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1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2001-2005 Silicon Graphics, Inc. All rights reserved.
7  */
8 
9 #include <linux/types.h>
10 #include <linux/pci.h>
11 #include <asm/sn/addrs.h>
12 #include <asm/sn/geo.h>
13 #include <asm/sn/pcibr_provider.h>
14 #include <asm/sn/pcibus_provider_defs.h>
15 #include <asm/sn/pcidev.h>
16 #include <asm/sn/pic.h>
17 #include <asm/sn/sn_sal.h>
18 #include <asm/sn/tiocp.h>
19 #include "tio.h"
20 #include "xtalk/xwidgetdev.h"
21 #include "xtalk/hubdev.h"
22 
23 extern int sn_ioif_inited;
24 
25 /* =====================================================================
26  *    DMA MANAGEMENT
27  *
28  *      The Bridge ASIC provides three methods of doing DMA: via a "direct map"
29  *      register available in 32-bit PCI space (which selects a contiguous 2G
30  *	address space on some other widget), via "direct" addressing via 64-bit
31  *      PCI space (all destination information comes from the PCI address,
32  *      including transfer attributes), and via a "mapped" region that allows
33  *      a bunch of different small mappings to be established with the PMU.
34  *
35  *      For efficiency, we most prefer to use the 32bit direct mapping facility,
36  *      since it requires no resource allocations. The advantage of using the
37  *      PMU over the 64-bit direct is that single-cycle PCI addressing can be
38  *      used; the advantage of using 64-bit direct over PMU addressing is that
39  *      we do not have to allocate entries in the PMU.
40  */
41 
42 static dma_addr_t
pcibr_dmamap_ate32(struct pcidev_info * info,u64 paddr,size_t req_size,u64 flags,int dma_flags)43 pcibr_dmamap_ate32(struct pcidev_info *info,
44 		   u64 paddr, size_t req_size, u64 flags, int dma_flags)
45 {
46 
47 	struct pcidev_info *pcidev_info = info->pdi_host_pcidev_info;
48 	struct pcibus_info *pcibus_info = (struct pcibus_info *)pcidev_info->
49 	    pdi_pcibus_info;
50 	u8 internal_device = (PCI_SLOT(pcidev_info->pdi_host_pcidev_info->
51 					    pdi_linux_pcidev->devfn)) - 1;
52 	int ate_count;
53 	int ate_index;
54 	u64 ate_flags = flags | PCI32_ATE_V;
55 	u64 ate;
56 	u64 pci_addr;
57 	u64 xio_addr;
58 	u64 offset;
59 
60 	/* PIC in PCI-X mode does not supports 32bit PageMap mode */
61 	if (IS_PIC_SOFT(pcibus_info) && IS_PCIX(pcibus_info)) {
62 		return 0;
63 	}
64 
65 	/* Calculate the number of ATEs needed. */
66 	if (!(MINIMAL_ATE_FLAG(paddr, req_size))) {
67 		ate_count = IOPG((IOPGSIZE - 1)	/* worst case start offset */
68 				 +req_size	/* max mapping bytes */
69 				 - 1) + 1;	/* round UP */
70 	} else {		/* assume requested target is page aligned */
71 		ate_count = IOPG(req_size	/* max mapping bytes */
72 				 - 1) + 1;	/* round UP */
73 	}
74 
75 	/* Get the number of ATEs required. */
76 	ate_index = pcibr_ate_alloc(pcibus_info, ate_count);
77 	if (ate_index < 0)
78 		return 0;
79 
80 	/* In PCI-X mode, Prefetch not supported */
81 	if (IS_PCIX(pcibus_info))
82 		ate_flags &= ~(PCI32_ATE_PREF);
83 
84 	if (SN_DMA_ADDRTYPE(dma_flags == SN_DMA_ADDR_PHYS))
85 		xio_addr = IS_PIC_SOFT(pcibus_info) ? PHYS_TO_DMA(paddr) :
86 	    					      PHYS_TO_TIODMA(paddr);
87 	else
88 		xio_addr = paddr;
89 
90 	offset = IOPGOFF(xio_addr);
91 	ate = ate_flags | (xio_addr - offset);
92 
93 	/* If PIC, put the targetid in the ATE */
94 	if (IS_PIC_SOFT(pcibus_info)) {
95 		ate |= (pcibus_info->pbi_hub_xid << PIC_ATE_TARGETID_SHFT);
96 	}
97 
98 	/*
99 	 * If we're mapping for MSI, set the MSI bit in the ATE.  If it's a
100 	 * TIOCP based pci bus, we also need to set the PIO bit in the ATE.
