v4.19.13 snapshot.
diff --git a/drivers/char/mspec.c b/drivers/char/mspec.c
new file mode 100644
index 0000000..058876b
--- /dev/null
+++ b/drivers/char/mspec.c
@@ -0,0 +1,435 @@
+/*
+ * 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/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 <asm/pgtable.h>
+#include <linux/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_page_type {
+ MSPEC_FETCHOP = 1,
+ MSPEC_CACHED,
+ MSPEC_UNCACHED
+};
+
+#ifdef CONFIG_SGI_SN
+static int is_sn2;
+#else
+#define is_sn2 0
+#endif
+
+/*
+ * 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_sem 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[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, 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;
+ if (!mspec_zero_block(my_page, PAGE_SIZE))
+ uncached_free_page(my_page, 1);
+ else
+ printk(KERN_WARNING "mspec_close(): "
+ "failed to zero page %ld\n", my_page);
+ }
+
+ 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);
+ }
+
+ if (vdata->type == MSPEC_FETCHOP)
+ paddr = TO_AMO(maddr);
+ else
+ 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);
+ if (vdata_size <= PAGE_SIZE)
+ vdata = kzalloc(vdata_size, GFP_KERNEL);
+ else
+ vdata = vzalloc(vdata_size);
+ 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;
+
+ vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
+ 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 const struct file_operations fetchop_fops = {
+ .owner = THIS_MODULE,
+ .mmap = fetchop_mmap,
+ .llseek = noop_llseek,
+};
+
+static struct miscdevice fetchop_miscdev = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "sgi_fetchop",
+ .fops = &fetchop_fops
+};
+
+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;
+ int nid;
+
+ /*
+ * The fetchop device only works on SN2 hardware, uncached and cached
+ * memory drivers should both be valid on all ia64 hardware
+ */
+#ifdef CONFIG_SGI_SN
+ if (ia64_platform_is("sn2")) {
+ is_sn2 = 1;
+ if (is_shub2()) {
+ ret = -ENOMEM;
+ for_each_node_state(nid, N_ONLINE) {
+ int actual_nid;
+ int nasid;
+ unsigned long phys;
+
+ scratch_page[nid] = uncached_alloc_page(nid, 1);
+ 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;
+ }
+ }
+#endif
+ 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], 1);
+ }
+ 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], 1);
+ }
+ }
+}
+
+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");