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path: root/drivers/char/mspec.c
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Diffstat (limited to 'drivers/char/mspec.c')
-rw-r--r--drivers/char/mspec.c139
1 files changed, 84 insertions, 55 deletions
diff --git a/drivers/char/mspec.c b/drivers/char/mspec.c
index 5426b1e5595..f1d7fa45c27 100644
--- a/drivers/char/mspec.c
+++ b/drivers/char/mspec.c
@@ -30,7 +30,6 @@
* 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>
@@ -39,14 +38,14 @@
#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 <asm/page.h>
-#include <asm/system.h>
#include <asm/pgtable.h>
-#include <asm/atomic.h>
+#include <linux/atomic.h>
#include <asm/tlbflush.h>
#include <asm/uncached.h>
#include <asm/sn/addrs.h>
@@ -67,27 +66,41 @@
/*
* Page types allocated by the device.
*/
-enum {
+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 {
atomic_t refcnt; /* Number of vmas sharing the data. */
- spinlock_t lock; /* Serialize access to the vma. */
+ spinlock_t lock; /* Serialize access to this structure. */
int count; /* Number of pages allocated. */
- int type; /* Type of pages allocated. */
+ enum mspec_page_type type; /* Type of pages allocated. */
+ int flags; /* See VMD_xxx below. */
+ unsigned long vm_start; /* Original (unsplit) base. */
+ unsigned long vm_end; /* Original (unsplit) end. */
unsigned long maddr[0]; /* Array of MSPEC addresses. */
};
+#define VMD_VMALLOCED 0x1 /* vmalloc'd rather than kmalloc'd */
+
/* used on shub2 to clear FOP cache in the HUB */
static unsigned long scratch_page[MAX_NUMNODES];
#define SH2_AMO_CACHE_ENTRIES 4
@@ -125,8 +138,8 @@ mspec_zero_block(unsigned long addr, int len)
* 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.
+ * (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)
@@ -141,69 +154,68 @@ mspec_open(struct vm_area_struct *vma)
* mspec_close
*
* Called when unmapping a device mapping. Frees all mspec pages
- * belonging to the vma.
+ * 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 i, pages, result, vdata_size;
+ int index, last_index;
+ unsigned long my_page;
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)
+ 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.
*/
- result = mspec_zero_block(vdata->maddr[i], PAGE_SIZE);
- if (!result)
- uncached_free_page(vdata->maddr[i]);
+ 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 %i\n",
- result);
+ "failed to zero page %ld\n", my_page);
}
- if (vdata_size <= PAGE_SIZE)
- kfree(vdata);
- else
+ if (vdata->flags & VMD_VMALLOCED)
vfree(vdata);
+ else
+ kfree(vdata);
}
-
/*
- * mspec_nopfn
+ * mspec_fault
*
* Creates a mspec page and maps it to user space.
*/
-static unsigned long
-mspec_nopfn(struct vm_area_struct *vma, unsigned long address)
+static int
+mspec_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
unsigned long paddr, maddr;
unsigned long pfn;
- int index;
+ pgoff_t index = vmf->pgoff;
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());
+ maddr = uncached_alloc_page(numa_node_id(), 1);
if (maddr == 0)
- return NOPFN_OOM;
+ return VM_FAULT_OOM;
spin_lock(&vdata->lock);
if (vdata->maddr[index] == 0) {
vdata->count++;
vdata->maddr[index] = maddr;
} else {
- uncached_free_page(maddr);
+ uncached_free_page(maddr, 1);
maddr = vdata->maddr[index];
}
spin_unlock(&vdata->lock);
@@ -212,31 +224,39 @@ mspec_nopfn(struct vm_area_struct *vma, unsigned long address)
if (vdata->type == MSPEC_FETCHOP)
paddr = TO_AMO(maddr);
else
- paddr = __pa(TO_CAC(maddr));
+ paddr = maddr & ~__IA64_UNCACHED_OFFSET;
pfn = paddr >> PAGE_SHIFT;
- return pfn;
+ /*
+ * vm_insert_pfn can fail with -EBUSY, but in that case it will
+ * be because another thread has installed the pte first, so it
+ * is no problem.
