From 5bc71b8285f09733fe210b0a8dfa753411ed29c3 Mon Sep 17 00:00:00 2001 From: Frederic Barrat Date: Tue, 23 Jan 2018 12:31:42 +0100 Subject: [PATCH] ocxl: Add AFU interrupt support BugLink: http://bugs.launchpad.net/bugs/1746988 Add user APIs through ioctl to allocate, free, and be notified of an AFU interrupt. For opencapi, an AFU can trigger an interrupt on the host by sending a specific command targeting a 64-bit object handle. On POWER9, this is implemented by mapping a special page in the address space of a process and a write to that page will trigger an interrupt. Signed-off-by: Frederic Barrat Signed-off-by: Michael Ellerman (cherry picked from commit aeddad1760aeb206d912b27b230269407efd5b06) Signed-off-by: Seth Forshee --- arch/powerpc/include/asm/pnv-ocxl.h | 3 + arch/powerpc/platforms/powernv/ocxl.c | 30 ++++ drivers/misc/ocxl/afu_irq.c | 197 ++++++++++++++++++++++++++ drivers/misc/ocxl/context.c | 51 ++++++- drivers/misc/ocxl/file.c | 34 +++++ drivers/misc/ocxl/link.c | 28 ++++ drivers/misc/ocxl/ocxl_internal.h | 7 + include/uapi/misc/ocxl.h | 9 ++ 8 files changed, 357 insertions(+), 2 deletions(-) create mode 100644 drivers/misc/ocxl/afu_irq.c diff --git a/arch/powerpc/include/asm/pnv-ocxl.h b/arch/powerpc/include/asm/pnv-ocxl.h index 398d05b30600..f6945d3bc971 100644 --- a/arch/powerpc/include/asm/pnv-ocxl.h +++ b/arch/powerpc/include/asm/pnv-ocxl.h @@ -30,4 +30,7 @@ extern int pnv_ocxl_spa_setup(struct pci_dev *dev, void *spa_mem, int PE_mask, extern void pnv_ocxl_spa_release(void *platform_data); extern int pnv_ocxl_spa_remove_pe(void *platform_data, int pe_handle); +extern int pnv_ocxl_alloc_xive_irq(u32 *irq, u64 *trigger_addr); +extern void pnv_ocxl_free_xive_irq(u32 irq); + #endif /* _ASM_PNV_OCXL_H */ diff --git a/arch/powerpc/platforms/powernv/ocxl.c b/arch/powerpc/platforms/powernv/ocxl.c index 1faaa4ef6903..fa9b53af3c7b 100644 --- a/arch/powerpc/platforms/powernv/ocxl.c +++ b/arch/powerpc/platforms/powernv/ocxl.c @@ -2,6 +2,7 @@ // Copyright 2017 IBM Corp. #include #include +#include #include #include "pci.h" @@ -483,3 +484,32 @@ int pnv_ocxl_spa_remove_pe(void *platform_data, int pe_handle) return rc; } EXPORT_SYMBOL_GPL(pnv_ocxl_spa_remove_pe); + +int pnv_ocxl_alloc_xive_irq(u32 *irq, u64 *trigger_addr) +{ + __be64 flags, trigger_page; + s64 rc; + u32 hwirq; + + hwirq = xive_native_alloc_irq(); + if (!hwirq) + return -ENOENT; + + rc = opal_xive_get_irq_info(hwirq, &flags, NULL, &trigger_page, NULL, + NULL); + if (rc || !trigger_page) { + xive_native_free_irq(hwirq); + return -ENOENT; + } + *irq = hwirq; + *trigger_addr = be64_to_cpu(trigger_page); + return 0; + +} +EXPORT_SYMBOL_GPL(pnv_ocxl_alloc_xive_irq); + +void pnv_ocxl_free_xive_irq(u32 irq) +{ + xive_native_free_irq(irq); +} +EXPORT_SYMBOL_GPL(pnv_ocxl_free_xive_irq); diff --git a/drivers/misc/ocxl/afu_irq.c b/drivers/misc/ocxl/afu_irq.c new file mode 100644 index 000000000000..f40d853de401 --- /dev/null +++ b/drivers/misc/ocxl/afu_irq.