b2d4383480
Choose PAGE_OFFSET dynamically based upon cpu type. Original UltraSPARC-I (spitfire) chips only supported a 44-bit virtual address space. Newer chips (T4 and later) support 52-bit virtual addresses and up to 47-bits of physical memory space. Therefore we have to adjust PAGE_SIZE dynamically based upon the capabilities of the chip. Note that this change alone does not allow us to support > 43-bit physical memory, to do that we need to re-arrange our page table support. The current encodings of the pmd_t and pgd_t pointers restricts us to "32 + 11" == 43 bits. This change can waste quite a bit of memory for the various tables. In particular, a future change should work to size and allocate kern_linear_bitmap[] and sparc64_valid_addr_bitmap[] dynamically. This isn't easy as we really cannot take a TLB miss when accessing kern_linear_bitmap[]. We'd have to lock it into the TLB or similar. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Bob Picco <bob.picco@oracle.com>
104 lines
2.4 KiB
ArmAsm
104 lines
2.4 KiB
ArmAsm
/* clear_page.S: UltraSparc optimized clear page.
|
|
*
|
|
* Copyright (C) 1996, 1998, 1999, 2000, 2004 David S. Miller (davem@redhat.com)
|
|
* Copyright (C) 1997 Jakub Jelinek (jakub@redhat.com)
|
|
*/
|
|
|
|
#include <asm/visasm.h>
|
|
#include <asm/thread_info.h>
|
|
#include <asm/page.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/spitfire.h>
|
|
#include <asm/head.h>
|
|
|
|
/* What we used to do was lock a TLB entry into a specific
|
|
* TLB slot, clear the page with interrupts disabled, then
|
|
* restore the original TLB entry. This was great for
|
|
* disturbing the TLB as little as possible, but it meant
|
|
* we had to keep interrupts disabled for a long time.
|
|
*
|
|
* Now, we simply use the normal TLB loading mechanism,
|
|
* and this makes the cpu choose a slot all by itself.
|
|
* Then we do a normal TLB flush on exit. We need only
|
|
* disable preemption during the clear.
|
|
*/
|
|
|
|
.text
|
|
|
|
.globl _clear_page
|
|
_clear_page: /* %o0=dest */
|
|
ba,pt %xcc, clear_page_common
|
|
clr %o4
|
|
|
|
/* This thing is pretty important, it shows up
|
|
* on the profiles via do_anonymous_page().
|
|
*/
|
|
.align 32
|
|
.globl clear_user_page
|
|
clear_user_page: /* %o0=dest, %o1=vaddr */
|
|
lduw [%g6 + TI_PRE_COUNT], %o2
|
|
sethi %hi(PAGE_OFFSET), %g2
|
|
sethi %hi(PAGE_SIZE), %o4
|
|
|
|
ldx [%g2 + %lo(PAGE_OFFSET)], %g2
|
|
sethi %hi(PAGE_KERNEL_LOCKED), %g3
|
|
|
|
ldx [%g3 + %lo(PAGE_KERNEL_LOCKED)], %g3
|
|
sub %o0, %g2, %g1 ! paddr
|
|
|
|
and %o1, %o4, %o0 ! vaddr D-cache alias bit
|
|
|
|
or %g1, %g3, %g1 ! TTE data
|
|
sethi %hi(TLBTEMP_BASE), %o3
|
|
|
|
add %o2, 1, %o4
|
|
add %o0, %o3, %o0 ! TTE vaddr
|
|
|
|
/* Disable preemption. */
|
|
mov TLB_TAG_ACCESS, %g3
|
|
stw %o4, [%g6 + TI_PRE_COUNT]
|
|
|
|
/* Load TLB entry. */
|
|
rdpr %pstate, %o4
|
|
wrpr %o4, PSTATE_IE, %pstate
|
|
stxa %o0, [%g3] ASI_DMMU
|
|
stxa %g1, [%g0] ASI_DTLB_DATA_IN
|
|
sethi %hi(KERNBASE), %g1
|
|
flush %g1
|
|
wrpr %o4, 0x0, %pstate
|
|
|
|
mov 1, %o4
|
|
|
|
clear_page_common:
|
|
VISEntryHalf
|
|
membar #StoreLoad | #StoreStore | #LoadStore
|
|
fzero %f0
|
|
sethi %hi(PAGE_SIZE/64), %o1
|
|
mov %o0, %g1 ! remember vaddr for tlbflush
|
|
fzero %f2
|
|
or %o1, %lo(PAGE_SIZE/64), %o1
|
|
faddd %f0, %f2, %f4
|
|
fmuld %f0, %f2, %f6
|
|
faddd %f0, %f2, %f8
|
|
fmuld %f0, %f2, %f10
|
|
|
|
faddd %f0, %f2, %f12
|
|
fmuld %f0, %f2, %f14
|
|
1: stda %f0, [%o0 + %g0] ASI_BLK_P
|
|
subcc %o1, 1, %o1
|
|
bne,pt %icc, 1b
|
|
add %o0, 0x40, %o0
|
|
membar #Sync
|
|
VISExitHalf
|
|
|
|
brz,pn %o4, out
|
|
nop
|
|
|
|
stxa %g0, [%g1] ASI_DMMU_DEMAP
|
|
membar #Sync
|
|
stw %o2, [%g6 + TI_PRE_COUNT]
|
|
|
|
out: retl
|
|
nop
|
|
|