Changeset 46321fb in mainline for kernel/arch/ia64/src/mm/tlb.c

Timestamp:

2008-11-25T20:22:04Z (16 years ago)

Author:

Jakub Vana <jakub.vana@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

83d9712

Parents:

14c331a

Message:

IA64: Userspace I/O support

File:

• kernel/arch/ia64/src/mm/tlb.c (modified) (2 diffs)

kernel/arch/ia64/src/mm/tlb.c

@@ -476 +476 @@
 }
 
+
+
+static int is_io_page_accessible(int page)
+{
+        if(TASK->arch.iomap) return bitmap_get(TASK->arch.iomap,page);
+        else return 0;
+}
+
+#define IO_FRAME_BASE 0xFFFFC000000
+
+/** There is special handling of memmaped lagacy io, because
+ * of 4KB sized access
+ * only for userspace
+ *
+ * @param va virtual address of page fault
+ * @param istate Structure with saved interruption state.
+ *
+ *
+ * @return 1 on success, 0 on fail
+ */
+static int try_memmap_io_insertion(uintptr_t va, istate_t *istate)
+{
+        if((va >= IO_OFFSET ) && (va < IO_OFFSET + (1<<IO_PAGE_WIDTH)))
+                if(TASK){
+                        
+                        uint64_t io_page=(va &  ((1<<IO_PAGE_WIDTH)-1)) >> (USPACE_IO_PAGE_WIDTH);
+                        if(is_io_page_accessible(io_page)){
+                                //printf("Insert %llX\n",va);
+
+                                uint64_t page,frame;
+
+                                page = IO_OFFSET + (1 << USPACE_IO_PAGE_WIDTH) * io_page;
+                                frame = IO_FRAME_BASE + (1 << USPACE_IO_PAGE_WIDTH) * io_page;
+
+
+                                tlb_entry_t entry;
+        
+                                entry.word[0] = 0;
+                                entry.word[1] = 0;
+        
+                                entry.p = true;                 /* present */
+                                entry.ma = MA_UNCACHEABLE;              
+                                entry.a = true;                 /* already accessed */
+                                entry.d = true;                 /* already dirty */
+                                entry.pl = PL_USER;
+                                entry.ar = AR_READ | AR_WRITE;
+                                entry.ppn = frame >> PPN_SHIFT;    //MUSIM spocitat frame
+                                entry.ps = USPACE_IO_PAGE_WIDTH;
+        
+                                dtc_mapping_insert(page, TASK->as->asid, entry); //Musim zjistit ASID
+                                return 1;
+                        }else {
+                                fault_if_from_uspace(istate,"IO access fault at %p",va);
+                                return 0;
+                        }               
+                } else 
+                        return 0;
+        else 
+                return 0;
+                
+        return 0;
+
+}
+
+
+
+
 /** Data TLB fault handler for faults with VHPT turned off.
  *
@@ -512 +579 @@
                 page_table_unlock(AS, true);
         } else {
+                page_table_unlock(AS, true);
+                if (try_memmap_io_insertion(va,istate)) return;
                 /*
                  * Forward the page fault to the address space page fault handler.
                  */
-                page_table_unlock(AS, true);
                 if (as_page_fault(va, PF_ACCESS_READ, istate) == AS_PF_FAULT) {
                         fault_if_from_uspace(istate,"Page fault at %p",va);