* 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 / \
#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.
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);
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)
extern int gru_copy_gpa(unsigned long dest_gpa, unsigned long src_gpa,
unsigned int bytes);
+/*
+ * Reserve GRU resources to be used asynchronously.
+ *
+ * input:
+ * blade_id - blade on which resources should be reserved
+ * cbrs - number of CBRs
+ * dsr_bytes - number of DSR bytes needed
+ * cmp - completion structure for waiting for
+ * async completions
+ * output:
+ * handle to identify resource
+ * (0 = no resources)
+ */
+extern unsigned long gru_reserve_async_resources(int blade_id, int cbrs, int dsr_bytes,
+ struct completion *cmp);
+
+/*
+ * Release async resources previously reserved.
+ *
+ * input:
+ * han - handle to identify resources
+ */
+extern void gru_release_async_resources(unsigned long han);
+
+/*
+ * Wait for async GRU instructions to complete.
+ *
+ * input:
+ * han - handle to identify resources
+ */
+extern void gru_wait_async_cbr(unsigned long han);
+
+/*
+ * Lock previous reserved async GRU resources
+ *
+ * input:
+ * han - handle to identify resources
+ * output:
+ * cb - pointer to first CBR
+ * dsr - pointer to first DSR
+ */
+extern void gru_lock_async_resource(unsigned long han, void **cb, void **dsr);
+
+/*
+ * Unlock previous reserved async GRU resources
+ *
+ * input:
+ * han - handle to identify resources
+ */
+extern void gru_unlock_async_resource(unsigned long han);
+
#endif /* __GRU_KSERVICES_H_ */
git.openpandora.org / pandora-kernel.git / commitdiff