[Patch 19/29] GRU - preload tlb for bcopy instructions

steiner
2009-11-24T15:11:20Z

[-- Attachment #1: uv_gru_preload_tlb --]
[-- Type: text/plain, Size: 15286 bytes --]

From: Jack Steiner <steiner@sgi.com>

Add anticipatory TLB dropins for GRU TLB misses that occur on
BCOPY instructions that copy large amounts of data.

Signed-off-by: Jack Steiner <steiner@sgi.com>

---
drivers/misc/sgi-gru/grufault.c | 89 ++++++++++++++++++++++++++++++++++--
drivers/misc/sgi-gru/grufile.c | 1
drivers/misc/sgi-gru/gruhandles.c | 11 ++--
drivers/misc/sgi-gru/gruhandles.h | 20 +++++++-
drivers/misc/sgi-gru/grukservices.c | 2
drivers/misc/sgi-gru/grulib.h | 1
drivers/misc/sgi-gru/grumain.c | 8 ++-
drivers/misc/sgi-gru/gruprocfs.c | 4 +
drivers/misc/sgi-gru/grutables.h | 9 ++-
9 files changed, 129 insertions(+), 16 deletions(-)

Index: linux/drivers/misc/sgi-gru/grufault.c
===================================================================
--- linux.orig/drivers/misc/sgi-gru/grufault.c 2009-11-20 10:27:17.000000000 -0600
+++ linux/drivers/misc/sgi-gru/grufault.c 2009-11-20 10:37:51.000000000 -0600
@@ -290,6 +290,61 @@ upm:

/*
+ * Flush a CBE from cache. The CBE is clean in the cache. Dirty the
+ * CBE cacheline so that the line will be written back to home agent.
+ * Otherwise the line may be silently dropped. This has no impact
+ * except on performance.
+ */
+static void gru_flush_cache_cbe(struct gru_control_block_extended *cbe)
+{
+ if (unlikely(cbe)) {
+ cbe->cbrexecstatus = 0; /* make CL dirty */
+ gru_flush_cache(cbe);
+ }
+}
+
+/*
+ * Preload the TLB with entries that may be required. Currently, preloading
+ * is implemented only for BCOPY. Preload <tlb_preload_count> pages OR to
+ * the end of the bcopy tranfer, whichever is smaller.
+ */
+static void gru_preload_tlb(struct gru_state *gru,
+ struct gru_thread_state *gts, int atomic,
+ unsigned long fault_vaddr, int asid, int write,
+ unsigned char tlb_preload_count,
+ struct gru_tlb_fault_handle *tfh,
+ struct gru_control_block_extended *cbe)
+{
+ unsigned long vaddr = 0, gpa;
+ int ret, pageshift;
+
+ if (cbe->opccpy != OP_BCOPY)
+ return;
+
+ if (fault_vaddr == cbe->cbe_baddr0)
+ vaddr = fault_vaddr + GRU_CACHE_LINE_BYTES * cbe->cbe_src_cl - 1;
+ else if (fault_vaddr == cbe->cbe_baddr1)
+ vaddr = fault_vaddr + (1 << cbe->xtypecpy) * cbe->cbe_nelemcur - 1;
+
+ fault_vaddr &= PAGE_MASK;
+ vaddr &= PAGE_MASK;
+ vaddr = min(vaddr, fault_vaddr + tlb_preload_count * PAGE_SIZE);
+
+ while (vaddr > fault_vaddr) {
+ ret = gru_vtop(gts, vaddr, write, atomic, &gpa, &pageshift);
+ if (ret || tfh_write_only(tfh, gpa, GAA_RAM, vaddr, asid, write,
+ GRU_PAGESIZE(pageshift)))
+ return;
+ gru_dbg(grudev,
+ "%s: gid %d, gts 0x%p, tfh 0x%p, vaddr 0x%lx, asid 0x%x, rw %d, ps %d, gpa 0x%lx\n",
+ atomic ? "atomic" : "non-atomic", gru->gs_gid, gts, tfh,
+ vaddr, asid, write, pageshift, gpa);
+ vaddr -= PAGE_SIZE;
+ STAT(tlb_preload_page);
+ }
+}
+
+/*
* Drop a TLB entry into the GRU. The fault is described by info in an TFH.
* Input:
* cb Address of user CBR. Null if not running in user context
@@ -303,6 +358,8 @@ static int gru_try_dropin(struct gru_thr
struct gru_tlb_fault_handle *tfh,
struct gru_instruction_bits *cbk)
{
+ struct gru_control_block_extended *cbe = NULL;
+ unsigned char tlb_preload_count = gts->ts_tlb_preload_count;
int pageshift = 0, asid, write, ret, atomic = !cbk, indexway;
unsigned long gpa = 0, vaddr = 0;

