xref: /openbmc/linux/drivers/gpu/drm/gma500/psb_intel_display.c (revision 4984dd069f2995f239f075199ee8c0d9f020bcd9)
1 /*
2  * Copyright © 2006-2011 Intel Corporation
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc.,
15  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16  *
17  * Authors:
18  *	Eric Anholt <eric@anholt.net>
19  */
20 
21 #include <linux/delay.h>
22 #include <linux/i2c.h>
23 
24 #include <drm/drm_plane_helper.h>
25 
26 #include "framebuffer.h"
27 #include "gma_display.h"
28 #include "power.h"
29 #include "psb_drv.h"
30 #include "psb_intel_drv.h"
31 #include "psb_intel_reg.h"
32 
33 #define INTEL_LIMIT_I9XX_SDVO_DAC   0
34 #define INTEL_LIMIT_I9XX_LVDS	    1
35 
36 static const struct gma_limit_t psb_intel_limits[] = {
37 	{			/* INTEL_LIMIT_I9XX_SDVO_DAC */
38 	 .dot = {.min = 20000, .max = 400000},
39 	 .vco = {.min = 1400000, .max = 2800000},
40 	 .n = {.min = 1, .max = 6},
41 	 .m = {.min = 70, .max = 120},
42 	 .m1 = {.min = 8, .max = 18},
43 	 .m2 = {.min = 3, .max = 7},
44 	 .p = {.min = 5, .max = 80},
45 	 .p1 = {.min = 1, .max = 8},
46 	 .p2 = {.dot_limit = 200000, .p2_slow = 10, .p2_fast = 5},
47 	 .find_pll = gma_find_best_pll,
48 	 },
49 	{			/* INTEL_LIMIT_I9XX_LVDS */
50 	 .dot = {.min = 20000, .max = 400000},
51 	 .vco = {.min = 1400000, .max = 2800000},
52 	 .n = {.min = 1, .max = 6},
53 	 .m = {.min = 70, .max = 120},
54 	 .m1 = {.min = 8, .max = 18},
55 	 .m2 = {.min = 3, .max = 7},
56 	 .p = {.min = 7, .max = 98},
57 	 .p1 = {.min = 1, .max = 8},
58 	 /* The single-channel range is 25-112Mhz, and dual-channel
59 	  * is 80-224Mhz.  Prefer single channel as much as possible.
60 	  */
61 	 .p2 = {.dot_limit = 112000, .p2_slow = 14, .p2_fast = 7},
62 	 .find_pll = gma_find_best_pll,
63 	 },
64 };
65 
66 static const struct gma_limit_t *psb_intel_limit(struct drm_crtc *crtc,
67 						 int refclk)
68 {
69 	const struct gma_limit_t *limit;
70 
71 	if (gma_pipe_has_type(crtc, INTEL_OUTPUT_LVDS))
72 		limit = &psb_intel_limits[INTEL_LIMIT_I9XX_LVDS];
73 	else
74 		limit = &psb_intel_limits[INTEL_LIMIT_I9XX_SDVO_DAC];
75 	return limit;
76 }
77 
78 static void psb_intel_clock(int refclk, struct gma_clock_t *clock)
79 {
80 	clock->m = 5 * (clock->m1 + 2) + (clock->m2 + 2);
81 	clock->p = clock->p1 * clock->p2;
82 	clock->vco = refclk * clock->m / (clock->n + 2);
83 	clock->dot = clock->vco / clock->p;
84 }
85 
86 /**
87  * Return the pipe currently connected to the panel fitter,
88  * or -1 if the panel fitter is not present or not in use
89  */
90 static int psb_intel_panel_fitter_pipe(struct drm_device *dev)
91 {
92 	u32 pfit_control;
93 
94 	pfit_control = REG_READ(PFIT_CONTROL);
95 
96 	/* See if the panel fitter is in use */
97 	if ((pfit_control & PFIT_ENABLE) == 0)
98 		return -1;
99 	/* Must be on PIPE 1 for PSB */
100 	return 1;
101 }
102 
103 static int psb_intel_crtc_mode_set(struct drm_crtc *crtc,
104 			       struct drm_display_mode *mode,
105 			       struct drm_display_mode *adjusted_mode,
106 			       int x, int y,
107 			       struct drm_framebuffer *old_fb)
108 {
109 	struct drm_device *dev = crtc->dev;
110 	struct drm_psb_private *dev_priv = dev->dev_private;
111 	struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
112 	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
