Jan Beulich
2011-Dec-06 13:17 UTC
[PATCH linux-2.6.18/ACPI: eliminate restriction on ACPI processor ID range
Rather than storing the reference acpi_device pointers in an ACPI-ID-
indexed array (and having a bogus BUG_ON() check on a platform provided
value), use a radix tree instead.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -513,7 +513,14 @@ static int acpi_processor_get_info(struc
return 0;
}
-static void *processor_device_array[NR_ACPI_CPUS];
+#ifndef CONFIG_XEN
+static void *processor_device_array[NR_CPUS];
+#else
+#include <linux/mutex.h>
+#include <linux/radix-tree.h>
+static DEFINE_MUTEX(processor_device_mutex);
+static RADIX_TREE(processor_device_tree, GFP_KERNEL);
+#endif
static int acpi_processor_start(struct acpi_device *device)
{
@@ -541,9 +548,20 @@ static int __cpuinit acpi_processor_add(
* Don''t trust it blindly
*/
#ifdef CONFIG_XEN
- BUG_ON(pr->acpi_id >= NR_ACPI_CPUS);
- if (processor_device_array[pr->acpi_id] != NULL &&
- processor_device_array[pr->acpi_id] != (void *)device) {
+ mutex_lock(&processor_device_mutex);
+ result = radix_tree_insert(&processor_device_tree,
+ pr->acpi_id, device);
+ switch (result) {
+ default:
+ goto end_unlock;
+ case -EEXIST:
+ if (radix_tree_lookup(&processor_device_tree,
+ pr->acpi_id) == device) {
+ case 0:
+ mutex_unlock(&processor_device_mutex);
+ break;
+ }
+ mutex_unlock(&processor_device_mutex);
#else
if (processor_device_array[pr->id] != NULL &&
processor_device_array[pr->id] != (void *)device) {
@@ -553,14 +571,11 @@ static int __cpuinit acpi_processor_add(
return -ENODEV;
}
#ifdef CONFIG_XEN
- processor_device_array[pr->acpi_id] = (void *)device;
if (pr->id != -1)
- processors[pr->id] = pr;
#else
processor_device_array[pr->id] = (void *)device;
-
- processors[pr->id] = pr;
#endif /* CONFIG_XEN */
+ processors[pr->id] = pr;
result = acpi_processor_add_fs(device);
if (result)
@@ -602,6 +617,14 @@ err_thermal_unregister:
}
end:
+#ifdef CONFIG_XEN
+ mutex_lock(&processor_device_mutex);
+ if (radix_tree_lookup(&processor_device_tree,
+ pr->acpi_id) == device)
+ radix_tree_delete(&processor_device_tree, pr->acpi_id);
+ end_unlock:
+ mutex_unlock(&processor_device_mutex);
+#endif
return result;
}
@@ -692,10 +715,8 @@ static int acpi_processor_remove(struct
#ifdef CONFIG_XEN
if (pr->id != -1)
- processors[pr->id] = NULL;
-#else
+#endif
processors[pr->id] = NULL;
-#endif /* CONFIG_XEN */
kfree(pr);
@@ -992,6 +1013,30 @@ static void __exit acpi_processor_exit(v
remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
+#ifdef CONFIG_XEN
+ {
+ struct acpi_device *dev;
+ unsigned int idx = 0;
+
+ while (radix_tree_gang_lookup(&processor_device_tree,
+ (void **)&dev, idx, 1)) {
+ struct acpi_processor *pr = acpi_driver_data(dev);
+
+ /* prevent live lock */
+ if (pr->acpi_id < idx) {
+ printk(KERN_WARNING PREFIX "ID %u unexpected"
+ " (less than %u); leaking memory\n",
+ pr->acpi_id, idx);
+ break;
+ }
+ idx = pr->acpi_id;
+ radix_tree_delete(&processor_device_tree, idx);
+ if (!++idx)
+ break;
+ }
+ }
+#endif
+
return;
}
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -24,12 +24,6 @@
#define ACPI_TSD_REV0_REVISION 0 /* Support for _PSD as in ACPI 3.0 */
#define ACPI_TSD_REV0_ENTRIES 5
-#ifdef CONFIG_XEN
-#define NR_ACPI_CPUS (NR_CPUS < 256 ? 256 : NR_CPUS)
-#else
-#define NR_ACPI_CPUS NR_CPUS
-#endif /* CONFIG_XEN */
-
/*
* Types of coordination defined in ACPI 3.0. Same macros can be used across
* P, C and T states
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Keir Fraser
2011-Dec-06 15:19 UTC
Re: [PATCH linux-2.6.18/ACPI: eliminate restriction on ACPI processor ID range
On 06/12/2011 13:17, "Jan Beulich" <JBeulich@suse.com> wrote:> Rather than storing the reference acpi_device pointers in an ACPI-ID- > indexed array (and having a bogus BUG_ON() check on a platform provided > value), use a radix tree instead. > > Signed-off-by: Jan Beulich <jbeulich@suse.com>Acked-by: Keir Fraser <keir@xen.org>> --- a/drivers/acpi/processor_core.c > +++ b/drivers/acpi/processor_core.c > @@ -513,7 +513,14 @@ static int acpi_processor_get_info(struc > return 0; > } > > -static void *processor_device_array[NR_ACPI_CPUS]; > +#ifndef CONFIG_XEN > +static void *processor_device_array[NR_CPUS]; > +#else > +#include <linux/mutex.h> > +#include <linux/radix-tree.h> > +static DEFINE_MUTEX(processor_device_mutex); > +static RADIX_TREE(processor_device_tree, GFP_KERNEL); > +#endif > > static int acpi_processor_start(struct acpi_device *device) > { > @@ -541,9 +548,20 @@ static int __cpuinit acpi_processor_add( > * Don''t trust it blindly > */ > #ifdef CONFIG_XEN > - BUG_ON(pr->acpi_id >= NR_ACPI_CPUS); > - if (processor_device_array[pr->acpi_id] != NULL && > - processor_device_array[pr->acpi_id] != (void *)device) { > + mutex_lock(&processor_device_mutex); > + result = radix_tree_insert(&processor_device_tree, > + pr->acpi_id, device); > + switch (result) { > + default: > + goto end_unlock; > + case -EEXIST: > + if (radix_tree_lookup(&processor_device_tree, > + pr->acpi_id) == device) { > + case 0: > + mutex_unlock(&processor_device_mutex); > + break; > + } > + mutex_unlock(&processor_device_mutex); > #else > if (processor_device_array[pr->id] != NULL && > processor_device_array[pr->id] != (void *)device) { > @@ -553,14 +571,11 @@ static int __cpuinit acpi_processor_add( > return -ENODEV; > } > #ifdef CONFIG_XEN > - processor_device_array[pr->acpi_id] = (void *)device; > if (pr->id != -1) > - processors[pr->id] = pr; > #else > processor_device_array[pr->id] = (void *)device; > - > - processors[pr->id] = pr; > #endif /* CONFIG_XEN */ > + processors[pr->id] = pr; > > result = acpi_processor_add_fs(device); > if (result) > @@ -602,6 +617,14 @@ err_thermal_unregister: > } > > end: > +#ifdef CONFIG_XEN > + mutex_lock(&processor_device_mutex); > + if (radix_tree_lookup(&processor_device_tree, > + pr->acpi_id) == device) > + radix_tree_delete(&processor_device_tree, pr->acpi_id); > + end_unlock: > + mutex_unlock(&processor_device_mutex); > +#endif > > return result; > } > @@ -692,10 +715,8 @@ static int acpi_processor_remove(struct > > #ifdef CONFIG_XEN > if (pr->id != -1) > - processors[pr->id] = NULL; > -#else > +#endif > processors[pr->id] = NULL; > -#endif /* CONFIG_XEN */ > > > kfree(pr); > @@ -992,6 +1013,30 @@ static void __exit acpi_processor_exit(v > > remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir); > > +#ifdef CONFIG_XEN > + { > + struct acpi_device *dev; > + unsigned int idx = 0; > + > + while (radix_tree_gang_lookup(&processor_device_tree, > + (void **)&dev, idx, 1)) { > + struct acpi_processor *pr = acpi_driver_data(dev); > + > + /* prevent live lock */ > + if (pr->acpi_id < idx) { > + printk(KERN_WARNING PREFIX "ID %u unexpected" > + " (less than %u); leaking memory\n", > + pr->acpi_id, idx); > + break; > + } > + idx = pr->acpi_id; > + radix_tree_delete(&processor_device_tree, idx); > + if (!++idx) > + break; > + } > + } > +#endif > + > return; > } > > --- a/include/acpi/processor.h > +++ b/include/acpi/processor.h > @@ -24,12 +24,6 @@ > #define ACPI_TSD_REV0_REVISION 0 /* Support for _PSD as in ACPI 3.0 */ > #define ACPI_TSD_REV0_ENTRIES 5 > > -#ifdef CONFIG_XEN > -#define NR_ACPI_CPUS (NR_CPUS < 256 ? 256 : NR_CPUS) > -#else > -#define NR_ACPI_CPUS NR_CPUS > -#endif /* CONFIG_XEN */ > - > /* > * Types of coordination defined in ACPI 3.0. Same macros can be used across > * P, C and T states > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel