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-rw-r--r--drivers/char/mspec.c295
1 files changed, 0 insertions, 295 deletions
diff --git a/drivers/char/mspec.c b/drivers/char/mspec.c
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index b35f651837c8..000000000000
--- a/drivers/char/mspec.c
+++ /dev/null
@@ -1,295 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2001-2006 Silicon Graphics, Inc. All rights
- * reserved.
- */
-
-/*
- * SN Platform Special Memory (mspec) Support
- *
- * This driver exports the SN special memory (mspec) facility to user
- * processes.
- * There are two types of memory made available thru this driver:
- * uncached and cached.
- *
- * 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/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/fs.h>
-#include <linux/vmalloc.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/numa.h>
-#include <linux/refcount.h>
-#include <asm/page.h>
-#include <linux/atomic.h>
-#include <asm/tlbflush.h>
-#include <asm/uncached.h>
-
-
-#define CACHED_ID "Cached,"
-#define UNCACHED_ID "Uncached"
-#define REVISION "4.0"
-#define MSPEC_BASENAME "mspec"
-
-/*
- * Page types allocated by the device.
- */
-enum mspec_page_type {
- MSPEC_CACHED = 2,
- MSPEC_UNCACHED
-};
-
-/*
- * 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.
- * This structure is shared by all vma's that are split off from the
- * original vma when split_vma()'s are done.
- *
- * The refcnt is incremented atomically because mm->mmap_lock does not
- * protect in fork case where multiple tasks share the vma_data.
- */
-struct vma_data {
- refcount_t refcnt; /* Number of vmas sharing the data. */
- spinlock_t lock; /* Serialize access to this structure. */
- int count; /* Number of pages allocated. */
- enum mspec_page_type type; /* Type of pages allocated. */
- unsigned long vm_start; /* Original (unsplit) base. */
- unsigned long vm_end; /* Original (unsplit) end. */
- unsigned long maddr[]; /* Array of MSPEC addresses. */
-};
-
-/*
- * mspec_open
- *
- * Called when a device mapping is created by a means other than mmap
- * (via fork, munmap, 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;
- refcount_inc(&vdata->refcnt);
-}
-
-/*
- * mspec_close
- *
- * Called when unmapping a device mapping. Frees all mspec pages
- * belonging to all the vma's sharing this vma_data structure.
- */
-static void
-mspec_close(struct vm_area_struct *vma)
-{
- struct vma_data *vdata;
- int index, last_index;
- unsigned long my_page;
-
- vdata = vma->vm_private_data;
-
- if (!refcount_dec_and_test(&vdata->refcnt))
- return;
-
- last_index = (vdata->vm_end - vdata->vm_start) >> PAGE_SHIFT;
- for (index = 0; index < last_index; index++) {
- if (vdata->maddr[index] == 0)
- continue;
- /*
- * Clear the page before sticking it back
- * into the pool.
- */
- my_page = vdata->maddr[index];
- vdata->maddr[index] = 0;
- memset((char *)my_page, 0, PAGE_SIZE);
- uncached_free_page(my_page, 1);
- }
-
- kvfree(vdata);
-}
-
-/*
- * mspec_fault
- *
- * Creates a mspec page and maps it to user space.
- */
-static vm_fault_t
-mspec_fault(struct vm_fault *vmf)
-{
- unsigned long paddr, maddr;
- unsigned long pfn;
- pgoff_t index = vmf->pgoff;
- struct vma_data *vdata = vmf->vma->vm_private_data;
-
- maddr = (volatile unsigned long) vdata->maddr[index];
- if (maddr == 0) {
- maddr = uncached_alloc_page(numa_node_id(), 1);
- if (maddr == 0)
- return VM_FAULT_OOM;
-
- spin_lock(&vdata->lock);
- if (vdata->maddr[index] == 0) {
- vdata->count++;
- vdata->maddr[index] = maddr;
- } else {
- uncached_free_page(maddr, 1);
- maddr = vdata->maddr[index];
- }
- spin_unlock(&vdata->lock);
- }
-
- paddr = maddr & ~__IA64_UNCACHED_OFFSET;
- pfn = paddr >> PAGE_SHIFT;
-
- return vmf_insert_pfn(vmf->vma, vmf->address, pfn);
-}
-
-static const struct vm_operations_struct mspec_vm_ops = {
- .open = mspec_open,
- .close = mspec_close,
- .fault = mspec_fault,
-};
-
-/*
- * mspec_mmap
- *
- * Called when mmapping 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,
- enum mspec_page_type 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_pages(vma);
- vdata_size = sizeof(struct vma_data) + pages * sizeof(long);
- vdata = kvzalloc(vdata_size, GFP_KERNEL);
- if (!vdata)
- return -ENOMEM;
-
- vdata->vm_start = vma->vm_start;
- vdata->vm_end = vma->vm_end;
- vdata->type = type;
- spin_lock_init(&vdata->lock);
- refcount_set(&vdata->refcnt, 1);
- vma->vm_private_data = vdata;
-
- vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
- if (vdata->type == MSPEC_UNCACHED)
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- vma->vm_ops = &mspec_vm_ops;
-
- return 0;
-}
-
-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 const struct file_operations cached_fops = {
- .owner = THIS_MODULE,
- .mmap = cached_mmap,
- .llseek = noop_llseek,
-};
-
-static struct miscdevice cached_miscdev = {
- .minor = MISC_DYNAMIC_MINOR,
- .name = "mspec_cached",
- .fops = &cached_fops
-};
-
-static const struct file_operations uncached_fops = {
- .owner = THIS_MODULE,
- .mmap = uncached_mmap,
- .llseek = noop_llseek,
-};
-
-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;
-
- ret = misc_register(&cached_miscdev);
- if (ret) {
- printk(KERN_ERR "%s: failed to register device %i\n",
- CACHED_ID, ret);
- return ret;
- }
- ret = misc_register(&uncached_miscdev);
- if (ret) {
- printk(KERN_ERR "%s: failed to register device %i\n",
- UNCACHED_ID, ret);
- misc_deregister(&cached_miscdev);
- return ret;
- }
-
- printk(KERN_INFO "%s %s initialized devices: %s %s\n",
- MSPEC_BASENAME, REVISION, CACHED_ID, UNCACHED_ID);
-
- return 0;
-}
-
-static void __exit
-mspec_exit(void)
-{
- misc_deregister(&uncached_miscdev);
- misc_deregister(&cached_miscdev);
-}
-
-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");