GRU Driver V3: fixes to resolve code review comments
Fixes problems identified in a code review:
- add comment with high level dscription of the GRU
- prepend "gru_" to all global names
- delete unused function
- couple of trivial bug fixes
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/misc/sgi-gru/grutables.h b/drivers/misc/sgi-gru/grutables.h
index f97d846..4251018 100644
--- a/drivers/misc/sgi-gru/grutables.h
+++ b/drivers/misc/sgi-gru/grutables.h
@@ -24,6 +24,70 @@
#define __GRUTABLES_H__
/*
+ * GRU Chiplet:
+ * The GRU is a user addressible memory accelerator. It provides
+ * several forms of load, store, memset, bcopy instructions. In addition, it
+ * contains special instructions for AMOs, sending messages to message
+ * queues, etc.
+ *
+ * The GRU is an integral part of the node controller. It connects
+ * directly to the cpu socket. In its current implementation, there are 2
+ * GRU chiplets in the node controller on each blade (~node).
+ *
+ * The entire GRU memory space is fully coherent and cacheable by the cpus.
+ *
+ * Each GRU chiplet has a physical memory map that looks like the following:
+ *
+ * +-----------------+
+ * |/////////////////|
+ * |/////////////////|
+ * |/////////////////|
+ * |/////////////////|
+ * |/////////////////|
+ * |/////////////////|
+ * |/////////////////|
+ * |/////////////////|
+ * +-----------------+
+ * | system control |
+ * +-----------------+ _______ +-------------+
+ * |/////////////////| / | |
+ * |/////////////////| / | |
+ * |/////////////////| / | instructions|
+ * |/////////////////| / | |
+ * |/////////////////| / | |
+ * |/////////////////| / |-------------|
+ * |/////////////////| / | |
+ * +-----------------+ | |
+ * | context 15 | | data |
+ * +-----------------+ | |
+ * | ...... | \ | |
+ * +-----------------+ \____________ +-------------+
+ * | context 1 |
+ * +-----------------+
+ * | context 0 |
+ * +-----------------+
+ *
+ * Each of the "contexts" is a chunk of memory that can be mmaped into user
+ * space. The context consists of 2 parts:
+ *
+ * - an instruction space that can be directly accessed by the user
+ * to issue GRU instructions and to check instruction status.
+ *
+ * - a data area that acts as normal RAM.
+ *
+ * User instructions contain virtual addresses of data to be accessed by the
+ * GRU. The GRU contains a TLB that is used to convert these user virtual
+ * addresses to physical addresses.
+ *
+ * The "system control" area of the GRU chiplet is used by the kernel driver
+ * to manage user contexts and to perform functions such as TLB dropin and
+ * purging.
+ *
+ * One context may be reserved for the kernel and used for cross-partition
+ * communication. The GRU will also be used to asynchronously zero out
+ * large blocks of memory (not currently implemented).
+ *
+ *
* Tables:
*
* VDATA-VMA Data - Holds a few parameters. Head of linked list of
@@ -190,14 +254,14 @@
#define GRU_STEAL_DELAY ((HZ * 200) / 1000)
#define STAT(id) do { \
- if (options & OPT_STATS) \
+ if (gru_options & OPT_STATS) \
atomic_long_inc(&gru_stats.id); \
} while (0)
#ifdef CONFIG_SGI_GRU_DEBUG
#define gru_dbg(dev, fmt, x...) \
do { \
- if (options & OPT_DPRINT) \
+ if (gru_options & OPT_DPRINT) \
dev_dbg(dev, "%s: " fmt, __func__, x); \
} while (0)
#else
@@ -529,9 +593,9 @@
extern int gru_proc_init(void);
extern void gru_proc_exit(void);
-extern unsigned long reserve_gru_cb_resources(struct gru_state *gru,
+extern unsigned long gru_reserve_cb_resources(struct gru_state *gru,
int cbr_au_count, char *cbmap);
-extern unsigned long reserve_gru_ds_resources(struct gru_state *gru,
+extern unsigned long gru_reserve_ds_resources(struct gru_state *gru,
int dsr_au_count, char *dsmap);
extern int gru_fault(struct vm_area_struct *, struct vm_fault *vmf);
extern struct gru_mm_struct *gru_register_mmu_notifier(void);
@@ -540,6 +604,6 @@
extern void gru_flush_tlb_range(struct gru_mm_struct *gms, unsigned long start,
unsigned long len);
-extern unsigned long options;
+extern unsigned long gru_options;
#endif /* __GRUTABLES_H__ */