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-sli-defs.h>
19 #include <asm/octeon/cvmx-pexp-defs.h>
20 #include <asm/octeon/pci-octeon.h>
21
22 /*
23 * Each bit in msi_free_irq_bitmask represents a MSI interrupt that is
24 * in use.
25 */
26 static u64 msi_free_irq_bitmask[4];
27
28 /*
29 * Each bit in msi_multiple_irq_bitmask tells that the device using
30 * this bit in msi_free_irq_bitmask is also using the next bit. This
31 * is used so we can disable all of the MSI interrupts when a device
32 * uses multiple.
33 */
34 static u64 msi_multiple_irq_bitmask[4];
35
36 /*
37 * This lock controls updates to msi_free_irq_bitmask and
38 * msi_multiple_irq_bitmask.
39 */
40 static DEFINE_SPINLOCK(msi_free_irq_bitmask_lock);
41
42 /*
43 * Number of MSI IRQs used. This variable is set up in
44 * the module init time.
45 */
46 static int msi_irq_size;
47
48 /**
49 * arch_setup_msi_irq() - setup MSI IRQs for a device
50 * @dev: Device requesting MSI interrupts
51 * @desc: MSI descriptor
52 *
53 * Called when a driver requests MSI interrupts instead of the
54 * legacy INT A-D. This routine will allocate multiple interrupts
55 * for MSI devices that support them. A device can override this by
56 * programming the MSI control bits [6:4] before calling
57 * pci_enable_msi().
58 *
59 * Return: %0 on success, non-%0 on error.
60 */
arch_setup_msi_irq(struct pci_dev * dev,struct msi_desc * desc)61 int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
62 {
63 struct msi_msg msg;
64 u16 control;
65 int configured_private_bits;
66 int request_private_bits;
67 int irq = 0;
68 int irq_step;
69 u64 search_mask;
70 int index;
71
72 if (desc->pci.msi_attrib.is_msix)
73 return -EINVAL;
74
75 /*
76 * Read the MSI config to figure out how many IRQs this device
77 * wants. Most devices only want 1, which will give
78 * configured_private_bits and request_private_bits equal 0.
79 */
80 pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
81
82 /*
83 * If the number of private bits has been configured then use
84 * that value instead of the requested number. This gives the
85 * driver the chance to override the number of interrupts
86 * before calling pci_enable_msi().
87 */
88 configured_private_bits = (control & PCI_MSI_FLAGS_QSIZE) >> 4;
89 if (configured_private_bits == 0) {
90 /* Nothing is configured, so use the hardware requested size */
91 request_private_bits = (control & PCI_MSI_FLAGS_QMASK) >> 1;
92 } else {
93 /*
94 * Use the number of configured bits, assuming the
95 * driver wanted to override the hardware request
96 * value.
97 */
98 request_private_bits = configured_private_bits;
99 }
100
101 /*
102 * The PCI 2.3 spec mandates that there are at most 32
103 * interrupts. If this device asks for more, only give it one.
104 */
105 if (request_private_bits > 5)
106 request_private_bits = 0;
107
108 try_only_one:
109 /*
110 * The IRQs have to be aligned on a power of two based on the
111 * number being requested.
112 */
113 irq_step = 1 << request_private_bits;
114
115 /* Mask with one bit for each IRQ */
116 search_mask = (1 << irq_step) - 1;
117
118 /*
119 * We're going to search msi_free_irq_bitmask_lock for zero
120 * bits. This represents an MSI interrupt number that isn't in
121 * use.
