From 9ca8e40c130c906c1060d105e63628410c860261 Mon Sep 17 00:00:00 2001 From: Jack Steiner Date: Tue, 29 Jul 2008 22:34:02 -0700 Subject: [PATCH] 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 Cc: Nick Piggin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/misc/sgi-gru/gru_instructions.h | 10 ---- drivers/misc/sgi-gru/grufile.c | 8 ++- drivers/misc/sgi-gru/grukservices.c | 6 +- drivers/misc/sgi-gru/grumain.c | 16 ++++-- drivers/misc/sgi-gru/gruprocfs.c | 4 +- drivers/misc/sgi-gru/grutables.h | 74 +++++++++++++++++++++++-- drivers/misc/sgi-gru/grutlbpurge.c | 4 +- 7 files changed, 93 insertions(+), 29 deletions(-) diff --git a/drivers/misc/sgi-gru/gru_instructions.h b/drivers/misc/sgi-gru/gru_instructions.h index 3159b261c5..0dc36225c7 100644 --- a/drivers/misc/sgi-gru/gru_instructions.h +++ b/drivers/misc/sgi-gru/gru_instructions.h @@ -284,16 +284,6 @@ __opword(unsigned char opcode, unsigned char exopc, unsigned char xtype, (exopc << GRU_CB_EXOPC_SHFT); } -/* - * Prefetch a cacheline. Fetch is unconditional. Must page fault if - * no valid TLB entry is found. - * ??? should I use actual "load" or hardware prefetch??? - */ -static inline void gru_prefetch(void *p) -{ - *(volatile char *)p; -} - /* * Architecture specific intrinsics */ diff --git a/drivers/misc/sgi-gru/grufile.c b/drivers/misc/sgi-gru/grufile.c index 09c9c65ff9..23c91f5f6b 100644 --- a/drivers/misc/sgi-gru/grufile.c +++ b/drivers/misc/sgi-gru/grufile.c @@ -112,6 +112,10 @@ static int gru_file_mmap(struct file *file, struct vm_area_struct *vma) if ((vma->vm_flags & (VM_SHARED | VM_WRITE)) != (VM_SHARED | VM_WRITE)) return -EPERM; + if (vma->vm_start & (GRU_GSEG_PAGESIZE - 1) || + vma->vm_end & (GRU_GSEG_PAGESIZE - 1)) + return -EINVAL; + vma->vm_flags |= (VM_IO | VM_DONTCOPY | VM_LOCKED | VM_DONTEXPAND | VM_PFNMAP | VM_RESERVED); @@ -471,8 +475,8 @@ struct vm_operations_struct gru_vm_ops = { module_init(gru_init); module_exit(gru_exit); -module_param(options, ulong, 0644); -MODULE_PARM_DESC(options, "Various debug options"); +module_param(gru_options, ulong, 0644); +MODULE_PARM_DESC(gru_options, "Various debug options"); MODULE_AUTHOR("Silicon Graphics, Inc."); MODULE_LICENSE("GPL"); diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c index 234d165fb1..dfd49af0fe 100644 --- a/drivers/misc/sgi-gru/grukservices.c +++ b/drivers/misc/sgi-gru/grukservices.c @@ -638,11 +638,11 @@ int gru_kservices_init(struct gru_state *gru) cpus_possible = uv_blade_nr_possible_cpus(gru->gs_blade_id); num = GRU_NUM_KERNEL_CBR * cpus_possible; - cbr_map = reserve_gru_cb_resources(gru, GRU_CB_COUNT_TO_AU(num), NULL); + cbr_map = gru_reserve_cb_resources(gru, GRU_CB_COUNT_TO_AU(num), NULL); gru->gs_reserved_cbrs += num; num = GRU_NUM_KERNEL_DSR_BYTES * cpus_possible; - dsr_map = reserve_gru_ds_resources(gru, GRU_DS_BYTES_TO_AU(num), NULL); + dsr_map = gru_reserve_ds_resources(gru, GRU_DS_BYTES_TO_AU(num), NULL); gru->gs_reserved_dsr_bytes += num; gru->gs_active_contexts++; @@ -673,7 +673,7 @@ int gru_kservices_init(struct gru_state *gru) } unlock_cch_handle(cch); - if (options & GRU_QUICKLOOK) + if (gru_options & GRU_QUICKLOOK) quicktest(gru); return 0; } diff --git a/drivers/misc/sgi-gru/grumain.c b/drivers/misc/sgi-gru/grumain.c index aef6822cb8..0eeb8dddd2 100644 --- a/drivers/misc/sgi-gru/grumain.c +++ b/drivers/misc/sgi-gru/grumain.c @@ -22,7 +22,7 @@ #include "grutables.h" #include "gruhandles.h" -unsigned long options __read_mostly; +unsigned long gru_options __read_mostly; static struct device_driver gru_driver = { .name = "gru" @@ -163,14 +163,14 @@ static unsigned long reserve_resources(unsigned long *p, int n, int mmax, return bits; } -unsigned