xref: /linux/sound/soc/intel/catpt/dsp.c (revision 02680c23d7b3febe45ea3d4f9818c2b2dc89020a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 //
3 // Copyright(c) 2020 Intel Corporation. All rights reserved.
4 //
5 // Author: Cezary Rojewski <cezary.rojewski@intel.com>
6 //
7 
8 #include <linux/devcoredump.h>
9 #include <linux/dma-mapping.h>
10 #include <linux/firmware.h>
11 #include <linux/pci.h>
12 #include <linux/pxa2xx_ssp.h>
13 #include "core.h"
14 #include "messages.h"
15 #include "registers.h"
16 
17 static bool catpt_dma_filter(struct dma_chan *chan, void *param)
18 {
19 	return param == chan->device->dev;
20 }
21 
22 /*
23  * Either engine 0 or 1 can be used for image loading.
24  * Align with Windows driver equivalent and stick to engine 1.
25  */
26 #define CATPT_DMA_DEVID		1
27 #define CATPT_DMA_DSP_ADDR_MASK	GENMASK(31, 20)
28 
29 struct dma_chan *catpt_dma_request_config_chan(struct catpt_dev *cdev)
30 {
31 	struct dma_slave_config config;
32 	struct dma_chan *chan;
33 	dma_cap_mask_t mask;
34 	int ret;
35 
36 	dma_cap_zero(mask);
37 	dma_cap_set(DMA_MEMCPY, mask);
38 
39 	chan = dma_request_channel(mask, catpt_dma_filter, cdev->dev);
40 	if (!chan) {
41 		dev_err(cdev->dev, "request channel failed\n");
42 		return ERR_PTR(-ENODEV);
43 	}
44 
45 	memset(&config, 0, sizeof(config));
46 	config.direction = DMA_MEM_TO_DEV;
47 	config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
48 	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
49 	config.src_maxburst = 16;
50 	config.dst_maxburst = 16;
51 
52 	ret = dmaengine_slave_config(chan, &config);
53 	if (ret) {
54 		dev_err(cdev->dev, "slave config failed: %d\n", ret);
55 		dma_release_channel(chan);
56 		return ERR_PTR(ret);
57 	}
58 
59 	return chan;
60 }
61 
62 static int catpt_dma_memcpy(struct catpt_dev *cdev, struct dma_chan *chan,
63 			    dma_addr_t dst_addr, dma_addr_t src_addr,
64 			    size_t size)
65 {
66 	struct dma_async_tx_descriptor *desc;
67 	enum dma_status status;
68 
69 	desc = dmaengine_prep_dma_memcpy(chan, dst_addr, src_addr, size,
70 					 DMA_CTRL_ACK);
71 	if (!desc) {
72 		dev_err(cdev->dev, "prep dma memcpy failed\n");
73 		return -EIO;
74 	}
75 
76 	/* enable demand mode for dma channel */
77 	catpt_updatel_shim(cdev, HMDC,
78 			   CATPT_HMDC_HDDA(CATPT_DMA_DEVID, chan->chan_id),
79 			   CATPT_HMDC_HDDA(CATPT_DMA_DEVID, chan->chan_id));
80 	dmaengine_submit(desc);
81 	status = dma_wait_for_async_tx(desc);
82 	/* regardless of status, disable access to HOST memory in demand mode */
83 	catpt_updatel_shim(cdev, HMDC,
84 			   CATPT_HMDC_HDDA(CATPT_DMA_DEVID, chan->chan_id), 0);
85 
86 	return (status == DMA_COMPLETE) ? 0 : -EPROTO;
87 }
88 
89 int catpt_dma_memcpy_todsp(struct catpt_dev *cdev, struct dma_chan *chan,
90 			   dma_addr_t dst_addr, dma_addr_t src_addr,
91 			   size_t size)
92 {
93 	return catpt_dma_memcpy(cdev, chan, dst_addr | CATPT_DMA_DSP_ADDR_MASK,
94 				src_addr, size);
95 }
96 
97 int catpt_dma_memcpy_fromdsp(struct catpt_dev *cdev, struct dma_chan *chan,
98 			     dma_addr_t dst_addr, dma_addr_t src_addr,
99 			     size_t size)
100 {
101 	return catpt_dma_memcpy(cdev, chan, dst_addr,
102 				src_addr | CATPT_DMA_DSP_ADDR_MASK, size);
103 }
104 
105 int catpt_dmac_probe(struct catpt_dev *cdev)
106 {
107 	struct dw_dma_chip *dmac;
108 	int ret;
109 
110 	dmac = devm_kzalloc(cdev->dev, sizeof(*dmac), GFP_KERNEL);
111 	if (!dmac)
112 		return -ENOMEM;
113 
114 	dmac->regs = cdev->lpe_ba + cdev->spec->host_dma_offset[CATPT_DMA_DEVID];
115 	dmac->dev = cdev->dev;
116 	dmac->irq = cdev->irq;
117 
118 	ret = dma_coerce_mask_and_coherent(cdev->dev, DMA_BIT_MASK(31));
119 	if (ret)
120 		return ret;
121 	/*
122 	 * Caller is responsible for putting device in D0 to allow
123 	 * for I/O and memory access before probing DW.
