Module: xenomai-head
Branch: master
Commit: 8c05ad4fbbbd72ab0d02fff21319f0ccd0a93492
URL:
http://git.xenomai.org/?p=xenomai-head.git;a=commit;h=8c05ad4fbbbd72ab0d02fff21319f0ccd0a93492
Author: Philippe Gerum <r...@xenomai.org>
Date: Wed Jun 16 10:25:24 2010 +0200
rtdm: fix memory mapping services for nommu platforms
This patch is a follow-up to ada72009a, fixing the
rtdm_mmap/iomap_to_user() services, in the nommu case.
The rationale for it is that backing devices on nommu must have direct
mapping capabilities to support shared mapping requests (MAP_SHARED),
which are not available from /dev/zero.
We fix this by using /dev/rtheap instead of /dev/zero for issuing
non-anonymous mapping requests from rtdm_do_mmap(), since default caps
for character-based devices include BDI_CAP_MAP_DIRECT. In the same
move, we provide the missing .get_unmapped_area helper.
---
include/compat/linux/err.h | 2 +
ksrc/skins/rtdm/drvlib.c | 62 +++++++++++++++++++++++++++++++++----------
2 files changed, 49 insertions(+), 15 deletions(-)
diff --git a/include/compat/linux/err.h b/include/compat/linux/err.h
index ae980db..81a6134 100644
--- a/include/compat/linux/err.h
+++ b/include/compat/linux/err.h
@@ -23,4 +23,6 @@
#include <linux/fs.h>
+#define IS_ERR_VALUE(value) IS_ERR((void *)value)
+
#endif /* _XENO_COMPAT_LINUX_ERR_H */
diff --git a/ksrc/skins/rtdm/drvlib.c b/ksrc/skins/rtdm/drvlib.c
index 68a661c..3495e63 100644
--- a/ksrc/skins/rtdm/drvlib.c
+++ b/ksrc/skins/rtdm/drvlib.c
@@ -37,6 +37,7 @@
#include <asm/io.h>
#include <asm/pgtable.h>
#include <linux/highmem.h>
+#include <linux/err.h>
#include <rtdm/rtdm_driver.h>
@@ -1808,9 +1809,8 @@ static int rtdm_mmap_buffer(struct file *filp, struct
vm_area_struct *vma)
vaddr = (unsigned long)mmap_data->src_vaddr;
paddr = mmap_data->src_paddr;
- if (!paddr)
- /* kmalloc memory */
- paddr = virt_to_phys((void *)vaddr);
+ if (paddr == 0) /* kmalloc memory? */
+ paddr = __pa(vaddr);
maddr = vma->vm_start;
size = vma->vm_end - vma->vm_start;
@@ -1834,6 +1834,8 @@ static int rtdm_mmap_buffer(struct file *filp, struct
vm_area_struct *vma)
xnarch_fault_range(vma);
ret = 0;
} else
+#else
+ vma->vm_pgoff = paddr >> PAGE_SHIFT;
#endif /* CONFIG_MMU */
if (mmap_data->src_paddr)
ret = xnarch_remap_io_page_range(filp, vma, maddr, paddr,
@@ -1848,22 +1850,43 @@ static int rtdm_mmap_buffer(struct file *filp, struct
vm_area_struct *vma)
return ret;
}
+#ifndef CONFIG_MMU
+static unsigned long rtdm_unmapped_area(struct file *file,
+ unsigned long addr,
+ unsigned long len,
+ unsigned long pgoff,
+ unsigned long flags)
+{
+ struct rtdm_mmap_data *mmap_data = file->private_data;
+ unsigned long pa;
+
+ pa = mmap_data->src_paddr;
+ if (pa == 0)
+ pa = __pa(mmap_data->src_vaddr);
+
+ return pa;
+}
+#else
+#define rtdm_unmapped_area NULL
+#endif
+
static struct file_operations rtdm_mmap_fops = {
.mmap = rtdm_mmap_buffer,
+ .get_unmapped_area = rtdm_unmapped_area
};
static int rtdm_do_mmap(rtdm_user_info_t *user_info,
struct rtdm_mmap_data *mmap_data,
size_t len, int prot, void **pptr)
{
- struct file *filp;
const struct file_operations *old_fops;
+ unsigned long u_addr;
void *old_priv_data;
- void *user_ptr;
+ struct file *filp;
XENO_ASSERT(RTDM, xnpod_root_p(), return -EPERM;);
- filp = filp_open("/dev/zero", O_RDWR, 0);
+ filp = filp_open(XNHEAP_DEV_NAME, O_RDWR, 0);
if (IS_ERR(filp))
return PTR_ERR(filp);
@@ -1874,8 +1897,8 @@ static int rtdm_do_mmap(rtdm_user_info_t *user_info,
filp->private_data = mmap_data;
down_write(&user_info->mm->mmap_sem);
- user_ptr = (void *)do_mmap(filp, (unsigned long)*pptr, len, prot,
- MAP_SHARED, 0);
+ u_addr = do_mmap(filp, (unsigned long)*pptr, len, prot,
+ MAP_SHARED, 0);
up_write(&user_info->mm->mmap_sem);
filp->f_op = (typeof(filp->f_op))old_fops;
@@ -1883,10 +1906,11 @@ static int rtdm_do_mmap(rtdm_user_info_t *user_info,
filp_close(filp, user_info->files);
- if (IS_ERR(user_ptr))
- return PTR_ERR(user_ptr);
+ if (IS_ERR_VALUE(u_addr))
+ return (int)u_addr;
+
+ *pptr = (void *)u_addr;
- *pptr = user_ptr;
return 0;
}
@@ -1950,8 +1974,12 @@ int rtdm_mmap_to_user(rtdm_user_info_t *user_info,
struct vm_operations_struct *vm_ops,
void *vm_private_data)
{
- struct rtdm_mmap_data mmap_data =
- { src_addr, 0, vm_ops, vm_private_data };
+ struct rtdm_mmap_data mmap_data = {
+ .src_vaddr = src_addr,
+ .src_paddr = 0,
+ .vm_ops = vm_ops,
+ .vm_private_data = vm_private_data
+ };
return rtdm_do_mmap(user_info, &mmap_data, len, prot, pptr);
}
@@ -2014,8 +2042,12 @@ int rtdm_iomap_to_user(rtdm_user_info_t *user_info,
struct vm_operations_struct *vm_ops,
void *vm_private_data)
{
- struct rtdm_mmap_data mmap_data =
- { NULL, src_addr, vm_ops, vm_private_data };
+ struct rtdm_mmap_data mmap_data = {
+ .src_vaddr = NULL,
+ .src_paddr = src_addr,
+ .vm_ops = vm_ops,
+ .vm_private_data = vm_private_data
+ };
return rtdm_do_mmap(user_info, &mmap_data, len, prot, pptr);
}
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