Changeset 64f6ef04 in mainline for kernel/arch/amd64/src/mm/page.c

Timestamp:

2010-06-27T23:54:45Z (15 years ago)

Author:

Martin Decky <martin@…>

Branches:

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

Children:

05e3cb8

Parents:

a1f60f3

Message:

amd64: create identity mapping of the first 8 GB of physical memory (instead of just 4 GB) during the bootstrap process
remove the crude on-demand identity mapping creation which could lead to livelocks (unmapping the page pointing to 0 MB physical while trying to map the page pointing to 4096 MB physical)

(currently the implementation is in no way closer to the ideal solution of ticket #3, but at least it allows to debug non-trivial cases of physical memory sizes > 4 GB during the approach to solving #3)

File:

• kernel/arch/amd64/src/mm/page.c (modified) (3 diffs)

kernel/arch/amd64/src/mm/page.c

@@ -39 +39 @@
 #include <mm/frame.h>
 #include <mm/as.h>
-#include <arch/interrupt.h>
 #include <arch/asm.h>
 #include <config.h>
@@ -47 +46 @@
 #include <panic.h>
 #include <align.h>
-
-/* Definitions for identity page mapper */
-pte_t helper_ptl1[512] __attribute__((aligned (PAGE_SIZE)));
-pte_t helper_ptl2[512] __attribute__((aligned (PAGE_SIZE)));
-pte_t helper_ptl3[512] __attribute__((aligned (PAGE_SIZE)));
-
-static uintptr_t oldpage = 0;
-
-extern pte_t ptl_0;  /* From boot.S */
-
-#define PTL1_PRESENT(ptl0, page) \
-        (!(GET_PTL1_FLAGS_ARCH(ptl0, PTL0_INDEX_ARCH(page)) & PAGE_NOT_PRESENT))
-
-#define PTL2_PRESENT(ptl1, page) \
-        (!(GET_PTL2_FLAGS_ARCH(ptl1, PTL1_INDEX_ARCH(page)) & PAGE_NOT_PRESENT))
-
-#define PTL3_PRESENT(ptl2, page) \
-        (!(GET_PTL3_FLAGS_ARCH(ptl2, PTL2_INDEX_ARCH(page)) & PAGE_NOT_PRESENT))
-
-#define PTL1_ADDR(ptl0, page) \
-        ((pte_t *) PA2KA(GET_PTL1_ADDRESS_ARCH(ptl0, PTL0_INDEX_ARCH(page))))
-
-#define PTL2_ADDR(ptl1, page) \
-        ((pte_t *) PA2KA(GET_PTL2_ADDRESS_ARCH(ptl1, PTL1_INDEX_ARCH(page))))
-
-#define PTL3_ADDR(ptl2, page) \
-        ((pte_t *) PA2KA(GET_PTL3_ADDRESS_ARCH(ptl2, PTL2_INDEX_ARCH(page))))
-
-#define SETUP_PTL1(ptl0, page, tgt) \
-        { \
-                SET_PTL1_ADDRESS_ARCH(ptl0, PTL0_INDEX_ARCH(page), (uintptr_t)KA2PA(tgt)); \
-                SET_PTL1_FLAGS_ARCH(ptl0, PTL0_INDEX_ARCH(page), PAGE_WRITE | PAGE_EXEC); \
-        }
-
-#define SETUP_PTL2(ptl1, page, tgt) \
-        { \
-                SET_PTL2_ADDRESS_ARCH(ptl1, PTL1_INDEX_ARCH(page), (uintptr_t)KA2PA(tgt)); \
-                SET_PTL2_FLAGS_ARCH(ptl1, PTL1_INDEX_ARCH(page), PAGE_WRITE | PAGE_EXEC); \
-        }
-
-#define SETUP_PTL3(ptl2, page, tgt) \
-        { \
-                SET_PTL3_ADDRESS_ARCH(ptl2, PTL2_INDEX_ARCH(page), (uintptr_t)KA2PA(tgt)); \
-                SET_PTL3_FLAGS_ARCH(ptl2, PTL2_INDEX_ARCH(page), PAGE_WRITE | PAGE_EXEC); \
-        }
-
-#define SETUP_FRAME(ptl3, page, tgt) \
-        { \
-                SET_FRAME_ADDRESS_ARCH(ptl3, PTL3_INDEX_ARCH(page), (uintptr_t)KA2PA(tgt)); \
-                SET_FRAME_FLAGS_ARCH(ptl3, PTL3_INDEX_ARCH(page), PAGE_WRITE | PAGE_EXEC); \
-        }
 
 void page_arch_init(void)
@@ -122 +70 @@
         } else
                 write_cr3((uintptr_t) AS_KERNEL->genarch.page_table);
-}
-
-/** Identity page mapper
- *
- * We need to map whole physical memory identically before the page subsystem
- * is initializaed. This thing clears page table and fills in the specific
- * items.
- *
- */
-void ident_page_fault(unsigned int n, istate_t *istate)
-{
-        pte_t *aptl_1;
-        pte_t *aptl_2;
-        pte_t *aptl_3;
-        
-        uintptr_t page = read_cr2();
-        
-        /* Unmap old address */
-        if (oldpage) {
-                pte_t *aptl_1 = PTL1_ADDR(&ptl_0, oldpage);
-                pte_t *aptl_2 = PTL2_ADDR(aptl_1, oldpage);
-                pte_t *aptl_3 = PTL3_ADDR(aptl_2, oldpage);
-                
-                SET_FRAME_FLAGS_ARCH(aptl_3, PTL3_INDEX_ARCH(oldpage), PAGE_NOT_PRESENT);
-                
-                if (KA2PA(aptl_3) == KA2PA(helper_ptl3))
-                        SET_PTL3_FLAGS_ARCH(aptl_2, PTL2_INDEX_ARCH(oldpage), PAGE_NOT_PRESENT);
-                
-                if (KA2PA(aptl_2) == KA2PA(helper_ptl2))
-                        SET_PTL2_FLAGS_ARCH(aptl_1, PTL1_INDEX_ARCH(oldpage), PAGE_NOT_PRESENT);
-                
-                if (KA2PA(aptl_1) == KA2PA(helper_ptl1))
-                        SET_PTL1_FLAGS_ARCH(&ptl_0, PTL0_INDEX_ARCH(oldpage), PAGE_NOT_PRESENT);
-        }
-        
-        if (PTL1_PRESENT(&ptl_0, page))
-                aptl_1 = PTL1_ADDR(&ptl_0, page);
-        else {
-                SETUP_PTL1(&ptl_0, page, helper_ptl1);
-                aptl_1 = helper_ptl1;
-        }
-        
-        if (PTL2_PRESENT(aptl_1, page)) 
-                aptl_2 = PTL2_ADDR(aptl_1, page);
-        else {
-                SETUP_PTL2(aptl_1, page, helper_ptl2);
-                aptl_2 = helper_ptl2;
-        }
-        
-        if (PTL3_PRESENT(aptl_2, page))
-                aptl_3 = PTL3_ADDR(aptl_2, page);
-        else {
-                SETUP_PTL3(aptl_2, page, helper_ptl3);
-                aptl_3 = helper_ptl3;
-        }
-        
-        SETUP_FRAME(aptl_3, page, page);
-        
-        oldpage = page;
 }