113 	int pipe = gma_crtc->pipe;
114 	const struct psb_offset *map = &dev_priv->regmap[pipe];
115 	int refclk;
116 	struct gma_clock_t clock;
117 	u32 dpll = 0, fp = 0, dspcntr, pipeconf;
118 	bool ok, is_sdvo = false;
119 	bool is_lvds = false, is_tv = false;
120 	struct drm_mode_config *mode_config = &dev->mode_config;
121 	struct drm_connector *connector;
122 	const struct gma_limit_t *limit;
123 
124 	/* No scan out no play */
125 	if (crtc->primary->fb == NULL) {
126 		crtc_funcs->mode_set_base(crtc, x, y, old_fb);
127 		return 0;
128 	}
129 
130 	list_for_each_entry(connector, &mode_config->connector_list, head) {
131 		struct gma_encoder *gma_encoder = gma_attached_encoder(connector);
132 
133 		if (!connector->encoder
134 		    || connector->encoder->crtc != crtc)
135 			continue;
136 
137 		switch (gma_encoder->type) {
138 		case INTEL_OUTPUT_LVDS:
139 			is_lvds = true;
140 			break;
141 		case INTEL_OUTPUT_SDVO:
142 			is_sdvo = true;
143 			break;
144 		case INTEL_OUTPUT_TVOUT:
145 			is_tv = true;
146 			break;
147 		}
148 	}
149 
150 	refclk = 96000;
151 
152 	limit = gma_crtc->clock_funcs->limit(crtc, refclk);
153 
154 	ok = limit->find_pll(limit, crtc, adjusted_mode->clock, refclk,
155 				 &clock);
156 	if (!ok) {
157 		DRM_ERROR("Couldn't find PLL settings for mode! target: %d, actual: %d",
158 			  adjusted_mode->clock, clock.dot);
159 		return 0;
160 	}
161 
162 	fp = clock.n << 16 | clock.m1 << 8 | clock.m2;
163 
164 	dpll = DPLL_VGA_MODE_DIS;
165 	if (is_lvds) {
166 		dpll |= DPLLB_MODE_LVDS;
167 		dpll |= DPLL_DVO_HIGH_SPEED;
168 	} else
169 		dpll |= DPLLB_MODE_DAC_SERIAL;
170 	if (is_sdvo) {
171 		int sdvo_pixel_multiply =
172 			    adjusted_mode->clock / mode->clock;
173 		dpll |= DPLL_DVO_HIGH_SPEED;
174 		dpll |=
175 		    (sdvo_pixel_multiply - 1) << SDVO_MULTIPLIER_SHIFT_HIRES;
176 	}
177 
178 	/* compute bitmask from p1 value */
179 	dpll |= (1 << (clock.p1 - 1)) << 16;
180 	switch (clock.p2) {
181 	case 5:
182 		dpll |= DPLL_DAC_SERIAL_P2_CLOCK_DIV_5;
183 		break;
184 	case 7:
185 		dpll |= DPLLB_LVDS_P2_CLOCK_DIV_7;
186 		break;
187 	case 10:
188 		dpll |= DPLL_DAC_SERIAL_P2_CLOCK_DIV_10;
189 		break;
190 	case 14:
191 		dpll |= DPLLB_LVDS_P2_CLOCK_DIV_14;
192 		break;
193 	}
194 
195 	if (is_tv) {
196 		/* XXX: just matching BIOS for now */
197 /*	dpll |= PLL_REF_INPUT_TVCLKINBC; */
198 		dpll |= 3;
199 	}
200 	dpll |= PLL_REF_INPUT_DREFCLK;
201 
202 	/* setup pipeconf */
203 	pipeconf = REG_READ(map->conf);
204 
205 	/* Set up the display plane register */
206 	dspcntr = DISPPLANE_GAMMA_ENABLE;
207 
208 	if (pipe == 0)
209 		dspcntr |= DISPPLANE_SEL_PIPE_A;
210 	else
211 		dspcntr |= DISPPLANE_SEL_PIPE_B;
212 
213 	dspcntr |= DISPLAY_PLANE_ENABLE;
214 	pipeconf |= PIPEACONF_ENABLE;
215 	dpll |= DPLL_VCO_ENABLE;
216 
217 
218 	/* Disable the panel fitter if it was on our pipe */
219 	if (psb_intel_panel_fitter_pipe(dev) == pipe)
220 		REG_WRITE(PFIT_CONTROL, 0);
221 
222 	drm_mode_debug_printmodeline(mode);
223 
224 	if (dpll & DPLL_VCO_ENABLE) {
225 		REG_WRITE(map->fp0, fp);
226 		REG_WRITE(map->dpll, dpll & ~DPLL_VCO_ENABLE);
227 		REG_READ(map->dpll);
228 		udelay(150);
229 	}
230 
231 	/* The LVDS pin pair needs to be on before the DPLLs are enabled.
