| /* 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> |
| |
| /* 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. |
| */ |
| |
| #define TTE_BITS_TOP (_PAGE_VALID | _PAGE_SZBITS) |
| #define TTE_BITS_BOTTOM (_PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_L | _PAGE_W) |
| |
| .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 %uhi(PAGE_OFFSET), %g2 |
| sethi %hi(PAGE_SIZE), %o4 |
| |
| sllx %g2, 32, %g2 |
| sethi %uhi(TTE_BITS_TOP), %g3 |
| |
| sllx %g3, 32, %g3 |
| sub %o0, %g2, %g1 ! paddr |
| |
| or %g3, TTE_BITS_BOTTOM, %g3 |
| 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 |
| flush %g6 |
| 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 |
| |
