| // SPDX-License-Identifier: GPL-2.0 |
| #define KMSG_COMPONENT "zpci" |
| #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
| |
| #include <linux/kernel.h> |
| #include <linux/irq.h> |
| #include <linux/kernel_stat.h> |
| #include <linux/pci.h> |
| #include <linux/msi.h> |
| #include <linux/smp.h> |
| |
| #include <asm/isc.h> |
| #include <asm/airq.h> |
| |
| static enum {FLOATING, DIRECTED} irq_delivery; |
| |
| #define SIC_IRQ_MODE_ALL 0 |
| #define SIC_IRQ_MODE_SINGLE 1 |
| #define SIC_IRQ_MODE_DIRECT 4 |
| #define SIC_IRQ_MODE_D_ALL 16 |
| #define SIC_IRQ_MODE_D_SINGLE 17 |
| #define SIC_IRQ_MODE_SET_CPU 18 |
| |
| /* |
| * summary bit vector |
| * FLOATING - summary bit per function |
| * DIRECTED - summary bit per cpu (only used in fallback path) |
| */ |
| static struct airq_iv *zpci_sbv; |
| |
| /* |
| * interrupt bit vectors |
| * FLOATING - interrupt bit vector per function |
| * DIRECTED - interrupt bit vector per cpu |
| */ |
| static struct airq_iv **zpci_ibv; |
| |
| /* Modify PCI: Register floating adapter interruptions */ |
| static int zpci_set_airq(struct zpci_dev *zdev) |
| { |
| u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT); |
| struct zpci_fib fib = {0}; |
| u8 status; |
| |
| fib.fmt0.isc = PCI_ISC; |
| fib.fmt0.sum = 1; /* enable summary notifications */ |
| fib.fmt0.noi = airq_iv_end(zdev->aibv); |
| fib.fmt0.aibv = virt_to_phys(zdev->aibv->vector); |
| fib.fmt0.aibvo = 0; /* each zdev has its own interrupt vector */ |
| fib.fmt0.aisb = virt_to_phys(zpci_sbv->vector) + (zdev->aisb / 64) * 8; |
| fib.fmt0.aisbo = zdev->aisb & 63; |
| |
| return zpci_mod_fc(req, &fib, &status) ? -EIO : 0; |
| } |
| |
| /* Modify PCI: Unregister floating adapter interruptions */ |
| static int zpci_clear_airq(struct zpci_dev *zdev) |
| { |
| u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT); |
| struct zpci_fib fib = {0}; |
| u8 cc, status; |
| |
| cc = zpci_mod_fc(req, &fib, &status); |
| if (cc == 3 || (cc == 1 && status == 24)) |
| /* Function already gone or IRQs already deregistered. */ |
| cc = 0; |
| |
| return cc ? -EIO : 0; |
| } |
| |
| /* Modify PCI: Register CPU directed interruptions */ |
| static int zpci_set_directed_irq(struct zpci_dev *zdev) |
| { |
| u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT_D); |
| struct zpci_fib fib = {0}; |
| u8 status; |
| |
| fib.fmt = 1; |
| fib.fmt1.noi = zdev->msi_nr_irqs; |
| fib.fmt1.dibvo = zdev->msi_first_bit; |
| |
| return zpci_mod_fc(req, &fib, &status) ? -EIO : 0; |
| } |
| |
| /* Modify PCI: Unregister CPU directed interruptions */ |
| static int zpci_clear_directed_irq(struct zpci_dev *zdev) |
| { |
| u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT_D); |
| struct zpci_fib fib = {0}; |
| u8 cc, status; |
| |
| fib.fmt = 1; |
| cc = zpci_mod_fc(req, &fib, &status); |
| if (cc == 3 || (cc == 1 && status == 24)) |
| /* Function already gone or IRQs already deregistered. */ |
| cc = 0; |
| |
| return cc ? -EIO : 0; |
| } |
| |
| /* Register adapter interruptions */ |
| static int zpci_set_irq(struct zpci_dev *zdev) |
| { |
| int rc; |
| |
| if (irq_delivery == DIRECTED) |
| rc = zpci_set_directed_irq(zdev); |
| else |
| rc = zpci_set_airq(zdev); |
| |
| if (!rc) |
| zdev->irqs_registered = 1; |
| |
| return rc; |
| } |
| |
| /* Clear adapter interruptions */ |
| static int zpci_clear_irq(struct zpci_dev *zdev) |
| { |
| int rc; |
