Patchwork [3/3] CPU DLPAR handling

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Submitter Nathan Fontenot
Date Nov. 25, 2009, 1:53 a.m.
Message ID <4B0C8E31.9040608@austin.ibm.com>
Download mbox | patch
Permalink /patch/39271/
State Superseded
Headers show

Comments

Nathan Fontenot - Nov. 25, 2009, 1:53 a.m.
Register the pseries specific handlers for the powerpc architecture handlers
for the cpu probe and release files.  This also implements the cpu DLPAR
addition and removal of CPUS from the system.

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

arch/powerpc/platforms/pseries/dlpar.c |   88 +++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
Paul Mackerras - Nov. 25, 2009, 3:22 a.m.
Nathan Fontenot writes:

> Register the pseries specific handlers for the powerpc architecture handlers
> for the cpu probe and release files.  This also implements the cpu DLPAR
> addition and removal of CPUS from the system.

...

> +	/* configure-connector reports cpus as living in the base
> +	 * directory of the device tree.  CPUs actually live in the
> +	 * cpus directory so we need to fixup the full_name.
> +	 */
> +	cpu_name = kzalloc(strlen(dn->full_name) + strlen("/cpus/") + 1,
> +			   GFP_KERNEL);
> +	if (!cpu_name) {
> +		dlpar_free_cc_nodes(dn);
> +		return -ENOMEM;
> +	}
> +
> +	sprintf(cpu_name, "/cpus/%s", dn->full_name);

I would have expected dn->full_name to start with a '/' already, in
which case this will end up with two consecutive slashes after
'cpus'.  I think that will probably cause problems.

Paul.

Patch

Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c	2009-11-24 23:29:12.000000000 -0600
+++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-11-24 23:29:24.000000000 -0600
@@ -321,4 +321,92 @@ 
 	return 0;
 }
 
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 
+static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
+{
+	struct device_node *dn;
+	unsigned long drc_index;
+	char *cpu_name;
+	int rc;
+
+	rc = strict_strtoul(buf, 0, &drc_index);
+	if (rc)
+		return -EINVAL;
+
+	dn = dlpar_configure_connector(drc_index);
+	if (!dn)
+		return -EINVAL;
+
+	/* configure-connector reports cpus as living in the base
+	 * directory of the device tree.  CPUs actually live in the
+	 * cpus directory so we need to fixup the full_name.
+	 */
+	cpu_name = kzalloc(strlen(dn->full_name) + strlen("/cpus/") + 1,
+			   GFP_KERNEL);
+	if (!cpu_name) {
+		dlpar_free_cc_nodes(dn);
+		return -ENOMEM;
+	}
+
+	sprintf(cpu_name, "/cpus/%s", dn->full_name);
+	kfree(dn->full_name);
+	dn->full_name = cpu_name;
+
+	rc = dlpar_acquire_drc(drc_index);
+	if (rc) {
+		dlpar_free_cc_nodes(dn);
+		return -EINVAL;
+	}
+
+	rc = dlpar_attach_node(dn);
+	if (rc) {
+		dlpar_release_drc(drc_index);
+		dlpar_free_cc_nodes(dn);
+	}
+
+	return rc ? rc : count;
+}
+
+static ssize_t dlpar_cpu_release(const char *buf, size_t count)
+{
+	struct device_node *dn;
+	const 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) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+
+	rc = dlpar_release_drc(*drc_index);
+	if (rc) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+
+	rc = dlpar_detach_node(dn);
+	if (rc) {
+		dlpar_acquire_drc(*drc_index);
+		return rc;
+	}
+
+	of_node_put(dn);
+	return count;
+}
+
+static int __init pseries_dlpar_init(void)
+{
+	ppc_md.cpu_probe = dlpar_cpu_probe;
+	ppc_md.cpu_release = dlpar_cpu_release;
+
+	return 0;
+}
+machine_device_initcall(pseries, pseries_dlpar_init);
+
+#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */