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) 2005-2009, 2010 Cavium Networks
7 */
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/msi.h>
11 #include <linux/spinlock.h>
12 #include <linux/interrupt.h>
13
14 #include <asm/octeon/octeon.h>
15 #include <asm/octeon/cvmx-npi-defs.h>
16 #include <asm/octeon/cvmx-pci-defs.h>
17 #include <asm/octeon/cvmx-npei-defs.h>
18 #include <asm/octeon/cvmx-pexp-defs.h>
19 #include <asm/octeon/pci-octeon.h>
20
21 /*
22 * Each bit in msi_free_irq_bitmask represents a MSI interrupt that is
23 * in use.
24 */
25 static u64 msi_free_irq_bitmask[4];
26
27 /*
28 * Each bit in msi_multiple_irq_bitmask tells that the device using
29 * this bit in msi_free_irq_bitmask is also using the next bit. This
30 * is used so we can disable all of the MSI interrupts when a device
31 * uses multiple.
32 */
33 static u64 msi_multiple_irq_bitmask[4];
34
35 /*
36 * This lock controls updates to msi_free_irq_bitmask and
37 * msi_multiple_irq_bitmask.
38 */
39 static DEFINE_SPINLOCK(msi_free_irq_bitmask_lock);
40
41 /*
42 * Number of MSI IRQs used. This variable is set up in
43 * the module init time.
44 */
45 static int msi_irq_size;
46
47 /**
48 * Called when a driver request MSI interrupts instead of the
49 * legacy INT A-D. This routine will allocate multiple interrupts
50 * for MSI devices that support them. A device can override this by
51 * programming the MSI control bits [6:4] before calling
52 * pci_enable_msi().
53 *
54 * @dev: Device requesting MSI interrupts
55 * @desc: MSI descriptor
56 *
57 * Returns 0 on success.
58 */
arch_setup_msi_irq(struct pci_dev * dev,struct msi_desc * desc)59 int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
60 {
61 struct msi_msg msg;
62 u16 control;
63 int configured_private_bits;
64 int request_private_bits;
65 int irq = 0;
66 int irq_step;
67 u64 search_mask;
68 int index;
69
70 /*
71 * Read the MSI config to figure out how many IRQs this device
72 * wants. Most devices only want 1, which will give
73 * configured_private_bits and request_private_bits equal 0.
74 */
75 pci_read_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
76 &control);
77
78 /*
79 * If the number of private bits has been configured then use
80 * that value instead of the requested number. This gives the
81 * driver the chance to override the number of interrupts
82 * before calling pci_enable_msi().
83 */
84 configured_private_bits = (control & PCI_MSI_FLAGS_QSIZE) >> 4;
85 if (configured_private_bits == 0) {
86 /* Nothing is configured, so use the hardware requested size */
87 request_private_bits = (control & PCI_MSI_FLAGS_QMASK) >> 1;
88 } else {
89 /*
90 * Use the number of configured bits, assuming the
91 * driver wanted to override the hardware request
92 * value.
93 */
94 request_private_bits = configured_private_bits;
95 }
96
97 /*
98 * The PCI 2.3 spec mandates that there are at most 32
99 * interrupts. If this device asks for more, only give it one.
100 */
101 if (request_private_bits > 5)
102 request_private_bits = 0;
103
104 try_only_one:
105 /*
106 * The IRQs have to be aligned on a power of two based on the
107 * number being requested.
108 */
109 irq_step = 1 << request_private_bits;
110
111 /* Mask with one bit for each IRQ */
112 search_mask = (1 << irq_step) - 1;
113
114 /*
115 * We're going to search msi_free_irq_bitmask_lock for zero
116 * bits. This represents an MSI interrupt number that isn't in
117 * use.