| |
| if (irq_delivery == DIRECTED) |
| rc = zpci_clear_directed_irq(zdev); |
| else |
| rc = zpci_clear_airq(zdev); |
| |
| if (!rc) |
| zdev->irqs_registered = 0; |
| |
| return rc; |
| } |
| |
| static int zpci_set_irq_affinity(struct irq_data *data, const struct cpumask *dest, |
| bool force) |
| { |
| struct msi_desc *entry = irq_get_msi_desc(data->irq); |
| struct msi_msg msg = entry->msg; |
| int cpu_addr = smp_cpu_get_cpu_address(cpumask_first(dest)); |
| |
| msg.address_lo &= 0xff0000ff; |
| msg.address_lo |= (cpu_addr << 8); |
| pci_write_msi_msg(data->irq, &msg); |
| |
| return IRQ_SET_MASK_OK; |
| } |
| |
| static struct irq_chip zpci_irq_chip = { |
| .name = "PCI-MSI", |
| .irq_unmask = pci_msi_unmask_irq, |
| .irq_mask = pci_msi_mask_irq, |
| }; |
| |
| static void zpci_handle_cpu_local_irq(bool rescan) |
| { |
| struct airq_iv *dibv = zpci_ibv[smp_processor_id()]; |
| unsigned long bit; |
| int irqs_on = 0; |
| |
| for (bit = 0;;) { |
| /* Scan the directed IRQ bit vector */ |
| bit = airq_iv_scan(dibv, bit, airq_iv_end(dibv)); |
| if (bit == -1UL) { |
| if (!rescan || irqs_on++) |
| /* End of second scan with interrupts on. */ |
| break; |
| /* First scan complete, reenable interrupts. */ |
| if (zpci_set_irq_ctrl(SIC_IRQ_MODE_D_SINGLE, PCI_ISC)) |
| break; |
| bit = 0; |
| continue; |
| } |
| inc_irq_stat(IRQIO_MSI); |
| generic_handle_irq(airq_iv_get_data(dibv, bit)); |
| } |
| } |
| |
| struct cpu_irq_data { |
| call_single_data_t csd; |
| atomic_t scheduled; |
| }; |
| static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_irq_data, irq_data); |
| |
| static void zpci_handle_remote_irq(void *data) |
| { |
| atomic_t *scheduled = data; |
| |
| do { |
| zpci_handle_cpu_local_irq(false); |
| } while (atomic_dec_return(scheduled)); |
| } |
| |
| static void zpci_handle_fallback_irq(void) |
| { |
| struct cpu_irq_data *cpu_data; |
| unsigned long cpu; |
| int irqs_on = 0; |
| |
| for (cpu = 0;;) { |
| cpu = airq_iv_scan(zpci_sbv, cpu, airq_iv_end(zpci_sbv)); |
| if (cpu == -1UL) { |
| if (irqs_on++) |
| /* End of second scan with interrupts on. */ |
| break; |
| /* First scan complete, reenable interrupts. */ |
| if (zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC)) |
| break; |
| cpu = 0; |
| continue; |
| } |
| cpu_data = &per_cpu(irq_data, cpu); |
| if (atomic_inc_return(&cpu_data->scheduled) > 1) |
| continue; |
| |
| INIT_CSD(&cpu_data->csd, zpci_handle_remote_irq, &cpu_data->scheduled); |
| smp_call_function_single_async(cpu, &cpu_data->csd); |
| } |
| } |
| |
| static void zpci_directed_irq_handler(struct airq_struct *airq, bool floating) |
| { |
| if (floating) { |
| inc_irq_stat(IRQIO_PCF); |
| zpci_handle_fallback_irq(); |
| } else { |
| inc_irq_stat(IRQIO_PCD); |
| zpci_handle_cpu_local_irq(true); |
| } |
| } |
| |
| static void zpci_floating_irq_handler(struct airq_struct *airq, bool floating) |
| { |
| unsigned long si, ai; |
| struct airq_iv *aibv; |
| int irqs_on = 0; |
| |
| inc_irq_stat(IRQIO_PCF); |
| for (si = 0;;) { |
| /* Scan adapter summary indicator bit vector */ |
| si = airq_iv_scan(zpci_sbv, si, airq_iv_end(zpci_sbv)); |
| if (si == -1UL) { |
| if (irqs_on++) |
| /* End of second scan with interrupts on. */ |
| break; |
| /* First scan complete, reenable interrupts. */ |
| if (zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC)) |
| break; |
| si = 0; |
| continue; |
| } |
