Re: [PATCH] powerpc: Kill machine numbers

From: Olof Johansson
Date: Fri Mar 24 2006 - 01:24:19 EST


Hi,

A few comments below, I've cut out most of the patch to save
bandwidth...

On Fri, Mar 24, 2006 at 04:42:26PM +1100, Benjamin Herrenschmidt wrote:

> Index: linux-work/arch/powerpc/kernel/setup-common.c
> ===================================================================
> --- linux-work.orig/arch/powerpc/kernel/setup-common.c 2006-03-24 11:42:13.000000000 +1100
> +++ linux-work/arch/powerpc/kernel/setup-common.c 2006-03-24 11:45:28.000000000 +1100
> +void probe_machine(void)
> +{
> + extern struct machdep_calls __machine_desc_start;
> + extern struct machdep_calls __machine_desc_end;
> +
> + /*
> + * Iterate all ppc_md structures until we find the proper
> + * one for the current machine type
> + */
> + DBG("Probing machine type ...\n");
> +
> + for (machine_id = &__machine_desc_start;
> + machine_id < &__machine_desc_end;
> + machine_id++) {
> + DBG(" %s ...", machine_id->name);
> + memcpy(&ppc_md, machine_id, sizeof(struct machdep_calls));
> + if (ppc_md.probe()) {
> + DBG(" match !\n");
> + break;
> + }
> + DBG("\n");
> + }

It would be very useful to print the ppc_md.name of the found machine
here, even without debugging enabled.

> + /* What can we do if we didn't find ? */
> + if (machine_id >= &__machine_desc_end) {
> + DBG("No suitable machine found !\n");
> + for (;;);
> + }
> +}


> Index: linux-work/arch/powerpc/platforms/cell/setup.c
> ===================================================================
> --- linux-work.orig/arch/powerpc/platforms/cell/setup.c 2006-03-23 14:26:08.000000000 +1100
> +++ linux-work/arch/powerpc/platforms/cell/setup.c 2006-03-24 11:45:28.000000000 +1100
> @@ -195,9 +195,10 @@ static void __init cell_init_early(void)
> }
>
>
> -static int __init cell_probe(int platform)
> +static int __init cell_probe(void)
> {
> - if (platform != PLATFORM_CELL)
> + unsigned long root = of_get_flat_dt_root();
> + if (!of_flat_dt_is_compatible(root, "IBM,CPB"))
> return 0;
>
> return 1;
> @@ -212,7 +213,7 @@ static int cell_check_legacy_ioport(unsi
> return -ENODEV;
> }
>
> -struct machdep_calls __initdata cell_md = {
> +define_machine(cell) {
> .probe = cell_probe,
> .setup_arch = cell_setup_arch,
> .init_early = cell_init_early,

You forgot to add a .name value here.

> Index: linux-work/arch/powerpc/kernel/prom_init.c
> ===================================================================
> --- linux-work.orig/arch/powerpc/kernel/prom_init.c 2006-03-10 15:58:17.000000000 +1100
> +++ linux-work/arch/powerpc/kernel/prom_init.c 2006-03-24 14:41:14.000000000 +1100
[...]
> + /* If not a mac, try to figure out if it's an IBM pSeries. We assume
> + * it is if :
> + * - /device_type is "chrp" (please, do NOT use that for future
> + * non-IBM designs !
> + * - it has /rtas
> + */

It's really weird that IBM chose to use "chrp" to describe a
PAPR-compliant platform. I guess it's for historical reasons, but it
sure isn't CHRP any more.

Also, please change the wording. With power.org, there will likely be
non-IBM PAPR-compliant platforms at some point. "non-PAPR-compliant
designs" is a better term to use.

> Index: linux-work/Documentation/powerpc/booting-without-of.txt
> ===================================================================
> --- linux-work.orig/Documentation/powerpc/booting-without-of.txt 2006-03-24 11:42:13.000000000 +1100
> +++ linux-work/Documentation/powerpc/booting-without-of.txt 2006-03-24 14:28:27.000000000 +1100
> @@ -719,6 +719,10 @@ address which can extend beyond that lim
> - model : this is your board name/model
> - #address-cells : address representation for "root" devices
> - #size-cells: the size representation for "root" devices
> + - device_type : This property shouldn't be necessary. However, if
> + device to create a device_type for your root node, make sure it

if you device to create... ?

> + is _not_ "chrp" as this will be matched by the kernel to be a
> + CHRP machine on 32 bits kernel or a pSeries on 64 bits kernels

...or a PAPR-compliant machine on 64-bit kernels.

(Also, "xx-bit kernels", not "xx bits kernels").


-Olof
-
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