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altivec.c revision 1.7
      1 /*	$NetBSD: altivec.c,v 1.7 2004/04/16 23:58:08 matt Exp $	*/
      2 
      3 /*
      4  * Copyright (C) 1996 Wolfgang Solfrank.
      5  * Copyright (C) 1996 TooLs GmbH.
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by TooLs GmbH.
     19  * 4. The name of TooLs GmbH may not be used to endorse or promote products
     20  *    derived from this software without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
     23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     25  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     28  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     30  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     31  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 #include <sys/cdefs.h>
     35 __KERNEL_RCSID(0, "$NetBSD: altivec.c,v 1.7 2004/04/16 23:58:08 matt Exp $");
     36 
     37 #include "opt_multiprocessor.h"
     38 
     39 #include <sys/param.h>
     40 #include <sys/proc.h>
     41 #include <sys/sa.h>
     42 #include <sys/systm.h>
     43 #include <sys/user.h>
     44 #include <sys/malloc.h>
     45 #include <sys/pool.h>
     46 
     47 #include <uvm/uvm_extern.h>
     48 
     49 #include <powerpc/altivec.h>
     50 #include <powerpc/spr.h>
     51 #include <powerpc/psl.h>
     52 
     53 void
     54 enable_vec(void)
     55 {
     56 	struct cpu_info *ci = curcpu();
     57 	struct lwp *l = curlwp;
     58 	struct pcb *pcb = &l->l_addr->u_pcb;
     59 	struct trapframe *tf = trapframe(l);
     60 	struct vreg *vr = &pcb->pcb_vr;
     61 	register_t msr;
     62 
     63 	KASSERT(pcb->pcb_veccpu == NULL);
     64 
     65 	pcb->pcb_flags |= PCB_ALTIVEC;
     66 
     67 	/*
     68 	 * Enable AltiVec temporarily (and disable interrupts).
     69 	 */
     70 	msr = mfmsr();
     71 	mtmsr((msr & ~PSL_EE) | PSL_VEC);
     72 	__asm __volatile ("isync");
     73 	if (ci->ci_veclwp) {
     74 		save_vec_cpu();
     75 	}
     76 	KASSERT(curcpu()->ci_veclwp == NULL);
     77 
     78 	/*
     79 	 * Restore VSCR by first loading it into a vector and then into VSCR.
     80 	 * (this needs to done before loading the user's vector registers
     81 	 * since we need to use a scratch vector register)
     82 	 */
     83 	__asm __volatile("vxor %2,%2,%2; lvewx %2,%0,%1; mtvscr %2" \
     84 	    ::	"b"(vr), "r"(offsetof(struct vreg, vscr)), "n"(0));
     85 
     86 	/*
     87 	 * VRSAVE will be restored when trap frame returns
     88 	 */
     89 	tf->tf_xtra[TF_VRSAVE] = vr->vrsave;
     90 
     91 #define	LVX(n,vr)	__asm /*__volatile*/("lvx %2,%0,%1" \
     92 	    ::	"b"(vr), "r"(offsetof(struct vreg, vreg[n])), "n"(n));
     93 
     94 	/*
     95 	 * Load all 32 vector registers
     96 	 */
     97 	LVX( 0,vr);	LVX( 1,vr);	LVX( 2,vr);	LVX( 3,vr);
     98 	LVX( 4,vr);	LVX( 5,vr);	LVX( 6,vr);	LVX( 7,vr);
     99 	LVX( 8,vr);	LVX( 9,vr);	LVX(10,vr);	LVX(11,vr);
    100 	LVX(12,vr);	LVX(13,vr);	LVX(14,vr);	LVX(15,vr);
    101 
    102 	LVX(16,vr);	LVX(17,vr);	LVX(18,vr);	LVX(19,vr);
    103 	LVX(20,vr);	LVX(21,vr);	LVX(22,vr);	LVX(23,vr);
    104 	LVX(24,vr);	LVX(25,vr);	LVX(26,vr);	LVX(27,vr);
    105 	LVX(28,vr);	LVX(29,vr);	LVX(30,vr);	LVX(31,vr);
    106 	__asm __volatile ("isync");
    107 
    108 	/*
    109 	 * Enable AltiVec when we return to user-mode.
    110 	 * Record the new ownership of the AltiVec unit.
    111 	 */
    112 	curcpu()->ci_veclwp = l;
    113 	pcb->pcb_veccpu = curcpu();
    114 	__asm __volatile ("sync");
    115 
    116 	/*
    117 	 * Restore MSR (turn off AltiVec)
    118 	 */
    119 	mtmsr(msr);
    120 }
    121 
    122 void
    123 save_vec_cpu(void)
    124 {
    125 	struct cpu_info *ci = curcpu();
    126 	struct lwp *l;
    127 	struct pcb *pcb;
    128 	struct vreg *vr;
    129 	struct trapframe *tf;
    130 	register_t msr;
    131 
    132 	/*
    133 	 * Turn on AltiVEC, turn off interrupts.
