1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2006-2007 PA Semi, Inc
4 *
5 * Common functions for DMA access on PA Semi PWRficient
6 */
7
8#include <linux/kernel.h>
9#include <linux/export.h>
10#include <linux/pci.h>
11#include <linux/slab.h>
12#include <linux/of.h>
13#include <linux/of_address.h>
14#include <linux/of_irq.h>
15#include <linux/sched.h>
16
17#include <asm/pasemi_dma.h>
18
19#define MAX_TXCH 64
20#define MAX_RXCH 64
21#define MAX_FLAGS 64
22#define MAX_FUN 8
23
24static struct pasdma_status *dma_status;
25
26static void __iomem *iob_regs;
27static void __iomem *mac_regs[6];
28static void __iomem *dma_regs;
29
30static int base_hw_irq;
31
32static int num_txch, num_rxch;
33
34static struct pci_dev *dma_pdev;
35
36/* Bitmaps to handle allocation of channels */
37
38static DECLARE_BITMAP(txch_free, MAX_TXCH);
39static DECLARE_BITMAP(rxch_free, MAX_RXCH);
40static DECLARE_BITMAP(flags_free, MAX_FLAGS);
41static DECLARE_BITMAP(fun_free, MAX_FUN);
42
43/* pasemi_read_iob_reg - read IOB register
44 * @reg: Register to read (offset into PCI CFG space)
45 */
46unsigned int pasemi_read_iob_reg(unsigned int reg)
47{
48 return in_le32(iob_regs+reg);
49}
50EXPORT_SYMBOL(pasemi_read_iob_reg);
51
52/* pasemi_write_iob_reg - write IOB register
53 * @reg: Register to write to (offset into PCI CFG space)
54 * @val: Value to write
55 */
56void pasemi_write_iob_reg(unsigned int reg, unsigned int val)
57{
58 out_le32(iob_regs+reg, val);
59}
60EXPORT_SYMBOL(pasemi_write_iob_reg);
61
62/* pasemi_read_mac_reg - read MAC register
63 * @intf: MAC interface
64 * @reg: Register to read (offset into PCI CFG space)
65 */
66unsigned int pasemi_read_mac_reg(int intf, unsigned int reg)
67{
68 return in_le32(mac_regs[intf]+reg);
69}
70EXPORT_SYMBOL(pasemi_read_mac_reg);
71
72/* pasemi_write_mac_reg - write MAC register
73 * @intf: MAC interface
74 * @reg: Register to write to (offset into PCI CFG space)
75 * @val: Value to write
76 */
77void pasemi_write_mac_reg(int intf, unsigned int reg, unsigned int val)
78{
79 out_le32(mac_regs[intf]+reg, val);
80}
81EXPORT_SYMBOL(pasemi_write_mac_reg);
82
83/* pasemi_read_dma_reg - read DMA register
84 * @reg: Register to read (offset into PCI CFG space)
85 */
86unsigned int pasemi_read_dma_reg(unsigned int reg)
87{
88 return in_le32(dma_regs+reg);
89}
90EXPORT_SYMBOL(pasemi_read_dma_reg);
91
92/* pasemi_write_dma_reg - write DMA register
93 * @reg: Register to write to (offset into PCI CFG space)
94 * @val: Value to write
95 */
96void pasemi_write_dma_reg(unsigned int reg, unsigned int val)
97{
98 out_le32(dma_regs+reg, val);
99}
100EXPORT_SYMBOL(pasemi_write_dma_reg);
101
102static int pasemi_alloc_tx_chan(enum pasemi_dmachan_type type)
103{
104 int bit;
105 int start, limit;
106
107 switch (type & (TXCHAN_EVT0|TXCHAN_EVT1)) {
108 case TXCHAN_EVT0:
109 start = 0;
110 limit = 10;
111 break;
112 case TXCHAN_EVT1:
113 start = 10;
114 limit = MAX_TXCH;
115 break;
116 default:
117 start = 0;
118 limit = MAX_TXCH;
119 break;
120 }
121retry:
122 bit = find_next_bit(addr: txch_free, MAX_TXCH, offset: start);
123 if (bit >= limit)
124 return -ENOSPC;
125 if (!test_and_clear_bit(nr: bit, addr: txch_free))
126 goto retry;
127
128 return bit;
129}
130
