Hexagon: fix initial page table setup prior to jump to VA

Use the exact number of pages needed to be mapped pre-VA-jump,
then map 896MB afterwards, which the arch mem init will fix up.

Signed-off-by: Richard Kuo <rkuo@codeaurora.org>

diff --git a/arch/hexagon/kernel/head.S b/arch/hexagon/kernel/head.S
index 477320c..8e88d24 100644 (file)
--- a/arch/hexagon/kernel/head.S
+++ b/arch/hexagon/kernel/head.S
@@ -25,6 +25,9 @@
 #include <asm/mem-layout.h>
 #include <asm/vm_mmu.h>
 #include <asm/page.h>
+#include <asm/hexagon_vm.h>
+
+#define SEGTABLE_ENTRIES #0x0e0
 
        __INIT
 ENTRY(stext)
@@ -63,27 +66,73 @@ ENTRY(stext)
                  | __HEXAGON_C_WB_L2 << 6                      \
                  | __HVM_PDE_S_4MB)
 
-       r1 = pc
-       r2.H = #0xffc0
-       r2.L = #0x0000
-       r1 = and(r1,r2)         /* round PC to 4MB boundary     */
+       /*
+        * Get number of VA=PA entries; only really needed for jump
+        * to hyperspace; gets blown away immediately after
+        */
+
+       {
+               r1.l = #LO(_end);
+               r2.l = #LO(stext);
+               r3 = #1;
+       }
+       {
+               r1.h = #HI(_end);
+               r2.h = #HI(stext);
+               r3 = asl(r3, #22);
+       }
+       {
+               r1 = sub(r1, r2);
+               r3 = add(r3, #-1);
+       }  /* r1 =  _end - stext  */
+       r1 = add(r1, r3);  /*  + (4M-1) */
+       r26 = lsr(r1, #22); /*  / 4M = # of entries */
+
+       r1 = r25;
+       r2.h = #0xffc0;
+       r2.l = #0x0000;         /* round back down to 4MB boundary  */
+       r1 = and(r1,r2);
        r2 = lsr(r1, #22)       /* 4MB page number              */
        r2 = asl(r2, #2)        /* times sizeof(PTE) (4bytes)   */
        r0 = add(r0,r2)         /* r0 = address of correct PTE  */
        r2 = #PTE_BITS
        r1 = add(r1,r2)         /* r1 = 4MB PTE for the first entry     */
        r2.h = #0x0040
-       r2.l = #0x0000          /* 4MB  */
-       memw(r0 ++ #4) = r1
-       r1 = add(r1, r2)
+       r2.l = #0x0000          /* 4MB increments */
+       loop0(1f,r26);
+1:
        memw(r0 ++ #4) = r1
+       { r1 = add(r1, r2); } :endloop0
 
-       r0 = r24
+       /*  Also need to overwrite the initial 0xc0000000 entries  */
+       /*  PAGE_OFFSET >> (4MB shift - 4 bytes per entry shift)  */
+       R1.H = #HI(PAGE_OFFSET >> (22 - 2))
+       R1.L = #LO(PAGE_OFFSET >> (22 - 2))
+
+       r0 = add(r1, r24);      /* advance to 0xc0000000 entry */
+       r1 = r25;
+       r2.h = #0xffc0;
+       r2.l = #0x0000;         /* round back down to 4MB boundary  */
+       r1 = and(r1,r2);        /* for huge page */
+       r2 = #PTE_BITS
+       r1 = add(r1,r2);
+       r2.h = #0x0040
+       r2.l = #0x0000          /* 4MB increments */
+
+       loop0(1f,SEGTABLE_ENTRIES);
+1:
+       memw(r0 ++ #4) = r1;
+       { r1 = add(r1,r2); } :endloop0
+
+       r0 = r24;
 
        /*
         * The subroutine wrapper around the virtual instruction touches
         * no memory, so we should be able to use it even here.
+        * Note that in this version, R1 and R2 get "clobbered"; see
+        * vm_ops.S
         */
+       r1 = #VM_TRANS_TYPE_TABLE
        call    __vmnewmap;
 
        /*  Jump into virtual address range.  */
@@ -97,17 +146,29 @@ ENTRY(stext)
 __head_s_vaddr_target:
        /*
         * Tear down VA=PA translation now that we are running
-        * in the desgnated kernel segments.
+        * in kernel virtual space.
         */
        r0 = #__HVM_PDE_S_INVALID
-       r1 = r24
-       loop0(1f,#0x100)
+
+       r1.h = #0xffc0;
+       r1.l = #0x0000;
+       r2 = r25;               /* phys_offset */
+       r2 = and(r1,r2);
+
+       r1.l = #lo(swapper_pg_dir)
+       r1.h = #hi(swapper_pg_dir)
+       r2 = lsr(r2, #22)       /* 4MB page number              */
+       r2 = asl(r2, #2)        /* times sizeof(PTE) (4bytes)   */
+       r1 = add(r1,r2);
+       loop0(1f,r26)
+
 1:
        {
                memw(R1 ++ #4) = R0
        }:endloop0
 
        r0 = r24
+       r1 = #VM_TRANS_TYPE_TABLE
        call __vmnewmap
 
        /*  Go ahead and install the trap0 return so angel calls work  */
@@ -150,7 +211,7 @@ __head_s_vaddr_target:
        r2 = sub(r2,r0);
        call memset;
 
-       /*  Set PHYS_OFFSET; should still be in R25 */
+       /*  Set PHYS_OFFSET; should be in R25 */
 #ifdef CONFIG_HEXAGON_PHYS_OFFSET
        r0.l = #LO(__phys_offset);
        r0.h = #HI(__phys_offset);