[PATCH] - GRU driver, minor updates

From: Jack Steiner
Date: Thu Aug 28 2008 - 10:46:35 EST


A few minor updates for the GRU driver.
- documentation changes found in code reviews
- changes to #ifdefs to make them recognized by "unifdef"
(used in simulator testing)
- change GRU context load/unload to prefetch data

Signed-off-by: Jack Steiner <steiner@xxxxxxx>

---
drivers/misc/sgi-gru/gru.h | 4 ++--
drivers/misc/sgi-gru/gru_instructions.h | 10 ++++++----
drivers/misc/sgi-gru/grufault.c | 11 ++++++-----
drivers/misc/sgi-gru/grufile.c | 8 +++++++-
drivers/misc/sgi-gru/gruhandles.h | 5 -----
drivers/misc/sgi-gru/grukservices.c | 1 +
drivers/misc/sgi-gru/grumain.c | 29 ++++++++++++++++++-----------
7 files changed, 40 insertions(+), 28 deletions(-)

Index: linux/drivers/misc/sgi-gru/gru.h
===================================================================
--- linux.orig/drivers/misc/sgi-gru/gru.h 2008-08-27 19:56:45.000000000 -0500
+++ linux/drivers/misc/sgi-gru/gru.h 2008-08-28 09:02:29.000000000 -0500
@@ -30,9 +30,9 @@
/*
* Size used to map GRU GSeg
*/
-#if defined CONFIG_IA64
+#if defined(CONFIG_IA64)
#define GRU_GSEG_PAGESIZE (256 * 1024UL)
-#elif defined CONFIG_X86_64
+#elif defined(CONFIG_X86_64)
#define GRU_GSEG_PAGESIZE (256 * 1024UL) /* ZZZ 2MB ??? */
#else
#error "Unsupported architecture"
Index: linux/drivers/misc/sgi-gru/gru_instructions.h
===================================================================
--- linux.orig/drivers/misc/sgi-gru/gru_instructions.h 2008-08-27 19:56:45.000000000 -0500
+++ linux/drivers/misc/sgi-gru/gru_instructions.h 2008-08-28 09:02:30.000000000 -0500
@@ -26,7 +26,7 @@
* Architecture dependent functions
*/

-#if defined CONFIG_IA64
+#if defined(CONFIG_IA64)
#include <linux/compiler.h>
#include <asm/intrinsics.h>
#define __flush_cache(p) ia64_fc(p)
@@ -36,7 +36,7 @@
barrier(); \
*((volatile int *)(p)) = v; /* force st.rel */ \
} while (0)
-#elif defined CONFIG_X86_64
+#elif defined(CONFIG_X86_64)
#define __flush_cache(p) clflush(p)
#define gru_ordered_store_int(p,v) \
do { \
@@ -299,6 +299,7 @@ static inline void gru_flush_cache(void
static inline void gru_start_instruction(struct gru_instruction *ins, int op32)
{
gru_ordered_store_int(ins, op32);
+ gru_flush_cache(ins);
}


@@ -604,8 +605,9 @@ static inline int gru_get_cb_substatus(v
static inline int gru_check_status(void *cb)
{
struct gru_control_block_status *cbs = (void *)cb;
- int ret = cbs->istatus;
+ int ret;

+ ret = cbs->istatus;
if (ret == CBS_CALL_OS)
ret = gru_check_status_proc(cb);
return ret;
@@ -617,7 +619,7 @@ static inline int gru_check_status(void
static inline int gru_wait(void *cb)
{
struct gru_control_block_status *cbs = (void *)cb;
- int ret = cbs->istatus;;
+ int ret = cbs->istatus;

if (ret != CBS_IDLE)
ret = gru_wait_proc(cb);
Index: linux/drivers/misc/sgi-gru/grufault.c
===================================================================
--- linux.orig/drivers/misc/sgi-gru/grufault.c 2008-08-27 19:56:45.000000000 -0500
+++ linux/drivers/misc/sgi-gru/grufault.c 2008-08-28 09:02:29.000000000 -0500
@@ -220,6 +220,10 @@ static int non_atomic_pte_lookup(struct
* Convert a user virtual address to a physical address
* Only supports Intel large pages (2MB only) on x86_64.
* ZZZ - hugepage support is incomplete
+ *
+ * NOTE; mmap_sem is already held on entry to this function. This
+ * guarantees existence of the apge tables.
+ *
*/
static int atomic_pte_lookup(struct vm_area_struct *vma, unsigned long vaddr,
int write, unsigned long *paddr, int *pageshift)
@@ -229,9 +233,6 @@ static int atomic_pte_lookup(struct vm_a
pud_t *pudp;
pte_t pte;

