diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/char/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/char/Makefile | 1 | ||||
| -rw-r--r-- | drivers/char/mspec.c | 421 |
3 files changed, 430 insertions, 0 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 52ea94b891f5..6a3d3af45c59 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -439,6 +439,14 @@ config SGI_MBCS If you have an SGI Altix with an attached SABrick say Y or M here, otherwise say N. +config MSPEC + tristate "Memory special operations driver" + depends on IA64 + help + If you have an ia64 and you want to enable memory special + operations support (formerly known as fetchop), say Y here, + otherwise say N. + source "drivers/serial/Kconfig" config UNIX98_PTYS diff --git a/drivers/char/Makefile b/drivers/char/Makefile index 8c6dfc621520..b583d0cd9fbe 100644 --- a/drivers/char/Makefile +++ b/drivers/char/Makefile @@ -47,6 +47,7 @@ obj-$(CONFIG_HVC_RTAS) += hvc_rtas.o obj-$(CONFIG_HVC_DRIVER) += hvc_console.o obj-$(CONFIG_RAW_DRIVER) += raw.o obj-$(CONFIG_SGI_SNSC) += snsc.o snsc_event.o +obj-$(CONFIG_MSPEC) += mspec.o obj-$(CONFIG_MMTIMER) += mmtimer.o obj-$(CONFIG_VIOCONS) += viocons.o obj-$(CONFIG_VIOTAPE) += viotape.o diff --git a/drivers/char/mspec.c b/drivers/char/mspec.c new file mode 100644 index 000000000000..5426b1e5595f --- /dev/null +++ b/drivers/char/mspec.c @@ -0,0 +1,421 @@ +/* + * Copyright (C) 2001-2006 Silicon Graphics, Inc. All rights + * reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 of the GNU General Public License + * as published by the Free Software Foundation. + */ + +/* + * SN Platform Special Memory (mspec) Support + * + * This driver exports the SN special memory (mspec) facility to user + * processes. + * There are three types of memory made available thru this driver: + * fetchops, uncached and cached. + * + * Fetchops are atomic memory operations that are implemented in the + * memory controller on SGI SN hardware. + * + * Uncached are used for memory write combining feature of the ia64 + * cpu. + * + * Cached are used for areas of memory that are used as cached addresses + * on our partition and used as uncached addresses from other partitions. + * Due to a design constraint of the SN2 Shub, you can not have processors + * on the same FSB perform both a cached and uncached reference to the + * same cache line. These special memory cached regions prevent the + * kernel from ever dropping in a TLB entry and therefore prevent the + * processor from ever speculating a cache line from this page. + */ + +#include <linux/config.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/miscdevice.h> +#include <linux/spinlock.h> +#include <linux/mm.h> +#include <linux/vmalloc.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/numa.h> +#include <asm/page.h> +#include <asm/system.h> +#include <asm/pgtable.h> +#include <asm/atomic.h> +#include <asm/tlbflush.h> +#include <asm/uncached.h> +#include <asm/sn/addrs.h> +#include <asm/sn/arch.h> +#include <asm/sn/mspec.h> +#include <asm/sn/sn_cpuid.h> +#include <asm/sn/io.h> +#include <asm/sn/bte.h> +#include <asm/sn/shubio.h> + + +#define FETCHOP_ID "SGI Fetchop," +#define CACHED_ID "Cached," +#define UNCACHED_ID "Uncached" +#define REVISION "4.0" +#define MSPEC_BASENAME "mspec" + +/* + * Page types allocated by the device. + */ +enum { + MSPEC_FETCHOP = 1, + MSPEC_CACHED, + MSPEC_UNCACHED +}; + +static int is_sn2; + +/* + * One of these structures is allocated when an mspec region is mmaped. The + * structure is pointed to by the vma->vm_private_data field in the vma struct. + * This structure is used to record the addresses of the mspec pages. + */ +struct vma_data { + atomic_t refcnt; /* Number of vmas sharing the data. */ + spinlock_t