arch/powerpc/platforms/cell/spufs/gang.c
Source file repositories/reference/linux-study-clean/arch/powerpc/platforms/cell/spufs/gang.c
File Facts
- System
- Linux kernel
- Corpus path
arch/powerpc/platforms/cell/spufs/gang.c- Extension
.c- Size
- 1515 bytes
- Lines
- 76
- Domain
- Architecture Layer
- Bucket
- arch/powerpc
- Inferred role
- Architecture Layer: implementation source
- Status
- source implementation candidate
Why This File Exists
CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
- CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/list.hlinux/slab.hspufs.h
Detected Declarations
function destroy_spu_gangfunction put_spu_gangfunction spu_gang_add_ctxfunction spu_gang_remove_ctx
Annotated Snippet
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* SPU file system
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
*
* Author: Arnd Bergmann <arndb@de.ibm.com>
*/
#include <linux/list.h>
#include <linux/slab.h>
#include "spufs.h"
struct spu_gang *alloc_spu_gang(void)
{
struct spu_gang *gang;
gang = kzalloc_obj(*gang);
if (!gang)
goto out;
kref_init(&gang->kref);
mutex_init(&gang->mutex);
mutex_init(&gang->aff_mutex);
INIT_LIST_HEAD(&gang->list);
INIT_LIST_HEAD(&gang->aff_list_head);
gang->alive = 1;
out:
return gang;
}
static void destroy_spu_gang(struct kref *kref)
{
struct spu_gang *gang;
gang = container_of(kref, struct spu_gang, kref);
WARN_ON(gang->contexts || !list_empty(&gang->list));
kfree(gang);
}
struct spu_gang *get_spu_gang(struct spu_gang *gang)
{
kref_get(&gang->kref);
return gang;
}
int put_spu_gang(struct spu_gang *gang)
{
return kref_put(&gang->kref, &destroy_spu_gang);
}
void spu_gang_add_ctx(struct spu_gang *gang, struct spu_context *ctx)
{
mutex_lock(&gang->mutex);
ctx->gang = get_spu_gang(gang);
list_add(&ctx->gang_list, &gang->list);
gang->contexts++;
mutex_unlock(&gang->mutex);
}
void spu_gang_remove_ctx(struct spu_gang *gang, struct spu_context *ctx)
{
mutex_lock(&gang->mutex);
WARN_ON(ctx->gang != gang);
if (!list_empty(&ctx->aff_list)) {
list_del_init(&ctx->aff_list);
gang->aff_flags &= ~AFF_OFFSETS_SET;
}
list_del_init(&ctx->gang_list);
gang->contexts--;
mutex_unlock(&gang->mutex);
put_spu_gang(gang);
}
Annotation
- Immediate include surface: `linux/list.h`, `linux/slab.h`, `spufs.h`.
- Detected declarations: `function destroy_spu_gang`, `function put_spu_gang`, `function spu_gang_add_ctx`, `function spu_gang_remove_ctx`.
- Atlas domain: Architecture Layer / arch/powerpc.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.