@@ -314,6 +371,14 @@ static int gru_try_dropin(struct gru_thr
*/

/*
+ * Prefetch the CBE if doing TLB preloading
+ */
+ if (unlikely(tlb_preload_count)) {
+ cbe = gru_tfh_to_cbe(tfh);
+ prefetchw(cbe);
+ }
+
+ /*
* Error if TFH state is IDLE or FMM mode & the user issuing a UPM call.
* Might be a hardware race OR a stupid user. Ignore FMM because FMM
* is a transient state.
@@ -359,6 +424,12 @@ static int gru_try_dropin(struct gru_thr
goto failupm;
}
}
+
+ if (unlikely(cbe) && pageshift == PAGE_SHIFT) {
+ gru_preload_tlb(gts->ts_gru, gts, atomic, vaddr, asid, write, tlb_preload_count, tfh, cbe);
+ gru_flush_cache_cbe(cbe);
+ }
+
gru_cb_set_istatus_active(cbk);
tfh_write_restart(tfh, gpa, GAA_RAM, vaddr, asid, write,
GRU_PAGESIZE(pageshift));
@@ -378,11 +449,13 @@ failnoasid:
tfh_user_polling_mode(tfh);
else
gru_flush_cache(tfh);
+ gru_flush_cache_cbe(cbe);
return -EAGAIN;

failupm:
/* Atomic failure switch CBR to UPM */
tfh_user_polling_mode(tfh);
+ gru_flush_cache_cbe(cbe);
STAT(tlb_dropin_fail_upm);
gru_dbg(grudev, "FAILED upm tfh: 0x%p, vaddr 0x%lx\n", tfh, vaddr);
return 1;
@@ -390,6 +463,7 @@ failupm:
failfmm:
/* FMM state on UPM call */
gru_flush_cache(tfh);
+ gru_flush_cache_cbe(cbe);
STAT(tlb_dropin_fail_fmm);
gru_dbg(grudev, "FAILED fmm tfh: 0x%p, state %d\n", tfh, tfh->state);
return 0;
@@ -397,6 +471,7 @@ failfmm:
failnoexception:
/* TFH status did not show exception pending */
gru_flush_cache(tfh);
+ gru_flush_cache_cbe(cbe);
if (cbk)
gru_flush_cache(cbk);
STAT(tlb_dropin_fail_no_exception);
@@ -407,6 +482,7 @@ failnoexception:
failidle:
/* TFH state was idle - no miss pending */
gru_flush_cache(tfh);
+ gru_flush_cache_cbe(cbe);
if (cbk)
gru_flush_cache(cbk);
STAT(tlb_dropin_fail_idle);
@@ -416,6 +492,7 @@ failidle:
failinval:
/* All errors (atomic & non-atomic) switch CBR to EXCEPTION state */
tfh_exception(tfh);
+ gru_flush_cache_cbe(cbe);
STAT(tlb_dropin_fail_invalid);
gru_dbg(grudev, "FAILED inval tfh: 0x%p, vaddr 0x%lx\n", tfh, vaddr);
return -EFAULT;
@@ -426,6 +503,7 @@ failactive:
tfh_user_polling_mode(tfh);
else
gru_flush_cache(tfh);
+ gru_flush_cache_cbe(cbe);
STAT(tlb_dropin_fail_range_active);
gru_dbg(grudev, "FAILED range active: tfh 0x%p, vaddr 0x%lx\n",
tfh, vaddr);
@@ -627,7 +705,7 @@ int gru_get_exception_detail(unsigned lo
excdet.exceptdet1 = cbe->idef3upd;
excdet.cbrstate = cbe->cbrstate;
excdet.cbrexecstatus = cbe->cbrexecstatus;
- gru_flush_cache(cbe);
+ gru_flush_cache_cbe(cbe);
ret = 0;
} else {
ret = -EAGAIN;
@@ -770,9 +848,12 @@ int gru_set_context_option(unsigned long
return -EFAULT;
gru_dbg(grudev, "op %d, gseg 0x%lx, value1 0x%lx\n", req.op, req.gseg, req.val1);

