Subject: Re: [PATCH 1/5] dynamic logical partitioning infrastructure

From: Brian King <[email-masked]>
Date: Mon, 14 Sep 2009 13:30:54 -0500

Nathan Fontenot wrote:
> +#include <linux/kernel.h>
> +#include <linux/kref.h>
> +#include <linux/notifier.h>
> +#include <linux/proc_fs.h>
> +#include <linux/spinlock.h>
> +
> +#include <asm/prom.h>
> +#include <asm/machdep.h>
> +#include <asm/uaccess.h>
> +#include <asm/rtas.h>
> +#include <asm/pSeries_reconfig.h>
> +
> +#define CFG_CONN_WORK_SIZE    4096
> +static char workarea[CFG_CONN_WORK_SIZE];
> +spinlock_t workarea_lock;

This can be:

static DEFINE_SPINLOCK(workarea_lock);

Then you can get rid of the runtime initializer.

> +
> +int release_drc(u32 drc_index)
> +{
> +    int dr_status, rc;
> +
> +    rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
> +               DR_ENTITY_SENSE, drc_index);
> +    if (rc || dr_status != DR_ENTITY_PRESENT)
> +        return -1;
> +
> +    rc = rtas_set_indicator(ISOLATION_STATE, drc_index, ISOLATE);
> +    if (rc)
> +        return -1;
> +
> +    rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
> +    if (rc) {
> +        rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
> +        return -1;
> +    }

Is there a better return value here that might be more descriptive than -1?

> +
> +    return 0;
> +}
> +
> +static int pseries_dlpar_init(void)
> +{
> +    spin_lock_init(&workarea_lock);
> +
> +    if (!machine_is(pseries))
> +        return 0;

What's the point of this if check if you return 0 either way?

> +
> +    return 0;
> +}
> +__initcall(pseries_dlpar_init);

> Index: powerpc/arch/powerpc/platforms/pseries/reconfig.c
> ===================================================================
> --- powerpc.orig/arch/powerpc/platforms/pseries/reconfig.c    2009-09-11
> 12:43:39.000000000 -0500
> +++ powerpc/arch/powerpc/platforms/pseries/reconfig.c    2009-09-11
> 12:51:52.000000000 -0500
> @@ -95,7 +95,7 @@
>     return parent;
> }
> 
> -static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
> +struct blocking_notifier_head pSeries_reconfig_chain =
> BLOCKING_NOTIFIER_INIT(pSeries_reconfig_chain);

Can't this just be?

BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);

-- 
Brian King
Linux on Power Virtualization
IBM Linux Technology Center