lock; /* Serialize access to the vma. */ + int count; /* Number of pages allocated. */ + int type; /* Type of pages allocated. */ + unsigned long maddr[0]; /* Array of MSPEC addresses. */ +}; + +/* used on shub2 to clear FOP cache in the HUB */ +static unsigned long scratch_page[MAX_NUMNODES]; +#define SH2_AMO_CACHE_ENTRIES 4 + +static inline int +mspec_zero_block(unsigned long addr, int len) +{ + int status; + + if (is_sn2) { + if (is_shub2()) { + int nid; + void *p; + int i; + + nid = nasid_to_cnodeid(get_node_number(__pa(addr))); + p = (void *)TO_AMO(scratch_page[nid]); + + for (i=0; i < SH2_AMO_CACHE_ENTRIES; i++) { + FETCHOP_LOAD_OP(p, FETCHOP_LOAD); + p += FETCHOP_VAR_SIZE; + } + } + + status = bte_copy(0, addr & ~__IA64_UNCACHED_OFFSET, len, + BTE_WACQUIRE | BTE_ZERO_FILL, NULL); + } else { + memset((char *) addr, 0, len); + status = 0; + } + return status; +} + +/* + * mspec_open + * + * Called when a device mapping is created by a means other than mmap + * (via fork, etc.). Increments the reference count on the underlying + * mspec data so it is not freed prematurely. + */ +static void +mspec_open(struct vm_area_struct *vma) +{ + struct vma_data *vdata; + + vdata = vma->vm_private_data; + atomic_inc(&vdata->refcnt); +} + +/* + * mspec_close + * + * Called when unmapping a device mapping. Frees all mspec pages + * belonging to the vma. + */ +static void +mspec_close(struct vm_area_struct *vma) +{ + struct vma_data *vdata; + int i, pages, result, vdata_size; + + vdata = vma->vm_private_data; + if (!atomic_dec_and_test(&vdata->refcnt)) + return; + + pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + vdata_size = sizeof(struct vma_data) + pages * sizeof(long); + for (i = 0; i < pages; i++) { + if (vdata->maddr[i] == 0) + continue; + /* + * Clear the page before sticking it back + * into the pool. + */ + result = mspec_zero_block(vdata->maddr[i], PAGE_SIZE); + if (!result) + uncached_free_page(vdata->maddr[i]); + else + printk(KERN_WARNING "mspec_close(): " + "failed to zero page %i\n", + result); + } + + if (vdata_size <= PAGE_SIZE) + kfree(vdata); + else + vfree(vdata); +} + + +/* + * mspec_nopfn + * + * Creates a mspec page and maps it to user space. + */ +static unsigned long +mspec_nopfn(struct vm_area_struct *vma, unsigned long address) +{ + unsigned long paddr, maddr; + unsigned long pfn; + int index; + struct vma_data *vdata = vma->vm_private_data; + + index = (address - vma->vm_start) >> PAGE_SHIFT; + maddr = (volatile unsigned long) vdata->maddr[index]; + if (maddr == 0) { + maddr = uncached_alloc_page(numa_node_id()); + if (maddr == 0) + return NOPFN_OOM; + + spin_lock(&vdata->lock); + if (vdata->maddr[index] == 0) { + vdata->count++; + vdata->maddr[index] = maddr; + } else { + uncached_free_page(maddr); + maddr = vdata->maddr[index]; + } + spin_unlock(&vdata->lock); + } + + if (vdata->type == MSPEC_FETCHOP) + paddr = TO_AMO(maddr); + else + paddr = __pa(TO_CAC(maddr)); + + pfn = paddr >> PAGE_SHIFT; + + return pfn; +} + +static struct vm_operations_struct mspec_vm_ops = { + .open = mspec_open, + .close = mspec_close, + .nopfn = mspec_nopfn +}; + +/* + * mspec_mmap + * + * Called when mmaping the device. Initializes the vma with a fault handler + * and private data structure necessary to allocate, track, and free the + * underlying pages. + */ +static int +mspec_mmap(struct file *file, struct vm_area_struct *vma, int type) +{ + struct vma_data *vdata; + int pages, vdata_size; + + if (vma->vm_pgoff != 0) + return -EINVAL; + + if ((vma->vm_flags & VM_SHARED) == 0) + return -EINVAL; + + if ((vma->vm_flags & VM_WRITE) == 0) + return -EPERM; + + pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + vdata_size = sizeof(struct vma_data) + pages * sizeof(long); + if (vdata_size <= PAGE_SIZE) + vdata = kmalloc(vdata_size, GFP_KERNEL); + else + vdata = vmalloc(vdata_size); + if (!vdata) + return -ENOMEM; + memset(vdata, 0, vdata_size); + + vdata->type = type; + spin_lock_init(&vdata->lock); + vdata->refcnt = ATOMIC_INIT(1); + vma->vm_private_data = vdata; + + vma->vm_flags |= (VM_IO | VM_LOCKED | VM_RESERVED | VM_PFNMAP); + if (vdata->type == MSPEC_FETCHOP || vdata->type == MSPEC_UNCACHED) + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + vma->vm_ops = &mspec_vm_ops; + + return 0; +} + +static int +fetchop_mmap(struct file *file, struct vm_area_struct *vma) +{ + return mspec_mmap(file, vma, MSPEC_FETCHOP); +} + +static int +cached_mmap(struct file *file, struct vm_area_struct *vma) +{ + return mspec_mmap(file, vma, MSPEC_CACHED); +} + +static int +uncached_mmap(struct file *file, struct vm_area_struct *vma) +{ + return mspec_mmap(file, vma, MSPEC_UNCACHED); +} + +static struct file_operations fetchop_fops = { + .owner = THIS_MODULE, + .mmap = fetchop_mmap +}; + +static struct miscdevice fetchop_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "sgi_fetchop", + .fops = &fetchop_fops +}; + +static struct file_operations cached_fops = { + .owner = THIS_MODULE, + .mmap = cached_mmap +}; + +static struct miscdevice cached_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "mspec_cached", + .fops = &cached_fops +}; + +static struct file_operations uncached_fops = { + .owner = THIS_MODULE, + .mmap = uncached_mmap +}; + +static struct miscdevice uncached_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "mspec_uncached", + .fops = &uncached_fops +}; + +/* + * mspec_init + * + * Called at boot time to initialize the mspec facility. + */ +static int __init +mspec_init(void) +{ + int ret; + int nid; + + /* + * The fetchop device only works on SN2 hardware, uncached and cached + * memory drivers should both be valid on all ia64 hardware + */ + if (ia64_platform_is("sn2")) { + is_sn2 = 1; + if (is_shub2()) { + ret = -ENOMEM; + for_each_online_node(nid) { + int actual_nid; + int nasid; + unsigned long phys; + + scratch_page[nid] = uncached_alloc_page(nid); + if (scratch_page[nid] == 0) + goto free_scratch_pages; + phys = __pa(scratch_page[nid]); + nasid = get_node_number(phys); + actual_nid = nasid_to_cnodeid(nasid); + if (actual_nid != nid) + goto free_scratch_pages; + } + } + + ret = misc_register(&fetchop_miscdev); + if (ret) { + printk(KERN_ERR + "%s: failed to register device %i\n", + FETCHOP_ID, ret); + goto free_scratch_pages; + } + } + ret = misc_register(&cached_miscdev); + if (ret) { + printk(KERN_ERR "%s: failed to register device %i\n", + CACHED_ID, ret); + if (is_sn2) + misc_deregister(&fetchop_miscdev); + goto free_scratch_pages; + } + ret = misc_register(&uncached_miscdev); + if (ret) { + printk(KERN_ERR "%s: failed to register device %i\n", + UNCACHED_ID, ret); + misc_deregister(&cached_miscdev); + if (is_sn2) + misc_deregister(&fetchop_miscdev); + goto free_scratch_pages; + } + + printk(KERN_INFO "%s %s initialized devices: %s %s %s\n", + MSPEC_BASENAME, REVISION, is_sn2 ? FETCHOP_ID : "", + CACHED_ID, UNCACHED_ID); + + return 0; + + free_scratch_pages: + for_each_node(nid) { + if (scratch_page[nid] != 0) + uncached_free_page(scratch_page[nid]); + } + return ret; +} + +static void __exit +mspec_exit(void) +{ + int nid; + + misc_deregister(&uncached_miscdev); + misc_deregister(&cached_miscdev); + if (is_sn2) { + misc_deregister(&fetchop_miscdev); + + for_each_node(nid) { + if (scratch_page[nid] != 0) + uncached_free_page(scratch_page[nid]); + } + } +} + +module_init(mspec_init); +module_exit(mspec_exit); + +MODULE_AUTHOR("Silicon Graphics, Inc. <linux-altix@sgi.com>"); +MODULE_DESCRIPTION("Driver for SGI SN special memory operations"); +MODULE_LICENSE("GPL"); |