124 	 */
125 	ret = dw_dma_probe(dmac);
126 	if (ret)
127 		return ret;
128 
129 	cdev->dmac = dmac;
130 	return 0;
131 }
132 
133 void catpt_dmac_remove(struct catpt_dev *cdev)
134 {
135 	/*
136 	 * As do_dma_remove() juggles with pm_runtime_get_xxx() and
137 	 * pm_runtime_put_xxx() while both ADSP and DW 'devices' are part of
138 	 * the same module, caller makes sure pm_runtime_disable() is invoked
139 	 * before removing DW to prevent postmortem resume and suspend.
140 	 */
141 	dw_dma_remove(cdev->dmac);
142 }
143 
144 static void catpt_dsp_set_srampge(struct catpt_dev *cdev, struct resource *sram,
145 				  unsigned long mask, unsigned long new)
146 {
147 	unsigned long old;
148 	u32 off = sram->start;
149 	u32 b = __ffs(mask);
150 
151 	old = catpt_readl_pci(cdev, VDRTCTL0) & mask;
152 	dev_dbg(cdev->dev, "SRAMPGE [0x%08lx] 0x%08lx -> 0x%08lx",
153 		mask, old, new);
154 
155 	if (old == new)
156 		return;
157 
158 	catpt_updatel_pci(cdev, VDRTCTL0, mask, new);
159 	/* wait for SRAM power gating to propagate */
160 	udelay(60);
161 
162 	/*
163 	 * Dummy read as the very first access after block enable
164 	 * to prevent byte loss in future operations.
165 	 */
166 	for_each_clear_bit_from(b, &new, fls_long(mask)) {
167 		u8 buf[4];
168 
169 		/* newly enabled: new bit=0 while old bit=1 */
170 		if (test_bit(b, &old)) {
171 			dev_dbg(cdev->dev, "sanitize block %ld: off 0x%08x\n",
172 				b - __ffs(mask), off);
173 			memcpy_fromio(buf, cdev->lpe_ba + off, sizeof(buf));
174 		}
175 		off += CATPT_MEMBLOCK_SIZE;
176 	}
177 }
178 
179 void catpt_dsp_update_srampge(struct catpt_dev *cdev, struct resource *sram,
180 			      unsigned long mask)
181 {
182 	struct resource *res;
183 	unsigned long new = 0;
184 
185 	/* flag all busy blocks */
186 	for (res = sram->child; res; res = res->sibling) {
187 		u32 h, l;
188 
189 		h = (res->end - sram->start) / CATPT_MEMBLOCK_SIZE;
190 		l = (res->start - sram->start) / CATPT_MEMBLOCK_SIZE;
191 		new |= GENMASK(h, l);
192 	}
193 
194 	/* offset value given mask's start and invert it as ON=b0 */
195 	new = ~(new << __ffs(mask)) & mask;
196 
197 	/* disable core clock gating */
198 	catpt_updatel_pci(cdev, VDRTCTL2, CATPT_VDRTCTL2_DCLCGE, 0);
199 
200 	catpt_dsp_set_srampge(cdev, sram, mask, new);
201 
202 	/* enable core clock gating */
203 	catpt_updatel_pci(cdev, VDRTCTL2, CATPT_VDRTCTL2_DCLCGE,
204 			  CATPT_VDRTCTL2_DCLCGE);
205 }
206 
207 int catpt_dsp_stall(struct catpt_dev *cdev, bool stall)
208 {
209 	u32 reg, val;
210 
211 	val = stall ? CATPT_CS_STALL : 0;
212 	catpt_updatel_shim(cdev, CS1, CATPT_CS_STALL, val);
213 
214 	return catpt_readl_poll_shim(cdev, CS1,
