Commit 9120dec4 authored by Jack Steiner's avatar Jack Steiner Committed by Linus Torvalds
Browse files

gru: support for asynchronous gru instructions



Add support for asynchronous GRU instructions.  Currently, asynchronous
instructions are supported only for GRU instructions issued by the kernel.

[akpm@linux-foundation.org: build fix]
Signed-off-by: default avatarJack Steiner <steiner@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4a7a17c1
......@@ -468,10 +468,6 @@ irqreturn_t gru_intr(int irq, void *dev_id)
return IRQ_NONE;
}
get_clear_fault_map(gru, &imap, &dmap);
gru_dbg(grudev,
"irq %d, gid %d, imap %016lx %016lx, dmap %016lx %016lx\n",
irq, gru->gs_gid, dmap.fault_bits[0], dmap.fault_bits[1],
dmap.fault_bits[0], dmap.fault_bits[1]);
for_each_cbr_in_tfm(cbrnum, dmap.fault_bits) {
complete(gru->gs_blade->bs_async_wq);
......
......@@ -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 / \
......@@ -98,20 +144,6 @@ 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)
......
......@@ -146,4 +146,55 @@ extern void *gru_get_next_message(struct gru_message_queue_desc *mqd);
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_ */
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