* Re: [PATCH v20 14/14] Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec
[not found] ` <e212cd53fdf9d09923408eb906fe0228d22432a9.1466702804.git.geoff@infradead.org>
@ 2016-06-27 18:22 ` Thiago Jung Bauermann
2016-06-28 3:59 ` Michael Ellerman
0 siblings, 1 reply; 2+ messages in thread
From: Thiago Jung Bauermann @ 2016-06-27 18:22 UTC (permalink / raw)
To: Geoff Levand, James Morse, kexec, linuxppc-dev
Hello,
Am Donnerstag, 23 Juni 2016, 17:54:49 schrieb Geoff Levand:
> +linux,usable-memory
> +-------------------
> +
> +This property is set on PowerPC and arm64 by kexec-tools during kdump
> +to tell the crash kernel the base address of its reserved area of memory,
> and +the size. e.g.
> +
> +/ {
> + chosen {
> + linux,usable-memory = <0x9 0xf0000000 0x0 0x10000000>;
> + };
> +};
On powerpc, linux,usable-memory isn't in /chosen. It is put by kexec-tools
in each /memory node and has the same format as the reg property. During
early boot, the kernel goes through the /memory nodes to find usable memory
and for each node, if there's a linux,usable-memory property it will use it
instead of the reg property to find the ranges of memory it can use (see
early_init_dt_scan_memory in drivers/of/fdt.c).
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH v20 14/14] Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec
2016-06-27 18:22 ` [PATCH v20 14/14] Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec Thiago Jung Bauermann
@ 2016-06-28 3:59 ` Michael Ellerman
0 siblings, 0 replies; 2+ messages in thread
From: Michael Ellerman @ 2016-06-28 3:59 UTC (permalink / raw)
To: Thiago Jung Bauermann, Geoff Levand, James Morse, kexec,
linuxppc-dev
On Mon, 2016-06-27 at 15:22 -0300, Thiago Jung Bauermann wrote:
> Am Donnerstag, 23 Juni 2016, 17:54:49 schrieb Geoff Levand:
> > +linux,usable-memory
> > +-------------------
> > +
> > +This property is set on PowerPC and arm64 by kexec-tools during kdump
> > +to tell the crash kernel the base address of its reserved area of memory,
> > and +the size. e.g.
> > +
> > +/ {
> > + chosen {
> > + linux,usable-memory = <0x9 0xf0000000 0x0 0x10000000>;
> > + };
> > +};
>
> On powerpc, linux,usable-memory isn't in /chosen. It is put by kexec-tools
> in each /memory node and has the same format as the reg property. During
> early boot, the kernel goes through the /memory nodes to find usable memory
> and for each node, if there's a linux,usable-memory property it will use it
> instead of the reg property to find the ranges of memory it can use (see
> early_init_dt_scan_memory in drivers/of/fdt.c).
Yep that sounds right to me.
Added in:
ba7594852f4e ("[PATCH] powerpc: Add support for "linux,usable-memory" on memory nodes")
cheers
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2016-06-27 18:22 ` [PATCH v20 14/14] Documentation: dt: usable-memory and elfcorehdr nodes for arm64 kexec Thiago Jung Bauermann
2016-06-28 3:59 ` Michael Ellerman
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