/* 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