131static void pasemi_free_tx_chan(int chan)
132{
133 BUG_ON(test_bit(chan, txch_free));
134 set_bit(nr: chan, addr: txch_free);
135}
136
137static int pasemi_alloc_rx_chan(void)
138{
139 int bit;
140retry:
141 bit = find_first_bit(addr: rxch_free, MAX_RXCH);
142 if (bit >= MAX_TXCH)
143 return -ENOSPC;
144 if (!test_and_clear_bit(nr: bit, addr: rxch_free))
145 goto retry;
146
147 return bit;
148}
149
150static void pasemi_free_rx_chan(int chan)
151{
152 BUG_ON(test_bit(chan, rxch_free));
153 set_bit(nr: chan, addr: rxch_free);
154}
155
156/* pasemi_dma_alloc_chan - Allocate a DMA channel
157 * @type: Type of channel to allocate
158 * @total_size: Total size of structure to allocate (to allow for more
159 * room behind the structure to be used by the client)
160 * @offset: Offset in bytes from start of the total structure to the beginning
161 * of struct pasemi_dmachan. Needed when struct pasemi_dmachan is
162 * not the first member of the client structure.
163 *
164 * pasemi_dma_alloc_chan allocates a DMA channel for use by a client. The
165 * type argument specifies whether it's a RX or TX channel, and in the case
166 * of TX channels which group it needs to belong to (if any).
167 *
168 * Returns a pointer to the total structure allocated on success, NULL
169 * on failure.
170 */
171void *pasemi_dma_alloc_chan(enum pasemi_dmachan_type type,
172 int total_size, int offset)
173{
174 void *buf;
175 struct pasemi_dmachan *chan;
176 int chno;
177
178 BUG_ON(total_size < sizeof(struct pasemi_dmachan));
179
180 buf = kzalloc(total_size, GFP_KERNEL);
181
182 if (!buf)
183 return NULL;
184 chan = buf + offset;
185
186 chan->priv = buf;
187
188 switch (type & (TXCHAN|RXCHAN)) {
189 case RXCHAN:
190 chno = pasemi_alloc_rx_chan();
191 chan->chno = chno;
192 chan->irq = irq_create_mapping(NULL,
193 hwirq: base_hw_irq + num_txch + chno);
194 chan->status = &dma_status->rx_sta[chno];
195 break;
196 case TXCHAN:
197 chno = pasemi_alloc_tx_chan(type: type);
198 chan->chno = chno;
199 chan->irq = irq_create_mapping(NULL, hwirq: base_hw_irq + chno);
200 chan->status = &dma_status->tx_sta[chno];
201 break;
202 }
203
204 chan->chan_type = type;
205
206 return chan;
207}
208EXPORT_SYMBOL(pasemi_dma_alloc_chan);
209
210/* pasemi_dma_free_chan - Free a previously allocated channel
211 * @chan: Channel to free
212 *
213 * Frees a previously allocated channel. It will also deallocate any
214 * descriptor ring associated with the channel, if allocated.
215 */
216void pasemi_dma_free_chan(struct pasemi_dmachan *chan)
217{
218 if (chan->ring_virt)
219 pasemi_dma_free_ring(chan);
220
221 switch (chan->chan_type & (RXCHAN|TXCHAN)) {
222 case RXCHAN:
223 pasemi_free_rx_chan(chan: chan->chno);
224 break;
225 case TXCHAN:
226 pasemi_free_tx_chan(chan: chan->chno);
227 break;
228 }
229
230 kfree(objp: chan->priv);
231}
232EXPORT_SYMBOL(pasemi_dma_free_chan);
233
234/* pasemi_dma_alloc_ring - Allocate descriptor ring for a channel
235 * @chan: Channel for which to allocate
236 * @ring_size: Ring size in 64-bit (8-byte) words
237 *
238 * Allocate a descriptor ring for a channel. Returns 0 on success, errno
239 * on failure. The passed in struct pasemi_dmachan is updated with the
240 * virtual and DMA addresses of the ring.
