Subject: Re: [PATCH] pseries: Fix endianness in cpu hotplug and hotremove

From: Nathan Fontenot <[email-masked]>
Date: Mon, 08 Sep 2014 09:07:41 -0500

It looks like you have a lot of the same changes as the patch Bharata
sent out last week. Including the one issue I saw in Bharata's patch
below.

On 09/05/2014 02:09 PM, Thomas Falcon wrote:
> This patch attempts to ensure that all values are in the proper
> endianness format when both hotadding and hotremoving cpus.
> 
> Signed-off-by: Thomas Falcon <[email-masked]>
> ---
>  arch/powerpc/platforms/pseries/dlpar.c       | 56 ++++++++++++++--------------
>  arch/powerpc/platforms/pseries/hotplug-cpu.c | 20 +++++-----
>  2 files changed, 38 insertions(+), 38 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
> index a2450b8..c1d7e40 100644
> --- a/arch/powerpc/platforms/pseries/dlpar.c
> +++ b/arch/powerpc/platforms/pseries/dlpar.c
> @@ -24,11 +24,11 @@
>  #include <asm/rtas.h>
>  
>  struct cc_workarea {
> -	u32	drc_index;
> -	u32	zero;
> -	u32	name_offset;
> -	u32	prop_length;
> -	u32	prop_offset;
> +	__be32	drc_index;
> +	__be32	zero;
> +	__be32	name_offset;
> +	__be32	prop_length;
> +	__be32	prop_offset;
>  };
>  
>  void dlpar_free_cc_property(struct property *prop)
> @@ -48,11 +48,11 @@ static struct property *dlpar_parse_cc_property(struct cc_workarea *ccwa)
>  	if (!prop)
>  		return NULL;
>  
> -	name = (char *)ccwa + ccwa->name_offset;
> +	name = (char *)ccwa + be32_to_cpu(ccwa->name_offset);
>  	prop->name = kstrdup(name, GFP_KERNEL);
>  
> -	prop->length = ccwa->prop_length;
> -	value = (char *)ccwa + ccwa->prop_offset;
> +	prop->length = be32_to_cpu(ccwa->prop_length);
> +	value = (char *)ccwa + be32_to_cpu(ccwa->prop_offset);
>  	prop->value = kmemdup(value, prop->length, GFP_KERNEL);
>  	if (!prop->value) {
>  		dlpar_free_cc_property(prop);
> @@ -78,7 +78,7 @@ static struct device_node *dlpar_parse_cc_node(struct cc_workarea *ccwa,
>  	if (!dn)
>  		return NULL;
>  
> -	name = (char *)ccwa + ccwa->name_offset;
> +	name = (char *)ccwa + be32_to_cpu(ccwa->name_offset);
>  	dn->full_name = kasprintf(GFP_KERNEL, "%s/%s", path, name);
>  	if (!dn->full_name) {
>  		kfree(dn);
> @@ -148,7 +148,7 @@ struct device_node *dlpar_configure_connector(u32 drc_index,
>  		return NULL;
>  
>  	ccwa = (struct cc_workarea *)&data_buf[0];
> -	ccwa->drc_index = drc_index;
> +	ccwa->drc_index = cpu_to_be32(drc_index);

This will break partition migration.

The drc index valued passed into dlpar_configure_connector() from the migration
path, pseries_devicetree_update(), is already in BE format.

