WebSVN – HelenOS – Diff – /trunk/kernel/generic/src/ddi/ddi.c

 #include <security/cap.h>
 #include <mm/frame.h>
 #include <mm/as.h>
 #include <synch/spinlock.h>
 #include <syscall/copy.h>
+#include <adt/btree.h>
 #include <arch.h>
 #include <align.h>
 #include <errno.h>
+/** This lock protects the parea_btree. */
+SPINLOCK_INITIALIZE(parea_lock);
+/** B+tree with enabled physical memory areas. */
+static btree_t parea_btree;
+/** Initialize DDI. */
+void ddi_init(void)
+{
+    btree_create(&parea_btree);
+}
+/** Enable piece of physical memory for mapping by physmem_map().
+ *
+ * @param parea Pointer to physical area structure.
+ *
+ * @todo This function doesn't check for overlaps. It depends on the kernel to
+ * create disjunct physical memory areas.
+ */
+void ddi_parea_register(parea_t *parea)
+{
+    ipl_t ipl;
+    ipl = interrupts_disable();
+    spinlock_lock(&parea_lock);
+    /*
+     * TODO: we should really check for overlaps here.
+     * However, we should be safe because the kernel is pretty sane and
+     * memory of different devices doesn't overlap.
+     */
+    btree_insert(&parea_btree, (btree_key_t) parea->pbase, parea, NULL);
+    spinlock_unlock(&parea_lock);
+    interrupts_restore(ipl);
+}
 /** Map piece of physical memory into virtual address space of current task.
+ *
- * @param pf Physical frame address of the starting frame.
+ * @param pf Physical address of the starting frame.
- * @param vp Virtual page address of the starting page.
+ * @param vp Virtual address of the starting page.
  * @param pages Number of pages to map.
  * @param flags Address space area flags for the mapping.
+ *
- * @return 0 on success, EPERM if the caller lacks capabilities to use this syscall,
+ * @return 0 on success, EPERM if the caller lacks capabilities to use this
- *     ENOENT if there is no task matching the specified ID and ENOMEM if
+ *  syscall, ENOENT if there is no task matching the specified ID or the
+ *  physical address space is not enabled for mapping and ENOMEM if there
- *     there was a problem in creating address space area.
+ *  was a problem in creating address space area. ENOTSUP is returned when
+ *  an attempt to create an illegal address alias is detected.
  */
 static int ddi_physmem_map(uintptr_t pf, uintptr_t vp, count_t pages, int flags)
+{
     ipl_t ipl;
     cap_t caps;
     caps = cap_get(TASK);
     if (!(caps & CAP_MEM_MANAGER))
         return EPERM;
     ipl = interrupts_disable();
+    /*
+     * Check if the physical memory area is enabled for mapping.
+     * If the architecture supports virtually indexed caches, intercept
+     * attempts to create an illegal address alias.
+     */
+    spinlock_lock(&parea_lock);
+    parea_t *parea;
+    btree_node_t *nodep;
+    parea = btree_search(&parea_btree, (btree_key_t) pf, &nodep);
+    if (!parea || parea->frames < pages || ((flags & AS_AREA_CACHEABLE) &&
+        !parea->cacheable) || (!(flags & AS_AREA_CACHEABLE) &&
+        parea->cacheable)) {
+        /*
+         * This physical memory area cannot be mapped.
+         */
+        spinlock_unlock(&parea_lock);
+        interrupts_restore(ipl);
+        return ENOENT;
+    }
+#ifdef CONFIG_VIRT_IDX_DCACHE
+    if (PAGE_COLOR(parea->vbase) != PAGE_COLOR(vp)) {
+        /*
+         * Refuse to create an illegal address alias.
+         */
+        spinlock_unlock(&parea_lock);
+        interrupts_restore(ipl);
+        return ENOTSUP;
+    }
+#endif /* CONFIG_VIRT_IDX_DCACHE */
+    spinlock_unlock(&parea_lock);
     spinlock_lock(&TASK->lock);
     if (!as_area_create(TASK->as, flags, pages * PAGE_SIZE, vp, AS_AREA_ATTR_NONE,
         &phys_backend, &backend_data)) {
         /*
+ *
  * @param id Task ID of the destination task.
  * @param ioaddr Starting I/O address.
  * @param size Size of the enabled I/O space..
+ *
- * @return 0 on success, EPERM if the caller lacks capabilities to use this syscall,
+ * @return 0 on success, EPERM if the caller lacks capabilities to use this
- *     ENOENT if there is no task matching the specified ID.
+ *  syscall, ENOENT if there is no task matching the specified ID.
  */
 static int ddi_iospace_enable(task_id_t id, uintptr_t ioaddr, size_t size)
+{
     ipl_t ipl;
     cap_t caps;
  * @param pages Number of pages
  * @param flags Flags of newly mapped pages
+ *
  * @return 0 on success, otherwise it returns error code found in errno.h
  */
-unative_t sys_physmem_map(unative_t phys_base, unative_t virt_base, unative_t pages,
+unative_t sys_physmem_map(unative_t phys_base, unative_t virt_base, unative_t
-             unative_t flags)
+    pages, unative_t flags)
+{
-    return (unative_t) ddi_physmem_map(ALIGN_DOWN((uintptr_t) phys_base, FRAME_SIZE),
+    return (unative_t) ddi_physmem_map(ALIGN_DOWN((uintptr_t) phys_base,
-                      ALIGN_DOWN((uintptr_t) virt_base, PAGE_SIZE), (count_t) pages,
+        FRAME_SIZE), ALIGN_DOWN((uintptr_t) virt_base, PAGE_SIZE),
-                      (int) flags);
+        (count_t) pages, (int) flags);
+}
 /** Wrapper for SYS_ENABLE_IOSPACE syscall.
+ *
  * @param uspace_io_arg User space address of DDI argument structure.
     rc = copy_from_uspace(&arg, uspace_io_arg, sizeof(ddi_ioarg_t));
     if (rc != 0)
         return (unative_t) rc;
-    return (unative_t) ddi_iospace_enable((task_id_t) arg.task_id, (uintptr_t) arg.ioaddr, (size_t) arg.size);
+    return (unative_t) ddi_iospace_enable((task_id_t) arg.task_id,
+        (uintptr_t) arg.ioaddr, (size_t) arg.size);
+}
 /** Disable or enable preemption.
+ *
- * @param enable If non-zero, the preemption counter will be decremented, leading to potential
+ * @param enable If non-zero, the preemption counter will be decremented,
- *       enabling of preemption. Otherwise the preemption counter will be incremented,
+ *  leading to potential enabling of preemption. Otherwise the preemption
- *       preventing preemption from occurring.
+ *  counter will be incremented, preventing preemption from occurring.
+ *
  * @return Zero on success or EPERM if callers capabilities are not sufficient.
  */
 unative_t sys_preempt_control(int enable)
+{

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(root)/trunk/kernel/generic/src/ddi/ddi.c @ 2071 – Rev 2012 → 2015