241 */
242int pasemi_dma_alloc_ring(struct pasemi_dmachan *chan, int ring_size)
243{
244 BUG_ON(chan->ring_virt);
245
246 chan->ring_size = ring_size;
247
248 chan->ring_virt = dma_alloc_coherent(dev: &dma_pdev->dev,
249 size: ring_size * sizeof(u64),
250 dma_handle: &chan->ring_dma, GFP_KERNEL);
251
252 if (!chan->ring_virt)
253 return -ENOMEM;
254
255 return 0;
256}
257EXPORT_SYMBOL(pasemi_dma_alloc_ring);
258
259/* pasemi_dma_free_ring - Free an allocated descriptor ring for a channel
260 * @chan: Channel for which to free the descriptor ring
261 *
262 * Frees a previously allocated descriptor ring for a channel.
263 */
264void pasemi_dma_free_ring(struct pasemi_dmachan *chan)
265{
266 BUG_ON(!chan->ring_virt);
267
268 dma_free_coherent(dev: &dma_pdev->dev, size: chan->ring_size * sizeof(u64),
269 cpu_addr: chan->ring_virt, dma_handle: chan->ring_dma);
270 chan->ring_virt = NULL;
271 chan->ring_size = 0;
272 chan->ring_dma = 0;
273}
274EXPORT_SYMBOL(pasemi_dma_free_ring);
275
276/* pasemi_dma_start_chan - Start a DMA channel
277 * @chan: Channel to start
278 * @cmdsta: Additional CCMDSTA/TCMDSTA bits to write
279 *
280 * Enables (starts) a DMA channel with optional additional arguments.
281 */
282void pasemi_dma_start_chan(const struct pasemi_dmachan *chan, const u32 cmdsta)
283{
284 if (chan->chan_type == RXCHAN)
285 pasemi_write_dma_reg(reg: PAS_DMA_RXCHAN_CCMDSTA(chan->chno),
286 val: cmdsta | PAS_DMA_RXCHAN_CCMDSTA_EN);
287 else
288 pasemi_write_dma_reg(reg: PAS_DMA_TXCHAN_TCMDSTA(chan->chno),
289 val: cmdsta | PAS_DMA_TXCHAN_TCMDSTA_EN);
290}
291EXPORT_SYMBOL(pasemi_dma_start_chan);
292
293/* pasemi_dma_stop_chan - Stop a DMA channel
294 * @chan: Channel to stop
295 *
296 * Stops (disables) a DMA channel. This is done by setting the ST bit in the
297 * CMDSTA register and waiting on the ACT (active) bit to clear, then
298 * finally disabling the whole channel.
299 *
300 * This function will only try for a short while for the channel to stop, if
301 * it doesn't it will return failure.
302 *
303 * Returns 1 on success, 0 on failure.
