diff options
Diffstat (limited to 'arch/s390/pci/pci_irq.c')
| -rw-r--r-- | arch/s390/pci/pci_irq.c | 486 |
1 files changed, 486 insertions, 0 deletions
diff --git a/arch/s390/pci/pci_irq.c b/arch/s390/pci/pci_irq.c new file mode 100644 index 000000000000..d80616ae8dd8 --- /dev/null +++ b/arch/s390/pci/pci_irq.c @@ -0,0 +1,486 @@ +// 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 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 = (unsigned long) zdev->aibv->vector; + fib.fmt0.aibvo = 0; /* each zdev has its own interrupt vector */ + fib.fmt0.aisb = (unsigned long) 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 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; +} + +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; + + msg.address_lo &= 0xff0000ff; + msg.address_lo |= (cpumask_first(dest) << 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, + .irq_set_affinity = zpci_set_irq_affinity, +}; + +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; + + cpu_data->csd.func = zpci_handle_remote_irq; + cpu_data->csd.info = &cpu_data->scheduled; + cpu_data->csd.flags = 0; + 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 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; + for_each_pci_msi_entry(msi, pdev) { + rc = -EIO; + if (hwirq - bit >= msi_vecs) + break; + irq = __irq_alloc_descs(-1, 0, 1, 0, THIS_MODULE, msi->affinity); + 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; + if (irq_delivery == DIRECTED) { + msg.address_lo = zdev->msi_addr & 0xff0000ff; + msg.address_lo |= msi->affinity ? + (cpumask_first(&msi->affinity->mask) << 8) : 0; + 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; + + if (irq_delivery == DIRECTED) + rc = zpci_set_directed_irq(zdev); + else + rc = zpci_set_airq(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 */ + if (irq_delivery == DIRECTED) + rc = zpci_clear_directed_irq(zdev); + else + rc = zpci_clear_airq(zdev); + if (rc) + return; + + /* Release MSI interrupts */ + for_each_pci_msi_entry(msi, pdev) { + if (!msi->irq) + continue; + if (msi->msi_attrib.is_msix) + __pci_msix_desc_mask_irq(msi, 1); + else + __pci_msi_desc_mask_irq(msi, 1, 1); + 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); +} + +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 = (u64) 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); +} |