diff options
Diffstat (limited to 'drivers/misc/sgi-gru/grukservices.c')
| -rw-r--r-- | drivers/misc/sgi-gru/grukservices.c | 178 |
1 files changed, 162 insertions, 16 deletions
diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c index a0f981022a6..9dff33cb72e 100644 --- a/drivers/misc/sgi-gru/grukservices.c +++ b/drivers/misc/sgi-gru/grukservices.c @@ -52,7 +52,53 @@ * loaded on demand & can be stolen by a user if the user demand exceeds the * kernel demand. The kernel can always reload the kernel context but * a SLEEP may be required!!!. + * + * Async Overview: + * + * Each blade has one "kernel context" that owns GRU kernel resources + * located on the blade. Kernel drivers use GRU resources in this context + * for sending messages, zeroing memory, etc. + * + * The kernel context is dynamically loaded on demand. If it is not in + * use by the kernel, the kernel context can be unloaded & given to a user. + * The kernel context will be reloaded when needed. This may require that + * a context be stolen from a user. + * NOTE: frequent unloading/reloading of the kernel context is + * expensive. We are depending on batch schedulers, cpusets, sane + * drivers or some other mechanism to prevent the need for frequent + * stealing/reloading. + * + * The kernel context consists of two parts: + * - 1 CB & a few DSRs that are reserved for each cpu on the blade. + * Each cpu has it's own private resources & does not share them + * with other cpus. These resources are used serially, ie, + * locked, used & unlocked on each call to a function in + * grukservices. + * (Now that we have dynamic loading of kernel contexts, I + * may rethink this & allow sharing between cpus....) + * + * - Additional resources can be reserved long term & used directly + * by UV drivers located in the kernel. Drivers using these GRU + * resources can use asynchronous GRU instructions that send + * interrupts on completion. + * - these resources must be explicitly locked/unlocked + * - locked resources prevent (obviously) the kernel + * context from being unloaded. + * - drivers using these resource directly issue their own + * GRU instruction and must wait/check completion. + * + * When these resources are reserved, the caller can optionally + * associate a wait_queue with the resources and use asynchronous + * GRU instructions. When an async GRU instruction completes, the + * driver will do a wakeup on the event. + * */ + + +#define ASYNC_HAN_TO_BID(h) ((h) - 1) +#define ASYNC_BID_TO_HAN(b) ((b) + 1) +#define ASYNC_HAN_TO_BS(h) gru_base[ASYNC_HAN_TO_BID(h)] + #define GRU_NUM_KERNEL_CBR 1 #define GRU_NUM_KERNEL_DSR_BYTES 256 #define GRU_NUM_KERNEL_DSR_CL (GRU_NUM_KERNEL_DSR_BYTES / \ @@ -99,20 +145,6 @@ struct message_header { #define HSTATUS(mq, h) ((mq) + offsetof(struct message_queue, hstatus[h])) /* - * Allocate a kernel context (GTS) for the specified blade. - * - protected by writelock on bs_kgts_sema. - */ -static void gru_alloc_kernel_context(struct gru_blade_state *bs, int blade_id) -{ - int cbr_au_count, dsr_au_count, ncpus; - - ncpus = uv_blade_nr_possible_cpus(blade_id); - cbr_au_count = GRU_CB_COUNT_TO_AU(GRU_NUM_KERNEL_CBR * ncpus); - dsr_au_count = GRU_DS_BYTES_TO_AU(GRU_NUM_KERNEL_DSR_BYTES * ncpus); - bs->bs_kgts = gru_alloc_gts(NULL, cbr_au_count, dsr_au_count, 0, 0); -} - -/* * Reload the blade's kernel context into a GRU chiplet. Called holding * the bs_kgts_sema for READ. Will steal user contexts if necessary. */ @@ -121,17 +153,23 @@ static void gru_load_kernel_context(struct