long reserve_gru_cb_resources(struct gru_state *gru, int cbr_au_count, +unsigned long gru_reserve_cb_resources(struct gru_state *gru, int cbr_au_count, char *cbmap) { return reserve_resources(&gru->gs_cbr_map, cbr_au_count, GRU_CBR_AU, cbmap); } -unsigned long reserve_gru_ds_resources(struct gru_state *gru, int dsr_au_count, +unsigned long gru_reserve_ds_resources(struct gru_state *gru, int dsr_au_count, char *dsmap) { return reserve_resources(&gru->gs_dsr_map, dsr_au_count, GRU_DSR_AU, @@ -182,10 +182,10 @@ static void reserve_gru_resources(struct gru_state *gru, { gru->gs_active_contexts++; gts->ts_cbr_map = - reserve_gru_cb_resources(gru, gts->ts_cbr_au_count, + gru_reserve_cb_resources(gru, gts->ts_cbr_au_count, gts->ts_cbr_idx); gts->ts_dsr_map = - reserve_gru_ds_resources(gru, gts->ts_dsr_au_count, NULL); + gru_reserve_ds_resources(gru, gts->ts_dsr_au_count, NULL); } static void free_gru_resources(struct gru_state *gru, @@ -416,6 +416,7 @@ static void gru_free_gru_context(struct gru_thread_state *gts) /* * Prefetching cachelines help hardware performance. + * (Strictly a performance enhancement. Not functionally required). */ static void prefetch_data(void *p, int num, int stride) { @@ -746,6 +747,8 @@ again: * gru_nopage * * Map the user's GRU segment + * + * Note: gru segments alway mmaped on GRU_GSEG_PAGESIZE boundaries. */ int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { @@ -757,6 +760,7 @@ int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf) vma, vaddr, GSEG_BASE(vaddr)); STAT(nopfn); + /* The following check ensures vaddr is a valid address in the VMA */ gts = gru_find_thread_state(vma, TSID(vaddr, vma)); if (!gts) return VM_FAULT_SIGBUS; @@ -775,7 +779,7 @@ again: } if (!gts->ts_gru) { - while (!gru_assign_gru_context(gts)) { + if (!gru_assign_gru_context(gts)) { mutex_unlock(>s->ts_ctxlock); preempt_enable(); schedule_timeout(GRU_ASSIGN_DELAY); /* true hack ZZZ */ diff --git a/drivers/misc/sgi-gru/gruprocfs.c b/drivers/misc/sgi-gru/gruprocfs.c index bdb1ad83bb..533923f83f 100644 --- a/drivers/misc/sgi-gru/gruprocfs.c +++ b/drivers/misc/sgi-gru/gruprocfs.c @@ -122,7 +122,7 @@ static ssize_t statistics_write(struct file *file, const char __user *userbuf, static int options_show(struct seq_file *s, void *p) { - seq_printf(s, "0x%lx\n", options); + seq_printf(s, "0x%lx\n", gru_options); return 0; } @@ -136,7 +136,7 @@ static ssize_t options_write(struct file *file, const char __user *userbuf, (buf, userbuf, count < sizeof(buf) ? count : sizeof(buf))) return -EFAULT; if (!strict_strtoul(buf, 10, &val)) - options = val; + gru_options = val; return count; } diff --git a/drivers/misc/sgi-gru/grutables.h b/drivers/misc/sgi-gru/grutables.h index f97d846401..4251018f70 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 @@ struct gru_stats_s { #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 void gru_flush_all_tlb(struct gru_state *gru); 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_drop_mmu_notifier(struct gru_mm_struct *gms); 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__ */ diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c index bb6b0e64e1..bcfd5425e2 100644 --- a/drivers/misc/sgi-gru/grutlbpurge.c +++ b/drivers/misc/sgi-gru/grutlbpurge.c @@ -242,7 +242,9 @@ static void gru_invalidate_range_end(struct mmu_notifier *mn, struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct, ms_notifier); - atomic_dec(&gms->ms_range_active); + /* ..._and_test() provides needed barrier */ + (void)atomic_dec_and_test(&gms->ms_range_active); + wake_up_all(&gms->ms_wait_queue); gru_dbg(grudev, "gms %p, start 0x%lx, end 0x%lx\n", gms, start, end); } -- 2.39.5