aboutsummaryrefslogtreecommitdiffstats
path: root/arch/xtensa/kernel
diff options
context:
space:
mode:
authorChris Zankel <chris@zankel.net>2007-08-07 02:57:57 -0400
committerChris Zankel <chris@zankel.net>2007-08-27 16:54:01 -0400
commit01858d1b0b406307626bbc01238391b06aae2c20 (patch)
treed01d20f3f513e6a21880a60cdf195023e6aafc66 /arch/xtensa/kernel
parent26465f2f4f5a253f22596fc9245a6bb5c0856ee1 (diff)
[XTENSA] Add support for executable/non-executable feature in the mmu
Newer processor versions starting with Xtensa6/LX2 support an 'executable' bit for memory pages. This bit replaces the 'valid' bit, so it must be always set to one for older processor versions. To mark a page invalid, we now set the cache-attributes to b11, which is backward compatible. Signed-off-by: Chris Zankel <chris@zankel.net>
Diffstat (limited to 'arch/xtensa/kernel')
-rw-r--r--arch/xtensa/kernel/entry.S42
1 files changed, 28 insertions, 14 deletions
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 8dc7a2c26ff9..65741e3368e7 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1572,10 +1572,12 @@ ENTRY(fast_second_level_miss)
1572 l32i a0, a1, TASK_MM # tsk->mm 1572 l32i a0, a1, TASK_MM # tsk->mm
1573 beqz a0, 9f 1573 beqz a0, 9f
1574 1574
15758: rsr a1, EXCVADDR # fault address 1575
1576 _PGD_OFFSET(a0, a1, a1) 1576 /* We deliberately destroy a3 that holds the exception table. */
1577
15788: rsr a3, EXCVADDR # fault address
1579 _PGD_OFFSET(a0, a3, a1)
1577 l32i a0, a0, 0 # read pmdval 1580 l32i a0, a0, 0 # read pmdval
1578 //beqi a0, _PAGE_USER, 2f
1579 beqz a0, 2f 1581 beqz a0, 2f
1580 1582
1581 /* Read ptevaddr and convert to top of page-table page. 1583 /* Read ptevaddr and convert to top of page-table page.
@@ -1596,20 +1598,34 @@ ENTRY(fast_second_level_miss)
1596 extui a1, a0, 0, PAGE_SHIFT # ... & PAGE_MASK 1598 extui a1, a0, 0, PAGE_SHIFT # ... & PAGE_MASK
1597 xor a0, a0, a1 1599 xor a0, a0, a1
1598 1600
1599 1601 movi a1, _PAGE_DIRECTORY
1600 movi a1, PAGE_DIRECTORY
1601 or a0, a0, a1 # ... | PAGE_DIRECTORY 1602 or a0, a0, a1 # ... | PAGE_DIRECTORY
1602 1603
1604 /*
1605 * We utilize all three wired-ways (7-9( to hold pmd translations.
1606 * Memory regions are mapped to the DTLBs according to bits 28 and 29.
1607 * This allows to map the three most common regions to three different
1608 * DTLBs:
1609 * 0,1 -> way 7 program (0040.0000) and virtual (c000.0000)
1610 * 2 -> way 8 shared libaries (2000.0000)
1611 * 3 -> way 0 stack (3000.0000)
1612 */
1613
1614 extui a3, a3, 28, 2 # addr. bit 28 and 29 0,1,2,3
1603 rsr a1, PTEVADDR 1615 rsr a1, PTEVADDR
1616 addx2 a3, a3, a3 # -> 0,3,6,9
1604 srli a1, a1, PAGE_SHIFT 1617 srli a1, a1, PAGE_SHIFT
1618 extui a3, a3, 2, 2 # -> 0,0,1,2
1605 slli a1, a1, PAGE_SHIFT # ptevaddr & PAGE_MASK 1619 slli a1, a1, PAGE_SHIFT # ptevaddr & PAGE_MASK
1606 addi a1, a1, DTLB_WAY_PGD # ... + way_number 1620 addi a3, a3, DTLB_WAY_PGD
1621 add a1, a1, a3 # ... + way_number
1607 1622
1608 wdtlb a0, a1 16233: wdtlb a0, a1
1609 dsync 1624 dsync
1610 1625
1611 /* Exit critical section. */ 1626 /* Exit critical section. */
1612 1627
16284: movi a3, exc_table # restore a3
1613 movi a0, 0 1629 movi a0, 0
1614 s32i a0, a3, EXC_TABLE_FIXUP 1630 s32i a0, a3, EXC_TABLE_FIXUP
1615 1631
@@ -1638,6 +1654,7 @@ ENTRY(fast_second_level_miss)
1638 1654
16392: /* Invalid PGD, default exception handling */ 16552: /* Invalid PGD, default exception handling */
1640 1656
1657 movi a3, exc_table
1641 rsr a1, DEPC 1658 rsr a1, DEPC
1642 xsr a3, EXCSAVE_1 1659 xsr a3, EXCSAVE_1
1643 s32i a1, a2, PT_AREG2 1660 s32i a1, a2, PT_AREG2
@@ -1682,15 +1699,15 @@ ENTRY(fast_store_prohibited)
16828: rsr a1, EXCVADDR # fault address 16998: rsr a1, EXCVADDR # fault address
1683 _PGD_OFFSET(a0, a1, a4) 1700 _PGD_OFFSET(a0, a1, a4)
1684 l32i a0, a0, 0 1701 l32i a0, a0, 0
1685 //beqi a0, _PAGE_USER, 2f # FIXME use _PAGE_INVALID
1686 beqz a0, 2f 1702 beqz a0, 2f
1687 1703
1704 /* Note that we assume _PAGE_WRITABLE_BIT is only set if pte is valid.*/
1705
1688 _PTE_OFFSET(a0, a1, a4) 1706 _PTE_OFFSET(a0, a1, a4)
1689 l32i a4, a0, 0 # read pteval 1707 l32i a4, a0, 0 # read pteval
1690 movi a1, _PAGE_VALID | _PAGE_RW 1708 bbci.l a4, _PAGE_WRITABLE_BIT, 2f
1691 bnall a4, a1, 2f
1692 1709
1693 movi a1, _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_WRENABLE 1710 movi a1, _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_HW_WRITE
1694 or a4, a4, a1 1711 or a4, a4, a1
1695 rsr a1, EXCVADDR 1712 rsr a1, EXCVADDR
1696 s32i a4, a0, 0 1713 s32i a4, a0, 0
@@ -1700,10 +1717,7 @@ ENTRY(fast_store_prohibited)
1700 dhwb a0, 0 1717 dhwb a0, 0
1701#endif 1718#endif
1702 pdtlb a0, a1 1719 pdtlb a0, a1
1703 beqz a0, 1f
1704 idtlb a0 // FIXME do we need this?
1705 wdtlb a4, a0 1720 wdtlb a4, a0
17061:
1707 1721
1708 /* Exit critical section. */ 1722 /* Exit critical section. */
1709 1723