    134 	 */
    135 	msr = mfmsr();
    136 	mtmsr((msr & ~PSL_EE) | PSL_VEC);
    137 	__asm __volatile ("isync");
    138 	l = ci->ci_veclwp;
    139 	if (l == NULL)
    140 		goto out;
    141 	pcb = &l->l_addr->u_pcb;
    142 	vr = &pcb->pcb_vr;
    143 	tf = trapframe(l);
    144 
    145 #define	STVX(n,vr)	__asm /*__volatile*/("stvx %2,%0,%1" \
    146 	    ::	"b"(vr), "r"(offsetof(struct vreg, vreg[n])), "n"(n));
    147 
    148 	/*
    149 	 * Save the vector registers.
    150 	 */
    151 	STVX( 0,vr);	STVX( 1,vr);	STVX( 2,vr);	STVX( 3,vr);
    152 	STVX( 4,vr);	STVX( 5,vr);	STVX( 6,vr);	STVX( 7,vr);
    153 	STVX( 8,vr);	STVX( 9,vr);	STVX(10,vr);	STVX(11,vr);
    154 	STVX(12,vr);	STVX(13,vr);	STVX(14,vr);	STVX(15,vr);
    155 
    156 	STVX(16,vr);	STVX(17,vr);	STVX(18,vr);	STVX(19,vr);
    157 	STVX(20,vr);	STVX(21,vr);	STVX(22,vr);	STVX(23,vr);
    158 	STVX(24,vr);	STVX(25,vr);	STVX(26,vr);	STVX(27,vr);
    159 	STVX(28,vr);	STVX(29,vr);	STVX(30,vr);	STVX(31,vr);
    160 
    161 	/*
    162 	 * Save VSCR (this needs to be done after save the vector registers
    163 	 * since we need to use one as scratch).
    164 	 */
    165 	__asm __volatile("mfvscr %2; stvewx %2,%0,%1" \
    166 	    ::	"b"(vr), "r"(offsetof(struct vreg, vscr)), "n"(0));
    167 
    168 	/*
    169 	 * Save VRSAVE
    170 	 */
    171 	vr->vrsave = tf->tf_xtra[TF_VRSAVE];
    172 
    173 	/*
    174 	 * Note that we aren't using any CPU resources and stop any
    175 	 * data streams.
    176 	 */
    177 	pcb->pcb_veccpu = NULL;
    178 	ci->ci_veclwp = NULL;
    179 	__asm __volatile ("dssall; sync");
    180 
    181  out:
    182 
    183 	/*
    184 	 * Restore MSR (turn off AltiVec)
    185 	 */
    186 	mtmsr(msr);
    187 }
    188 
    189 /*
    190  * Save a process's AltiVEC state to its PCB.  The state may be in any CPU.
    191  * The process must either be curproc or traced by curproc (and stopped).
    192  * (The point being that the process must not run on another CPU during
    193  * this function).
    194  */
    195 void
    196 save_vec_lwp(struct lwp *l, int discard)
    197 {
    198 	struct pcb * const pcb = &l->l_addr->u_pcb;
    199 	struct cpu_info * const ci = curcpu();
    200 
    201 	/*
    202 	 * If it's already in the PCB, there's nothing to do.
    203 	 */
    204 	if (pcb->pcb_veccpu == NULL)
    205 		return;
    206 
    207 	/*
    208 	 * If we simply need to discard the information, then don't
    209 	 * to save anything.
    210 	 */
    211 	if (discard) {
    212 #ifndef MULTIPROCESSOR
    213 		KASSERT(ci == pcb->pcb_veccpu);
    214 #endif
    215 		KASSERT(l == pcb->pcb_veccpu->ci_veclwp);
    216 		pcb->pcb_veccpu->ci_veclwp = NULL;
    217 		pcb->pcb_veccpu = NULL;
    218 		pcb->pcb_flags &= ~PCB_ALTIVEC;
    219 		return;
    220 	}
    221 
    222 	/*
    223 	 * If the state is in the current CPU, just flush the current CPU's
    224 	 * state.
    225 	 */
    226 	if (l == ci->ci_veclwp) {
    227 		save_vec_cpu();
    228 		return;
    229 	}
    230 
    231 
    232 #ifdef MULTIPROCESSOR
    233 	/*
    234 	 * It must be on another CPU, flush it from there.
    235 	 */
    236 
    237 	mp_save_vec_lwp(l);
    238 #endif
    239 }
    240 
    241 #define ZERO_VEC	19
    242 
    243 void
    244 vzeropage(paddr_t pa)
    245 {
    246 	const paddr_t ea = pa + PAGE_SIZE;
    247 	uint32_t vec[7], *vp = (void *) roundup((uintptr_t) vec, 16);
    248 	register_t omsr, msr;
    249 
    250 	__asm __volatile("mfmsr %0" : "=r"(omsr) :);
    251 
    252 	/*
    253 	 * Turn on AltiVec, turn off interrupts.
