From: Arnd Bergmann Date: Wed, 4 Oct 2006 15:26:21 +0000 (+0200) Subject: [POWERPC] spufs: add infrastructure for finding elf objects X-Git-Tag: v2.6.19-rc1~3^2~3 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=867672777964b9309e4e914fe097648c938b67b2;p=linux-2.6 [POWERPC] spufs: add infrastructure for finding elf objects This adds an 'object-id' file that the spe library can use to store a pointer to its ELF object. This was originally meant for use by oprofile, but is now also used by the GNU debugger, if available. In order for oprofile to find the location in an spu-elf binary where an event counter triggered, we need a way to identify the binary in the first place. Unfortunately, that binary itself can be embedded in a powerpc ELF binary. Since we can assume it is mapped into the effective address space of the running process, have that one write the pointer value into a new spufs file. When a context switch occurs, pass the user value to the profiler so that can look at the mapped file (with some care). Signed-off-by: Arnd Bergmann Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c index e2c9d48a68..e0d7300452 100644 --- a/arch/powerpc/platforms/cell/spufs/file.c +++ b/arch/powerpc/platforms/cell/spufs/file.c @@ -1487,6 +1487,21 @@ static u64 spufs_id_get(void *data) } DEFINE_SIMPLE_ATTRIBUTE(spufs_id_ops, spufs_id_get, NULL, "0x%llx\n") +static u64 spufs_object_id_get(void *data) +{ + struct spu_context *ctx = data; + return ctx->object_id; +} + +static void spufs_object_id_set(void *data, u64 id) +{ + struct spu_context *ctx = data; + ctx->object_id = id; +} + +DEFINE_SIMPLE_ATTRIBUTE(spufs_object_id_ops, spufs_object_id_get, + spufs_object_id_set, "0x%llx\n"); + struct tree_descr spufs_dir_contents[] = { { "mem", &spufs_mem_fops, 0666, }, { "regs", &spufs_regs_fops, 0666, }, @@ -1510,7 +1525,8 @@ struct tree_descr spufs_dir_contents[] = { { "spu_tag_mask", &spufs_spu_tag_mask_ops, 0666, }, { "event_mask", &spufs_event_mask_ops, 0666, }, { "srr0", &spufs_srr0_ops, 0666, }, - { "phys-id", &spufs_id_ops, 0666, }, { "psmap", &spufs_psmap_fops, 0666, }, + { "phys-id", &spufs_id_ops, 0666, }, + { "object-id", &spufs_object_id_ops, 0666, }, {}, }; diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c index a824b60511..bd6fe4b7a8 100644 --- a/arch/powerpc/platforms/cell/spufs/sched.c +++ b/arch/powerpc/platforms/cell/spufs/sched.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include @@ -75,6 +76,25 @@ static inline void mm_needs_global_tlbie(struct mm_struct *mm) __cpus_setall(&mm->cpu_vm_mask, nr); } +static BLOCKING_NOTIFIER_HEAD(spu_switch_notifier); + +static void spu_switch_notify(struct spu *spu, struct spu_context *ctx) +{ + blocking_notifier_call_chain(&spu_switch_notifier, + ctx ? ctx->object_id : 0, spu); +} + +int spu_switch_event_register(struct notifier_block * n) +{ + return blocking_notifier_chain_register(&spu_switch_notifier, n); +} + +int spu_switch_event_unregister(struct notifier_block * n) +{ + return blocking_notifier_chain_unregister(&spu_switch_notifier, n); +} + + static inline void bind_context(struct spu *spu, struct spu_context *ctx) { pr_debug("%s: pid=%d SPU=%d NODE=%d\n", __FUNCTION__, current->pid, @@ -97,12 +117,14 @@ static inline void bind_context(struct spu *spu, struct spu_context *ctx) spu_restore(&ctx->csa, spu); spu->timestamp = jiffies; spu_cpu_affinity_set(spu, raw_smp_processor_id()); + spu_switch_notify(spu, ctx); } static inline void unbind_context(struct spu *spu, struct spu_context *ctx) { pr_debug("%s: unbind pid=%d SPU=%d NODE=%d\n", __FUNCTION__, spu->pid, spu->number, spu->node); + spu_switch_notify(spu, NULL); spu_unmap_mappings(ctx); spu_save(&ctx->csa, spu); spu->timestamp = jiffies; diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h index f6624ceedf..a0f55ca2d4 100644 --- a/arch/powerpc/platforms/cell/spufs/spufs.h +++ b/arch/powerpc/platforms/cell/spufs/spufs.h @@ -50,6 +50,7 @@ struct spu_context { struct address_space *cntl; /* 'control' area mappings. */ struct address_space *signal1; /* 'signal1' area mappings. */ struct address_space *signal2; /* 'signal2' area mappings. */ + u64 object_id; /* user space pointer for oprofile */ enum { SPU_STATE_RUNNABLE, SPU_STATE_SAVED } state; struct rw_semaphore state_sema; diff --git a/include/asm-powerpc/spu.h b/include/asm-powerpc/spu.h index 83b6dae48e..e73ea00efd 100644 --- a/include/asm-powerpc/spu.h +++ b/include/asm-powerpc/spu.h @@ -200,6 +200,24 @@ static inline void unregister_spu_syscalls(struct spufs_calls *calls) #endif /* MODULE */ +/* + * Notifier blocks: + * + * oprofile can get notified when a context switch is performed + * on an spe. The notifer function that gets called is passed + * a pointer to the SPU structure as well as the object-id that + * identifies the binary running on that SPU now. + * + * For a context save, the object-id that is passed is zero, + * identifying that the kernel will run from that moment on. + * + * For a context restore, the object-id is the value written + * to object-id spufs file from user space and the notifer + * function can assume that spu->ctx is valid. + */ +int spu_switch_event_register(struct notifier_block * n); +int spu_switch_event_unregister(struct notifier_block * n); + /* * This defines the Local Store, Problem Area and Privlege Area of an SPU. */