gru_blade_state *bs, int blade_id) struct gru_state *gru; struct gru_thread_state *kgts; void *vaddr; - int ctxnum; + int ctxnum, ncpus; up_read(&bs->bs_kgts_sema); down_write(&bs->bs_kgts_sema); if (!bs->bs_kgts) - gru_alloc_kernel_context(bs, blade_id); + bs->bs_kgts = gru_alloc_gts(NULL, 0, 0, 0, 0); kgts = bs->bs_kgts; if (!kgts->ts_gru) { STAT(load_kernel_context); + ncpus = uv_blade_nr_possible_cpus(blade_id); + kgts->ts_cbr_au_count = GRU_CB_COUNT_TO_AU( + GRU_NUM_KERNEL_CBR * ncpus + bs->bs_async_cbrs); + kgts->ts_dsr_au_count = GRU_DS_BYTES_TO_AU( + GRU_NUM_KERNEL_DSR_BYTES * ncpus + + bs->bs_async_dsr_bytes); while (!gru_assign_gru_context(kgts, blade_id)) { msleep(1); gru_steal_context(kgts, blade_id); @@ -203,6 +241,114 @@ static void gru_free_cpu_resources(void *cb, void *dsr) preempt_enable(); } +/* + * Reserve GRU resources to be used asynchronously. + * Note: currently supports only 1 reservation per blade. + * + * input: + * blade_id - blade on which resources should be reserved + * cbrs - number of CBRs + * dsr_bytes - number of DSR bytes needed + * output: + * handle to identify resource + * (0 = async resources already reserved) + */ +unsigned long gru_reserve_async_resources(int blade_id, int cbrs, int dsr_bytes, + struct completion *cmp) +{ + struct gru_blade_state *bs; + struct gru_thread_state *kgts; + int ret = 0; + + bs = gru_base[blade_id]; + + down_write(&bs->bs_kgts_sema); + + /* Verify no resources already reserved */ + if (bs->bs_async_dsr_bytes + bs->bs_async_cbrs) + goto done; + bs->bs_async_dsr_bytes = dsr_bytes; + bs->bs_async_cbrs = cbrs; + bs->bs_async_wq = cmp; + kgts = bs->bs_kgts; + + /* Resources changed. Unload context if already loaded */ + if (kgts && kgts->ts_gru) + gru_unload_context(kgts, 0); + ret = ASYNC_BID_TO_HAN(blade_id); + +done: + up_write(&bs->bs_kgts_sema); + return ret; +} + +/* + * Release async resources previously reserved. + * + * input: + * han - handle to identify resources + */ +void gru_release_async_resources(unsigned long han) +{ + struct gru_blade_state *bs = ASYNC_HAN_TO_BS(han); + + down_write(&bs->bs_kgts_sema); + bs->bs_async_dsr_bytes = 0; + bs->bs_async_cbrs = 0; + bs->bs_async_wq = NULL; + up_write(&bs->bs_kgts_sema); +} + +/* + * Wait for async GRU instructions to complete. + * + * input: + * han - handle to identify resources + */ +void gru_wait_async_cbr(unsigned long han) +{ + struct gru_blade_state *bs = ASYNC_HAN_TO_BS(han); + + wait_for_completion(bs->bs_async_wq); + mb(); +} + +/* + * Lock previous reserved async GRU resources + * + * input: + * han - handle to identify resources + * output: + * cb - pointer to first CBR + * dsr - pointer to first DSR + */ +void gru_lock_async_resource(unsigned long han, void **cb, void **dsr) +{ + struct gru_blade_state *bs = ASYNC_HAN_TO_BS(han); + int blade_id = ASYNC_HAN_TO_BID(han); + int ncpus; + + gru_lock_kernel_context(blade_id); + ncpus = uv_blade_nr_possible_cpus(blade_id); + if (cb) + *cb = bs->kernel_cb + ncpus * GRU_HANDLE_STRIDE; + if (dsr) + *dsr = bs->kernel_dsr + ncpus * GRU_NUM_KERNEL_DSR_BYTES; +} + +/* + * Unlock previous reserved async GRU resources + * + * input: + * han - handle to identify resources + */ +void gru_unlock_async_resource(unsigned long han) +{ + int blade_id = ASYNC_HAN_TO_BID(han); + + gru_unlock_kernel_context(blade_id); +} + /*----------------------------------------------------------------------*/ int gru_get_cb_exception_detail(void *cb, struct control_block_extended_exc_detail *excdet) |