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright 2017 IBM Corp. +#include +#include +#include +#include "ocxl_internal.h" + +struct afu_irq { + int id; + int hw_irq; + unsigned int virq; + char *name; + u64 trigger_page; + struct eventfd_ctx *ev_ctx; +}; + +static int irq_offset_to_id(struct ocxl_context *ctx, u64 offset) +{ + return (offset - ctx->afu->irq_base_offset) >> PAGE_SHIFT; +} + +static u64 irq_id_to_offset(struct ocxl_context *ctx, int id) +{ + return ctx->afu->irq_base_offset + (id << PAGE_SHIFT); +} + +static irqreturn_t afu_irq_handler(int virq, void *data) +{ + struct afu_irq *irq = (struct afu_irq *) data; + + if (irq->ev_ctx) + eventfd_signal(irq->ev_ctx, 1); + return IRQ_HANDLED; +} + +static int setup_afu_irq(struct ocxl_context *ctx, struct afu_irq *irq) +{ + int rc; + + irq->virq = irq_create_mapping(NULL, irq->hw_irq); + if (!irq->virq) { + pr_err("irq_create_mapping failed\n"); + return -ENOMEM; + } + pr_debug("hw_irq %d mapped to virq %u\n", irq->hw_irq, irq->virq); + + irq->name = kasprintf(GFP_KERNEL, "ocxl-afu-%u", irq->virq); + if (!irq->name) { + irq_dispose_mapping(irq->virq); + return -ENOMEM; + } + + rc = request_irq(irq->virq, afu_irq_handler, 0, irq->name, irq); + if (rc) { + kfree(irq->name); + irq->name = NULL; + irq_dispose_mapping(irq->virq); + pr_err("request_irq failed: %d\n", rc); + return rc; + } + return 0; +} + +static void release_afu_irq(struct afu_irq *irq) +{ + free_irq(irq->virq, irq); + irq_dispose_mapping(irq->virq); + kfree(irq->name); +} + +int ocxl_afu_irq_alloc(struct ocxl_context *ctx, u64 *irq_offset) +{ + struct afu_irq *irq; + int rc; + + irq = kzalloc(sizeof(struct afu_irq), GFP_KERNEL); + if (!irq) + return -ENOMEM; + + /* + * We limit the number of afu irqs per context and per link to + * avoid a single process or user depleting the pool of IPIs + */ + + mutex_lock(&ctx->irq_lock); + + irq->id = idr_alloc(&ctx->irq_idr, irq, 0, MAX_IRQ_PER_CONTEXT, + GFP_KERNEL); + if (irq->id < 0) { + rc = -ENOSPC; + goto err_unlock; + } + + rc = ocxl_link_irq_alloc(ctx->afu->fn->link, &irq->hw_irq, + &irq->trigger_page); + if (rc) + goto err_idr; + + rc = setup_afu_irq(ctx, irq); + if (rc) + goto err_alloc; + + *irq_offset = irq_id_to_offset(ctx, irq->id); + + mutex_unlock(&ctx->irq_lock); + return 0; + +err_alloc: + ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq); +err_idr: + idr_remove(&ctx->irq_idr, irq->id); +err_unlock: + mutex_unlock(&ctx->irq_lock); + kfree(irq); + return rc; +} + +static void afu_irq_free(struct afu_irq *irq, struct ocxl_context *ctx) +{ + if (ctx->mapping) + unmap_mapping_range(ctx->mapping, + irq_id_to_offset(ctx, irq->id), + 1 << PAGE_SHIFT, 1); + release_afu_irq(irq); + if (irq->ev_ctx) + eventfd_ctx_put(irq->ev_ctx); + ocxl_link_free_irq(ctx->afu->fn->link, irq->hw_irq); + kfree(irq); +} + +int ocxl_afu_irq_free(struct ocxl_context *ctx, u64 irq_offset) +{ + struct afu_irq *irq; + int id = irq_offset_to_id(ctx, irq_offset); + + mutex_lock(&ctx->irq_lock); + + irq = idr_find(&ctx->irq_idr, id); + if (!irq) { + mutex_unlock(&ctx->irq_lock); + return -EINVAL; + } + idr_remove(&ctx->irq_idr, irq->id); + afu_irq_free(irq, ctx); + mutex_unlock(&ctx->irq_lock); + return 0; +} + +void ocxl_afu_irq_free_all(struct ocxl_context *ctx) +{ + struct afu_irq *irq; + int id; + + mutex_lock(&ctx->irq_lock); + idr_for_each_entry(&ctx->irq_idr, irq, id) + afu_irq_free(irq, ctx); + mutex_unlock(&ctx->irq_lock); +} + +int ocxl_afu_irq_set_fd(struct ocxl_context *ctx, u64 irq_offset, int eventfd) +{ + struct afu_irq *irq; + struct eventfd_ctx *ev_ctx; + int rc = 0, id = irq_offset_to_id(ctx, irq_offset); + + mutex_lock(&ctx->irq_lock); + irq = idr_find(&ctx->irq_idr, id); + if (!irq) { + rc = -EINVAL; + goto unlock; + } + + ev_ctx = eventfd_ctx_fdget(eventfd); + if (IS_ERR(ev_ctx)) { + rc = -EINVAL; + goto unlock; + } + + irq->ev_ctx = ev_ctx; +unlock: + mutex_unlock(&ctx->irq_lock); + return rc; +} + +u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, u64 irq_offset) +{ + struct afu_irq *irq; + int id = irq_offset_to_id(ctx, irq_offset); + u64 addr = 0; + + mutex_lock(&ctx->irq_lock); + irq = idr_find(&ctx->irq_idr, id); + if (irq) + addr = irq->trigger_page; + mutex_unlock(&ctx->irq_lock); + return addr; +} diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c index b34b836f924c..269149490063 100644 --- a/drivers/misc/ocxl/context.c +++ b/drivers/misc/ocxl/context.c @@ -31,6 +31,8 @@ int ocxl_context_init(struct ocxl_context *ctx, struct ocxl_afu *afu, mutex_init(&ctx->mapping_lock); init_waitqueue_head(&ctx->events_wq); mutex_init(&ctx->xsl_error_lock); + mutex_init(&ctx->irq_lock); + idr_init(&ctx->irq_idr); /* * Keep a reference on the AFU to make sure it's valid for the * duration of the life of the context @@ -80,6 +82,19 @@ out: return rc; } +static int map_afu_irq(struct vm_area_struct *vma, unsigned long address, + u64 offset, struct ocxl_context *ctx) +{ + u64 trigger_addr; + + trigger_addr = ocxl_afu_irq_get_addr(ctx, offset); + if (!trigger_addr) + return VM_FAULT_SIGBUS; + + vm_insert_pfn(vma, address, trigger_addr >> PAGE_SHIFT); + return VM_FAULT_NOPAGE; +} + static int map_pp_mmio(struct vm_area_struct *vma, unsigned long address, u64 offset, struct ocxl_context *ctx) { @@ -118,7 +133,10 @@ static int ocxl_mmap_fault(struct vm_fault *vmf) pr_debug("%s: pasid %d address 0x%lx offset 0x%llx\n", __func__, ctx->pasid, vmf->address, offset); - rc = map_pp_mmio(vma, vmf->address, offset, ctx); + if (offset < ctx->afu->irq_base_offset) + rc = map_pp_mmio(vma, vmf->address, offset, ctx); + else + rc = map_afu_irq(vma, vmf->address, offset, ctx); return rc; } @@ -126,6 +144,30 @@ static const struct vm_operations_struct ocxl_vmops = { .fault = ocxl_mmap_fault, }; +static int check_mmap_afu_irq(struct ocxl_context *ctx, + struct vm_area_struct *vma) +{ + /* only one page */ + if (vma_pages(vma) != 1) + return -EINVAL; + + /* check offset validty */ + if (!ocxl_afu_irq_get_addr(ctx, vma->vm_pgoff << PAGE_SHIFT)) + return -EINVAL; + + /* + * trigger page should only be accessible in write mode. + * + * It's a bit theoretical, as a page mmaped with only + * PROT_WRITE is currently readable, but it doesn't hurt. + */ + if ((vma->vm_flags & VM_READ) || (vma->vm_flags & VM_EXEC) || + !