215 				     reg, (reg & CATPT_CS_STALL) == val,
216 				     500, 10000);
217 }
218 
219 static int catpt_dsp_reset(struct catpt_dev *cdev, bool reset)
220 {
221 	u32 reg, val;
222 
223 	val = reset ? CATPT_CS_RST : 0;
224 	catpt_updatel_shim(cdev, CS1, CATPT_CS_RST, val);
225 
226 	return catpt_readl_poll_shim(cdev, CS1,
227 				     reg, (reg & CATPT_CS_RST) == val,
228 				     500, 10000);
229 }
230 
231 void lpt_dsp_pll_shutdown(struct catpt_dev *cdev, bool enable)
232 {
233 	u32 val;
234 
235 	val = enable ? LPT_VDRTCTL0_APLLSE : 0;
236 	catpt_updatel_pci(cdev, VDRTCTL0, LPT_VDRTCTL0_APLLSE, val);
237 }
238 
239 void wpt_dsp_pll_shutdown(struct catpt_dev *cdev, bool enable)
240 {
241 	u32 val;
242 
243 	val = enable ? WPT_VDRTCTL2_APLLSE : 0;
244 	catpt_updatel_pci(cdev, VDRTCTL2, WPT_VDRTCTL2_APLLSE, val);
245 }
246 
247 static int catpt_dsp_select_lpclock(struct catpt_dev *cdev, bool lp, bool waiti)
248 {
249 	u32 mask, reg, val;
250 	int ret;
251 
252 	mutex_lock(&cdev->clk_mutex);
253 
254 	val = lp ? CATPT_CS_LPCS : 0;
255 	reg = catpt_readl_shim(cdev, CS1) & CATPT_CS_LPCS;
256 	dev_dbg(cdev->dev, "LPCS [0x%08lx] 0x%08x -> 0x%08x",
257 		CATPT_CS_LPCS, reg, val);
258 
259 	if (reg == val) {
260 		mutex_unlock(&cdev->clk_mutex);
261 		return 0;
262 	}
263 
264 	if (waiti) {
265 		/* wait for DSP to signal WAIT state */
266 		ret = catpt_readl_poll_shim(cdev, ISD,
267 					    reg, (reg & CATPT_ISD_DCPWM),
268 					    500, 10000);
269 		if (ret) {
270 			dev_warn(cdev->dev, "await WAITI timeout\n");
271 			/* no signal - only high clock selection allowed */
272 			if (lp) {
273 				mutex_unlock(&cdev->clk_mutex);
274 				return 0;
275 			}
276 		}
277 	}
278 
279 	ret = catpt_readl_poll_shim(cdev, CLKCTL,
280 				    reg, !(reg & CATPT_CLKCTL_CFCIP),
281 				    500, 10000);
282 	if (ret)
283 		dev_warn(cdev->dev, "clock change still in progress\n");
284 
285 	/* default to DSP core & audio fabric high clock */
286 	val |= CATPT_CS_DCS_HIGH;
287 	mask = CATPT_CS_LPCS | CATPT_CS_DCS;
288 	catpt_updatel_shim(cdev, CS1, mask, val);
289 
290 	ret = catpt_readl_poll_shim(cdev, CLKCTL,
291 				    reg, !(reg & CATPT_CLKCTL_CFCIP),
292 				    500, 10000);
293 	if (ret)
294 		dev_warn(cdev->dev, "clock change still in progress\n");
295 
296 	/* update PLL accordingly */
297 	cdev->spec->pll_shutdown(cdev, lp);
298 
299 	mutex_unlock(&cdev->clk_mutex);
300 	return 0;
301 }
302 
303 int catpt_dsp_update_lpclock(struct catpt_dev *cdev)
304 {
305 	struct catpt_stream_runtime *stream;
306 
307 	list_for_each_entry(stream, &cdev->stream_list, node)
308 		if (stream->prepared)