304 */
305#define MAX_RETRIES 5000
306int pasemi_dma_stop_chan(const struct pasemi_dmachan *chan)
307{
308 int reg, retries;
309 u32 sta;
310
311 if (chan->chan_type == RXCHAN) {
312 reg = PAS_DMA_RXCHAN_CCMDSTA(chan->chno);
313 pasemi_write_dma_reg(reg, val: PAS_DMA_RXCHAN_CCMDSTA_ST);
314 for (retries = 0; retries < MAX_RETRIES; retries++) {
315 sta = pasemi_read_dma_reg(reg);
316 if (!(sta & PAS_DMA_RXCHAN_CCMDSTA_ACT)) {
317 pasemi_write_dma_reg(reg, val: 0);
318 return 1;
319 }
320 cond_resched();
321 }
322 } else {
323 reg = PAS_DMA_TXCHAN_TCMDSTA(chan->chno);
324 pasemi_write_dma_reg(reg, val: PAS_DMA_TXCHAN_TCMDSTA_ST);
325 for (retries = 0; retries < MAX_RETRIES; retries++) {
326 sta = pasemi_read_dma_reg(reg);
327 if (!(sta & PAS_DMA_TXCHAN_TCMDSTA_ACT)) {
328 pasemi_write_dma_reg(reg, val: 0);
329 return 1;
330 }
331 cond_resched();
332 }
333 }
334
335 return 0;
336}
337EXPORT_SYMBOL(pasemi_dma_stop_chan);
338
339/* pasemi_dma_alloc_buf - Allocate a buffer to use for DMA
340 * @chan: Channel to allocate for
341 * @size: Size of buffer in bytes
342 * @handle: DMA handle
343 *
344 * Allocate a buffer to be used by the DMA engine for read/write,
345 * similar to dma_alloc_coherent().
346 *
347 * Returns the virtual address of the buffer, or NULL in case of failure.
348 */
349void *pasemi_dma_alloc_buf(struct pasemi_dmachan *chan, int size,
350 dma_addr_t *handle)
351{
352 return dma_alloc_coherent(dev: &dma_pdev->dev, size, dma_handle: handle, GFP_KERNEL);
353}
354EXPORT_SYMBOL(pasemi_dma_alloc_buf);
355
356/* pasemi_dma_free_buf - Free a buffer used for DMA
357 * @chan: Channel the buffer was allocated for
358 * @size: Size of buffer in bytes
359 * @handle: DMA handle
360 *
361 * Frees a previously allocated buffer.
362 */
363void pasemi_dma_free_buf(struct pasemi_dmachan *chan, int size,
364 dma_addr_t *handle)
365{
366 dma_free_coherent(dev: &dma_pdev->dev, size, cpu_addr: handle, GFP_KERNEL);
367}
368EXPORT_SYMBOL(pasemi_dma_free_buf);
369
370/* pasemi_dma_alloc_flag - Allocate a flag (event) for channel synchronization
371 *
372 * Allocates a flag for use with channel synchronization (event descriptors).
373 * Returns allocated flag (0-63), < 0 on error.
374 */
375int pasemi_dma_alloc_flag(void)
376{
377 int bit;
378
379retry:
380 bit = find_first_bit(addr: flags_free, MAX_FLAGS);
381 if (bit >= MAX_FLAGS)
382 return -ENOSPC;
383 if (!test_and_clear_bit(nr: bit, addr: flags_free))
384 goto retry;
385
386 return bit;
387}
388EXPORT_SYMBOL(pasemi_dma_alloc_flag);
389
390
391/* pasemi_dma_free_flag - Deallocates a flag (event)
392 * @flag: Flag number to deallocate
393 *
394 * Frees up a flag so it can be reused for other purposes.
395 */
396void pasemi_dma_free_flag(int flag)
397{
398 BUG_ON(test_bit(flag, flags_free));
399 BUG_ON(flag >= MAX_FLAGS);
400 set_bit(nr: flag, addr: flags_free);
401}
402EXPORT_SYMBOL(pasemi_dma_free_flag);
403
404
405/* pasemi_dma_set_flag - Sets a flag (event) to 1
406 * @flag: Flag number to set active
407 *
408 * Sets the flag provided to 1.
409 */
410void pasemi_dma_set_flag(int flag)
411{
412 BUG_ON(flag >= MAX_FLAGS);
413 if (flag < 32)
414 pasemi_write_dma_reg(reg: PAS_DMA_TXF_SFLG0, val: 1 << flag);
415 else
416 pasemi_write_dma_reg(reg: PAS_DMA_TXF_SFLG1, val: 1 << flag);
417}
418EXPORT_SYMBOL(pasemi_dma_set_flag);
419
420/* pasemi_dma_clear_flag - Sets a flag (event) to 0
421 * @flag: Flag number to set inactive
422 *
423 * Sets the flag provided to 0.