    254 	 */
    255 	msr = (omsr & ~PSL_EE) | PSL_VEC;
    256 	__asm __volatile("sync; mtmsr %0; isync" :: "r"(msr));
    257 
    258 	/*
    259 	 * Save the VEC register we are going to use before we disable
    260 	 * relocation.
    261 	 */
    262 	__asm("stvx %1,0,%0" :: "r"(vp), "n"(ZERO_VEC));
    263 	__asm("vxor %0,%0,%0" :: "n"(ZERO_VEC));
    264 
    265 	/*
    266 	 * Turn off data relocation (DMMU off).
    267 	 */
    268 	msr &= ~PSL_DR;
    269 	__asm __volatile("sync; mtmsr %0; isync" :: "r"(msr));
    270 
    271 	/*
    272 	 * Zero the page using a single cache line.
    273 	 */
    274 	do {
    275 		__asm("stvx %2,%0,%1" ::  "b"(pa), "r"( 0), "n"(ZERO_VEC));
    276 		__asm("stvxl %2,%0,%1" :: "b"(pa), "r"(16), "n"(ZERO_VEC));
    277 		__asm("stvx %2,%0,%1" ::  "b"(pa), "r"(32), "n"(ZERO_VEC));
    278 		__asm("stvxl %2,%0,%1" :: "b"(pa), "r"(48), "n"(ZERO_VEC));
    279 		pa += 64;
    280 	} while (pa < ea);
    281 
    282 	/*
    283 	 * Restore data relocation (DMMU on);
    284 	 */
    285 	msr |= PSL_DR;
    286 	__asm __volatile("sync; mtmsr %0; isync" :: "r"(msr));
    287 
    288 	/*
    289 	 * Restore VEC register (now that we can access the stack again).
    290 	 */
    291 	__asm("lvx %1,0,%0" :: "r"(vp), "n"(ZERO_VEC));
    292 
    293 	/*
    294 	 * Restore old MSR (AltiVec OFF).
    295 	 */
    296 	__asm __volatile("sync; mtmsr %0; isync" :: "r"(omsr));
    297 }
    298 
    299 #define LO_VEC	16
    300 #define HI_VEC	17
    301 
    302 void
    303 vcopypage(paddr_t dst, paddr_t src)
    304 {
    305 	const paddr_t edst = dst + PAGE_SIZE;
    306 	uint32_t vec[11], *vp = (void *) roundup((uintptr_t) vec, 16);
    307 	register_t omsr, msr;
    308 
    309 	__asm __volatile("mfmsr %0" : "=r"(omsr) :);
    310 
    311 	/*
    312 	 * Turn on AltiVec, turn off interrupts.
    313 	 */
    314 	msr = (omsr & ~PSL_EE) | PSL_VEC;
    315 	__asm __volatile("sync; mtmsr %0; isync" :: "r"(msr));
    316 
    317 	/*
    318 	 * Save the VEC registers we will be using before we disable
    319 	 * relocation.
    320 	 */
    321 	__asm("stvx %2,%1,%0" :: "b"(vp), "r"( 0), "n"(LO_VEC));
    322 	__asm("stvx %2,%1,%0" :: "b"(vp), "r"(16), "n"(HI_VEC));
    323 
    324 	/*
    325 	 * Turn off data relocation (DMMU off).
    326 	 */
    327 	msr &= ~PSL_DR;
    328 	__asm __volatile("sync; mtmsr %0; isync" :: "r"(msr));
    329 
    330 	/*
    331 	 * Copy the page using a single cache line.  On most PPCs, two
    332 	 * vector registers occupy one cache line.
    333 	 */
    334 	do {
    335 		__asm("lvx %2,%0,%1"   :: "b"(src), "r"( 0), "n"(LO_VEC));
    336 		__asm("stvx %2,%0,%1"  :: "b"(dst), "r"( 0), "n"(LO_VEC));
    337 		__asm("lvxl %2,%0,%1"  :: "b"(src), "r"(16), "n"(HI_VEC));
    338 		__asm("stvxl %2,%0,%1" :: "b"(dst), "r"(16), "n"(HI_VEC));
    339 		src += 32;
    340 		dst += 32;
    341 	} while (dst < edst);
    342 
    343 	/*
    344 	 * Restore data relocation (DMMU on);
    345 	 */
    346 	msr |= PSL_DR;
    347 	__asm __volatile("sync; mtmsr %0; isync" :: "r"(msr));
    348 
    349 	/*
    350 	 * Restore VEC registers (now that we can access the stack again).
    351 	 */
    352 	__asm("lvx %2,%1,%0" :: "b"(vp), "r"( 0), "n"(LO_VEC));
    353 	__asm("lvx %2,%1,%0" :: "b"(vp), "r"(16), "n"(HI_VEC));
    354 
    355 	/*
    356 	 * Restore old MSR (AltiVec OFF).
    357 	 */
    358 	__asm __volatile("sync; mtmsr %0; isync" :: "r"(omsr));
    359 }
    360