Changeset e12ccc5 in mainline for kernel/arch/xen32/src/xen32.c

Timestamp:

2006-08-01T17:27:11Z (18 years ago)

Author:

Martin Decky <martin@…>

Branches:

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

Children:

0fbfa0d

Parents:

e386cbf

Message:

xen32: use writable page tables, cleanup mm

File:

• kernel/arch/xen32/src/xen32.c (modified) (2 diffs)

kernel/arch/xen32/src/xen32.c

@@ -37 +37 @@
 #include <arch/types.h>
 #include <typedefs.h>
+#include <align.h>
 
 #include <arch/pm.h>
 
 #include <arch/drivers/xconsole.h>
+#include <arch/mm/page.h>
 
 #include <arch/context.h>
@@ -61 +63 @@
 
 start_info_t start_info;
+memzone_t meminfo;
+
+void arch_pre_main(void)
+{
+        xen_vm_assist(VMASST_CMD_ENABLE, VMASST_TYPE_WRITABLE_PAGETABLES);
+        
+        pte_t pte;
+        memsetb((uintptr_t) &pte, sizeof(pte), 0);
+        
+        pte.present = 1;
+        pte.writeable = 1;
+        pte.frame_address = ADDR2PFN((uintptr_t) start_info.shared_info);
+        xen_update_va_mapping(&shared_info, pte, UVMF_INVLPG);
+        
+        /* Create identity mapping */
+        
+        meminfo.start = ADDR2PFN(ALIGN_UP(KA2PA(start_info.ptl0), PAGE_SIZE)) + start_info.pt_frames;
+        meminfo.size = start_info.frames - meminfo.start;
+        meminfo.reserved = 0;
+        
+        uintptr_t pa;
+        index_t last_ptl0 = 0;
+        for (pa = PFN2ADDR(meminfo.start); pa < PFN2ADDR(meminfo.start + meminfo.size); pa += FRAME_SIZE) {
+                uintptr_t va = PA2KA(pa);
+                
+                if ((PTL0_INDEX(va) != last_ptl0) && (GET_PTL1_FLAGS(start_info.ptl0, PTL0_INDEX(va)) & PAGE_NOT_PRESENT)) {
+                        /* New page directory entry needed */
+                        uintptr_t tpa = PFN2ADDR(meminfo.start + meminfo.reserved);
+                        uintptr_t tva = PA2KA(tpa);
+                        
+                        memsetb(tva, PAGE_SIZE, 0);
+                        
+                        pte_t *tptl3 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(start_info.ptl0, PTL0_INDEX(tva)));
+                        SET_FRAME_FLAGS(tptl3, PTL3_INDEX(tva), PAGE_PRESENT);
+                        SET_PTL1_ADDRESS(start_info.ptl0, PTL0_INDEX(va), tpa);
+                        
+                        last_ptl0 = PTL0_INDEX(va);
+                        meminfo.reserved++;
+                }
+                
+                pte_t *ptl3 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(start_info.ptl0, PTL0_INDEX(va)));
+                
+                SET_FRAME_ADDRESS(ptl3, PTL3_INDEX(va), pa);
+                SET_FRAME_FLAGS(ptl3, PTL3_INDEX(va), PAGE_PRESENT | PAGE_WRITE);
+        }
+}
 
 void arch_pre_mm_init(void)