101 	 */
102 	if (dma_flags & SN_DMA_MSI) {
103 		ate |= PCI32_ATE_MSI;
104 		if (IS_TIOCP_SOFT(pcibus_info))
105 			ate |= PCI32_ATE_PIO;
106 	}
107 
108 	ate_write(pcibus_info, ate_index, ate_count, ate);
109 
110 	/*
111 	 * Set up the DMA mapped Address.
112 	 */
113 	pci_addr = PCI32_MAPPED_BASE + offset + IOPGSIZE * ate_index;
114 
115 	/*
116 	 * If swap was set in device in pcibr_endian_set()
117 	 * we need to turn swapping on.
118 	 */
119 	if (pcibus_info->pbi_devreg[internal_device] & PCIBR_DEV_SWAP_DIR)
120 		ATE_SWAP_ON(pci_addr);
121 
122 
123 	return pci_addr;
124 }
125 
126 static dma_addr_t
pcibr_dmatrans_direct64(struct pcidev_info * info,u64 paddr,u64 dma_attributes,int dma_flags)127 pcibr_dmatrans_direct64(struct pcidev_info * info, u64 paddr,
128 			u64 dma_attributes, int dma_flags)
129 {
130 	struct pcibus_info *pcibus_info = (struct pcibus_info *)
131 	    ((info->pdi_host_pcidev_info)->pdi_pcibus_info);
132 	u64 pci_addr;
133 
134 	/* Translate to Crosstalk View of Physical Address */
135 	if (SN_DMA_ADDRTYPE(dma_flags) == SN_DMA_ADDR_PHYS)
136 		pci_addr = IS_PIC_SOFT(pcibus_info) ?
137 				PHYS_TO_DMA(paddr) :
138 				PHYS_TO_TIODMA(paddr);
139 	else
140 		pci_addr = paddr;
141 	pci_addr |= dma_attributes;
142 
143 	/* Handle Bus mode */
144 	if (IS_PCIX(pcibus_info))
145 		pci_addr &= ~PCI64_ATTR_PREF;
146 
147 	/* Handle Bridge Chipset differences */
148 	if (IS_PIC_SOFT(pcibus_info)) {
149 		pci_addr |=
150 		    ((u64) pcibus_info->
151 		     pbi_hub_xid << PIC_PCI64_ATTR_TARG_SHFT);
152 	} else
153 		pci_addr |= (dma_flags & SN_DMA_MSI) ?
154 				TIOCP_PCI64_CMDTYPE_MSI :
155 				TIOCP_PCI64_CMDTYPE_MEM;
156 
157 	/* If PCI mode, func zero uses VCHAN0, every other func uses VCHAN1 */
158 	if (!IS_PCIX(pcibus_info) && PCI_FUNC(info->pdi_linux_pcidev->devfn))
159 		pci_addr |= PCI64_ATTR_VIRTUAL;
160 
161 	return pci_addr;
162 }
163 
164 static dma_addr_t
pcibr_dmatrans_direct32(struct pcidev_info * info,u64 paddr,size_t req_size,u64 flags,int dma_flags)165 pcibr_dmatrans_direct32(struct pcidev_info * info,
166 			u64 paddr, size_t req_size, u64 flags, int dma_flags)
167 {
168 	struct pcidev_info *pcidev_info = info->pdi_host_pcidev_info;
169 	struct pcibus_info *pcibus_info = (struct pcibus_info *)pcidev_info->
170 	    pdi_pcibus_info;
171 	u64 xio_addr;
172 
173 	u64 xio_base;
174 	u64 offset;
175 	u64 endoff;
176 
177 	if (IS_PCIX(pcibus_info)) {
178 		return 0;
179 	}
180 
181 	if (dma_flags & SN_DMA_MSI)
182 		return 0;
183 
184 	if (SN_DMA_ADDRTYPE(dma_flags) == SN_DMA_ADDR_PHYS)
185 		xio_addr = IS_PIC_SOFT(pcibus_info) ? PHYS_TO_DMA(paddr) :
186 	    					      PHYS_TO_TIODMA(paddr);
187 	else
188 		xio_addr = paddr;
189 
190 	xio_base = pcibus_info->pbi_dir_xbase;
191 	offset = xio_addr - xio_base;
192 	endoff = req_size + offset;
193 	if ((req_size > (1ULL << 31)) ||	/* Too Big */
194 	    (xio_addr < xio_base) ||	/* Out of range for mappings */
195 	    (endoff > (1ULL << 31))) {	/* Too Big */
196 		return 0;
197 	}
198 
199 	return PCI32_DIRECT_BASE | offset;
200 }
201 
202 /*
203  * Wrapper routine for freeing DMA maps
204  * DMA mappings for Direct 64 and 32 do not have any DMA maps.
