1 // SPDX-License-Identifier: GPL-2.0
2 #define KMSG_COMPONENT "zpci"
3 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
5 #include <linux/kernel.h>
7 #include <linux/kernel_stat.h>
10 #include <linux/smp.h>
15 static enum {FLOATING, DIRECTED} irq_delivery;
17 #define SIC_IRQ_MODE_ALL 0
18 #define SIC_IRQ_MODE_SINGLE 1
19 #define SIC_IRQ_MODE_DIRECT 4
20 #define SIC_IRQ_MODE_D_ALL 16
21 #define SIC_IRQ_MODE_D_SINGLE 17
22 #define SIC_IRQ_MODE_SET_CPU 18
26 * FLOATING - summary bit per function
27 * DIRECTED - summary bit per cpu (only used in fallback path)
29 static struct airq_iv *zpci_sbv;
32 * interrupt bit vectors
33 * FLOATING - interrupt bit vector per function
34 * DIRECTED - interrupt bit vector per cpu
36 static struct airq_iv **zpci_ibv;
38 /* Modify PCI: Register floating adapter interruptions */
39 static int zpci_set_airq(struct zpci_dev *zdev)
41 u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT);
42 struct zpci_fib fib = {0};
45 fib.fmt0.isc = PCI_ISC;
46 fib.fmt0.sum = 1; /* enable summary notifications */
47 fib.fmt0.noi = airq_iv_end(zdev->aibv);
48 fib.fmt0.aibv = virt_to_phys(zdev->aibv->vector);
49 fib.fmt0.aibvo = 0; /* each zdev has its own interrupt vector */
50 fib.fmt0.aisb = virt_to_phys(zpci_sbv->vector) + (zdev->aisb / 64) * 8;
51 fib.fmt0.aisbo = zdev->aisb & 63;
53 return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
56 /* Modify PCI: Unregister floating adapter interruptions */
57 static int zpci_clear_airq(struct zpci_dev *zdev)
59 u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT);
60 struct zpci_fib fib = {0};
63 cc = zpci_mod_fc(req, &fib, &status);
64 if (cc == 3 || (cc == 1 && status == 24))
65 /* Function already gone or IRQs already deregistered. */
71 /* Modify PCI: Register CPU directed interruptions */
72 static int zpci_set_directed_irq(struct zpci_dev *zdev)
74 u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT_D);
75 struct zpci_fib fib = {0};
79 fib.fmt1.noi = zdev->msi_nr_irqs;
80 fib.fmt1.dibvo = zdev->msi_first_bit;
82 return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
85 /* Modify PCI: Unregister CPU directed interruptions */
86 static int zpci_clear_directed_irq(struct zpci_dev *zdev)
88 u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT_D);
89 struct zpci_fib fib = {0};
93 cc = zpci_mod_fc(req, &fib, &status);
94 if (cc == 3 || (cc == 1 && status == 24))
95 /* Function already gone or IRQs already deregistered. */
101 /* Register adapter interruptions */
102 static int zpci_set_irq(struct zpci_dev *zdev)
106 if (irq_delivery == DIRECTED)
107 rc = zpci_set_directed_irq(zdev);
109 rc = zpci_set_airq(zdev);
112 zdev->irqs_registered = 1;
117 /* Clear adapter interruptions */
118 static int zpci_clear_irq(struct zpci_dev *zdev)
122 if (irq_delivery == DIRECTED)
123 rc = zpci_clear_directed_irq(zdev);
125 rc = zpci_clear_airq(zdev);
128 zdev->irqs_registered = 0;
133 static int zpci_set_irq_affinity(struct irq_data *data, const struct cpumask *dest,
136 struct msi_desc *entry = irq_get_msi_desc(data->irq);
137 struct msi_msg msg = entry->msg;
138 int cpu_addr = smp_cpu_get_cpu_address(cpumask_first(dest));
140 msg.address_lo &= 0xff0000ff;
141 msg.address_lo |= (cpu_addr << 8);
142 pci_write_msi_msg(data->irq, &msg);
144 return IRQ_SET_MASK_OK;