- gts = gru_alloc_locked_gts(req.gseg);
- if (IS_ERR(gts))
- return PTR_ERR(gts);
+ gts = gru_find_lock_gts(req.gseg);
+ if (!gts) {
+ gts = gru_alloc_locked_gts(req.gseg);
+ if (IS_ERR(gts))
+ return PTR_ERR(gts);
+ }

switch (req.op) {
case sco_blade_chiplet:
Index: linux/drivers/misc/sgi-gru/grufile.c
===================================================================
--- linux.orig/drivers/misc/sgi-gru/grufile.c 2009-11-20 10:27:17.000000000 -0600
+++ linux/drivers/misc/sgi-gru/grufile.c 2009-11-20 10:37:44.000000000 -0600
@@ -152,6 +152,7 @@ static int gru_create_new_context(unsign
vdata->vd_dsr_au_count =
GRU_DS_BYTES_TO_AU(req.data_segment_bytes);
vdata->vd_cbr_au_count = GRU_CB_COUNT_TO_AU(req.control_blocks);
+ vdata->vd_tlb_preload_count = req.tlb_preload_count;
ret = 0;
}
up_write(&current->mm->mmap_sem);
Index: linux/drivers/misc/sgi-gru/gruhandles.c
===================================================================
--- linux.orig/drivers/misc/sgi-gru/gruhandles.c 2009-11-20 10:30:11.000000000 -0600
+++ linux/drivers/misc/sgi-gru/gruhandles.c 2009-11-20 10:37:44.000000000 -0600
@@ -165,17 +165,20 @@ int tgh_invalidate(struct gru_tlb_global
return wait_instruction_complete(tgh, tghop_invalidate);
}

-void tfh_write_only(struct gru_tlb_fault_handle *tfh,
- unsigned long pfn, unsigned long vaddr,
- int asid, int dirty, int pagesize)
+int tfh_write_only(struct gru_tlb_fault_handle *tfh,
+ unsigned long paddr, int gaa,
+ unsigned long vaddr, int asid, int dirty,
+ int pagesize)
{
tfh->fillasid = asid;
tfh->fillvaddr = vaddr;
- tfh->pfn = pfn;
+ tfh->pfn = paddr >> GRU_PADDR_SHIFT;
+ tfh->gaa = gaa;
tfh->dirty = dirty;
tfh->pagesize = pagesize;
tfh->opc = TFHOP_WRITE_ONLY;
start_instruction(tfh);
+ return wait_instruction_complete(tfh, tfhop_write_only);
}

void tfh_write_restart(struct gru_tlb_fault_handle *tfh,
Index: linux/drivers/misc/sgi-gru/gruhandles.h
===================================================================
--- linux.orig/drivers/misc/sgi-gru/gruhandles.h 2009-11-20 10:23:34.000000000 -0600
+++ linux/drivers/misc/sgi-gru/gruhandles.h 2009-11-20 10:37:49.000000000 -0600
@@ -164,6 +164,16 @@ static inline void *gru_chiplet_vaddr(vo
return vaddr + GRU_SIZE * (2 * pnode + chiplet);
}

+static inline struct gru_control_block_extended *gru_tfh_to_cbe(
+ struct gru_tlb_fault_handle *tfh)
+{
+ unsigned long cbe;
+
+ cbe = (unsigned long)tfh - GRU_TFH_BASE + GRU_CBE_BASE;
+ return (struct gru_control_block_extended*)cbe;
+}
+
+

/*
@@ -446,6 +456,12 @@ struct gru_control_block_extended {
unsigned int cbrexecstatus:8;
};