-Nathan

>  	ccwa->zero = 0;
>  
>  	do {
> @@ -363,10 +363,10 @@ static int dlpar_online_cpu(struct device_node *dn)
>  	int rc = 0;
>  	unsigned int cpu;
>  	int len, nthreads, i;
> -	const u32 *intserv;
> +	const __be32 *intserv_be;
>  
> -	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
> -	if (!intserv)
> +	intserv_be = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
> +	if (!intserv_be)
>  		return -EINVAL;
>  
>  	nthreads = len / sizeof(u32);
> @@ -374,7 +374,7 @@ static int dlpar_online_cpu(struct device_node *dn)
>  	cpu_maps_update_begin();
>  	for (i = 0; i < nthreads; i++) {
>  		for_each_present_cpu(cpu) {
> -			if (get_hard_smp_processor_id(cpu) != intserv[i])
> +			if (get_hard_smp_processor_id(cpu) != be32_to_cpu(intserv_be[i]))
>  				continue;
>  			BUG_ON(get_cpu_current_state(cpu)
>  					!= CPU_STATE_OFFLINE);
> @@ -388,7 +388,7 @@ static int dlpar_online_cpu(struct device_node *dn)
>  		}
>  		if (cpu == num_possible_cpus())
>  			printk(KERN_WARNING "Could not find cpu to online "
> -			       "with physical id 0x%x\n", intserv[i]);
> +			       "with physical id 0x%x\n", be32_to_cpu(intserv_be[i]));
>  	}
>  	cpu_maps_update_done();
>  
> @@ -442,18 +442,17 @@ static int dlpar_offline_cpu(struct device_node *dn)
>  	int rc = 0;
>  	unsigned int cpu;
>  	int len, nthreads, i;
> -	const u32 *intserv;
> +	const __be32 *intserv_be;
>  
> -	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
> -	if (!intserv)
> +	intserv_be = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
> +	if (!intserv_be)
>  		return -EINVAL;
>  
>  	nthreads = len / sizeof(u32);
> -
>  	cpu_maps_update_begin();
>  	for (i = 0; i < nthreads; i++) {
>  		for_each_present_cpu(cpu) {
> -			if (get_hard_smp_processor_id(cpu) != intserv[i])
> +			if (get_hard_smp_processor_id(cpu) != be32_to_cpu(intserv_be[i]))
>  				continue;
>  
>  			if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
> @@ -469,20 +468,19 @@ static int dlpar_offline_cpu(struct device_node *dn)
>  				break;
>  
>  			}
> -
>  			/*
>  			 * The cpu is in CPU_STATE_INACTIVE.
>  			 * Upgrade it's state to CPU_STATE_OFFLINE.
>  			 */
>  			set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
> -			BUG_ON(plpar_hcall_norets(H_PROD, intserv[i])
> +			BUG_ON(plpar_hcall_norets(H_PROD, be32_to_cpu(intserv_be[i]))
>  								!= H_SUCCESS);
>  			__cpu_die(cpu);
>  			break;
>  		}
>  		if (cpu == num_possible_cpus())
>  			printk(KERN_WARNING "Could not find cpu to offline "
> -			       "with physical id 0x%x\n", intserv[i]);
> +			       "with physical id 0x%x\n", be32_to_cpu(intserv_be[i]));
>  	}
>  	cpu_maps_update_done();
>  
> @@ -494,26 +492,28 @@ out:
>  static ssize_t dlpar_cpu_release(const char *buf, size_t count)
>  {
>  	struct device_node *dn;
> -	const u32 *drc_index;
> +	const __be32 *drc_index_be;
> +	u32 drc_index;
>  	int rc;
>  
>  	dn = of_find_node_by_path(buf);
>  	if (!dn)
>  		return -EINVAL;
>  
> -	drc_index = of_get_property(dn, "ibm,my-drc-index", NULL);
> -	if (!drc_index) {
> +	drc_index_be = of_get_property(dn, "ibm,my-drc-index", NULL);
> +	if (!drc_index_be) {
>  		of_node_put(dn);
>  		return -EINVAL;
>  	}
>  
> +	drc_index = be32_to_cpup(drc_index_be);
>  	rc = dlpar_offline_cpu(dn);
>  	if (rc) {
>  		of_node_put(dn);
>  		return -EINVAL;
>  	}
>  
> -	rc = dlpar_release_drc(*drc_index);
> +	rc = dlpar_release_drc(drc_index);
>  	if (rc) {
>  		of_node_put(dn);
>  		return rc;
> @@ -521,7 +521,7 @@ static ssize_t dlpar_cpu_release(const char *buf, size_t count)
>  
>  	rc = dlpar_detach_node(dn);
>  	if (rc) {
> -		dlpar_acquire_drc(*drc_index);
> +		dlpar_acquire_drc(drc_index);
>  		return rc;
>  	}
>  
> diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
> index 20d6297..fc9c2cd 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
> @@ -90,7 +90,7 @@ static void rtas_stop_self(void)
>  {
>  	static struct rtas_args args = {
>  		.nargs = 0,
> -		.nret = 1,
> +		.nret = cpu_to_be32(1),
>  		.rets = &args.args[0],
>  	};
>  
> @@ -247,10 +247,10 @@ static int pseries_add_processor(struct device_node *np)
>  	unsigned int cpu;
>  	cpumask_var_t candidate_mask, tmp;
>  	int err = -ENOSPC, len, nthreads, i;
> -	const u32 *intserv;
> +	const __be32 *intserv_be;
>  
> -	intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len);
> -	if (!intserv)
> +	intserv_be = of_get_property(np, "ibm,ppc-interrupt-server#s", &len);
> +	if (!intserv_be)
>  		return 0;
>  
>  	zalloc_cpumask_var(&candidate_mask, GFP_KERNEL);
> @@ -293,7 +293,7 @@ static int pseries_add_processor(struct device_node *np)
>  	for_each_cpu(cpu, tmp) {
>  		BUG_ON(cpu_present(cpu));
>  		set_cpu_present(cpu, true);
> -		set_hard_smp_processor_id(cpu, *intserv++);
> +		set_hard_smp_processor_id(cpu, be32_to_cpu(*intserv_be++));
>  	}
>  	err = 0;
>  out_unlock:
> @@ -312,10 +312,10 @@ static void pseries_remove_processor(struct device_node *np)
>  {
>  	unsigned int cpu;
>  	int len, nthreads, i;
> -	const u32 *intserv;
> +	const __be32 *intserv_be;
>  
> -	intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len);
> -	if (!intserv)
> +	intserv_be = of_get_property(np, "ibm,ppc-interrupt-server#s", &len);
> +	if (!intserv_be)
>  		return;
>  
>  	nthreads = len / sizeof(u32);
> @@ -323,7 +323,7 @@ static void pseries_remove_processor(struct device_node *np)
>  	cpu_maps_update_begin();
>  	for (i = 0; i < nthreads; i++) {
>  		for_each_present_cpu(cpu) {
> -			if (get_hard_smp_processor_id(cpu) != intserv[i])
> +			if (get_hard_smp_processor_id(cpu) != be32_to_cpu(intserv_be[i]))
>  				continue;
>  			BUG_ON(cpu_online(cpu));
>  			set_cpu_present(cpu, false);
> @@ -332,7 +332,7 @@ static void pseries_remove_processor(struct device_node *np)
>  		}
>  		if (cpu >= nr_cpu_ids)
>  			printk(KERN_WARNING "Could not find cpu to remove "
> -			       "with physical id 0x%x\n", intserv[i]);
> +			       "with physical id 0x%x\n", be32_to_cpu(intserv_be[i]));
>  	}
>  	cpu_maps_update_done();
>  }
>