122 */
123 spin_lock(&msi_free_irq_bitmask_lock);
124 for (index = 0; index < msi_irq_size/64; index++) {
125 for (irq = 0; irq < 64; irq += irq_step) {
126 if ((msi_free_irq_bitmask[index] & (search_mask << irq)) == 0) {
127 msi_free_irq_bitmask[index] |= search_mask << irq;
128 msi_multiple_irq_bitmask[index] |= (search_mask >> 1) << irq;
129 goto msi_irq_allocated;
130 }
131 }
132 }
133 msi_irq_allocated:
134 spin_unlock(&msi_free_irq_bitmask_lock);
135
136 /* Make sure the search for available interrupts didn't fail */
137 if (irq >= 64) {
138 if (request_private_bits) {
139 pr_err("arch_setup_msi_irq: Unable to find %d free interrupts, trying just one",
140 1 << request_private_bits);
141 request_private_bits = 0;
142 goto try_only_one;
143 } else
144 panic("arch_setup_msi_irq: Unable to find a free MSI interrupt");
145 }
146
147 /* MSI interrupts start at logical IRQ OCTEON_IRQ_MSI_BIT0 */
148 irq += index*64;
149 irq += OCTEON_IRQ_MSI_BIT0;
150
151 switch (octeon_dma_bar_type) {
152 case OCTEON_DMA_BAR_TYPE_SMALL:
153 /* When not using big bar, Bar 0 is based at 128MB */
154 msg.address_lo =
155 ((128ul << 20) + CVMX_PCI_MSI_RCV) & 0xffffffff;
156 msg.address_hi = ((128ul << 20) + CVMX_PCI_MSI_RCV) >> 32;
157 break;
158 case OCTEON_DMA_BAR_TYPE_BIG:
159 /* When using big bar, Bar 0 is based at 0 */
160 msg.address_lo = (0 + CVMX_PCI_MSI_RCV) & 0xffffffff;
161 msg.address_hi = (0 + CVMX_PCI_MSI_RCV) >> 32;
162 break;
163 case OCTEON_DMA_BAR_TYPE_PCIE:
164 /* When using PCIe, Bar 0 is based at 0 */
165 /* FIXME CVMX_NPEI_MSI_RCV* other than 0? */
166 msg.address_lo = (0 + CVMX_NPEI_PCIE_MSI_RCV) & 0xffffffff;
167 msg.address_hi = (0 + CVMX_NPEI_PCIE_MSI_RCV) >> 32;
168 break;
169 case OCTEON_DMA_BAR_TYPE_PCIE2:
170 /* When using PCIe2, Bar 0 is based at 0 */
171 msg.address_lo = (0 + CVMX_SLI_PCIE_MSI_RCV) & 0xffffffff;
172 msg.address_hi = (0 + CVMX_SLI_PCIE_MSI_RCV) >> 32;
173 break;
174 default:
175 panic("arch_setup_msi_irq: Invalid octeon_dma_bar_type");
176 }
177 msg.data = irq - OCTEON_IRQ_MSI_BIT0;
178
179 /* Update the number of IRQs the device has available to it */
180 control &= ~PCI_MSI_FLAGS_QSIZE;
181 control |= request_private_bits << 4;
182 pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
183
184 irq_set_msi_desc(irq, desc);
185 pci_write_msi_msg(irq, &msg);
186 return 0;
187 }
188
189 /**
190 * arch_teardown_msi_irq() - release MSI IRQs for a device
191 * @irq: The devices first irq number. There may be multiple in sequence.
192 *
193 * Called when a device no longer needs its MSI interrupts. All
194 * MSI interrupts for the device are freed.
195 */
arch_teardown_msi_irq(unsigned int irq)196 void arch_teardown_msi_irq(unsigned int irq)
197 {
198 int number_irqs;
199 u64 bitmask;
200 int index = 0;
201 int irq0;
202
203 if ((irq < OCTEON_IRQ_MSI_BIT0)
204 || (irq > msi_irq_size + OCTEON_IRQ_MSI_BIT0))
205 panic("arch_teardown_msi_irq: Attempted to teardown illegal "
206 "MSI interrupt (%d)", irq);
207
208 irq -= OCTEON_IRQ_MSI_BIT0;
209 index = irq / 64;
210 irq0 = irq % 64;
211
212 /*
213 * Count the number of IRQs we need to free by looking at the
214 * msi_multiple_irq_bitmask. Each bit set means that the next
215 * IRQ is also owned by this device.