- WARN_ON(irqs_disabled()); /* ZZZ debug */
-
- local_irq_disable();
pgdp = pgd_offset(vma->vm_mm, vaddr);
if (unlikely(pgd_none(*pgdp)))
goto err;
@@ -250,8 +251,6 @@ static int atomic_pte_lookup(struct vm_a
#endif
pte = *pte_offset_kernel(pmdp, vaddr);

- local_irq_enable();
-
if (unlikely(!pte_present(pte) ||
(write && (!pte_write(pte) || !pte_dirty(pte)))))
return 1;
@@ -324,6 +323,7 @@ static int gru_try_dropin(struct gru_thr
* Atomic lookup is faster & usually works even if called in non-atomic
* context.
*/
+ rmb(); /* Must/check ms_range_active before loading PTEs */
ret = atomic_pte_lookup(vma, vaddr, write, &paddr, &pageshift);
if (ret) {
if (!cb)
@@ -543,6 +543,7 @@ int gru_get_exception_detail(unsigned lo
ucbnum = get_cb_number((void *)excdet.cb);
cbrnum = thread_cbr_number(gts, ucbnum);
cbe = get_cbe_by_index(gts->ts_gru, cbrnum);
+ prefetchw(cbe); /* Harmless on hardware, required for emulator */
excdet.opc = cbe->opccpy;
excdet.exopc = cbe->exopccpy;
excdet.ecause = cbe->ecause;
Index: linux/drivers/misc/sgi-gru/grufile.c
===================================================================
--- linux.orig/drivers/misc/sgi-gru/grufile.c 2008-08-27 19:56:45.000000000 -0500
+++ linux/drivers/misc/sgi-gru/grufile.c 2008-08-28 09:40:16.000000000 -0500
@@ -113,7 +113,7 @@ static int gru_file_mmap(struct file *fi
return -EPERM;

if (vma->vm_start & (GRU_GSEG_PAGESIZE - 1) ||
- vma->vm_end & (GRU_GSEG_PAGESIZE - 1))
+ vma->vm_end & (GRU_GSEG_PAGESIZE - 1))
return -EINVAL;

vma->vm_flags |=
@@ -398,6 +398,12 @@ static int __init gru_init(void)
irq = get_base_irq();
for (chip = 0; chip < GRU_CHIPLETS_PER_BLADE; chip++) {
ret = request_irq(irq + chip, gru_intr, 0, id, NULL);
+ /* TODO: fix irq handling on x86. For now ignore failures because
+ * interrupts are not required & not yet fully supported */
+ if (ret) {
+ printk("!!!WARNING: GRU ignoring request failure!!!\n");
+ ret = 0;
+ }
if (ret) {
printk(KERN_ERR "%s: request_irq failed\n",
GRU_DRIVER_ID_STR);
Index: linux/drivers/misc/sgi-gru/gruhandles.h
===================================================================
--- linux.orig/drivers/misc/sgi-gru/gruhandles.h 2008-08-27 19:56:45.000000000 -0500
+++ linux/drivers/misc/sgi-gru/gruhandles.h 2008-08-28 09:02:29.000000000 -0500
@@ -91,12 +91,7 @@
#define GSEGPOFF(h) ((h) & (GRU_SIZE - 1))

/* Convert an arbitrary handle address to the beginning of the GRU segment */
-#ifndef __PLUGIN__
#define GRUBASE(h) ((void *)((unsigned long)(h) & ~(GRU_SIZE - 1)))
-#else
-extern void *gmu_grubase(void *h);
-#define GRUBASE(h) gmu_grubase(h)
-#endif