424 */
425void pasemi_dma_clear_flag(int flag)
426{
427 BUG_ON(flag >= MAX_FLAGS);
428 if (flag < 32)
429 pasemi_write_dma_reg(reg: PAS_DMA_TXF_CFLG0, val: 1 << flag);
430 else
431 pasemi_write_dma_reg(reg: PAS_DMA_TXF_CFLG1, val: 1 << flag);
432}
433EXPORT_SYMBOL(pasemi_dma_clear_flag);
434
435/* pasemi_dma_alloc_fun - Allocate a function engine
436 *
437 * Allocates a function engine to use for crypto/checksum offload
438 * Returns allocated engine (0-8), < 0 on error.
439 */
440int pasemi_dma_alloc_fun(void)
441{
442 int bit;
443
444retry:
445 bit = find_first_bit(addr: fun_free, MAX_FLAGS);
446 if (bit >= MAX_FLAGS)
447 return -ENOSPC;
448 if (!test_and_clear_bit(nr: bit, addr: fun_free))
449 goto retry;
450
451 return bit;
452}
453EXPORT_SYMBOL(pasemi_dma_alloc_fun);
454
455
456/* pasemi_dma_free_fun - Deallocates a function engine
457 * @flag: Engine number to deallocate
458 *
459 * Frees up a function engine so it can be used for other purposes.
460 */
461void pasemi_dma_free_fun(int fun)
462{
463 BUG_ON(test_bit(fun, fun_free));
464 BUG_ON(fun >= MAX_FLAGS);
465 set_bit(nr: fun, addr: fun_free);
466}
467EXPORT_SYMBOL(pasemi_dma_free_fun);
468
469
470static void *map_onedev(struct pci_dev *p, int index)
471{
472 struct device_node *dn;
473 void __iomem *ret;
474
475 dn = pci_device_to_OF_node(pdev: p);
476 if (!dn)
477 goto fallback;
478
479 ret = of_iomap(node: dn, index);
480 if (!ret)
481 goto fallback;
482
483 return ret;
484fallback:
485 /* This is hardcoded and ugly, but we have some firmware versions
486 * that don't provide the register space in the device tree. Luckily
487 * they are at well-known locations so we can just do the math here.
488 */
489 return ioremap(offset: 0xe0000000 + (p->devfn << 12), size: 0x2000);
490}
491
492/* pasemi_dma_init - Initialize the PA Semi DMA library
493 *
494 * This function initializes the DMA library. It must be called before
495 * any other function in the library.
496 *
497 * Returns 0 on success, errno on failure.
498 */
499int pasemi_dma_init(void)
500{
501 static DEFINE_SPINLOCK(init_lock);
502 struct pci_dev *iob_pdev;
503 struct pci_dev *pdev;
504 struct resource res;
505 struct device_node *dn;
506 int i, intf, err = 0;
507 unsigned long timeout;
508 u32 tmp;
509
510 if (!machine_is(pasemi))
511 return -ENODEV;
512
513 spin_lock(lock: &init_lock);
514
515 /* Make sure we haven't already initialized */
516 if (dma_pdev)
517 goto out;
518
519 iob_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, device: 0xa001, NULL);
520 if (!iob_pdev) {
521 BUG();
522 pr_warn("Can't find I/O Bridge\n");
523 err = -ENODEV;
524 goto out;
525 }
526 iob_regs = map_onedev(p: iob_pdev, index: 0);
527
528 dma_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, device: 0xa007, NULL);
529 if (!dma_pdev) {
530 BUG();
531 pr_warn("Can't find DMA controller\n");
532 err = -ENODEV;
533 goto out;
534 }