232 	 * This is an exception to the general rule that mode_set doesn't turn
233 	 * things on.
234 	 */
235 	if (is_lvds) {
236 		u32 lvds = REG_READ(LVDS);
237 
238 		lvds &= ~LVDS_PIPEB_SELECT;
239 		if (pipe == 1)
240 			lvds |= LVDS_PIPEB_SELECT;
241 
242 		lvds |= LVDS_PORT_EN | LVDS_A0A2_CLKA_POWER_UP;
243 		/* Set the B0-B3 data pairs corresponding to
244 		 * whether we're going to
245 		 * set the DPLLs for dual-channel mode or not.
246 		 */
247 		lvds &= ~(LVDS_B0B3_POWER_UP | LVDS_CLKB_POWER_UP);
248 		if (clock.p2 == 7)
249 			lvds |= LVDS_B0B3_POWER_UP | LVDS_CLKB_POWER_UP;
250 
251 		/* It would be nice to set 24 vs 18-bit mode (LVDS_A3_POWER_UP)
252 		 * appropriately here, but we need to look more
253 		 * thoroughly into how panels behave in the two modes.
254 		 */
255 
256 		REG_WRITE(LVDS, lvds);
257 		REG_READ(LVDS);
258 	}
259 
260 	REG_WRITE(map->fp0, fp);
261 	REG_WRITE(map->dpll, dpll);
262 	REG_READ(map->dpll);
263 	/* Wait for the clocks to stabilize. */
264 	udelay(150);
265 
266 	/* write it again -- the BIOS does, after all */
267 	REG_WRITE(map->dpll, dpll);
268 
269 	REG_READ(map->dpll);
270 	/* Wait for the clocks to stabilize. */
271 	udelay(150);
272 
273 	REG_WRITE(map->htotal, (adjusted_mode->crtc_hdisplay - 1) |
274 		  ((adjusted_mode->crtc_htotal - 1) << 16));
275 	REG_WRITE(map->hblank, (adjusted_mode->crtc_hblank_start - 1) |
276 		  ((adjusted_mode->crtc_hblank_end - 1) << 16));
277 	REG_WRITE(map->hsync, (adjusted_mode->crtc_hsync_start - 1) |
278 		  ((adjusted_mode->crtc_hsync_end - 1) << 16));
279 	REG_WRITE(map->vtotal, (adjusted_mode->crtc_vdisplay - 1) |
280 		  ((adjusted_mode->crtc_vtotal - 1) << 16));
281 	REG_WRITE(map->vblank, (adjusted_mode->crtc_vblank_start - 1) |
282 		  ((adjusted_mode->crtc_vblank_end - 1) << 16));
283 	REG_WRITE(map->vsync, (adjusted_mode->crtc_vsync_start - 1) |
284 		  ((adjusted_mode->crtc_vsync_end - 1) << 16));
285 	/* pipesrc and dspsize control the size that is scaled from,
286 	 * which should always be the user's requested size.