205  */
206 void
pcibr_dma_unmap(struct pci_dev * hwdev,dma_addr_t dma_handle,int direction)207 pcibr_dma_unmap(struct pci_dev *hwdev, dma_addr_t dma_handle, int direction)
208 {
209 	struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(hwdev);
210 	struct pcibus_info *pcibus_info =
211 	    (struct pcibus_info *)pcidev_info->pdi_pcibus_info;
212 
213 	if (IS_PCI32_MAPPED(dma_handle)) {
214 		int ate_index;
215 
216 		ate_index =
217 		    IOPG((ATE_SWAP_OFF(dma_handle) - PCI32_MAPPED_BASE));
218 		pcibr_ate_free(pcibus_info, ate_index);
219 	}
220 }
221 
222 /*
223  * On SN systems there is a race condition between a PIO read response and
224  * DMA's.  In rare cases, the read response may beat the DMA, causing the
225  * driver to think that data in memory is complete and meaningful.  This code
226  * eliminates that race.  This routine is called by the PIO read routines
227  * after doing the read.  For PIC this routine then forces a fake interrupt
228  * on another line, which is logically associated with the slot that the PIO
229  * is addressed to.  It then spins while watching the memory location that
230  * the interrupt is targetted to.  When the interrupt response arrives, we
231  * are sure that the DMA has landed in memory and it is safe for the driver
232  * to proceed.	For TIOCP use the Device(x) Write Request Buffer Flush
233  * Bridge register since it ensures the data has entered the coherence domain,
234  * unlike the PIC Device(x) Write Request Buffer Flush register.
235  */
236 
sn_dma_flush(u64 addr)237 void sn_dma_flush(u64 addr)
238 {
239 	nasid_t nasid;
240 	int is_tio;
241 	int wid_num;
242 	int i, j;
243 	unsigned long flags;
244 	u64 itte;
245 	struct hubdev_info *hubinfo;
246 	struct sn_flush_device_kernel *p;
247 	struct sn_flush_device_common *common;
248 	struct sn_flush_nasid_entry *flush_nasid_list;
249 
250 	if (!sn_ioif_inited)
251 		return;
252 
253 	nasid = NASID_GET(addr);
254 	if (-1 == nasid_to_cnodeid(nasid))
255 		return;
256 
257 	hubinfo = (NODEPDA(nasid_to_cnodeid(nasid)))->pdinfo;
258 
259 	if (!hubinfo) {
260 		BUG();
261 	}
262 
263 	flush_nasid_list = &hubinfo->hdi_flush_nasid_list;
264 	if (flush_nasid_list->widget_p == NULL)
265 		return;
266 
267 	is_tio = (nasid & 1);
268 	if (is_tio) {
269 		int itte_index;
270 
271 		if (TIO_HWIN(addr))
272 			itte_index = 0;
273 		else if (TIO_BWIN_WINDOWNUM(addr))
274 			itte_index = TIO_BWIN_WINDOWNUM(addr);
275 		else
276 			itte_index = -1;
277 
278 		if (itte_index >= 0) {
279 			itte = flush_nasid_list->iio_itte[itte_index];
280 			if (! TIO_ITTE_VALID(itte))
281 				return;
282 			wid_num = TIO_ITTE_WIDGET(itte);
283 		} else
284 			wid_num = TIO_SWIN_WIDGETNUM(addr);
285 	} else {
286 		if (BWIN_WINDOWNUM(addr)) {
287 			itte = flush_nasid_list->iio_itte[BWIN_WINDOWNUM(addr)];
288 			wid_num = IIO_ITTE_WIDGET(itte);
289 		} else
290 			wid_num = SWIN_WIDGETNUM(addr);
291 	}
292 	if (flush_nasid_list->widget_p[wid_num] == NULL)
293 		return;
294 	p = &flush_nasid_list->widget_p[wid_num][0];
295 
296 	/* find a matching BAR */
297 	for (i = 0; i < DEV_PER_WIDGET; i++,p++) {
298 		common = p->common;
299 		for (j = 0; j < PCI_ROM_RESOURCE; j++) {
300 			if (common->sfdl_bar_list[j].start == 0)
301 				break;
302 			if (addr >= common->sfdl_bar_list[j].start
303 			    && addr <= common->sfdl_bar_list[j].end)
304 				break;
305 		}
306 		if (j < PCI_ROM_RESOURCE && common->sfdl_bar_list[j].start != 0)
307 			break;
308 	}
309 
310 	/* if no matching BAR, return without doing anything. */
311 	if (i == DEV_PER_WIDGET)
312 		return;
313 
314 	/*
315 	 * For TIOCP use the Device(x) Write Request Buffer Flush Bridge
316 	 * register since it ensures the data has entered the coherence
317 	 * domain, unlike PIC.