| |
| /* Scan the adapter interrupt vector for this device. */ |
| aibv = zpci_ibv[si]; |
| for (ai = 0;;) { |
| ai = airq_iv_scan(aibv, ai, airq_iv_end(aibv)); |
| if (ai == -1UL) |
| break; |
| inc_irq_stat(IRQIO_MSI); |
| airq_iv_lock(aibv, ai); |
| generic_handle_irq(airq_iv_get_data(aibv, ai)); |
| airq_iv_unlock(aibv, ai); |
| } |
| } |
| } |
| |
| int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) |
| { |
| struct zpci_dev *zdev = to_zpci(pdev); |
| unsigned int hwirq, msi_vecs, cpu; |
| unsigned long bit; |
| struct msi_desc *msi; |
| struct msi_msg msg; |
| int cpu_addr; |
| int rc, irq; |
| |
| zdev->aisb = -1UL; |
| zdev->msi_first_bit = -1U; |
| if (type == PCI_CAP_ID_MSI && nvec > 1) |
| return 1; |
| msi_vecs = min_t(unsigned int, nvec, zdev->max_msi); |
| |
| if (irq_delivery == DIRECTED) { |
| /* Allocate cpu vector bits */ |
| bit = airq_iv_alloc(zpci_ibv[0], msi_vecs); |
| if (bit == -1UL) |
| return -EIO; |
| } else { |
| /* Allocate adapter summary indicator bit */ |
| bit = airq_iv_alloc_bit(zpci_sbv); |
| if (bit == -1UL) |
| return -EIO; |
| zdev->aisb = bit; |
| |
| /* Create adapter interrupt vector */ |
| zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK); |
| if (!zdev->aibv) |
| return -ENOMEM; |
| |
| /* Wire up shortcut pointer */ |
| zpci_ibv[bit] = zdev->aibv; |
| /* Each function has its own interrupt vector */ |
| bit = 0; |
| } |
| |
| /* Request MSI interrupts */ |
| hwirq = bit; |
| msi_for_each_desc(msi, &pdev->dev, MSI_DESC_NOTASSOCIATED) { |
| rc = -EIO; |
| if (hwirq - bit >= msi_vecs) |
| break; |
| irq = __irq_alloc_descs(-1, 0, 1, 0, THIS_MODULE, |
| (irq_delivery == DIRECTED) ? |
| msi->affinity : NULL); |
| if (irq < 0) |
| return -ENOMEM; |
| rc = irq_set_msi_desc(irq, msi); |
| if (rc) |
| return rc; |
| irq_set_chip_and_handler(irq, &zpci_irq_chip, |
| handle_percpu_irq); |
| msg.data = hwirq - bit; |
| if (irq_delivery == DIRECTED) { |
| if (msi->affinity) |
| cpu = cpumask_first(&msi->affinity->mask); |
| else |
| cpu = 0; |
| cpu_addr = smp_cpu_get_cpu_address(cpu); |
| |
| msg.address_lo = zdev->msi_addr & 0xff0000ff; |
| msg.address_lo |= (cpu_addr << 8); |
| |
| for_each_possible_cpu(cpu) { |
| airq_iv_set_data(zpci_ibv[cpu], hwirq, irq); |
| } |
| } else { |
| msg.address_lo = zdev->msi_addr & 0xffffffff; |
| airq_iv_set_data(zdev->aibv, hwirq, irq); |
| } |
| msg.address_hi = zdev->msi_addr >> 32; |
| pci_write_msi_msg(irq, &msg); |
| hwirq++; |
| } |
| |
| zdev->msi_first_bit = bit; |
| zdev->msi_nr_irqs = msi_vecs; |
| |
| rc = zpci_set_irq(zdev); |
| if (rc) |
| return rc; |
| |
| return (msi_vecs == nvec) ? 0 : msi_vecs; |
| } |
| |
| void arch_teardown_msi_irqs(struct pci_dev *pdev) |
| { |
| struct zpci_dev *zdev = to_zpci(pdev); |
| struct msi_desc *msi; |
| int rc; |
| |
| /* Disable interrupts */ |
| rc = zpci_clear_irq(zdev); |
| if (rc) |
| return; |
| |
| /* Release MSI interrupts */ |
| msi_for_each_desc(msi, &pdev->dev, MSI_DESC_ASSOCIATED) { |
| irq_set_msi_desc(msi->irq, NULL); |
| irq_free_desc(msi->irq); |
| msi->msg.address_lo = 0; |
| msi->msg.address_hi = 0; |
| msi->msg.data = 0; |
| msi->irq = 0; |
| } |
| |
| if (zdev->aisb != -1UL) { |
| zpci_ibv[zdev->aisb] = NULL; |
| airq_iv_free_bit(zpci_sbv, zdev->aisb); |
| zdev->aisb = -1UL; |
| } |
| if (zdev->aibv) { |
| airq_iv_release(zdev->aibv); |
| zdev->aibv = NULL; |
| } |
| |
