_xen_node(node) and use it here too. If in future we want to do the same for other hypervisors we can add explicit checks for their compatible strings and/or wrap that in a more generic helper to cater for any hypervisor-specific details. Thanks, Mark. [1] Documentation/devicetree/bindings/arm/xen.txt -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index d1ce8e2..4e92be0 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -67,10 +67,13 @@ static int __init dt_scan_depth1_nodes(unsigned long node, { /* * Return 1 as soon as we encounter a node at depth 1 that is - * not the /chosen node. + * not the /chosen node, or /hypervisor node when running on Xen. */ - if (depth == 1 && (strcmp(uname, "chosen") != 0)) - return 1; + if (depth == 1 && (strcmp(uname, "chosen") != 0)) { + if (!xen_initial_domain() || (strcmp(uname, "hypervisor") != 0)) + return 1; + } + return 0; } @@ -184,7 +187,8 @@ void __init acpi_boot_table_init(void) /* * Enable ACPI instead of device tree unless * - ACPI has been disabled explicitly (acpi=off), or - * - the device tree is not empty (it has more than just a /chosen node) + * - the device tree is not empty (it has more than just a /chosen node, + * and a /hypervisor node when running on Xen) * and ACPI has not been force enabled (acpi=force) */ if (param_acpi_off ||