Mailing List Archive

[IA64] Allow multiple-time mmap of the privcmd device
# HG changeset patch
# User awilliam@xenbuild.aw
# Node ID 06e5c5599147cd34caab554ca71ab03e52c85e6f
# Parent 608ac00f4cfc9020958ab5e15d00daf752ab73a2
[IA64] Allow multiple-time mmap of the privcmd device

Allow multiple-time mmap of the privcmd device. The old implemntation
doesn't allow multiple-time mmap for a same struct file_struct.
However xend or qemu does multiple-time mmap.
This patch affects only dom0 vp model. With this patch multiple domu can
boot simultaneously and vti domain can boot on vp model dom0.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
---
linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c | 104 +++++++++++-------------
1 files changed, 49 insertions(+), 55 deletions(-)

diff -r 608ac00f4cfc -r 06e5c5599147 linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c
--- a/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c Tue May 16 08:59:26 2006 -0600
+++ b/linux-2.6-xen-sparse/arch/ia64/xen/hypervisor.c Tue May 16 09:05:36 2006 -0600
@@ -23,6 +23,7 @@
//#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/bootmem.h>
+#include <linux/vmalloc.h>
#include <asm/page.h>
#include <asm/hypervisor.h>
#include <asm/hypercall.h>
@@ -363,7 +364,6 @@ struct xen_ia64_privcmd_entry {
struct xen_ia64_privcmd_entry {
atomic_t map_count;
struct page* page;
- unsigned long mfn;
};

static void
@@ -371,9 +371,13 @@ xen_ia64_privcmd_init_entry(struct xen_i
{
atomic_set(&entry->map_count, 0);
entry->page = NULL;
- entry->mfn = INVALID_MFN;
-}
-
+}
+
+//TODO alloc_page() to allocate pseudo physical address space is
+// waste of memory.
+// When vti domain is created, qemu maps all of vti domain pages which
+// reaches to several hundred megabytes at least.
+// remove alloc_page().
static int
xen_ia64_privcmd_entry_mmap(struct vm_area_struct* vma,
unsigned long addr,
@@ -418,7 +422,6 @@ xen_ia64_privcmd_entry_mmap(struct vm_ar
} else {
atomic_inc(&entry->map_count);
entry->page = page;
- entry->mfn = mfn;
}

out:
@@ -443,7 +446,6 @@ xen_ia64_privcmd_entry_munmap(struct xen
}

entry->page = NULL;
- entry->mfn = INVALID_MFN;
__free_page(page);
}

@@ -465,9 +467,8 @@ xen_ia64_privcmd_entry_close(struct xen_
}
}

-struct xen_ia64_privcmd_file {
- struct file* file;
- atomic_t map_count;
+struct xen_ia64_privcmd_range {
+ atomic_t ref_count;
unsigned long pgoff; // in PAGE_SIZE

unsigned long num_entries;
@@ -475,7 +476,8 @@ struct xen_ia64_privcmd_file {
};

struct xen_ia64_privcmd_vma {
- struct xen_ia64_privcmd_file* file;
+ struct xen_ia64_privcmd_range* range;
+
unsigned long num_entries;
struct xen_ia64_privcmd_entry* entries;
};
@@ -490,20 +492,19 @@ struct vm_operations_struct xen_ia64_pri

static void
__xen_ia64_privcmd_vma_open(struct vm_area_struct* vma,
- struct xen_ia64_privcmd_vma* privcmd_vma)
-{
- struct xen_ia64_privcmd_file* privcmd_file =
- (struct xen_ia64_privcmd_file*)vma->vm_file->private_data;
- unsigned long entry_offset = vma->vm_pgoff - privcmd_file->pgoff;
+ struct xen_ia64_privcmd_vma* privcmd_vma,
+ struct xen_ia64_privcmd_range* privcmd_range)
+{
+ unsigned long entry_offset = vma->vm_pgoff - privcmd_range->pgoff;
unsigned long num_entries = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
unsigned long i;

BUG_ON(entry_offset < 0);
- BUG_ON(entry_offset + num_entries > privcmd_file->num_entries);
-
- privcmd_vma->file = privcmd_file;
+ BUG_ON(entry_offset + num_entries > privcmd_range->num_entries);
+
+ privcmd_vma->range = privcmd_range;
privcmd_vma->num_entries = num_entries;
- privcmd_vma->entries = &privcmd_file->entries[entry_offset];
+ privcmd_vma->entries = &privcmd_range->entries[entry_offset];
vma->vm_private_data = privcmd_vma;
for (i = 0; i < privcmd_vma->num_entries; i++) {
xen_ia64_privcmd_entry_open(&privcmd_vma->entries[i]);
@@ -516,15 +517,14 @@ static void
static void
xen_ia64_privcmd_vma_open(struct vm_area_struct* vma)
{
- struct xen_ia64_privcmd_file* privcmd_file =
- (struct xen_ia64_privcmd_file*)vma->vm_file->private_data;
- struct xen_ia64_privcmd_vma* privcmd_vma;
-
- atomic_inc(&privcmd_file->map_count);
+ struct xen_ia64_privcmd_vma* privcmd_vma = (struct xen_ia64_privcmd_vma*)vma->vm_private_data;
+ struct xen_ia64_privcmd_range* privcmd_range = privcmd_vma->range;
+
+ atomic_inc(&privcmd_range->ref_count);
// vm_op->open() can't fail.
privcmd_vma = kmalloc(sizeof(*privcmd_vma), GFP_KERNEL | __GFP_NOFAIL);