287 	 */
288 	REG_WRITE(map->size,
289 		  ((mode->vdisplay - 1) << 16) | (mode->hdisplay - 1));
290 	REG_WRITE(map->pos, 0);
291 	REG_WRITE(map->src,
292 		  ((mode->hdisplay - 1) << 16) | (mode->vdisplay - 1));
293 	REG_WRITE(map->conf, pipeconf);
294 	REG_READ(map->conf);
295 
296 	gma_wait_for_vblank(dev);
297 
298 	REG_WRITE(map->cntr, dspcntr);
299 
300 	/* Flush the plane changes */
301 	crtc_funcs->mode_set_base(crtc, x, y, old_fb);
302 
303 	gma_wait_for_vblank(dev);
304 
305 	return 0;
306 }
307 
308 /* Returns the clock of the currently programmed mode of the given pipe. */
309 static int psb_intel_crtc_clock_get(struct drm_device *dev,
310 				struct drm_crtc *crtc)
311 {
312 	struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
313 	struct drm_psb_private *dev_priv = dev->dev_private;
314 	int pipe = gma_crtc->pipe;
315 	const struct psb_offset *map = &dev_priv->regmap[pipe];
316 	u32 dpll;
317 	u32 fp;
318 	struct gma_clock_t clock;
319 	bool is_lvds;
320 	struct psb_pipe *p = &dev_priv->regs.pipe[pipe];
321 
322 	if (gma_power_begin(dev, false)) {
323 		dpll = REG_READ(map->dpll);
324 		if ((dpll & DISPLAY_RATE_SELECT_FPA1) == 0)
325 			fp = REG_READ(map->fp0);
326 		else
327 			fp = REG_READ(map->fp1);
328 		is_lvds = (pipe == 1) && (REG_READ(LVDS) & LVDS_PORT_EN);
329 		gma_power_end(dev);
330 	} else {
331 		dpll = p->dpll;
332 
333 		if ((dpll & DISPLAY_RATE_SELECT_FPA1) == 0)
334 			fp = p->fp0;
335 		else
336 		        fp = p->fp1;
337 
338 		is_lvds = (pipe == 1) && (dev_priv->regs.psb.saveLVDS &
339 								LVDS_PORT_EN);
340 	}
341 
342 	clock.m1 = (fp & FP_M1_DIV_MASK) >> FP_M1_DIV_SHIFT;
343 	clock.m2 = (fp & FP_M2_DIV_MASK) >> FP_M2_DIV_SHIFT;
344 	clock.n = (fp & FP_N_DIV_MASK) >> FP_N_DIV_SHIFT;
345 
346 	if (is_lvds) {
347 		clock.p1 =
348 		    ffs((dpll &
349 			 DPLL_FPA01_P1_POST_DIV_MASK_I830_LVDS) >>
350 			DPLL_FPA01_P1_POST_DIV_SHIFT);
351 		clock.p2 = 14;
352 
353 		if ((dpll & PLL_REF_INPUT_MASK) ==
354 		    PLLB_REF_INPUT_SPREADSPECTRUMIN) {
355 			/* XXX: might not be 66MHz */
356 			psb_intel_clock(66000, &clock);
357 		} else
358 			psb_intel_clock(48000, &clock);
359 	} else {
360 		if (dpll & PLL_P1_DIVIDE_BY_TWO)
361 			clock.p1 = 2;
362 		else {
363 			clock.p1 =
364 			    ((dpll &
365 			      DPLL_FPA01_P1_POST_DIV_MASK_I830) >>
366 			     DPLL_FPA01_P1_POST_DIV_SHIFT) + 2;
367 		}
368 		if (dpll & PLL_P2_DIVIDE_BY_4)
369 			clock.p2 = 4;
370 		else
371 			clock.p2 = 2;
372 
373 		psb_intel_clock(48000, &clock);
374 	}
375 
376 	/* XXX: It would be nice to validate the clocks, but we can't reuse
377 	 * i830PllIsValid() because it relies on the xf86_config connector
378 	 * configuration being accurate, which it isn't necessarily.
