--- /dev/null
+/*
+ * tbicore.S
+ *
+ * Copyright (C) 2001, 2002, 2007, 2012 Imagination Technologies.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ *
+ * Core functions needed to support use of the thread binary interface for META
+ * processors
+ */
+
+ .file "tbicore.S"
+/* Get data structures and defines from the TBI C header */
+#include <asm/metag_mem.h>
+#include <asm/metag_regs.h>
+#include <asm/tbx.h>
+
+ .data
+ .balign 8
+ .global ___pTBISegs
+ .type ___pTBISegs,object
+___pTBISegs:
+ .quad 0 /* Segment list pointer with it's */
+ .size ___pTBISegs,.-___pTBISegs
+ /* own id or spin-lock location */
+/*
+ * Return ___pTBISegs value specific to privilege level - not very complicated
+ * at the moment
+ *
+ * Register Usage: D0Re0 is the result, D1Re0 is used as a scratch
+ */
+ .text
+ .balign 4
+ .global ___TBISegList
+ .type ___TBISegList,function
+___TBISegList:
+ MOVT A1LbP,#HI(___pTBISegs)
+ ADD A1LbP,A1LbP,#LO(___pTBISegs)
+ GETL D0Re0,D1Re0,[A1LbP]
+ MOV PC,D1RtP
+ .size ___TBISegList,.-___TBISegList
+
+/*
+ * Search the segment list for a match given Id, pStart can be NULL
+ *
+ * Register Usage: D1Ar1 is pSeg, D0Ar2 is Id, D0Re0 is the result
+ * D0Ar4, D1Ar3 are used as a scratch
+ * NB: The PSTAT bit if Id in D0Ar2 may be toggled
+ */
+ .text
+ .balign 4
+ .global ___TBIFindSeg
+ .type ___TBIFindSeg,function
+___TBIFindSeg:
+ MOVT A1LbP,#HI(___pTBISegs)
+ ADD A1LbP,A1LbP,#LO(___pTBISegs)
+ GETL D1Ar3,D0Ar4,[A1LbP] /* Read segment list head */
+ MOV D0Re0,TXSTATUS /* What priv level are we at? */
+ CMP D1Ar1,#0 /* Is pStart provided? */
+/* Disable privilege adaption for now */
+ ANDT D0Re0,D0Re0,#0 /*HI(TXSTATUS_PSTAT_BIT) ; Is PSTAT set? Zero if not */
+ LSL D0Re0,D0Re0,#(TBID_PSTAT_S-TXSTATUS_PSTAT_S)
+ XOR D0Ar2,D0Ar2,D0Re0 /* Toggle Id PSTAT if privileged */
+ MOVNZ D1Ar3,D1Ar1 /* Use pStart if provided */
+$LFindSegLoop:
+ ADDS D0Re0,D1Ar3,#0 /* End of list? Load result into D0Re0 */
+ MOVZ PC,D1RtP /* If result is NULL we leave */
+ GETL D1Ar3,D0Ar4,[D1Ar3] /* Read pLink and Id */
+ CMP D0Ar4,D0Ar2 /* Does it match? */
+ BNZ $LFindSegLoop /* Loop if there is no match */
+ TST D0Re0,D0Re0 /* Clear zero flag - we found it! */
+ MOV PC,D1RtP /* Return */
+ .size ___TBIFindSeg,.-___TBIFindSeg
+
+/* Useful offsets to encode the lower bits of the lock/unlock addresses */
+#define UON (LINSYSEVENT_WR_ATOMIC_LOCK & 0xFFF8)
+#define UOFF (LINSYSEVENT_WR_ATOMIC_UNLOCK & 0xFFF8)
+
+/*
+ * Perform a whole spin-lock sequence as used by the TBISignal routine
+ *
+ * Register Usage: D1Ar1 is pLock, D0Ar2 is Mask, D0Re0 is the result
+ * (All other usage due to ___TBIPoll - D0Ar6, D1Re0)
+ */
+ .text
+ .balign 4
+ .global ___TBISpin
+ .type ___TBISpin,function
+___TBISpin:
+ SETL [A0StP++],D0FrT,D1RtP /* Save our return address */
+ ORS D0Re0,D0Re0,#1 /* Clear zero flag */
+ MOV D1RtP,PC /* Setup return address to form loop */
+$LSpinLoop:
+ BNZ ___TBIPoll /* Keep repeating if fail to set */
+ GETL D0FrT,D1RtP,[--A0StP] /* Restore return address */
+ MOV PC,D1RtP /* Return */
+ .size ___TBISpin,.-___TBISpin
+
+/*
+ * Perform an attempt to gain access to a spin-lock and set some bits
+ *
+ * Register Usage: D1Ar1 is pLock, D0Ar2 is Mask, D0Re0 is the result
+ * !!On return Zero flag is SET if we are sucessfull!!
+ * A0.3 is used to hold base address of system event region
+ * D1Re0 use to hold TXMASKI while interrupts are off
+ */
+ .text
+ .balign 4
+ .global ___TBIPoll
+ .type ___TBIPoll,function
+___TBIPoll:
+ MOV D1Re0,#0 /* Prepare to disable ints */
+ MOVT A0.3,#HI(LINSYSEVENT_WR_ATOMIC_LOCK)
+ SWAP D1Re0,TXMASKI /* Really stop ints */
+ LOCK2 /* Gain all locks */
+ SET [A0.3+#UON],D1RtP /* Stop shared memory access too */
+ DCACHE [D1Ar1],A0.3 /* Flush Cache line */
+ GETD D0Re0,[D1Ar1] /* Get new state from memory or hit */
+ DCACHE [D1Ar1],A0.3 /* Flush Cache line */
+ GETD D0Re0,[D1Ar1] /* Get current state */
+ TST D0Re0,D0Ar2 /* Are we clear to send? */
+ ORZ D0Re0,D0Re0,D0Ar2 /* Yes: So set bits and */
+ SETDZ [D1Ar1],D0Re0 /* transmit new state */
+ SET [A0.3+#UOFF],D1RtP /* Allow shared memory access */
+ LOCK0 /* Release all locks */
+ MOV TXMASKI,D1Re0 /* Allow ints */
+$LPollEnd:
+ XORNZ D0Re0,D0Re0,D0Re0 /* No: Generate zero result */
+ MOV PC,D1RtP /* Return (NZ indicates failure) */
+ .size ___TBIPoll,.-___TBIPoll
+
+/*
+ * End of tbicore.S
+ */
Code Review / kvmfornfv.git / blobdiff