216 */
217 number_irqs = 0;
218 while ((irq0 + number_irqs < 64) &&
219 (msi_multiple_irq_bitmask[index]
220 & (1ull << (irq0 + number_irqs))))
221 number_irqs++;
222 number_irqs++;
223 /* Mask with one bit for each IRQ */
224 bitmask = (1 << number_irqs) - 1;
225 /* Shift the mask to the correct bit location */
226 bitmask <<= irq0;
227 if ((msi_free_irq_bitmask[index] & bitmask) != bitmask)
228 panic("arch_teardown_msi_irq: Attempted to teardown MSI "
229 "interrupt (%d) not in use", irq);
230
231 /* Checks are done, update the in use bitmask */
232 spin_lock(&msi_free_irq_bitmask_lock);
233 msi_free_irq_bitmask[index] &= ~bitmask;
234 msi_multiple_irq_bitmask[index] &= ~bitmask;
235 spin_unlock(&msi_free_irq_bitmask_lock);
236 }
237
238 static DEFINE_RAW_SPINLOCK(octeon_irq_msi_lock);
239
240 static u64 msi_rcv_reg[4];
241 static u64 mis_ena_reg[4];
242
octeon_irq_msi_enable_pcie(struct irq_data * data)243 static void octeon_irq_msi_enable_pcie(struct irq_data *data)
244 {
245 u64 en;
246 unsigned long flags;
247 int msi_number = data->irq - OCTEON_IRQ_MSI_BIT0;
248 int irq_index = msi_number >> 6;
249 int irq_bit = msi_number & 0x3f;
250
251 raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags);
252 en = cvmx_read_csr(mis_ena_reg[irq_index]);
253 en |= 1ull << irq_bit;
254 cvmx_write_csr(mis_ena_reg[irq_index], en);
255 cvmx_read_csr(mis_ena_reg[irq_index]);
256 raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
257 }
258
octeon_irq_msi_disable_pcie(struct irq_data * data)259 static void octeon_irq_msi_disable_pcie(struct irq_data *data)
260 {
261 u64 en;
262 unsigned long flags;
263 int msi_number = data->irq - OCTEON_IRQ_MSI_BIT0;
264 int irq_index = msi_number >> 6;
265 int irq_bit = msi_number & 0x3f;
266
267 raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags);
268 en = cvmx_read_csr(mis_ena_reg[irq_index]);
269 en &= ~(1ull << irq_bit);
270 cvmx_write_csr(mis_ena_reg[irq_index], en);
271 cvmx_read_csr(mis_ena_reg[irq_index]);
272 raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
273 }
274
275 static struct irq_chip octeon_irq_chip_msi_pcie = {
276 .name = "MSI",
277 .irq_enable = octeon_irq_msi_enable_pcie,
278 .irq_disable = octeon_irq_msi_disable_pcie,
279 };
280
octeon_irq_msi_enable_pci(struct irq_data * data)281 static void octeon_irq_msi_enable_pci(struct irq_data *data)
282 {
283 /*
284 * Octeon PCI doesn't have the ability to mask/unmask MSI
285 * interrupts individually. Instead of masking/unmasking them
286 * in groups of 16, we simple assume MSI devices are well
287 * behaved. MSI interrupts are always enable and the ACK is
288 * assumed to be enough
289 */
290 }
291
octeon_irq_msi_disable_pci(struct irq_data * data)292 static void octeon_irq_msi_disable_pci(struct irq_data *data)
293 {
294 /* See comment in enable */
295 }
296
297 static struct irq_chip octeon_irq_chip_msi_pci = {
298 .name = "MSI",
299 .irq_enable = octeon_irq_msi_enable_pci,
300 .irq_disable = octeon_irq_msi_disable_pci,
301 };
302
303 /*
304 * Called by the interrupt handling code when an MSI interrupt
305 * occurs.