379 	 */
380 
381 	return clock.dot;
382 }
383 
384 /** Returns the currently programmed mode of the given pipe. */
385 struct drm_display_mode *psb_intel_crtc_mode_get(struct drm_device *dev,
386 					     struct drm_crtc *crtc)
387 {
388 	struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
389 	int pipe = gma_crtc->pipe;
390 	struct drm_display_mode *mode;
391 	int htot;
392 	int hsync;
393 	int vtot;
394 	int vsync;
395 	struct drm_psb_private *dev_priv = dev->dev_private;
396 	struct psb_pipe *p = &dev_priv->regs.pipe[pipe];
397 	const struct psb_offset *map = &dev_priv->regmap[pipe];
398 
399 	if (gma_power_begin(dev, false)) {
400 		htot = REG_READ(map->htotal);
401 		hsync = REG_READ(map->hsync);
402 		vtot = REG_READ(map->vtotal);
403 		vsync = REG_READ(map->vsync);
404 		gma_power_end(dev);
405 	} else {
406 		htot = p->htotal;
407 		hsync = p->hsync;
408 		vtot = p->vtotal;
409 		vsync = p->vsync;
410 	}
411 
412 	mode = kzalloc(sizeof(*mode), GFP_KERNEL);
413 	if (!mode)
414 		return NULL;
415 
416 	mode->clock = psb_intel_crtc_clock_get(dev, crtc);
417 	mode->hdisplay = (htot & 0xffff) + 1;
418 	mode->htotal = ((htot & 0xffff0000) >> 16) + 1;
419 	mode->hsync_start = (hsync & 0xffff) + 1;
420 	mode->hsync_end = ((hsync & 0xffff0000) >> 16) + 1;
421 	mode->vdisplay = (vtot & 0xffff) + 1;
422 	mode->vtotal = ((vtot & 0xffff0000) >> 16) + 1;
423 	mode->vsync_start = (vsync & 0xffff) + 1;
424 	mode->vsync_end = ((vsync & 0xffff0000) >> 16) + 1;
425 
426 	drm_mode_set_name(mode);
427 	drm_mode_set_crtcinfo(mode, 0);
428 
429 	return mode;
430 }
431 
432 const struct drm_crtc_helper_funcs psb_intel_helper_funcs = {
433 	.dpms = gma_crtc_dpms,
434 	.mode_set = psb_intel_crtc_mode_set,
435 	.mode_set_base = gma_pipe_set_base,
436 	.prepare = gma_crtc_prepare,
437 	.commit = gma_crtc_commit,
438 	.disable = gma_crtc_disable,
439 };
440 
441 const struct drm_crtc_funcs psb_intel_crtc_funcs = {
442 	.cursor_set = gma_crtc_cursor_set,
443 	.cursor_move = gma_crtc_cursor_move,
444 	.gamma_set = gma_crtc_gamma_set,
445 	.set_config = gma_crtc_set_config,
446 	.destroy = gma_crtc_destroy,
447 };
448 
449 const struct gma_clock_funcs psb_clock_funcs = {
450 	.clock = psb_intel_clock,
451 	.limit = psb_intel_limit,
452 	.pll_is_valid = gma_pll_is_valid,
453 };
454 
455 /*
456  * Set the default value of cursor control and base register
457  * to zero. This is a workaround for h/w defect on Oaktrail
458  */
459 static void psb_intel_cursor_init(struct drm_device *dev,
460 				  struct gma_crtc *gma_crtc)
461 {
462 	struct drm_psb_private *dev_priv = dev->dev_private;
463 	u32 control[3] = { CURACNTR, CURBCNTR, CURCCNTR };
464 	u32 base[3] = { CURABASE, CURBBASE, CURCBASE };
465 	struct gtt_range *cursor_gt;
466 
467 	if (dev_priv->ops->cursor_needs_phys) {
468 		/* Allocate 4 pages of stolen mem for a hardware cursor. That
469 		 * is enough for the 64 x 64 ARGB cursors we support.