147 static struct irq_chip zpci_irq_chip = {
149 .irq_unmask = pci_msi_unmask_irq,
150 .irq_mask = pci_msi_mask_irq,
153 static void zpci_handle_cpu_local_irq(bool rescan)
155 struct airq_iv *dibv = zpci_ibv[smp_processor_id()];
160 /* Scan the directed IRQ bit vector */
161 bit = airq_iv_scan(dibv, bit, airq_iv_end(dibv));
163 if (!rescan || irqs_on++)
164 /* End of second scan with interrupts on. */
166 /* First scan complete, reenable interrupts. */
167 if (zpci_set_irq_ctrl(SIC_IRQ_MODE_D_SINGLE, PCI_ISC))
172 inc_irq_stat(IRQIO_MSI);
173 generic_handle_irq(airq_iv_get_data(dibv, bit));
177 struct cpu_irq_data {
178 call_single_data_t csd;
181 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_irq_data, irq_data);
183 static void zpci_handle_remote_irq(void *data)
185 atomic_t *scheduled = data;
188 zpci_handle_cpu_local_irq(false);
189 } while (atomic_dec_return(scheduled));
192 static void zpci_handle_fallback_irq(void)
194 struct cpu_irq_data *cpu_data;
199 cpu = airq_iv_scan(zpci_sbv, cpu, airq_iv_end(zpci_sbv));
202 /* End of second scan with interrupts on. */
204 /* First scan complete, reenable interrupts. */
205 if (zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC))
210 cpu_data = &per_cpu(irq_data, cpu);
211 if (atomic_inc_return(&cpu_data->scheduled) > 1)
214 INIT_CSD(&cpu_data->csd, zpci_handle_remote_irq, &cpu_data->scheduled);
215 smp_call_function_single_async(cpu, &cpu_data->csd);
219 static void zpci_directed_irq_handler(struct airq_struct *airq, bool floating)
222 inc_irq_stat(IRQIO_PCF);
223 zpci_handle_fallback_irq();
225 inc_irq_stat(IRQIO_PCD);
226 zpci_handle_cpu_local_irq(true);
230 static void zpci_floating_irq_handler(struct airq_struct *airq, bool floating)
232 unsigned long si, ai;
233 struct airq_iv *aibv;
236 inc_irq_stat(IRQIO_PCF);
238 /* Scan adapter summary indicator bit vector */
239 si = airq_iv_scan(zpci_sbv, si, airq_iv_end(zpci_sbv));
242 /* End of second scan with interrupts on. */
244 /* First scan complete, reenable interrupts. */
245 if (zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC))
251 /* Scan the adapter interrupt vector for this device. */
254 ai = airq_iv_scan(aibv, ai, airq_iv_end(aibv));
257 inc_irq_stat(IRQIO_MSI);
258 airq_iv_lock(aibv, ai);
259 generic_handle_irq(airq_iv_get_data(aibv, ai));
260 airq_iv_unlock(aibv, ai);
265 int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
267 struct zpci_dev *zdev = to_zpci(pdev);
268 unsigned int hwirq, msi_vecs, cpu;
270 struct msi_desc *msi;
276 zdev->msi_first_bit = -1U;
277 if (type == PCI_CAP_ID_MSI && nvec > 1)
279 msi_vecs = min_t(unsigned int, nvec, zdev->max_msi);
281 if (irq_delivery == DIRECTED) {
282 /* Allocate cpu vector bits */
283 bit = airq_iv_alloc(zpci_ibv[0], msi_vecs);
287 /* Allocate adapter summary indicator bit */
288 bit = airq_iv_alloc_bit(zpci_sbv);
293 /* Create adapter interrupt vector */
294 zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK);
298 /* Wire up shortcut pointer */
299 zpci_ibv[bit] = zdev->aibv;
300 /* Each function has its own interrupt vector */
304 /* Request MSI interrupts */
306 msi_for_each_desc(msi, &pdev->dev, MSI_DESC_NOTASSOCIATED) {
308 if (hwirq - bit >= msi_vecs)
310 irq = __irq_alloc_descs(-1, 0, 1, 0, THIS_MODULE,
311 (irq_delivery == DIRECTED) ?