306 */
__octeon_msi_do_interrupt(int index,u64 msi_bits)307 static irqreturn_t __octeon_msi_do_interrupt(int index, u64 msi_bits)
308 {
309 int irq;
310 int bit;
311
312 bit = fls64(msi_bits);
313 if (bit) {
314 bit--;
315 /* Acknowledge it first. */
316 cvmx_write_csr(msi_rcv_reg[index], 1ull << bit);
317
318 irq = bit + OCTEON_IRQ_MSI_BIT0 + 64 * index;
319 do_IRQ(irq);
320 return IRQ_HANDLED;
321 }
322 return IRQ_NONE;
323 }
324
325 #define OCTEON_MSI_INT_HANDLER_X(x) \
326 static irqreturn_t octeon_msi_interrupt##x(int cpl, void *dev_id) \
327 { \
328 u64 msi_bits = cvmx_read_csr(msi_rcv_reg[(x)]); \
329 return __octeon_msi_do_interrupt((x), msi_bits); \
330 }
331
332 /*
333 * Create octeon_msi_interrupt{0-3} function body
334 */
335 OCTEON_MSI_INT_HANDLER_X(0);
336 OCTEON_MSI_INT_HANDLER_X(1);
337 OCTEON_MSI_INT_HANDLER_X(2);
338 OCTEON_MSI_INT_HANDLER_X(3);
339
340 /*
341 * Initializes the MSI interrupt handling code
342 */
octeon_msi_initialize(void)343 int __init octeon_msi_initialize(void)
344 {
345 int irq;
346 struct irq_chip *msi;
347
348 if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_INVALID) {
349 return 0;
350 } else if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
351 msi_rcv_reg[0] = CVMX_PEXP_NPEI_MSI_RCV0;
352 msi_rcv_reg[1] = CVMX_PEXP_NPEI_MSI_RCV1;
353 msi_rcv_reg[2] = CVMX_PEXP_NPEI_MSI_RCV2;
354 msi_rcv_reg[3] = CVMX_PEXP_NPEI_MSI_RCV3;
355 mis_ena_reg[0] = CVMX_PEXP_NPEI_MSI_ENB0;
356 mis_ena_reg[1] = CVMX_PEXP_NPEI_MSI_ENB1;
357 mis_ena_reg[2] = CVMX_PEXP_NPEI_MSI_ENB2;
358 mis_ena_reg[3] = CVMX_PEXP_NPEI_MSI_ENB3;
359 msi = &octeon_irq_chip_msi_pcie;
360 } else {
361 msi_rcv_reg[0] = CVMX_NPI_NPI_MSI_RCV;
362 #define INVALID_GENERATE_ADE 0x8700000000000000ULL;
363 msi_rcv_reg[1] = INVALID_GENERATE_ADE;
364 msi_rcv_reg[2] = INVALID_GENERATE_ADE;
365 msi_rcv_reg[3] = INVALID_GENERATE_ADE;
366 mis_ena_reg[0] = INVALID_GENERATE_ADE;
367 mis_ena_reg[1] = INVALID_GENERATE_ADE;
368 mis_ena_reg[2] = INVALID_GENERATE_ADE;
369 mis_ena_reg[3] = INVALID_GENERATE_ADE;
370 msi = &octeon_irq_chip_msi_pci;
371 }
372
373 for (irq = OCTEON_IRQ_MSI_BIT0; irq <= OCTEON_IRQ_MSI_LAST; irq++)
374 irq_set_chip_and_handler(irq, msi, handle_simple_irq);
375
376 if (octeon_has_feature(OCTEON_FEATURE_PCIE)) {
377 if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt0,
378 0, "MSI[0:63]", octeon_msi_interrupt0))
379 panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
380
381 if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt1,
382 0, "MSI[64:127]", octeon_msi_interrupt1))
383 panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed");
384
385 if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt2,
386 0, "MSI[127:191]", octeon_msi_interrupt2))
387 panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed");
388
389 if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt3,
390 0, "MSI[192:255]", octeon_msi_interrupt3))
391 panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed");
392
393 msi_irq_size = 256;
394 } else if (octeon_is_pci_host()) {
395 if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt0,
396 0, "MSI[0:15]", octeon_msi_interrupt0))
397 panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
398
399 if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt0,
400 0, "MSI[16:31]", octeon_msi_interrupt0))
401 panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed");
402
403 if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt0,
404 0, "MSI[32:47]", octeon_msi_interrupt0))
405 panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed");
406
407 if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt0,
408 0, "MSI[48:63]", octeon_msi_interrupt0))
409 panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed");
410 msi_irq_size = 64;
411 }
412 return 0;
413 }
414 subsys_initcall(octeon_msi_initialize);
415