535 dma_regs = map_onedev(p: dma_pdev, index: 0);
536 base_hw_irq = virq_to_hw(dma_pdev->irq);
537
538 pci_read_config_dword(dma_pdev, PAS_DMA_CAP_TXCH, &tmp);
539 num_txch = (tmp & PAS_DMA_CAP_TXCH_TCHN_M) >> PAS_DMA_CAP_TXCH_TCHN_S;
540
541 pci_read_config_dword(dma_pdev, PAS_DMA_CAP_RXCH, &tmp);
542 num_rxch = (tmp & PAS_DMA_CAP_RXCH_RCHN_M) >> PAS_DMA_CAP_RXCH_RCHN_S;
543
544 intf = 0;
545 for (pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, device: 0xa006, NULL);
546 pdev;
547 pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, device: 0xa006, from: pdev))
548 mac_regs[intf++] = map_onedev(p: pdev, index: 0);
549
550 pci_dev_put(dev: pdev);
551
552 for (pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, device: 0xa005, NULL);
553 pdev;
554 pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, device: 0xa005, from: pdev))
555 mac_regs[intf++] = map_onedev(p: pdev, index: 0);
556
557 pci_dev_put(dev: pdev);
558
559 dn = pci_device_to_OF_node(pdev: iob_pdev);
560 if (dn)
561 err = of_address_to_resource(dev: dn, index: 1, r: &res);
562 if (!dn || err) {
563 /* Fallback for old firmware */
564 res.start = 0xfd800000;
565 res.end = res.start + 0x1000;
566 }
567 dma_status = ioremap_cache(offset: res.start, size: resource_size(res: &res));
568 pci_dev_put(dev: iob_pdev);
569
570 for (i = 0; i < MAX_TXCH; i++)
571 __set_bit(i, txch_free);
572
573 for (i = 0; i < MAX_RXCH; i++)
574 __set_bit(i, rxch_free);
575
576 timeout = jiffies + HZ;
577 pasemi_write_dma_reg(PAS_DMA_COM_RXCMD, 0);
578 while (pasemi_read_dma_reg(PAS_DMA_COM_RXSTA) & 1) {
579 if (time_after(jiffies, timeout)) {
580 pr_warn("Warning: Could not disable RX section\n");
581 break;
582 }
583 }
584
585 timeout = jiffies + HZ;
586 pasemi_write_dma_reg(PAS_DMA_COM_TXCMD, 0);
587 while (pasemi_read_dma_reg(PAS_DMA_COM_TXSTA) & 1) {
588 if (time_after(jiffies, timeout)) {
589 pr_warn("Warning: Could not disable TX section\n");
590 break;
591 }
592 }
593
594 /* setup resource allocations for the different DMA sections */
595 tmp = pasemi_read_dma_reg(PAS_DMA_COM_CFG);
596 pasemi_write_dma_reg(PAS_DMA_COM_CFG, tmp | 0x18000000);
597
598 /* enable tx section */
599 pasemi_write_dma_reg(PAS_DMA_COM_TXCMD, PAS_DMA_COM_TXCMD_EN);
600
601 /* enable rx section */
602 pasemi_write_dma_reg(PAS_DMA_COM_RXCMD, PAS_DMA_COM_RXCMD_EN);
603
604 for (i = 0; i < MAX_FLAGS; i++)
605 __set_bit(i, flags_free);
606
607 for (i = 0; i < MAX_FUN; i++)
608 __set_bit(i, fun_free);
609
610 /* clear all status flags */
611 pasemi_write_dma_reg(PAS_DMA_TXF_CFLG0, 0xffffffff);
612 pasemi_write_dma_reg(PAS_DMA_TXF_CFLG1, 0xffffffff);
613
614 pr_info("PA Semi PWRficient DMA library initialized "
615 "(%d tx, %d rx channels)\n", num_txch, num_rxch);
616
617out:
618 spin_unlock(lock: &init_lock);
619 return err;
620}
621EXPORT_SYMBOL(pasemi_dma_init);
622

source code of linux/arch/powerpc/platforms/pasemi/dma_lib.c