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
6 * Copyright (C) 2005-2009, 2010 Cavium Networks
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>
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>
22 * Each bit in msi_free_irq_bitmask represents a MSI interrupt that is
25 static u64 msi_free_irq_bitmask[4];
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
33 static u64 msi_multiple_irq_bitmask[4];
36 * This lock controls updates to msi_free_irq_bitmask and
37 * msi_multiple_irq_bitmask.
39 static DEFINE_SPINLOCK(msi_free_irq_bitmask_lock);
42 * Number of MSI IRQs used. This variable is set up in
43 * the module init time.
45 static int msi_irq_size;
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
54 * @dev: Device requesting MSI interrupts
55 * @desc: MSI descriptor
57 * Returns 0 on success.
59 int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
63 int configured_private_bits;
64 int request_private_bits;
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.
75 pci_read_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS,
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().
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;
90 * Use the number of configured bits, assuming the
91 * driver wanted to override the hardware request
94 request_private_bits = configured_private_bits;
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.
101 if (request_private_bits > 5)
102 request_private_bits = 0;
106 * The IRQs have to be aligned on a power of two based on the
107 * number being requested.
109 irq_step = 1 << request_private_bits;
111 /* Mask with one bit for each IRQ */
112 search_mask = (1 << irq_step) - 1;
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
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;
130 spin_unlock(&msi_free_irq_bitmask_lock);
132 /* Make sure the search for available interrupts didn't fail */
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;
140 panic("arch_setup_msi_irq: Unable to find a free MSI interrupt");
143 /* MSI interrupts start at logical IRQ OCTEON_IRQ_MSI_BIT0 */
145 irq += OCTEON_IRQ_MSI_BIT0;
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 */
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;
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;
165 panic("arch_setup_msi_irq: Invalid octeon_dma_bar_type\n");
167 msg.data = irq - OCTEON_IRQ_MSI_BIT0;
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,
175 set_irq_msi(irq, desc);
176 write_msi_msg(irq, &msg);
182 * Called when a device no longer needs its MSI interrupts. All
183 * MSI interrupts for the device are freed.
185 * @irq: The devices first irq number. There may be multple in sequence.
187 void arch_teardown_msi_irq(unsigned int irq)
194 if ((irq < OCTEON_IRQ_MSI_BIT0)
195 || (irq > msi_irq_size + OCTEON_IRQ_MSI_BIT0))
196 panic("arch_teardown_msi_irq: Attempted to teardown illegal "
197 "MSI interrupt (%d)", irq);
199 irq -= OCTEON_IRQ_MSI_BIT0;
204 * Count the number of IRQs we need to free by looking at the
205 * msi_multiple_irq_bitmask. Each bit set means that the next
206 * IRQ is also owned by this device.
209 while ((irq0 + number_irqs < 64) &&
210 (msi_multiple_irq_bitmask[index]
211 & (1ull << (irq0 + number_irqs))))
214 /* Mask with one bit for each IRQ */
215 bitmask = (1 << number_irqs) - 1;
216 /* Shift the mask to the correct bit location */
218 if ((msi_free_irq_bitmask[index] & bitmask) != bitmask)
219 panic("arch_teardown_msi_irq: Attempted to teardown MSI "
220 "interrupt (%d) not in use", irq);
222 /* Checks are done, update the in use bitmask */
223 spin_lock(&msi_free_irq_bitmask_lock);
224 msi_free_irq_bitmask[index] &= ~bitmask;
225 msi_multiple_irq_bitmask[index] &= ~bitmask;
226 spin_unlock(&msi_free_irq_bitmask_lock);
229 static DEFINE_RAW_SPINLOCK(octeon_irq_msi_lock);
231 static u64 msi_rcv_reg[4];
232 static u64 mis_ena_reg[4];
234 static void octeon_irq_msi_enable_pcie(unsigned int irq)
238 int msi_number = irq - OCTEON_IRQ_MSI_BIT0;
239 int irq_index = msi_number >> 6;
240 int irq_bit = msi_number & 0x3f;
242 raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags);
243 en = cvmx_read_csr(mis_ena_reg[irq_index]);
244 en |= 1ull << irq_bit;
245 cvmx_write_csr(mis_ena_reg[irq_index], en);
246 cvmx_read_csr(mis_ena_reg[irq_index]);
247 raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
250 static void octeon_irq_msi_disable_pcie(unsigned int irq)