+/* CBE fields for active BCOPY instructions */
+#define cbe_baddr0 idef1upd
+#define cbe_baddr1 idef3upd
+#define cbe_src_cl idef6cpy
+#define cbe_nelemcur idef5upd
+
enum gru_cbr_state {
CBRSTATE_INACTIVE,
CBRSTATE_IDLE,
@@ -493,8 +509,8 @@ int cch_interrupt_sync(struct gru_contex
int tgh_invalidate(struct gru_tlb_global_handle *tgh, unsigned long vaddr,
unsigned long vaddrmask, int asid, int pagesize, int global, int n,
unsigned short ctxbitmap);
-void tfh_write_only(struct gru_tlb_fault_handle *tfh, unsigned long pfn,
- unsigned long vaddr, int asid, int dirty, int pagesize);
+int tfh_write_only(struct gru_tlb_fault_handle *tfh, unsigned long paddr,
+ int gaa, unsigned long vaddr, int asid, int dirty, int pagesize);
void tfh_write_restart(struct gru_tlb_fault_handle *tfh, unsigned long paddr,
int gaa, unsigned long vaddr, int asid, int dirty, int pagesize);
void tfh_restart(struct gru_tlb_fault_handle *tfh);
Index: linux/drivers/misc/sgi-gru/grukservices.c
===================================================================
--- linux.orig/drivers/misc/sgi-gru/grukservices.c 2009-11-20 10:27:17.000000000 -0600
+++ linux/drivers/misc/sgi-gru/grukservices.c 2009-11-20 10:37:52.000000000 -0600
@@ -161,7 +161,7 @@ static void gru_load_kernel_context(stru
down_write(&bs->bs_kgts_sema);

if (!bs->bs_kgts) {
- bs->bs_kgts = gru_alloc_gts(NULL, 0, 0, 0, 0);
+ bs->bs_kgts = gru_alloc_gts(NULL, 0, 0, 0, 0, 0);
bs->bs_kgts->ts_user_blade_id = blade_id;
}
kgts = bs->bs_kgts;
Index: linux/drivers/misc/sgi-gru/grulib.h
===================================================================
--- linux.orig/drivers/misc/sgi-gru/grulib.h 2009-11-20 10:24:20.000000000 -0600
+++ linux/drivers/misc/sgi-gru/grulib.h 2009-11-20 10:37:46.000000000 -0600
@@ -86,6 +86,7 @@ struct gru_create_context_req {
unsigned int control_blocks;
unsigned int maximum_thread_count;
unsigned int options;
+ unsigned char tlb_preload_count;
};

/*
Index: linux/drivers/misc/sgi-gru/grumain.c
===================================================================
--- linux.orig/drivers/misc/sgi-gru/grumain.c 2009-11-20 10:27:17.000000000 -0600
+++ linux/drivers/misc/sgi-gru/grumain.c 2009-11-20 10:37:50.000000000 -0600
@@ -316,7 +316,8 @@ static struct gru_thread_state *gru_find
* Allocate a thread state structure.
*/
struct gru_thread_state *gru_alloc_gts(struct vm_area_struct *vma,
- int cbr_au_count, int dsr_au_count, int options, int tsid)
+ int cbr_au_count, int dsr_au_count,
+ unsigned char tlb_preload_count, int options, int tsid)
{
struct gru_thread_state *gts;
struct gru_mm_struct *gms;
@@ -334,6 +335,7 @@ struct gru_thread_state *gru_alloc_gts(s
mutex_init(&gts->ts_ctxlock);
gts->ts_cbr_au_count = cbr_au_count;
gts->ts_dsr_au_count = dsr_au_count;
+ gts->ts_tlb_preload_count = tlb_preload_count;
gts->ts_user_options = options;
gts->ts_user_blade_id = -1;
gts->ts_user_chiplet_id = -1;
@@ -403,7 +405,9 @@ struct gru_thread_state *gru_alloc_threa
struct gru_vma_data *vdata = vma->vm_private_data;
struct gru_thread_state *gts, *ngts;