118 */
119 spin_lock(&msi_free_irq_bitmask_lock);
120 for (index = 0; index < msi_irq_size/64; index++) {
121 for (irq = 0; irq < 64; irq += irq_step) {
122 if ((msi_free_irq_bitmask[index] & (search_mask << irq)) == 0) {
123 msi_free_irq_bitmask[index] |= search_mask << irq;
124 msi_multiple_irq_bitmask[index] |= (search_mask >> 1) << irq;
125 goto msi_irq_allocated;
126 }
127 }
128 }
129 msi_irq_allocated:
130 spin_unlock(&msi_free_irq_bitmask_lock);
131
132 /* Make sure the search for available interrupts didn't fail */
133 if (irq >= 64) {
134 if (request_private_bits) {
135 pr_err("arch_setup_msi_irq: Unable to find %d free interrupts, trying just one",
136 1 << request_private_bits);
137 request_private_bits = 0;
138 goto try_only_one;
139 } else
140 panic("arch_setup_msi_irq: Unable to find a free MSI interrupt");
141 }
142
143 /* MSI interrupts start at logical IRQ OCTEON_IRQ_MSI_BIT0 */
144 irq += index*64;
145 irq += OCTEON_IRQ_MSI_BIT0;
146
147 switch (octeon_dma_bar_type) {
148 case OCTEON_DMA_BAR_TYPE_SMALL:
149 /* When not using big bar, Bar 0 is based at 128MB */
150 msg.address_lo =
151 ((128ul << 20) + CVMX_PCI_MSI_RCV) & 0xffffffff;
152 msg.address_hi = ((128ul << 20) + CVMX_PCI_MSI_RCV) >> 32;
153 case OCTEON_DMA_BAR_TYPE_BIG:
154 /* When using big bar, Bar 0 is based at 0 */
155 msg.address_lo = (0 + CVMX_PCI_MSI_RCV) & 0xffffffff;
156 msg.address_hi = (0 + CVMX_PCI_MSI_RCV) >> 32;
157 break;
158 case OCTEON_DMA_BAR_TYPE_PCIE:
159 /* When using PCIe, Bar 0 is based at 0 */
160 /* FIXME CVMX_NPEI_MSI_RCV* other than 0? */
161 msg.address_lo = (0 + CVMX_NPEI_PCIE_MSI_RCV) & 0xffffffff;
162 msg.address_hi = (0 + CVMX_NPEI_PCIE_MSI_RCV) >> 32;
163 break;
164 default:
165 panic("arch_setup_msi_irq: Invalid octeon_dma_bar_type\n");
166 }
167 msg.data = irq - OCTEON_IRQ_MSI_BIT0;
168
169 /* Update the number of IRQs the device has available to it */
170 control &= ~PCI_MSI_FLAGS_QSIZE;
171 control |= request_private_bits << 4;
172 pci_write_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
173 control);
174
175 irq_set_msi_desc(irq, desc);
176 write_msi_msg(irq, &msg);
177 return 0;
178 }
179
arch_setup_msi_irqs(struct pci_dev * dev,int nvec,int type)180 int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
181 {
182 struct msi_desc *entry;
183 int ret;
184
185 /*
186 * MSI-X is not supported.
187 */
188 if (type == PCI_CAP_ID_MSIX)
189 return -EINVAL;
190
191 /*
192 * If an architecture wants to support multiple MSI, it needs to
193 * override arch_setup_msi_irqs()
194 */
195 if (type == PCI_CAP_ID_MSI && nvec > 1)
196 return 1;
197
198 list_for_each_entry(entry, &dev->msi_list, list) {
199 ret = arch_setup_msi_irq(dev, entry);
200 if (ret < 0)
201 return ret;
202 if (ret > 0)
203 return -ENOSPC;
204 }
205
206 return 0;
207 }
208
209 /**
210 * Called when a device no longer needs its MSI interrupts. All
211 * MSI interrupts for the device are freed.
212 *
213 * @irq: The devices first irq number. There may be multple in sequence.
214 */
arch_teardown_msi_irq(unsigned int irq)215 void arch_teardown_msi_irq(unsigned int irq)
216 {
217 int number_irqs;
218 u64 bitmask;
219 int index = 0;
220 int irq0;
221
222 if ((irq < OCTEON_IRQ_MSI_BIT0)
223 || (irq > msi_irq_size + OCTEON_IRQ_MSI_BIT0))
224 panic("arch_teardown_msi_irq: Attempted to teardown illegal "
225 "MSI interrupt (%d)", irq);
226
227 irq -= OCTEON_IRQ_MSI_BIT0;
228 index = irq / 64;
229 irq0 = irq % 64;
230
231 /*
232 * Count the number of IRQs we need to free by looking at the
233 * msi_multiple_irq_bitmask. Each bit set means that the next
234 * IRQ is also owned by this device.