/* General addressing macros. */
static inline void *get_gseg_base_address(void *base, int ctxnum)
Index: linux/drivers/misc/sgi-gru/grukservices.c
===================================================================
--- linux.orig/drivers/misc/sgi-gru/grukservices.c 2008-08-27 19:56:45.000000000 -0500
+++ linux/drivers/misc/sgi-gru/grukservices.c 2008-08-28 09:02:30.000000000 -0500
@@ -122,6 +122,7 @@ int gru_get_cb_exception_detail(void *cb
struct gru_control_block_extended *cbe;

cbe = get_cbe(GRUBASE(cb), get_cb_number(cb));
+ prefetchw(cbe); /* Harmless on hardware, required for emulator */
excdet->opc = cbe->opccpy;
excdet->exopc = cbe->exopccpy;
excdet->ecause = cbe->ecause;
Index: linux/drivers/misc/sgi-gru/grumain.c
===================================================================
--- linux.orig/drivers/misc/sgi-gru/grumain.c 2008-08-27 19:56:45.000000000 -0500
+++ linux/drivers/misc/sgi-gru/grumain.c 2008-08-28 09:02:30.000000000 -0500
@@ -432,29 +432,35 @@ static inline long gru_copy_handle(void
return GRU_HANDLE_BYTES;
}

-/* rewrite in assembly & use lots of prefetch */
-static void gru_load_context_data(void *save, void *grubase, int ctxnum,
- unsigned long cbrmap, unsigned long dsrmap)
+static void gru_prefetch_context(void *gseg, void *cb, void *cbe, unsigned long cbrmap,
+ unsigned long length)
{
- void *gseg, *cb, *cbe;
- unsigned long length;
int i, scr;

- gseg = grubase + ctxnum * GRU_GSEG_STRIDE;
- length = hweight64(dsrmap) * GRU_DSR_AU_BYTES;
prefetch_data(gseg + GRU_DS_BASE, length / GRU_CACHE_LINE_BYTES,
GRU_CACHE_LINE_BYTES);

- cb = gseg + GRU_CB_BASE;
- cbe = grubase + GRU_CBE_BASE;
for_each_cbr_in_allocation_map(i, &cbrmap, scr) {
prefetch_data(cb, 1, GRU_CACHE_LINE_BYTES);
prefetch_data(cbe + i * GRU_HANDLE_STRIDE, 1,
GRU_CACHE_LINE_BYTES);
cb += GRU_HANDLE_STRIDE;
}
+}
+
+static void gru_load_context_data(void *save, void *grubase, int ctxnum,
+ unsigned long cbrmap, unsigned long dsrmap)
+{
+ void *gseg, *cb, *cbe;
+ unsigned long length;
+ int i, scr;

+ gseg = grubase + ctxnum * GRU_GSEG_STRIDE;
cb = gseg + GRU_CB_BASE;
+ cbe = grubase + GRU_CBE_BASE;
+ length = hweight64(dsrmap) * GRU_DSR_AU_BYTES;
+ gru_prefetch_context(gseg, cb, cbe, cbrmap, length);
+
for_each_cbr_in_allocation_map(i, &cbrmap, scr) {
save += gru_copy_handle(cb, save);
save += gru_copy_handle(cbe + i * GRU_HANDLE_STRIDE, save);
@@ -472,15 +478,16 @@ static void gru_unload_context_data(void
int i, scr;

gseg = grubase + ctxnum * GRU_GSEG_STRIDE;
-
cb = gseg + GRU_CB_BASE;
cbe = grubase + GRU_CBE_BASE;
+ length = hweight64(dsrmap) * GRU_DSR_AU_BYTES;
+ gru_prefetch_context(gseg, cb, cbe, cbrmap, length);
+
for_each_cbr_in_allocation_map(i, &cbrmap, scr) {
save += gru_copy_handle(save, cb);
save += gru_copy_handle(save, cbe + i * GRU_HANDLE_STRIDE);
cb += GRU_HANDLE_STRIDE;
}
- length = hweight64(dsrmap) * GRU_DSR_AU_BYTES;
memcpy(save, gseg + GRU_DS_BASE, length);
}

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/