309 			return catpt_dsp_select_lpclock(cdev, false, true);
310 
311 	return catpt_dsp_select_lpclock(cdev, true, true);
312 }
313 
314 /* bring registers to their defaults as HW won't reset itself */
315 static void catpt_dsp_set_regs_defaults(struct catpt_dev *cdev)
316 {
317 	int i;
318 
319 	catpt_writel_shim(cdev, CS1, CATPT_CS_DEFAULT);
320 	catpt_writel_shim(cdev, ISC, CATPT_ISC_DEFAULT);
321 	catpt_writel_shim(cdev, ISD, CATPT_ISD_DEFAULT);
322 	catpt_writel_shim(cdev, IMC, CATPT_IMC_DEFAULT);
323 	catpt_writel_shim(cdev, IMD, CATPT_IMD_DEFAULT);
324 	catpt_writel_shim(cdev, IPCC, CATPT_IPCC_DEFAULT);
325 	catpt_writel_shim(cdev, IPCD, CATPT_IPCD_DEFAULT);
326 	catpt_writel_shim(cdev, CLKCTL, CATPT_CLKCTL_DEFAULT);
327 	catpt_writel_shim(cdev, CS2, CATPT_CS2_DEFAULT);
328 	catpt_writel_shim(cdev, LTRC, CATPT_LTRC_DEFAULT);
329 	catpt_writel_shim(cdev, HMDC, CATPT_HMDC_DEFAULT);
330 
331 	for (i = 0; i < CATPT_SSP_COUNT; i++) {
332 		catpt_writel_ssp(cdev, i, SSCR0, CATPT_SSC0_DEFAULT);
333 		catpt_writel_ssp(cdev, i, SSCR1, CATPT_SSC1_DEFAULT);
334 		catpt_writel_ssp(cdev, i, SSSR, CATPT_SSS_DEFAULT);
335 		catpt_writel_ssp(cdev, i, SSITR, CATPT_SSIT_DEFAULT);
336 		catpt_writel_ssp(cdev, i, SSDR, CATPT_SSD_DEFAULT);
337 		catpt_writel_ssp(cdev, i, SSTO, CATPT_SSTO_DEFAULT);
338 		catpt_writel_ssp(cdev, i, SSPSP, CATPT_SSPSP_DEFAULT);
339 		catpt_writel_ssp(cdev, i, SSTSA, CATPT_SSTSA_DEFAULT);
340 		catpt_writel_ssp(cdev, i, SSRSA, CATPT_SSRSA_DEFAULT);
341 		catpt_writel_ssp(cdev, i, SSTSS, CATPT_SSTSS_DEFAULT);
342 		catpt_writel_ssp(cdev, i, SSCR2, CATPT_SSCR2_DEFAULT);
343 		catpt_writel_ssp(cdev, i, SSPSP2, CATPT_SSPSP2_DEFAULT);
344 	}
345 }
346 
347 int catpt_dsp_power_down(struct catpt_dev *cdev)
348 {
349 	u32 mask, val;
350 
351 	/* disable core clock gating */
352 	catpt_updatel_pci(cdev, VDRTCTL2, CATPT_VDRTCTL2_DCLCGE, 0);
353 
354 	catpt_dsp_reset(cdev, true);
355 	/* set 24Mhz clock for both SSPs */
356 	catpt_updatel_shim(cdev, CS1, CATPT_CS_SBCS(0) | CATPT_CS_SBCS(1),
357 			   CATPT_CS_SBCS(0) | CATPT_CS_SBCS(1));
358 	catpt_dsp_select_lpclock(cdev, true, false);
359 	/* disable MCLK */
360 	catpt_updatel_shim(cdev, CLKCTL, CATPT_CLKCTL_SMOS, 0);
361 
362 	catpt_dsp_set_regs_defaults(cdev);
363 
364 	/* switch clock gating */
365 	mask = CATPT_VDRTCTL2_CGEALL & (~CATPT_VDRTCTL2_DCLCGE);
366 	val = mask & (~CATPT_VDRTCTL2_DTCGE);
367 	catpt_updatel_pci(cdev, VDRTCTL2, mask, val);
368 	/* enable DTCGE separatelly */
369 	catpt_updatel_pci(cdev, VDRTCTL2, CATPT_VDRTCTL2_DTCGE,
370 			  CATPT_VDRTCTL2_DTCGE);
371 
372 	/* SRAM power gating all */
373 	catpt_dsp_set_srampge(cdev, &cdev->dram, cdev->spec->dram_mask,