- gts = gru_alloc_gts(vma, vdata->vd_cbr_au_count, vdata->vd_dsr_au_count,
+ gts = gru_alloc_gts(vma, vdata->vd_cbr_au_count,
+ vdata->vd_dsr_au_count,
+ vdata->vd_tlb_preload_count,
vdata->vd_user_options, tsid);
if (IS_ERR(gts))
return gts;
Index: linux/drivers/misc/sgi-gru/gruprocfs.c
===================================================================
--- linux.orig/drivers/misc/sgi-gru/gruprocfs.c 2009-11-20 10:27:17.000000000 -0600
+++ linux/drivers/misc/sgi-gru/gruprocfs.c 2009-11-20 10:38:48.000000000 -0600
@@ -76,6 +76,7 @@ static int statistics_show(struct seq_fi
printstat(s, check_context_retarget_intr);
printstat(s, check_context_unload);
printstat(s, tlb_dropin);
+ printstat(s, tlb_preload_page);
printstat(s, tlb_dropin_fail_no_asid);
printstat(s, tlb_dropin_fail_upm);
printstat(s, tlb_dropin_fail_invalid);
@@ -127,7 +128,8 @@ static int mcs_statistics_show(struct se
int op;
unsigned long total, count, max;
static char *id[] = {"cch_allocate", "cch_start", "cch_interrupt",
- "cch_interrupt_sync", "cch_deallocate", "tgh_invalidate"};
+ "cch_interrupt_sync", "cch_deallocate", "tfh_write_only",
+ "tfh_write_restart", "tgh_invalidate"};

seq_printf(s, "%-20s%12s%12s%12s\n", "#id", "count", "aver-clks", "max-clks");
for (op = 0; op < mcsop_last; op++) {
Index: linux/drivers/misc/sgi-gru/grutables.h
===================================================================
--- linux.orig/drivers/misc/sgi-gru/grutables.h 2009-11-20 10:27:17.000000000 -0600
+++ linux/drivers/misc/sgi-gru/grutables.h 2009-11-20 10:37:47.000000000 -0600
@@ -202,6 +202,7 @@ struct gru_stats_s {
atomic_long_t check_context_retarget_intr;
atomic_long_t check_context_unload;
atomic_long_t tlb_dropin;
+ atomic_long_t tlb_preload_page;
atomic_long_t tlb_dropin_fail_no_asid;
atomic_long_t tlb_dropin_fail_upm;
atomic_long_t tlb_dropin_fail_invalid;
@@ -245,7 +246,8 @@ struct gru_stats_s {
};

enum mcs_op {cchop_allocate, cchop_start, cchop_interrupt, cchop_interrupt_sync,
- cchop_deallocate, tghop_invalidate, mcsop_last};
+ cchop_deallocate, tfhop_write_only, tfhop_write_restart,
+ tghop_invalidate, mcsop_last};

struct mcs_op_statistic {
atomic_long_t count;
@@ -335,6 +337,7 @@ struct gru_vma_data {
long vd_user_options;/* misc user option flags */
int vd_cbr_au_count;
int vd_dsr_au_count;
+ unsigned char vd_tlb_preload_count;
};

/*
@@ -350,6 +353,7 @@ struct gru_thread_state {
struct gru_state *ts_gru; /* GRU where the context is
loaded */
struct gru_mm_struct *ts_gms; /* asid & ioproc struct */
+ unsigned char ts_tlb_preload_count; /* TLB preload pages */
unsigned long ts_cbr_map; /* map of allocated CBRs */
unsigned long ts_dsr_map; /* map of allocated DATA
resources */
@@ -661,7 +665,8 @@ extern int gru_proc_init(void);
extern void gru_proc_exit(void);

extern struct gru_thread_state *gru_alloc_gts(struct vm_area_struct *vma,
- int cbr_au_count, int dsr_au_count, int options, int tsid);
+ int cbr_au_count, int dsr_au_count,
+ unsigned char tlb_preload_count, int options, int tsid);
extern unsigned long gru_reserve_cb_resources(struct gru_state *gru,
int cbr_au_count, char *cbmap);
extern unsigned long gru_reserve_ds_resources(struct gru_state *gru,