318 	 */
319 	if (is_tio) {
320 		/*
321 	 	 * Note:  devices behind TIOCE should never be matched in the
322 		 * above code, and so the following code is PIC/CP centric.
323 		 * If CE ever needs the sn_dma_flush mechanism, we will have
324 		 * to account for that here and in tioce_bus_fixup().
325 	 	 */
326 		u32 tio_id = HUB_L(TIO_IOSPACE_ADDR(nasid, TIO_NODE_ID));
327 		u32 revnum = XWIDGET_PART_REV_NUM(tio_id);
328 
329 		/* TIOCP BRINGUP WAR (PV907516): Don't write buffer flush reg */
330 		if ((1 << XWIDGET_PART_REV_NUM_REV(revnum)) & PV907516) {
331 			return;
332 		} else {
333 			pcireg_wrb_flush_get(common->sfdl_pcibus_info,
334 					     (common->sfdl_slot - 1));
335 		}
336 	} else {
337 		spin_lock_irqsave(&p->sfdl_flush_lock, flags);
338 		*common->sfdl_flush_addr = 0;
339 
340 		/* force an interrupt. */
341 		*(volatile u32 *)(common->sfdl_force_int_addr) = 1;
342 
343 		/* wait for the interrupt to come back. */
344 		while (*(common->sfdl_flush_addr) != 0x10f)
345 			cpu_relax();
346 
347 		/* okay, everything is synched up. */
348 		spin_unlock_irqrestore(&p->sfdl_flush_lock, flags);
349 	}
350 	return;
351 }
352 
353 /*
354  * DMA interfaces.  Called from pci_dma.c routines.
355  */
356 
357 dma_addr_t
pcibr_dma_map(struct pci_dev * hwdev,unsigned long phys_addr,size_t size,int dma_flags)358 pcibr_dma_map(struct pci_dev * hwdev, unsigned long phys_addr, size_t size, int dma_flags)
359 {
360 	dma_addr_t dma_handle;
361 	struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(hwdev);
362 
363 	/* SN cannot support DMA addresses smaller than 32 bits. */
364 	if (hwdev->dma_mask < 0x7fffffff) {
365 		return 0;
366 	}
367 
368 	if (hwdev->dma_mask == ~0UL) {
369 		/*
370 		 * Handle the most common case: 64 bit cards.  This
371 		 * call should always succeed.
372 		 */
373 
374 		dma_handle = pcibr_dmatrans_direct64(pcidev_info, phys_addr,
375 						     PCI64_ATTR_PREF, dma_flags);
376 	} else {
377 		/* Handle 32-63 bit cards via direct mapping */
378 		dma_handle = pcibr_dmatrans_direct32(pcidev_info, phys_addr,
379 						     size, 0, dma_flags);
380 		if (!dma_handle) {
381 			/*
382 			 * It is a 32 bit card and we cannot do direct mapping,
383 			 * so we use an ATE.
384 			 */
385 
386 			dma_handle = pcibr_dmamap_ate32(pcidev_info, phys_addr,
387 							size, PCI32_ATE_PREF,
388 							dma_flags);
389 		}
390 	}
391 
392 	return dma_handle;
393 }
394 
395 dma_addr_t
pcibr_dma_map_consistent(struct pci_dev * hwdev,unsigned long phys_addr,size_t size,int dma_flags)396 pcibr_dma_map_consistent(struct pci_dev * hwdev, unsigned long phys_addr,
397 			 size_t size, int dma_flags)
398 {
399 	dma_addr_t dma_handle;
400 	struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(hwdev);
401 
402 	if (hwdev->dev.coherent_dma_mask == ~0UL) {
403 		dma_handle = pcibr_dmatrans_direct64(pcidev_info, phys_addr,
404 					    PCI64_ATTR_BAR, dma_flags);
405 	} else {
406 		dma_handle = (dma_addr_t) pcibr_dmamap_ate32(pcidev_info,
407 						    phys_addr, size,
408 						    PCI32_ATE_BAR, dma_flags);
409 	}
410 
411 	return dma_handle;
412 }
413 
414 EXPORT_SYMBOL(sn_dma_flush);
415