+ */
+ vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
+
+ return VM_FAULT_NOPAGE;
}
-static struct vm_operations_struct mspec_vm_ops = {
+static const struct vm_operations_struct mspec_vm_ops = {
.open = mspec_open,
.close = mspec_close,
- .nopfn = mspec_nopfn
+ .fault = mspec_fault,
};
/*
* mspec_mmap
*
- * Called when mmaping the device. Initializes the vma with a fault handler
+ * 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, int type)
+mspec_mmap(struct file *file, struct vm_area_struct *vma,
+ enum mspec_page_type type)
{
struct vma_data *vdata;
- int pages, vdata_size;
+ int pages, vdata_size, flags = 0;
if (vma->vm_pgoff != 0)
return -EINVAL;
@@ -247,22 +267,26 @@ mspec_mmap(struct file *file, struct vm_area_struct *vma, int type)
if ((vma->vm_flags & VM_WRITE) == 0)
return -EPERM;
- pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+ pages = vma_pages(vma);
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);
+ vdata = kzalloc(vdata_size, GFP_KERNEL);
+ else {
+ vdata = vzalloc(vdata_size);
+ flags = VMD_VMALLOCED;
+ }
if (!vdata)
return -ENOMEM;
- memset(vdata, 0, vdata_size);
+ vdata->vm_start = vma->vm_start;
+ vdata->vm_end = vma->vm_end;
+ vdata->flags = flags;
vdata->type = type;
spin_lock_init(&vdata->lock);
- vdata->refcnt = ATOMIC_INIT(1);
+ atomic_set(&vdata->refcnt, 1);
vma->vm_private_data = vdata;
- vma->vm_flags |= (VM_IO | VM_LOCKED | VM_RESERVED | VM_PFNMAP);
+ 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;
@@ -288,9 +312,10 @@ uncached_mmap(struct file *file, struct vm_area_struct *vma)
return mspec_mmap(file, vma, MSPEC_UNCACHED);
}
-static struct file_operations fetchop_fops = {
+static const struct file_operations fetchop_fops = {
.owner = THIS_MODULE,
- .mmap = fetchop_mmap
+ .mmap = fetchop_mmap,
+ .llseek = noop_llseek,
};
static struct miscdevice fetchop_miscdev = {
@@ -299,9 +324,10 @@ static struct miscdevice fetchop_miscdev = {
.fops = &fetchop_fops
};
-static struct file_operations cached_fops = {
+static const struct file_operations cached_fops = {
.owner = THIS_MODULE,
- .mmap = cached_mmap
+ .mmap = cached_mmap,
+ .llseek = noop_llseek,
};
static struct miscdevice cached_miscdev = {
@@ -310,9 +336,10 @@ static struct miscdevice cached_miscdev = {
.fops = &cached_fops
};
-static struct file_operations uncached_fops = {
+static const struct file_operations uncached_fops = {
.owner = THIS_MODULE,
- .mmap = uncached_mmap
+ .mmap = uncached_mmap,
+ .llseek = noop_llseek,
};
static struct miscdevice uncached_miscdev = {
@@ -336,16 +363,17 @@ mspec_init(void)
* 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_online_node(nid) {
+ for_each_node_state(nid, N_ONLINE) {
int actual_nid;
int nasid;
unsigned long phys;
- scratch_page[nid] = uncached_alloc_page(nid);
+ scratch_page[nid] = uncached_alloc_page(nid, 1);
if (scratch_page[nid] == 0)
goto free_scratch_pages;
phys = __pa(scratch_page[nid]);
@@ -364,6 +392,7 @@ mspec_init(void)
goto free_scratch_pages;
}
}
+#endif
ret = misc_register(&cached_miscdev);
if (ret) {
printk(KERN_ERR "%s: failed to register device %i\n",
@@ -391,7 +420,7 @@ mspec_init(void)
free_scratch_pages:
for_each_node(nid) {
if (scratch_page[nid] != 0)
- uncached_free_page(scratch_page[nid]);
+ uncached_free_page(scratch_page[nid], 1);
}
return ret;
}
@@ -408,7 +437,7 @@ mspec_exit(void)
for_each_node(nid) {
if (scratch_page[nid] != 0)
- uncached_free_page(scratch_page[nid]);
+ uncached_free_page(scratch_page[nid], 1);
}
}
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-08 09:03:25 +0000