LinuxPPC-Dev Archive on lore.kernel.org
 help / color / Atom feed
From: Thomas Falcon <tlfalcon@linux.ibm.com>
To: Tyrel Datwyler <tyreld@linux.ibm.com>, mpe@ellerman.id.au
Cc: nathanl@linux.ibm.com, linuxppc-dev@lists.ozlabs.org,
	Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Subject: Re: [PATCH 3/9] powerpc/pseries: Add cpu DLPAR support for drc-info property
Date: Tue, 5 Nov 2019 10:55:25 -0600
Message-ID: <d0bb5aa2-3a52-5d5b-f5bb-0a1ee90f353a@linux.ibm.com> (raw)
In-Reply-To: <1572967453-9586-4-git-send-email-tyreld@linux.ibm.com>


On 11/5/19 9:24 AM, Tyrel Datwyler wrote:
> From: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
>
> Older firmwares provided information about Dynamic Reconfig
> Connectors (DRC) through several device tree properties, namely
> ibm,drc-types, ibm,drc-indexes, ibm,drc-names, and
> ibm,drc-power-domains. New firmwares have the ability to present this
> same information in a much condensed format through a device tree
> property called ibm,drc-info.
>
> The existing cpu DLPAR hotplug code only understands the older DRC
> property format when validating the drc-index of a cpu during a
> hotplug add. This updates those code paths to use the ibm,drc-info
> property, when present, instead for validation.
>
> Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
> ---
>   arch/powerpc/platforms/pseries/hotplug-cpu.c | 101 ++++++++++++++++++++++-----
>   1 file changed, 85 insertions(+), 16 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
> index bbda646..9ba006c 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
> @@ -407,17 +407,58 @@ static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index)
>   	return found;
>   }
>
> +static bool drc_info_valid_index(struct device_node *parent, u32 drc_index)
> +{
> +	struct property *info;
> +	struct of_drc_info drc;
> +	const __be32 *value;
> +	int count, i, j;
> +
> +	info = of_find_property(parent, "ibm,drc-info", NULL);
> +	if (!info)
> +		return false;
> +
> +	value = of_prop_next_u32(info, NULL, &count);
> +
> +	/* First value of ibm,drc-info is number of drc-info records */
> +	if (value)
> +		value++;
> +	else
> +		return false;
> +
> +	for (i = 0; i < count; i++) {
> +		if (of_read_drc_info_cell(&info, &value, &drc))
> +			return false;
> +
> +		if (strncmp(drc.drc_type, "CPU", 3))
> +			break;
> +
> +		if (drc_index > drc.last_drc_index)
> +			continue;
> +
> +		for (j = 0; j < drc.num_sequential_elems; j++)
> +			if (drc_index == (drc.drc_index_start + (drc.sequential_inc * j)))
> +					return true;
> +	}
> +
> +	return false;
> +}
> +
>   static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index)
>   {
>   	bool found = false;
>   	int rc, index;
>
> -	index = 0;
> +	if (of_find_property(parent, "ibm,drc-info", NULL))
> +		return drc_info_valid_index(parent, drc_index);
> +
> +	index = 1;

Hi, this change was confusing to me until I continued reading the patch 
and saw the comment below regarding the first element of the 
ibm,drc-info property.  Would it be good to have a similar comment here too?


>   	while (!found) {
>   		u32 drc;
>
>   		rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
>   						index++, &drc);
> +

Another nitpick but this could be cleaned up.