470 		 */
471 		cursor_gt = psb_gtt_alloc_range(dev, 4 * PAGE_SIZE, "cursor", 1,
472 						PAGE_SIZE);
473 		if (!cursor_gt) {
474 			gma_crtc->cursor_gt = NULL;
475 			goto out;
476 		}
477 		gma_crtc->cursor_gt = cursor_gt;
478 		gma_crtc->cursor_addr = dev_priv->stolen_base +
479 							cursor_gt->offset;
480 	} else {
481 		gma_crtc->cursor_gt = NULL;
482 	}
483 
484 out:
485 	REG_WRITE(control[gma_crtc->pipe], 0);
486 	REG_WRITE(base[gma_crtc->pipe], 0);
487 }
488 
489 void psb_intel_crtc_init(struct drm_device *dev, int pipe,
490 		     struct psb_intel_mode_device *mode_dev)
491 {
492 	struct drm_psb_private *dev_priv = dev->dev_private;
493 	struct gma_crtc *gma_crtc;
494 	int i;
495 
496 	/* We allocate a extra array of drm_connector pointers
497 	 * for fbdev after the crtc */
498 	gma_crtc = kzalloc(sizeof(struct gma_crtc) +
499 			(INTELFB_CONN_LIMIT * sizeof(struct drm_connector *)),
500 			GFP_KERNEL);
501 	if (gma_crtc == NULL)
502 		return;
503 
504 	gma_crtc->crtc_state =
505 		kzalloc(sizeof(struct psb_intel_crtc_state), GFP_KERNEL);
506 	if (!gma_crtc->crtc_state) {
507 		dev_err(dev->dev, "Crtc state error: No memory\n");
508 		kfree(gma_crtc);
509 		return;
510 	}
511 
512 	/* Set the CRTC operations from the chip specific data */
513 	drm_crtc_init(dev, &gma_crtc->base, dev_priv->ops->crtc_funcs);
514 
515 	/* Set the CRTC clock functions from chip specific data */
516 	gma_crtc->clock_funcs = dev_priv->ops->clock_funcs;
517 
518 	drm_mode_crtc_set_gamma_size(&gma_crtc->base, 256);
519 	gma_crtc->pipe = pipe;
520 	gma_crtc->plane = pipe;
521 
522 	for (i = 0; i < 256; i++)
523 		gma_crtc->lut_adj[i] = 0;
524 
525 	gma_crtc->mode_dev = mode_dev;
526 	gma_crtc->cursor_addr = 0;
527 
528 	drm_crtc_helper_add(&gma_crtc->base,
529 						dev_priv->ops->crtc_helper);
530 
531 	/* Setup the array of drm_connector pointer array */
532 	gma_crtc->mode_set.crtc = &gma_crtc->base;
533 	BUG_ON(pipe >= ARRAY_SIZE(dev_priv->plane_to_crtc_mapping) ||
534 	       dev_priv->plane_to_crtc_mapping[gma_crtc->plane] != NULL);
535 	dev_priv->plane_to_crtc_mapping[gma_crtc->plane] = &gma_crtc->base;
536 	dev_priv->pipe_to_crtc_mapping[gma_crtc->pipe] = &gma_crtc->base;
537 	gma_crtc->mode_set.connectors = (struct drm_connector **)(gma_crtc + 1);
538 	gma_crtc->mode_set.num_connectors = 0;
539 	psb_intel_cursor_init(dev, gma_crtc);
540 
541 	/* Set to true so that the pipe is forced off on initial config. */
542 	gma_crtc->active = true;
543 }
544 
545 struct drm_crtc *psb_intel_get_crtc_from_pipe(struct drm_device *dev, int pipe)
546 {
547 	struct drm_crtc *crtc = NULL;
548 
549 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
550 		struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
551 		if (gma_crtc->pipe == pipe)
552 			break;
553 	}
554 	return crtc;
555 }
556 
557 int gma_connector_clones(struct drm_device *dev, int type_mask)
558 {
559 	int index_mask = 0;
560 	struct drm_connector *connector;
561 	int entry = 0;
562 
563 	list_for_each_entry(connector, &dev->mode_config.connector_list,
564 			    head) {
565 		struct gma_encoder *gma_encoder = gma_attached_encoder(connector);
566 		if (type_mask & (1 << gma_encoder->type))
567 			index_mask |= (1 << entry);
568 		entry++;
569 	}
570 	return index_mask;
571 }
572