312 msi->affinity : NULL);
315 rc = irq_set_msi_desc(irq, msi);
318 irq_set_chip_and_handler(irq, &zpci_irq_chip,
320 msg.data = hwirq - bit;
321 if (irq_delivery == DIRECTED) {
323 cpu = cpumask_first(&msi->affinity->mask);
326 cpu_addr = smp_cpu_get_cpu_address(cpu);
328 msg.address_lo = zdev->msi_addr & 0xff0000ff;
329 msg.address_lo |= (cpu_addr << 8);
331 for_each_possible_cpu(cpu) {
332 airq_iv_set_data(zpci_ibv[cpu], hwirq, irq);
335 msg.address_lo = zdev->msi_addr & 0xffffffff;
336 airq_iv_set_data(zdev->aibv, hwirq, irq);
338 msg.address_hi = zdev->msi_addr >> 32;
339 pci_write_msi_msg(irq, &msg);
343 zdev->msi_first_bit = bit;
344 zdev->msi_nr_irqs = msi_vecs;
346 rc = zpci_set_irq(zdev);
350 return (msi_vecs == nvec) ? 0 : msi_vecs;
353 void arch_teardown_msi_irqs(struct pci_dev *pdev)
355 struct zpci_dev *zdev = to_zpci(pdev);
356 struct msi_desc *msi;
359 /* Disable interrupts */
360 rc = zpci_clear_irq(zdev);
364 /* Release MSI interrupts */
365 msi_for_each_desc(msi, &pdev->dev, MSI_DESC_ASSOCIATED) {
366 irq_set_msi_desc(msi->irq, NULL);
367 irq_free_desc(msi->irq);
368 msi->msg.address_lo = 0;
369 msi->msg.address_hi = 0;
374 if (zdev->aisb != -1UL) {
375 zpci_ibv[zdev->aisb] = NULL;
376 airq_iv_free_bit(zpci_sbv, zdev->aisb);
380 airq_iv_release(zdev->aibv);
384 if ((irq_delivery == DIRECTED) && zdev->msi_first_bit != -1U)
385 airq_iv_free(zpci_ibv[0], zdev->msi_first_bit, zdev->msi_nr_irqs);
388 bool arch_restore_msi_irqs(struct pci_dev *pdev)
390 struct zpci_dev *zdev = to_zpci(pdev);
392 if (!zdev->irqs_registered)
397 static struct airq_struct zpci_airq = {
398 .handler = zpci_floating_irq_handler,
402 static void __init cpu_enable_directed_irq(void *unused)
404 union zpci_sic_iib iib = {{0}};
406 iib.cdiib.dibv_addr = (u64) zpci_ibv[smp_processor_id()]->vector;
408 __zpci_set_irq_ctrl(SIC_IRQ_MODE_SET_CPU, 0, &iib);
409 zpci_set_irq_ctrl(SIC_IRQ_MODE_D_SINGLE, PCI_ISC);
412 static int __init zpci_directed_irq_init(void)
414 union zpci_sic_iib iib = {{0}};
417 zpci_sbv = airq_iv_create(num_possible_cpus(), 0);
421 iib.diib.isc = PCI_ISC;
422 iib.diib.nr_cpus = num_possible_cpus();
423 iib.diib.disb_addr = virt_to_phys(zpci_sbv->vector);
424 __zpci_set_irq_ctrl(SIC_IRQ_MODE_DIRECT, 0, &iib);
426 zpci_ibv = kcalloc(num_possible_cpus(), sizeof(*zpci_ibv),
431 for_each_possible_cpu(cpu) {
433 * Per CPU IRQ vectors look the same but bit-allocation
434 * is only done on the first vector.
436 zpci_ibv[cpu] = airq_iv_create(cache_line_size() * BITS_PER_BYTE,
439 (!cpu ? AIRQ_IV_ALLOC : 0));
443 on_each_cpu(cpu_enable_directed_irq, NULL, 1);
445 zpci_irq_chip.irq_set_affinity = zpci_set_irq_affinity;
450 static int __init zpci_floating_irq_init(void)
452 zpci_ibv = kcalloc(ZPCI_NR_DEVICES, sizeof(*zpci_ibv), GFP_KERNEL);
456 zpci_sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC);
467 int __init zpci_irq_init(void)
471 irq_delivery = sclp.has_dirq ? DIRECTED : FLOATING;
472 if (s390_pci_force_floating)
473 irq_delivery = FLOATING;
475 if (irq_delivery == DIRECTED)
476 zpci_airq.handler = zpci_directed_irq_handler;
478 rc = register_adapter_interrupt(&zpci_airq);
481 /* Set summary to 1 to be called every time for the ISC. */
482 *zpci_airq.lsi_ptr = 1;
484 switch (irq_delivery) {
486 rc = zpci_floating_irq_init();
489 rc = zpci_directed_irq_init();
497 * Enable floating IRQs (with suppression after one IRQ). When using
498 * directed IRQs this enables the fallback path.
500 zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC);
504 unregister_adapter_interrupt(&zpci_airq);
509 void __init zpci_irq_exit(void)
513 if (irq_delivery == DIRECTED) {
514 for_each_possible_cpu(cpu) {
515 airq_iv_release(zpci_ibv[cpu]);
520 airq_iv_release(zpci_sbv);
521 unregister_adapter_interrupt(&zpci_airq);