374 			      cdev->spec->dram_mask);
375 	catpt_dsp_set_srampge(cdev, &cdev->iram, cdev->spec->iram_mask,
376 			      cdev->spec->iram_mask);
377 	mask = cdev->spec->d3srampgd_bit | cdev->spec->d3pgd_bit;
378 	catpt_updatel_pci(cdev, VDRTCTL0, mask, cdev->spec->d3pgd_bit);
379 
380 	catpt_updatel_pci(cdev, PMCS, PCI_PM_CTRL_STATE_MASK, PCI_D3hot);
381 	/* give hw time to drop off */
382 	udelay(50);
383 
384 	/* enable core clock gating */
385 	catpt_updatel_pci(cdev, VDRTCTL2, CATPT_VDRTCTL2_DCLCGE,
386 			  CATPT_VDRTCTL2_DCLCGE);
387 	udelay(50);
388 
389 	return 0;
390 }
391 
392 int catpt_dsp_power_up(struct catpt_dev *cdev)
393 {
394 	u32 mask, val;
395 
396 	/* disable core clock gating */
397 	catpt_updatel_pci(cdev, VDRTCTL2, CATPT_VDRTCTL2_DCLCGE, 0);
398 
399 	/* switch clock gating */
400 	mask = CATPT_VDRTCTL2_CGEALL & (~CATPT_VDRTCTL2_DCLCGE);
401 	val = mask & (~CATPT_VDRTCTL2_DTCGE);
402 	catpt_updatel_pci(cdev, VDRTCTL2, mask, val);
403 
404 	catpt_updatel_pci(cdev, PMCS, PCI_PM_CTRL_STATE_MASK, PCI_D0);
405 
406 	/* SRAM power gating none */
407 	mask = cdev->spec->d3srampgd_bit | cdev->spec->d3pgd_bit;
408 	catpt_updatel_pci(cdev, VDRTCTL0, mask, mask);
409 	catpt_dsp_set_srampge(cdev, &cdev->dram, cdev->spec->dram_mask, 0);
410 	catpt_dsp_set_srampge(cdev, &cdev->iram, cdev->spec->iram_mask, 0);
411 
412 	catpt_dsp_set_regs_defaults(cdev);
413 
414 	/* restore MCLK */
415 	catpt_updatel_shim(cdev, CLKCTL, CATPT_CLKCTL_SMOS, CATPT_CLKCTL_SMOS);
416 	catpt_dsp_select_lpclock(cdev, false, false);
417 	/* set 24Mhz clock for both SSPs */
418 	catpt_updatel_shim(cdev, CS1, CATPT_CS_SBCS(0) | CATPT_CS_SBCS(1),
419 			   CATPT_CS_SBCS(0) | CATPT_CS_SBCS(1));
420 	catpt_dsp_reset(cdev, false);
421 
422 	/* enable core clock gating */
423 	catpt_updatel_pci(cdev, VDRTCTL2, CATPT_VDRTCTL2_DCLCGE,
424 			  CATPT_VDRTCTL2_DCLCGE);
425 
426 	/* generate int deassert msg to fix inversed int logic */
427 	catpt_updatel_shim(cdev, IMC, CATPT_IMC_IPCDB | CATPT_IMC_IPCCD, 0);
428 
429 	return 0;
430 }
431 
432 #define CATPT_DUMP_MAGIC		0xcd42
433 #define CATPT_DUMP_SECTION_ID_FILE	0x00
434 #define CATPT_DUMP_SECTION_ID_IRAM	0x01
435 #define CATPT_DUMP_SECTION_ID_DRAM	0x02
436 #define CATPT_DUMP_SECTION_ID_REGS	0x03
437 #define CATPT_DUMP_HASH_SIZE		20
438 
439 struct catpt_dump_section_hdr {
440 	u16 magic;
441 	u8 core_id;
442 	u8 section_id;
443 	u32 size;
444 };
445 
446 int catpt_coredump(struct catpt_dev *cdev)
447 {
448 	struct catpt_dump_section_hdr *hdr;
449 	size_t dump_size, regs_size;
450 	u8 *dump, *pos;
451 	const char *eof;
452 	char *info;
453 	int i;
454 
455 	regs_size = CATPT_SHIM_REGS_SIZE;