235 */
236 number_irqs = 0;
237 while ((irq0 + number_irqs < 64) &&
238 (msi_multiple_irq_bitmask[index]
239 & (1ull << (irq0 + number_irqs))))
240 number_irqs++;
241 number_irqs++;
242 /* Mask with one bit for each IRQ */
243 bitmask = (1 << number_irqs) - 1;
244 /* Shift the mask to the correct bit location */
245 bitmask <<= irq0;
246 if ((msi_free_irq_bitmask[index] & bitmask) != bitmask)
247 panic("arch_teardown_msi_irq: Attempted to teardown MSI "
248 "interrupt (%d) not in use", irq);
249
250 /* Checks are done, update the in use bitmask */
251 spin_lock(&msi_free_irq_bitmask_lock);
252 msi_free_irq_bitmask[index] &= ~bitmask;
253 msi_multiple_irq_bitmask[index] &= ~bitmask;
254 spin_unlock(&msi_free_irq_bitmask_lock);
255 }
256
257 static DEFINE_RAW_SPINLOCK(octeon_irq_msi_lock);
258
259 static u64 msi_rcv_reg[4];
260 static u64 mis_ena_reg[4];
261
octeon_irq_msi_enable_pcie(struct irq_data * data)262 static void octeon_irq_msi_enable_pcie(struct irq_data *data)
263 {
264 u64 en;
265 unsigned long flags;
266 int msi_number = data->irq - OCTEON_IRQ_MSI_BIT0;
267 int irq_index = msi_number >> 6;
268 int irq_bit = msi_number & 0x3f;
269
270 raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags);
271 en = cvmx_read_csr(mis_ena_reg[irq_index]);
272 en |= 1ull << irq_bit;
273 cvmx_write_csr(mis_ena_reg[irq_index], en);
274 cvmx_read_csr(mis_ena_reg[irq_index]);
275 raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
276 }
277
octeon_irq_msi_disable_pcie(struct irq_data * data)278 static void octeon_irq_msi_disable_pcie(struct irq_data *data)
279 {
280 u64 en;
281 unsigned long flags;
282 int msi_number = data->irq - OCTEON_IRQ_MSI_BIT0;
283 int irq_index = msi_number >> 6;
284 int irq_bit = msi_number & 0x3f;
285
286 raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags);
287 en = cvmx_read_csr(mis_ena_reg[irq_index]);
288 en &= ~(1ull << irq_bit);
289 cvmx_write_csr(mis_ena_reg[irq_index], en);
290 cvmx_read_csr(mis_ena_reg[irq_index]);
291 raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
292 }
293
294 static struct irq_chip octeon_irq_chip_msi_pcie = {
295 .name = "MSI",
296 .irq_enable = octeon_irq_msi_enable_pcie,
297 .irq_disable = octeon_irq_msi_disable_pcie,
298 };
299
octeon_irq_msi_enable_pci(struct irq_data * data)300 static void octeon_irq_msi_enable_pci(struct irq_data *data)
301 {
302 /*
303 * Octeon PCI doesn't have the ability to mask/unmask MSI
304 * interrupts individually. Instead of masking/unmasking them
305 * in groups of 16, we simple assume MSI devices are well
306 * behaved. MSI interrupts are always enable and the ACK is
307 * assumed to be enough
308 */
309 }
310
octeon_irq_msi_disable_pci(struct irq_data * data)311 static void octeon_irq_msi_disable_pci(struct irq_data *data)
312 {
313 /* See comment in enable */
314 }
315
316 static struct irq_chip octeon_irq_chip_msi_pci = {
317 .name = "MSI",
318 .irq_enable = octeon_irq_msi_enable_pci,
319 .irq_disable = octeon_irq_msi_disable_pci,
320 };
321
322 /*
323 * Called by the interrupt handling code when an MSI interrupt
324 * occurs.