- __xen_ia64_privcmd_vma_open(vma, privcmd_vma);
+ __xen_ia64_privcmd_vma_open(vma, privcmd_vma, privcmd_range);
}

static void
@@ -532,7 +532,7 @@ xen_ia64_privcmd_vma_close(struct vm_are
{
struct xen_ia64_privcmd_vma* privcmd_vma =
(struct xen_ia64_privcmd_vma*)vma->vm_private_data;
- struct xen_ia64_privcmd_file* privcmd_file = privcmd_vma->file;
+ struct xen_ia64_privcmd_range* privcmd_range = privcmd_vma->range;
unsigned long i;

for (i = 0; i < privcmd_vma->num_entries; i++) {
@@ -541,17 +541,16 @@ xen_ia64_privcmd_vma_close(struct vm_are
vma->vm_private_data = NULL;
kfree(privcmd_vma);

- if (atomic_dec_and_test(&privcmd_file->map_count)) {
+ if (atomic_dec_and_test(&privcmd_range->ref_count)) {
#if 1
- for (i = 0; i < privcmd_file->num_entries; i++) {
+ for (i = 0; i < privcmd_range->num_entries; i++) {
struct xen_ia64_privcmd_entry* entry =
- &privcmd_vma->entries[i];
+ &privcmd_range->entries[i];
BUG_ON(atomic_read(&entry->map_count) != 0);
BUG_ON(entry->page != NULL);
}
#endif
- privcmd_file->file->private_data = NULL;
- kfree(privcmd_file->file->private_data);
+ vfree(privcmd_range);
}
}

@@ -559,22 +558,16 @@ privcmd_mmap(struct file * file, struct
privcmd_mmap(struct file * file, struct vm_area_struct * vma)
{
unsigned long num_entries = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
- struct xen_ia64_privcmd_file* privcmd_file;
+ struct xen_ia64_privcmd_range* privcmd_range;
struct xen_ia64_privcmd_vma* privcmd_vma;
unsigned long i;
BUG_ON(!running_on_xen);

- /* DONTCOPY is essential for Xen as copy_page_range is broken. */
- vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY;
-
- if (file->private_data != NULL) {
- return -EBUSY;
- }
-
- privcmd_file = kmalloc(sizeof(*privcmd_file) +
- sizeof(privcmd_file->entries[0]) * num_entries,
- GFP_KERNEL);
- if (privcmd_file == NULL) {
+ BUG_ON(file->private_data != NULL);
+ privcmd_range =
+ vmalloc(sizeof(*privcmd_range) +
+ sizeof(privcmd_range->entries[0]) * num_entries);
+ if (privcmd_range == NULL) {
goto out_enomem0;
}
privcmd_vma = kmalloc(sizeof(*privcmd_vma), GFP_KERNEL);
@@ -582,22 +575,23 @@ privcmd_mmap(struct file * file, struct
goto out_enomem1;
}

- atomic_set(&privcmd_file->map_count, 1);
- privcmd_file->num_entries = num_entries;
- for (i = 0; i < privcmd_file->num_entries; i++) {
- xen_ia64_privcmd_init_entry(&privcmd_file->entries[i]);
- }
- file->private_data = privcmd_file;
- privcmd_file->file = file;
- privcmd_file->pgoff = vma->vm_pgoff;
-
- __xen_ia64_privcmd_vma_open(vma, privcmd_vma);
+ /* DONTCOPY is essential for Xen as copy_page_range is broken. */
+ vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;
+
+ atomic_set(&privcmd_range->ref_count, 1);
+ privcmd_range->pgoff = vma->vm_pgoff;
+ privcmd_range->num_entries = num_entries;
+ for (i = 0; i < privcmd_range->num_entries; i++) {
+ xen_ia64_privcmd_init_entry(&privcmd_range->entries[i]);
+ }
+
+ __xen_ia64_privcmd_vma_open(vma, privcmd_vma, privcmd_range);
return 0;

out_enomem1:
kfree(privcmd_vma);
out_enomem0:
- kfree(privcmd_file);
+ vfree(privcmd_range);
return -ENOMEM;
}

@@ -625,7 +619,7 @@ direct_remap_pfn_range(struct vm_area_st
i = (address - vma->vm_start) >> PAGE_SHIFT;
for (offset = 0; offset < size; offset += PAGE_SIZE) {
struct xen_ia64_privcmd_entry* entry =
- &privcmd_vma->file->entries[i];
+ &privcmd_vma->entries[i];
error = xen_ia64_privcmd_entry_mmap(vma, (address + offset) & PAGE_MASK, entry, mfn, prot, domid);
if (error != 0) {
break;

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