Bug #8707, 2.6.19-rc compatibility for memory manager code.

linux-core/drm_compat.c

@@ -28,6 +28,11 @@
 #include "drmP.h"
 
 #if defined(CONFIG_X86) && (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
+
+/*
+ * These have bad performance in the AGP module for the indicated kernel versions.
+ */
+
 int drm_map_page_into_agp(struct page *page)
 {
         int i;
@@ -45,9 +50,15 @@ int drm_unmap_page_from_agp(struct page *page)
          * performance reasons */
         return i;
 }
-#endif
+#endif 
 
 
+#if  (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
+
+/*
+ * The protection map was exported in 2.6.19
+ */
+
 pgprot_t vm_get_page_prot(unsigned long vm_flags)
 {
 #ifdef MODULE
@@ -62,8 +73,17 @@ pgprot_t vm_get_page_prot(unsigned long vm_flags)
 	return protection_map[vm_flags & 0x0F];
 #endif
 };
+#endif
 
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
+
+/*
+ * vm code for kernels below 2,6,15 in which version a major vm write
+ * occured. This implement a simple straightforward 
+ * version similar to what's going to be
+ * in kernel 2.6.20+?
+ */ 
 
 static int drm_pte_is_clear(struct vm_area_struct *vma,
 			    unsigned long addr)
@@ -76,12 +96,7 @@ static int drm_pte_is_clear(struct vm_area_struct *vma,
 	pgd_t *pgd;
 	
 
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
 	spin_lock(&mm->page_table_lock);
-#else
-	spinlock_t *ptl;
-#endif
-	
 	pgd = pgd_offset(mm, addr);
 	if (pgd_none(*pgd))
 		goto unlock;
@@ -91,22 +106,13 @@ static int drm_pte_is_clear(struct vm_area_struct *vma,
 	pmd = pmd_offset(pud, addr);
 	if (pmd_none(*pmd))
 		goto unlock;
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
 	pte = pte_offset_map(pmd, addr);
-#else 
-	pte = pte_offset_map_lock(mm, pmd, addr, &ptl); 
-#endif
 	if (!pte)
 		goto unlock;
 	ret = pte_none(*pte);
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
 	pte_unmap(pte);
  unlock:	
 	spin_unlock(&mm->page_table_lock);
-#else
-	pte_unmap_unlock(pte, ptl);
- unlock:
-#endif
 	return ret;
 }
 	
@@ -121,7 +127,6 @@ int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
 	return ret;
 }
 
-
 static struct {
 	spinlock_t lock;
 	struct page *dummy_page;
@@ -154,9 +159,6 @@ void free_nopage_retry(void)
 		spin_unlock(&drm_np_retry.lock);
 	}
 }
-#endif
-
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
 
 struct page *drm_vm_ttm_nopage(struct vm_area_struct *vma,
 			       unsigned long address, 
@@ -186,6 +188,17 @@ struct page *drm_vm_ttm_nopage(struct vm_area_struct *vma,
 
 #ifdef DRM_ODD_MM_COMPAT
 
+/*
+ * VM compatibility code for 2.6.15-2.6.19(?). This code implements a complicated
+ * workaround for a single BUG statement in do_no_page in these versions. The
+ * tricky thing is that we need to take the mmap_sem in exclusive mode for _all_
+ * vmas mapping the ttm, before dev->struct_mutex is taken. The way we do this is to 
+ * check first take the dev->struct_mutex, and then trylock all mmap_sems. If this
+ * fails for a single mmap_sem, we have to release all sems and the dev->struct_mutex,
+ * release the cpu and retry. We also need to keep track of all vmas mapping the ttm.
+ * phew.
+ */
+
 typedef struct p_mm_entry {
 	struct list_head head;
 	struct mm_struct *mm;

linux-core/drm_compat.h

@@ -231,7 +231,7 @@ static inline int remap_pfn_range(struct vm_area_struct *vma, unsigned long from
 #include <linux/mm.h>
 #include <asm/page.h>
 
-#if ((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)) && \
+#if ((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)) && \
      (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,15))) 
 #define DRM_ODD_MM_COMPAT
 #endif
@@ -277,7 +277,18 @@ extern int drm_map_page_into_agp(struct page *page);
 #define unmap_page_from_agp drm_unmap_page_from_agp
 #endif
 
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
+extern struct page *get_nopage_retry(void);
+extern void free_nopage_retry(void);
+struct fault_data;
+extern struct page *drm_vm_ttm_fault(struct vm_area_struct *vma, 
+				     struct fault_data *data);
+
+#define NOPAGE_REFAULT get_nopage_retry()
+#endif
+
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20))
 
 /*
  * Hopefully, real NOPAGE_RETRY functionality will be in 2.6.19. 
@@ -295,10 +306,6 @@ struct fault_data {
 	int type;
 };
 
-extern struct page *get_nopage_retry(void);
-extern void free_nopage_retry(void);
-
-#define NOPAGE_REFAULT get_nopage_retry()
 
 extern int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, 
 			 unsigned long pfn, pgprot_t pgprot);
@@ -307,9 +314,6 @@ extern struct page *drm_vm_ttm_nopage(struct vm_area_struct *vma,
 				      unsigned long address, 
 				      int *type);
 
-extern struct page *drm_vm_ttm_fault(struct vm_area_struct *vma, 
-				     struct fault_data *data);
-
 #endif
 
 #ifdef DRM_ODD_MM_COMPAT

linux-core/drm_drv.c

@@ -433,7 +433,7 @@ void drm_exit(struct drm_driver *driver)
 		}
 	} else
 		pci_unregister_driver(&driver->pci_driver);
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
 	free_nopage_retry();
 #endif
 	DRM_INFO("Module unloaded\n");
@@ -472,10 +472,14 @@ static void drm_free_mem_cache(kmem_cache_t *cache,
 {
 	if (!cache)
 		return;
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
 	if (kmem_cache_destroy(cache)) {
 		DRM_ERROR("Warning! DRM is leaking %s memory.\n",
 			  name);
 	}
+#else
+	kmem_cache_destroy(cache);
+#endif
 }
 
 static void drm_free_memory_caches(void )

linux-core/drm_vm.c

@@ -159,7 +159,9 @@ static __inline__ struct page *drm_do_vm_nopage(struct vm_area_struct *vma,
 }
 #endif				/* __OS_HAS_AGP */
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19))
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20) || \
+     LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20))
 static
 #endif
 struct page *drm_vm_ttm_fault(struct vm_area_struct *vma, 
@@ -244,7 +246,7 @@ struct page *drm_vm_ttm_fault(struct vm_area_struct *vma,
 	mutex_unlock(&dev->struct_mutex);
 	return NULL;
 }
-
+#endif
 
 /**
  * \c nopage method for shared virtual memory.
@@ -535,7 +537,7 @@ static struct vm_operations_struct drm_vm_sg_ops = {
 	.close = drm_vm_close,
 };
 
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19))
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20))
 static struct vm_operations_struct drm_vm_ttm_ops = {
 	.nopage = drm_vm_ttm_nopage,
 	.open = drm_vm_ttm_open_wrapper,