325 */
__octeon_msi_do_interrupt(int index,u64 msi_bits)326 static irqreturn_t __octeon_msi_do_interrupt(int index, u64 msi_bits)
327 {
328 int irq;
329 int bit;
330
331 bit = fls64(msi_bits);
332 if (bit) {
333 bit--;
334 /* Acknowledge it first. */
335 cvmx_write_csr(msi_rcv_reg[index], 1ull << bit);
336
337 irq = bit + OCTEON_IRQ_MSI_BIT0 + 64 * index;
338 do_IRQ(irq);
339 return IRQ_HANDLED;
340 }
341 return IRQ_NONE;
342 }
343
344 #define OCTEON_MSI_INT_HANDLER_X(x) \
345 static irqreturn_t octeon_msi_interrupt##x(int cpl, void *dev_id) \
346 { \
347 u64 msi_bits = cvmx_read_csr(msi_rcv_reg[(x)]); \
348 return __octeon_msi_do_interrupt((x), msi_bits); \
349 }
350
351 /*
352 * Create octeon_msi_interrupt{0-3} function body
353 */
354 OCTEON_MSI_INT_HANDLER_X(0);
355 OCTEON_MSI_INT_HANDLER_X(1);
356 OCTEON_MSI_INT_HANDLER_X(2);
357 OCTEON_MSI_INT_HANDLER_X(3);
358
359 /*
360 * Initializes the MSI interrupt handling code
361 */
octeon_msi_initialize(void)362 int __init octeon_msi_initialize(void)
363 {
364 int irq;
365 struct irq_chip *msi;
366
367 if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
368 msi_rcv_reg[0] = CVMX_PEXP_NPEI_MSI_RCV0;
369 msi_rcv_reg[1] = CVMX_PEXP_NPEI_MSI_RCV1;
370 msi_rcv_reg[2] = CVMX_PEXP_NPEI_MSI_RCV2;
371 msi_rcv_reg[3] = CVMX_PEXP_NPEI_MSI_RCV3;
372 mis_ena_reg[0] = CVMX_PEXP_NPEI_MSI_ENB0;
373 mis_ena_reg[1] = CVMX_PEXP_NPEI_MSI_ENB1;
374 mis_ena_reg[2] = CVMX_PEXP_NPEI_MSI_ENB2;
375 mis_ena_reg[3] = CVMX_PEXP_NPEI_MSI_ENB3;
376 msi = &octeon_irq_chip_msi_pcie;
377 } else {
378 msi_rcv_reg[0] = CVMX_NPI_NPI_MSI_RCV;
379 #define INVALID_GENERATE_ADE 0x8700000000000000ULL;
380 msi_rcv_reg[1] = INVALID_GENERATE_ADE;
381 msi_rcv_reg[2] = INVALID_GENERATE_ADE;
382 msi_rcv_reg[3] = INVALID_GENERATE_ADE;
383 mis_ena_reg[0] = INVALID_GENERATE_ADE;
384 mis_ena_reg[1] = INVALID_GENERATE_ADE;
385 mis_ena_reg[2] = INVALID_GENERATE_ADE;
386 mis_ena_reg[3] = INVALID_GENERATE_ADE;
387 msi = &octeon_irq_chip_msi_pci;
388 }
389
390 for (irq = OCTEON_IRQ_MSI_BIT0; irq <= OCTEON_IRQ_MSI_LAST; irq++)
391 irq_set_chip_and_handler(irq, msi, handle_simple_irq);
392
393 if (octeon_has_feature(OCTEON_FEATURE_PCIE)) {
394 if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt0,
395 0, "MSI[0:63]", octeon_msi_interrupt0))
396 panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
397
398 if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt1,
399 0, "MSI[64:127]", octeon_msi_interrupt1))
400 panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed");
401
402 if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt2,
403 0, "MSI[127:191]", octeon_msi_interrupt2))
404 panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed");
405
406 if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt3,
407 0, "MSI[192:255]", octeon_msi_interrupt3))
408 panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed");
409
410 msi_irq_size = 256;
411 } else if (octeon_is_pci_host()) {
412 if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt0,
413 0, "MSI[0:15]", octeon_msi_interrupt0))
414 panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
415
416 if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt0,
417 0, "MSI[16:31]", octeon_msi_interrupt0))
418 panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed");
419
420 if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt0,
421 0, "MSI[32:47]", octeon_msi_interrupt0))
422 panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed");
423
424 if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt0,
425 0, "MSI[48:63]", octeon_msi_interrupt0))
426 panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed");
427 msi_irq_size = 64;
428 }
429 return 0;
430 }
431 subsys_initcall(octeon_msi_initialize);
432