456 	regs_size += CATPT_DMA_COUNT * CATPT_DMA_REGS_SIZE;
457 	regs_size += CATPT_SSP_COUNT * CATPT_SSP_REGS_SIZE;
458 	dump_size = resource_size(&cdev->dram);
459 	dump_size += resource_size(&cdev->iram);
460 	dump_size += regs_size;
461 	/* account for header of each section and hash chunk */
462 	dump_size += 4 * sizeof(*hdr) + CATPT_DUMP_HASH_SIZE;
463 
464 	dump = vzalloc(dump_size);
465 	if (!dump)
466 		return -ENOMEM;
467 
468 	pos = dump;
469 
470 	hdr = (struct catpt_dump_section_hdr *)pos;
471 	hdr->magic = CATPT_DUMP_MAGIC;
472 	hdr->core_id = cdev->spec->core_id;
473 	hdr->section_id = CATPT_DUMP_SECTION_ID_FILE;
474 	hdr->size = dump_size - sizeof(*hdr);
475 	pos += sizeof(*hdr);
476 
477 	info = cdev->ipc.config.fw_info;
478 	eof = info + FW_INFO_SIZE_MAX;
479 	/* navigate to fifth info segment (fw hash) */
480 	for (i = 0; i < 4 && info < eof; i++, info++) {
481 		/* info segments are separated by space each */
482 		info = strnchr(info, eof - info, ' ');
483 		if (!info)
484 			break;
485 	}
486 
487 	if (i == 4 && info)
488 		memcpy(pos, info, min_t(u32, eof - info, CATPT_DUMP_HASH_SIZE));
489 	pos += CATPT_DUMP_HASH_SIZE;
490 
491 	hdr = (struct catpt_dump_section_hdr *)pos;
492 	hdr->magic = CATPT_DUMP_MAGIC;
493 	hdr->core_id = cdev->spec->core_id;
494 	hdr->section_id = CATPT_DUMP_SECTION_ID_IRAM;
495 	hdr->size = resource_size(&cdev->iram);
496 	pos += sizeof(*hdr);
497 
498 	memcpy_fromio(pos, cdev->lpe_ba + cdev->iram.start, hdr->size);
499 	pos += hdr->size;
500 
501 	hdr = (struct catpt_dump_section_hdr *)pos;
502 	hdr->magic = CATPT_DUMP_MAGIC;
503 	hdr->core_id = cdev->spec->core_id;
504 	hdr->section_id = CATPT_DUMP_SECTION_ID_DRAM;
505 	hdr->size = resource_size(&cdev->dram);
506 	pos += sizeof(*hdr);
507 
508 	memcpy_fromio(pos, cdev->lpe_ba + cdev->dram.start, hdr->size);
509 	pos += hdr->size;
510 
511 	hdr = (struct catpt_dump_section_hdr *)pos;
512 	hdr->magic = CATPT_DUMP_MAGIC;
513 	hdr->core_id = cdev->spec->core_id;
514 	hdr->section_id = CATPT_DUMP_SECTION_ID_REGS;
515 	hdr->size = regs_size;
516 	pos += sizeof(*hdr);
517 
518 	memcpy_fromio(pos, catpt_shim_addr(cdev), CATPT_SHIM_REGS_SIZE);
519 	pos += CATPT_SHIM_REGS_SIZE;
520 
521 	for (i = 0; i < CATPT_SSP_COUNT; i++) {
522 		memcpy_fromio(pos, catpt_ssp_addr(cdev, i),
523 			      CATPT_SSP_REGS_SIZE);
524 		pos += CATPT_SSP_REGS_SIZE;
525 	}
526 	for (i = 0; i < CATPT_DMA_COUNT; i++) {
527 		memcpy_fromio(pos, catpt_dma_addr(cdev, i),
528 			      CATPT_DMA_REGS_SIZE);
529 		pos += CATPT_DMA_REGS_SIZE;
530 	}
531 
532 	dev_coredumpv(cdev->dev, dump, dump_size, GFP_KERNEL);
533 
534 	return 0;
535 }
536