[1/5] dynamic logical partitioning infrastructure

This patch provides the kernel DLPAR infrastructure in a new filed named
dlpar.c.  The functionality provided is for acquiring and releasing a 
resource from firmware and the parsing of information returned from the
ibm,configure-connector rtas call.  Additionally this exports the 
pSeries reconfiguration notifier chain so that it can be invoked when
device tree updates are made.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
---

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 wrote:
> 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.

Good catch,  I will fix it in the updated patches.

> 
>> +
>> +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?

Yes,  I could return the rtas error code to the user to allow the caller to
evaluate it if they wanted to.  For what I am doing I am only concerned with
success/failure so I did not deal with returning anything other than -1.

I'll update the next patch to return the rtas error for failures and 0
for success.

> 
> 
>> +
>> +    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?

Yes, it seems a bit odd here, but in patches later in this series I
add additional initialization steps after the machine_is() check
such that it makes sense to bail out here if the check fails.

> 
>> +
>> +    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);
> 

I think I tried this and was having issues,  I don't remember what they
were though.  I will try to fix this in the updated patch.

-Nathan Fontenot

On Fri, 2009-09-11 at 16:10 -0500, Nathan Fontenot wrote:
> This patch provides the kernel DLPAR infrastructure in a new filed named
> dlpar.c.  The functionality provided is for acquiring and releasing a 
> resource from firmware and the parsing of information returned from the
> ibm,configure-connector rtas call.  Additionally this exports the 
> pSeries reconfiguration notifier chain so that it can be invoked when
> device tree updates are made.
> 
> Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
> ---
> 
> Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-09-11 12:51:52.000000000 -0500
> @@ -0,0 +1,416 @@
> +/*
> + * dlpar.c - support for dynamic reconfiguration (including PCI
> + * Hotplug and Dynamic Logical Partitioning on RPA platforms).
> + *
> + * Copyright (C) 2009 Nathan Fontenot
> + * Copyright (C) 2009 IBM Corporation
> + *
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License version
> + * 2 as published by the Free Software Foundation.
> + */
> +
> +#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;
> +
> +static struct property *parse_cc_property(char *workarea)
> +{
> +	struct property *prop;
> +	u32 *work_ints;
> +	char *name;
> +	char *value;
> +
> +	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
> +	if (!prop)
> +		return NULL;
> +
> +	work_ints = (u32 *)workarea;
> +	name = workarea + work_ints[2];
> +	prop->name = kzalloc(strlen(name) + 1, GFP_KERNEL);
> +	if (!prop->name) {
> +		kfree(prop);
> +		return NULL;
> +	}
> +
> +	strcpy(prop->name, name);
> +
> +	prop->length = work_ints[3];
> +	value = workarea + work_ints[4];
> +	prop->value = kzalloc(prop->length, GFP_KERNEL);


The use of work_ints is a bit opaque, it might be clearer if you define
a struct, something like:

struct cc_prop {
	u32 ?;
	u32 ?;
	u32 name_offset;
	u32 length;
	u32 value_offset;
};

cc = (struct cc_prop *)workarea;

name = workarea + cc->name_offset;
..
prop->length = cc->length;
value = workarea + cc->value_offset;

etc.


Also I don't see any checking of the offsets into workarea (for name &
value), vs the size of workarea.

cheers

Michael Ellerman wrote:
> On Fri, 2009-09-11 at 16:10 -0500, Nathan Fontenot wrote:
>> This patch provides the kernel DLPAR infrastructure in a new filed named
>> dlpar.c.  The functionality provided is for acquiring and releasing a 
>> resource from firmware and the parsing of information returned from the
>> ibm,configure-connector rtas call.  Additionally this exports the 
>> pSeries reconfiguration notifier chain so that it can be invoked when
>> device tree updates are made.
>>
>> Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
>> ---
>>
>> Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
>> ===================================================================
>> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
>> +++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-09-11 12:51:52.000000000 -0500
>> @@ -0,0 +1,416 @@
>> +/*
>> + * dlpar.c - support for dynamic reconfiguration (including PCI
>> + * Hotplug and Dynamic Logical Partitioning on RPA platforms).
>> + *
>> + * Copyright (C) 2009 Nathan Fontenot
>> + * Copyright (C) 2009 IBM Corporation
>> + *
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License version
>> + * 2 as published by the Free Software Foundation.
>> + */
>> +
>> +#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;
>> +
>> +static struct property *parse_cc_property(char *workarea)
>> +{
>> +	struct property *prop;
>> +	u32 *work_ints;
>> +	char *name;
>> +	char *value;
>> +
>> +	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
>> +	if (!prop)
>> +		return NULL;
>> +
>> +	work_ints = (u32 *)workarea;
>> +	name = workarea + work_ints[2];
>> +	prop->name = kzalloc(strlen(name) + 1, GFP_KERNEL);
>> +	if (!prop->name) {
>> +		kfree(prop);
>> +		return NULL;
>> +	}
>> +
>> +	strcpy(prop->name, name);
>> +
>> +	prop->length = work_ints[3];
>> +	value = workarea + work_ints[4];
>> +	prop->value = kzalloc(prop->length, GFP_KERNEL);
> 
> 
> The use of work_ints is a bit opaque, it might be clearer if you define
> a struct, something like:
> 
> struct cc_prop {
> 	u32 ?;
> 	u32 ?;
> 	u32 name_offset;
> 	u32 length;
> 	u32 value_offset;
> };
> 
> cc = (struct cc_prop *)workarea;
> 
> name = workarea + cc->name_offset;
> ..
> prop->length = cc->length;
> value = workarea + cc->value_offset;
> 

Good idea, and I agree that the use of the workarea/work_ints is a bit vague.
The current way works because sometimes its easier to think of the workarea
as a char buffer and sometimes as a int buffer.

I'll try to come up with something to make the parsing of the workarea buffer
easier to understand.

-Nathan Fontenot
 
> etc.
> 
> 
> Also I don't see any checking of the offsets into workarea (for name &
> value), vs the size of workarea.
> 
> cheers
>