| if ((irq_delivery == DIRECTED) && zdev->msi_first_bit != -1U) |
| airq_iv_free(zpci_ibv[0], zdev->msi_first_bit, zdev->msi_nr_irqs); |
| } |
| |
| bool arch_restore_msi_irqs(struct pci_dev *pdev) |
| { |
| struct zpci_dev *zdev = to_zpci(pdev); |
| |
| if (!zdev->irqs_registered) |
| zpci_set_irq(zdev); |
| return true; |
| } |
| |
| static struct airq_struct zpci_airq = { |
| .handler = zpci_floating_irq_handler, |
| .isc = PCI_ISC, |
| }; |
| |
| static void __init cpu_enable_directed_irq(void *unused) |
| { |
| union zpci_sic_iib iib = {{0}}; |
| |
| iib.cdiib.dibv_addr = (u64) zpci_ibv[smp_processor_id()]->vector; |
| |
| __zpci_set_irq_ctrl(SIC_IRQ_MODE_SET_CPU, 0, &iib); |
| zpci_set_irq_ctrl(SIC_IRQ_MODE_D_SINGLE, PCI_ISC); |
| } |
| |
| static int __init zpci_directed_irq_init(void) |
| { |
| union zpci_sic_iib iib = {{0}}; |
| unsigned int cpu; |
| |
| zpci_sbv = airq_iv_create(num_possible_cpus(), 0); |
| if (!zpci_sbv) |
| return -ENOMEM; |
| |
| iib.diib.isc = PCI_ISC; |
| iib.diib.nr_cpus = num_possible_cpus(); |
| iib.diib.disb_addr = virt_to_phys(zpci_sbv->vector); |
| __zpci_set_irq_ctrl(SIC_IRQ_MODE_DIRECT, 0, &iib); |
| |
| zpci_ibv = kcalloc(num_possible_cpus(), sizeof(*zpci_ibv), |
| GFP_KERNEL); |
| if (!zpci_ibv) |
| return -ENOMEM; |
| |
| for_each_possible_cpu(cpu) { |
| /* |
| * Per CPU IRQ vectors look the same but bit-allocation |
| * is only done on the first vector. |
| */ |
| zpci_ibv[cpu] = airq_iv_create(cache_line_size() * BITS_PER_BYTE, |
| AIRQ_IV_DATA | |
| AIRQ_IV_CACHELINE | |
| (!cpu ? AIRQ_IV_ALLOC : 0)); |
| if (!zpci_ibv[cpu]) |
| return -ENOMEM; |
| } |
| on_each_cpu(cpu_enable_directed_irq, NULL, 1); |
| |
| zpci_irq_chip.irq_set_affinity = zpci_set_irq_affinity; |
| |
| return 0; |
| } |
| |
| static int __init zpci_floating_irq_init(void) |
| { |
| zpci_ibv = kcalloc(ZPCI_NR_DEVICES, sizeof(*zpci_ibv), GFP_KERNEL); |
| if (!zpci_ibv) |
| return -ENOMEM; |
| |
| zpci_sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC); |
| if (!zpci_sbv) |
| goto out_free; |
| |
| return 0; |
| |
| out_free: |
| kfree(zpci_ibv); |
| return -ENOMEM; |
| } |
| |
| int __init zpci_irq_init(void) |
| { |
| int rc; |
| |
| irq_delivery = sclp.has_dirq ? DIRECTED : FLOATING; |
| if (s390_pci_force_floating) |
| irq_delivery = FLOATING; |
| |
| if (irq_delivery == DIRECTED) |
| zpci_airq.handler = zpci_directed_irq_handler; |
| |
| rc = register_adapter_interrupt(&zpci_airq); |
| if (rc) |
| goto out; |
| /* Set summary to 1 to be called every time for the ISC. */ |
| *zpci_airq.lsi_ptr = 1; |
| |
| switch (irq_delivery) { |
| case FLOATING: |
| rc = zpci_floating_irq_init(); |
| break; |
| case DIRECTED: |
| rc = zpci_directed_irq_init(); |
| break; |
| } |
| |
| if (rc) |
| goto out_airq; |
| |
| /* |
| * Enable floating IRQs (with suppression after one IRQ). When using |
| * directed IRQs this enables the fallback path. |
| */ |
| zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, PCI_ISC); |
| |
| return 0; |
| out_airq: |
| unregister_adapter_interrupt(&zpci_airq); |
| out: |
| return rc; |
| } |
| |
| void __init zpci_irq_exit(void) |
| { |
| unsigned int cpu; |
| |
| if (irq_delivery == DIRECTED) { |
| for_each_possible_cpu(cpu) { |
| airq_iv_release(zpci_ibv[cpu]); |
| } |
| } |
| kfree(zpci_ibv); |
| if (zpci_sbv) |
| airq_iv_release(zpci_sbv); |
| unregister_adapter_interrupt(&zpci_airq); |
| } |