Thanks,

Tom


>   		if (rc)
>   			break;
>
> @@ -720,8 +761,11 @@ static int dlpar_cpu_remove_by_count(u32 cpus_to_remove)
>   static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add)
>   {
>   	struct device_node *parent;
> +	struct property *info;
>   	int cpus_found = 0;
>   	int index, rc;
> +	int i, j;
> +	u32 drc_index;
>
>   	parent = of_find_node_by_path("/cpus");
>   	if (!parent) {
> @@ -730,24 +774,49 @@ static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add)
>   		return -1;
>   	}
>
> -	/* Search the ibm,drc-indexes array for possible CPU drcs to
> -	 * add. Note that the format of the ibm,drc-indexes array is
> -	 * the number of entries in the array followed by the array
> -	 * of drc values so we start looking at index = 1.
> -	 */
> -	index = 1;
> -	while (cpus_found < cpus_to_add) {
> -		u32 drc;
> +	info = of_find_property(parent, "ibm,drc-info", NULL);
> +	if (info) {
> +		struct of_drc_info drc;
> +		const __be32 *value;
> +		int count;
>
> -		rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
> -						index++, &drc);
> -		if (rc)
> -			break;
> +		value = of_prop_next_u32(info, NULL, &count);
> +		if (value)
> +			value++;
>
> -		if (dlpar_cpu_exists(parent, drc))
> -			continue;
> +		for (i = 0; i < count; i++) {
> +			of_read_drc_info_cell(&info, &value, &drc);
> +			if (strncmp(drc.drc_type, "CPU", 3))
> +				break;
> +
> +			for (j = 0; j < drc.num_sequential_elems && cpus_found < cpus_to_add; j++) {
> +				drc_index = drc.drc_index_start + (drc.sequential_inc * j);
> +
> +				if (dlpar_cpu_exists(parent, drc_index))
> +					continue;
> +
> +				cpu_drcs[cpus_found++] = drc_index;
> +			}
> +		}
> +	} else {
> +		/* Search the ibm,drc-indexes array for possible CPU drcs to
> +		 * add. Note that the format of the ibm,drc-indexes array is
> +		 * the number of entries in the array followed by the array
> +		 * of drc values so we start looking at index = 1.
> +		 */
> +		index = 1;
> +		while (cpus_found < cpus_to_add) {
> +			rc = of_property_read_u32_index(parent, "ibm,drc-indexes",
> +							index++, &drc_index);
> +
> +			if (rc)
> +				break;
>
> -		cpu_drcs[cpus_found++] = drc;
> +			if (dlpar_cpu_exists(parent, drc_index))
> +				continue;
> +
> +			cpu_drcs[cpus_found++] = drc_index;
> +		}
>   	}
>
>   	of_node_put(parent);

  reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-05 15:24 [PATCH 0/9] Fixes and Enablement of ibm,drc-info property Tyrel Datwyler
2019-11-05 15:24 ` [PATCH 1/9] powerpc/pseries: Fix bad drc_index_start value parsing of drc-info entry Tyrel Datwyler
2019-11-05 15:24 ` [PATCH 2/9] powerpc/pseries: Fix drc-info mappings of logical cpus to drc-index Tyrel Datwyler
2019-11-05 15:24 ` [PATCH 3/9] powerpc/pseries: Add cpu DLPAR support for drc-info property Tyrel Datwyler
2019-11-05 16:55   ` Thomas Falcon [this message]
2019-11-06 20:15     ` Tyrel Datwyler
2019-11-07 11:35   ` Michael Ellerman
2019-11-05 15:24 ` [PATCH 4/9] PCI: rpaphp: Fix up pointer to first drc-info entry Tyrel Datwyler
2019-11-05 15:24 ` [PATCH 5/9] PCI: rpaphp: Don't rely on firmware feature to imply drc-info support Tyrel Datwyler
2019-11-05 15:24 ` [PATCH 6/9] PCI: rpaphp: Add drc-info support for hotplug slot registration Tyrel Datwyler
2019-11-05 15:24 ` [PATCH 7/9] PCI: rpaphp: annotate and correctly byte swap DRC properties Tyrel Datwyler
2019-11-07 11:40   ` Michael Ellerman
2019-11-05 15:24 ` [PATCH 8/9] PCI: rpaphp: Correctly match ibm, my-drc-index to drc-name when using drc-info Tyrel Datwyler
2019-11-05 15:24 ` [PATCH 9/9] powerpc/pseries: Enable support for ibm, drc-info property Tyrel Datwyler
2019-11-07 11:38   ` Michael Ellerman
2019-11-05 17:03 ` [PATCH 0/9] Fixes and Enablement of ibm,drc-info property Thomas Falcon
2019-11-06 20:12   ` Tyrel Datwyler
2019-11-07 11:26     ` Michael Ellerman

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=d0bb5aa2-3a52-5d5b-f5bb-0a1ee90f353a@linux.ibm.com \
    --to=tlfalcon@linux.ibm.com \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mpe@ellerman.id.au \
    --cc=nathanl@linux.ibm.com \
    --cc=tyreld@linux.ibm.com \
    --cc=tyreld@linux.vnet.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LinuxPPC-Dev Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linuxppc-dev/0 linuxppc-dev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linuxppc-dev linuxppc-dev/ https://lore.kernel.org/linuxppc-dev \
		linuxppc-dev@lists.ozlabs.org linuxppc-dev@ozlabs.org
	public-inbox-index linuxppc-dev

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.ozlabs.lists.linuxppc-dev


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git