Hi,
I need to be able to map an IO memory buffer to userspace from a RTDM
driver.
rtdm_mmap_to_user() seems to do what I need, but it doesn't work. Its
code thinks that all virtual addresses between VMALLOC_START and
VMALLOC_END are obtained through vmalloc() and tries to call
xnarch_remap_vm_page() on them, which fails.
Virtual addresses coming from ioremap() need to go through
xnarch_remap_io_page_range(), and their physical address cannot be
obtained with a simple virt_to_phys().
A working patch is attached below, but there might (should ?) be a
better way to do it. Some of the code may also belong to
asm-generic/system.h instead of the RTDM skin.
Note that you may also need to EXPORT_SYMBOL(vmlist and vmlist_lock) in
mm/vmalloc.c if you want to build the RTDM skin as a module.
Comments ?
Stelian.
Index: ksrc/skins/rtdm/drvlib.c
===================================================================
--- ksrc/skins/rtdm/drvlib.c (révision 1624)
+++ ksrc/skins/rtdm/drvlib.c (copie de travail)
@@ -1377,6 +1377,7 @@
{
struct rtdm_mmap_data *mmap_data = filp->private_data;
unsigned long vaddr, maddr, size;
+ struct vm_struct *vm;
vma->vm_ops = mmap_data->vm_ops;
vma->vm_private_data = mmap_data->vm_private_data;
@@ -1385,7 +1386,21 @@
maddr = vma->vm_start;
size = vma->vm_end - vma->vm_start;
+ write_lock(&vmlist_lock);
+ for (vm = vmlist; vm != NULL; vm = vm->next) {
+ if (vm->addr == (void *)vaddr)
+ break;
+ }
+ write_unlock(&vmlist_lock);
+
+ /* ioremap'ed memory */
+ if (vm && vm->flags & VM_IOREMAP)
+ return xnarch_remap_io_page_range(vma, maddr,
+ vm->phys_addr,
+ size, PAGE_SHARED);
+ else
#ifdef CONFIG_MMU
+ /* vmalloc'ed memory */
if ((vaddr >= VMALLOC_START) && (vaddr < VMALLOC_END)) {
unsigned long mapped_size = 0;
--
Stelian Pop <[EMAIL PROTECTED]>
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