254 int msi_number = irq - OCTEON_IRQ_MSI_BIT0;
255 int irq_index = msi_number >> 6;
256 int irq_bit = msi_number & 0x3f;
258 raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags);
259 en = cvmx_read_csr(mis_ena_reg[irq_index]);
260 en &= ~(1ull << irq_bit);
261 cvmx_write_csr(mis_ena_reg[irq_index], en);
262 cvmx_read_csr(mis_ena_reg[irq_index]);
263 raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
266 static struct irq_chip octeon_irq_chip_msi_pcie = {
268 .enable = octeon_irq_msi_enable_pcie,
269 .disable = octeon_irq_msi_disable_pcie,
272 static void octeon_irq_msi_enable_pci(unsigned int irq)
275 * Octeon PCI doesn't have the ability to mask/unmask MSI
276 * interrupts individually. Instead of masking/unmasking them
277 * in groups of 16, we simple assume MSI devices are well
278 * behaved. MSI interrupts are always enable and the ACK is
279 * assumed to be enough
283 static void octeon_irq_msi_disable_pci(unsigned int irq)
285 /* See comment in enable */
288 static struct irq_chip octeon_irq_chip_msi_pci = {
290 .enable = octeon_irq_msi_enable_pci,
291 .disable = octeon_irq_msi_disable_pci,
295 * Called by the interrupt handling code when an MSI interrupt
298 static irqreturn_t __octeon_msi_do_interrupt(int index, u64 msi_bits)
303 bit = fls64(msi_bits);
306 /* Acknowledge it first. */
307 cvmx_write_csr(msi_rcv_reg[index], 1ull << bit);
309 irq = bit + OCTEON_IRQ_MSI_BIT0 + 64 * index;
316 #define OCTEON_MSI_INT_HANDLER_X(x) \
317 static irqreturn_t octeon_msi_interrupt##x(int cpl, void *dev_id) \
319 u64 msi_bits = cvmx_read_csr(msi_rcv_reg[(x)]); \
320 return __octeon_msi_do_interrupt((x), msi_bits); \
324 * Create octeon_msi_interrupt{0-3} function body
326 OCTEON_MSI_INT_HANDLER_X(0);
327 OCTEON_MSI_INT_HANDLER_X(1);
328 OCTEON_MSI_INT_HANDLER_X(2);
329 OCTEON_MSI_INT_HANDLER_X(3);
332 * Initializes the MSI interrupt handling code
334 int __init octeon_msi_initialize(void)
337 struct irq_chip *msi;
339 if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
340 msi_rcv_reg[0] = CVMX_PEXP_NPEI_MSI_RCV0;
341 msi_rcv_reg[1] = CVMX_PEXP_NPEI_MSI_RCV1;
342 msi_rcv_reg[2] = CVMX_PEXP_NPEI_MSI_RCV2;
343 msi_rcv_reg[3] = CVMX_PEXP_NPEI_MSI_RCV3;
344 mis_ena_reg[0] = CVMX_PEXP_NPEI_MSI_ENB0;
345 mis_ena_reg[1] = CVMX_PEXP_NPEI_MSI_ENB1;
346 mis_ena_reg[2] = CVMX_PEXP_NPEI_MSI_ENB2;
347 mis_ena_reg[3] = CVMX_PEXP_NPEI_MSI_ENB3;
348 msi = &octeon_irq_chip_msi_pcie;
350 msi_rcv_reg[0] = CVMX_NPI_NPI_MSI_RCV;
351 #define INVALID_GENERATE_ADE 0x8700000000000000ULL;
352 msi_rcv_reg[1] = INVALID_GENERATE_ADE;
353 msi_rcv_reg[2] = INVALID_GENERATE_ADE;
354 msi_rcv_reg[3] = INVALID_GENERATE_ADE;
355 mis_ena_reg[0] = INVALID_GENERATE_ADE;
356 mis_ena_reg[1] = INVALID_GENERATE_ADE;
357 mis_ena_reg[2] = INVALID_GENERATE_ADE;
358 mis_ena_reg[3] = INVALID_GENERATE_ADE;
359 msi = &octeon_irq_chip_msi_pci;
362 for (irq = OCTEON_IRQ_MSI_BIT0; irq <= OCTEON_IRQ_MSI_LAST; irq++)
363 set_irq_chip_and_handler(irq, msi, handle_simple_irq);
365 if (octeon_has_feature(OCTEON_FEATURE_PCIE)) {
366 if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt0,
367 0, "MSI[0:63]", octeon_msi_interrupt0))
368 panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
370 if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt1,
371 0, "MSI[64:127]", octeon_msi_interrupt1))
372 panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed");
374 if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt2,
375 0, "MSI[127:191]", octeon_msi_interrupt2))
376 panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed");
378 if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt3,
379 0, "MSI[192:255]", octeon_msi_interrupt3))
380 panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed");
383 } else if (octeon_is_pci_host()) {
384 if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt0,
385 0, "MSI[0:15]", octeon_msi_interrupt0))
386 panic("request_irq(OCTEON_IRQ_PCI_MSI0) failed");
388 if (request_irq(OCTEON_IRQ_PCI_MSI1, octeon_msi_interrupt0,
389 0, "MSI[16:31]", octeon_msi_interrupt0))
390 panic("request_irq(OCTEON_IRQ_PCI_MSI1) failed");
392 if (request_irq(OCTEON_IRQ_PCI_MSI2, octeon_msi_interrupt0,
393 0, "MSI[32:47]", octeon_msi_interrupt0))
394 panic("request_irq(OCTEON_IRQ_PCI_MSI2) failed");
396 if (request_irq(OCTEON_IRQ_PCI_MSI3, octeon_msi_interrupt0,
397 0, "MSI[48:63]", octeon_msi_interrupt0))
398 panic("request_irq(OCTEON_IRQ_PCI_MSI3) failed");
403 subsys_initcall(octeon_msi_initialize);