Stelian Pop wrote: > Le vendredi 15 septembre 2006 à 18:40 +0200, Jan Kiszka a écrit : > >> In case no one comes up with an easy, portable way to detect remapped >> memory as well: What about some flags the caller of rtdm_mmap_to_user >> has to pass, telling what kind of memory it is? Would simplify the RTDM >> part, and the user normally knows quite well where the memory came from. >> And I love to break APIs. :) > > This would be perfect. We could even reuse the prot field for that > (PROT_READ | PROT_WRITE | PROT_VMALLOC | PROT_IOREMAP). Not the cleanest > solution, but it won't break the API this way.
It would not change the function signature, but its argument semantics. We should better make a clean cut which signals via compiler errors that something changed. > > Or maybe we should lower the API level a little bit, and let the user > specify the physical address of the mapping instead of the virtual > one.... How would this help? You still need the virtual address for VMA blocks in order to collect the pages. I really think a separate mem-type argument is what we should do. And here comes a first patch in this direction. Only compile-tested so far, feedback is welcome. Jan
Index: include/rtdm/rtdm_driver.h
===================================================================
--- include/rtdm/rtdm_driver.h (revision 1648)
+++ include/rtdm/rtdm_driver.h (working copy)
@@ -1021,6 +1021,25 @@ int rtdm_mutex_timedlock(rtdm_mutex_t *m
/* --- utility functions --- */
+/*!
+ * @addtogroup util
+ * @{
+ */
+
+/*!
+ * @anchor RTDM_MEMTYPE_xxx @name Memory Types
+ * Flags defining the type of a memory region
+ * @{
+ */
+/** Allocated with kmalloc() */
+#define RTDM_MEMTYPE_KMALLOC 0x00
+/** Remapped physical memory */
+#define RTDM_MEMTYPE_IOREMAP 0x01
+/** Allocated with vmalloc() */
+#define RTDM_MEMTYPE_VMALLOC 0x02
+/** @} Memory Types */
+/** @} util */
+
#define rtdm_printk(format, ...) printk(format, ##__VA_ARGS__)
#ifndef DOXYGEN_CPP /* Avoid static inline tags for RTDM in doxygen */
@@ -1036,7 +1055,7 @@ static inline void rtdm_free(void *ptr)
#ifdef CONFIG_XENO_OPT_PERVASIVE
int rtdm_mmap_to_user(rtdm_user_info_t *user_info, void *src_addr, size_t len,
- int prot, void **pptr,
+ int mem_type, int prot, void **pptr,
struct vm_operations_struct *vm_ops,
void *vm_private_data);
int rtdm_munmap(rtdm_user_info_t *user_info, void *ptr, size_t len);
Index: ksrc/skins/rtdm/drvlib.c
===================================================================
--- ksrc/skins/rtdm/drvlib.c (revision 1648)
+++ ksrc/skins/rtdm/drvlib.c (working copy)
@@ -1369,6 +1369,7 @@ void rtdm_nrtsig_pend(rtdm_nrtsig_t *nrt
#if defined(CONFIG_XENO_OPT_PERVASIVE) || defined(DOXYGEN_CPP)
struct rtdm_mmap_data {
void *src_addr;
+ int mem_type;
struct vm_operations_struct *vm_ops;
void *vm_private_data;
};
@@ -1386,7 +1387,7 @@ static int rtdm_mmap_buffer(struct file
size = vma->vm_end - vma->vm_start;
#ifdef CONFIG_MMU
- if ((vaddr >= VMALLOC_START) && (vaddr < VMALLOC_END)) {
+ if (mmap_data->mem_type == RTDM_MEMTYPE_VMALLOC) {
unsigned long mapped_size = 0;
XENO_ASSERT(RTDM, (vaddr == PAGE_ALIGN(vaddr)), return -EINVAL);
@@ -1419,6 +1420,8 @@ static struct file_operations rtdm_mmap_
* device operation handler
* @param[in] src_addr Kernel address to be mapped
* @param[in] len Length of the memory range
+ * @param[in] mem_type Type of the passed memory range, see
+ * @ref RTDM_MEMTYPE_xxx
* @param[in] prot Protection flags for the user's memory range, typically
* either PROT_READ or PROT_READ|PROT_WRITE
* @param[in,out] pptr Address of a pointer containing the desired user
@@ -1463,11 +1466,12 @@ static struct file_operations rtdm_mmap_
* Rescheduling: possible.
*/
int rtdm_mmap_to_user(rtdm_user_info_t *user_info, void *src_addr, size_t len,
- int prot, void **pptr,
+ int mem_type, int prot, void **pptr,
struct vm_operations_struct *vm_ops,
void *vm_private_data)
{
- struct rtdm_mmap_data mmap_data = {src_addr, vm_ops, vm_private_data};
+ struct rtdm_mmap_data mmap_data = { src_addr, mem_type, vm_ops,
+ vm_private_data };
struct file *filp;
const struct file_operations *old_fops;
void *old_priv_data;
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