(vma->vm_flags & VM_WRITE)) + return -EINVAL; + vma->vm_flags &= ~(VM_MAYREAD | VM_MAYEXEC); + return 0; +} + static int check_mmap_mmio(struct ocxl_context *ctx, struct vm_area_struct *vma) { @@ -139,7 +181,10 @@ int ocxl_context_mmap(struct ocxl_context *ctx, struct vm_area_struct *vma) { int rc; - rc = check_mmap_mmio(ctx, vma); + if ((vma->vm_pgoff << PAGE_SHIFT) < ctx->afu->irq_base_offset) + rc = check_mmap_mmio(ctx, vma); + else + rc = check_mmap_afu_irq(ctx, vma); if (rc) return rc; @@ -224,6 +269,8 @@ void ocxl_context_free(struct ocxl_context *ctx) idr_remove(&ctx->afu->contexts_idr, ctx->pasid); mutex_unlock(&ctx->afu->contexts_lock); + ocxl_afu_irq_free_all(ctx); + idr_destroy(&ctx->irq_idr); /* reference to the AFU taken in ocxl_context_init */ ocxl_afu_put(ctx->afu); kfree(ctx); diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c index 6f0befda6a8a..c90c1a578d2f 100644 --- a/drivers/misc/ocxl/file.c +++ b/drivers/misc/ocxl/file.c @@ -103,12 +103,17 @@ static long afu_ioctl_attach(struct ocxl_context *ctx, } #define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" : \ + x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" : \ + x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" : \ + x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" : \ "UNKNOWN") static long afu_ioctl(struct file *file, unsigned int cmd, unsigned long args) { struct ocxl_context *ctx = file->private_data; + struct ocxl_ioctl_irq_fd irq_fd; + u64 irq_offset; long rc; pr_debug("%s for context %d, command %s\n", __func__, ctx->pasid, @@ -123,6 +128,35 @@ static long afu_ioctl(struct file *file, unsigned int cmd, (struct ocxl_ioctl_attach __user *) args); break; + case OCXL_IOCTL_IRQ_ALLOC: + rc = ocxl_afu_irq_alloc(ctx, &irq_offset); + if (!rc) { + rc = copy_to_user((u64 __user *) args, &irq_offset, + sizeof(irq_offset)); + if (rc) + ocxl_afu_irq_free(ctx, irq_offset); + } + break; + + case OCXL_IOCTL_IRQ_FREE: + rc = copy_from_user(&irq_offset, (u64 __user *) args, + sizeof(irq_offset)); + if (rc) + return -EFAULT; + rc = ocxl_afu_irq_free(ctx, irq_offset); + break; + + case OCXL_IOCTL_IRQ_SET_FD: + rc = copy_from_user(&irq_fd, (u64 __user *) args, + sizeof(irq_fd)); + if (rc) + return -EFAULT; + if (irq_fd.reserved) + return -EINVAL; + rc = ocxl_afu_irq_set_fd(ctx, irq_fd.irq_offset, + irq_fd.eventfd); + break; + default: rc = -EINVAL; } diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c index 64d7a98c904a..8bdcef9c3cba 100644 --- a/drivers/misc/ocxl/link.c +++ b/drivers/misc/ocxl/link.c @@ -601,3 +601,31 @@ unlock: mutex_unlock(&spa->spa_lock); return rc; } + +int ocxl_link_irq_alloc(void *link_handle, int *hw_irq, u64 *trigger_addr) +{ + struct link *link = (struct link *) link_handle; + int rc, irq; + u64 addr; + + if (atomic_dec_if_positive(&link->irq_available) < 0) + return -ENOSPC; + + rc = pnv_ocxl_alloc_xive_irq(&irq, &addr); + if (rc) { + atomic_inc(&link->irq_available); + return rc; + } + + *hw_irq = irq; + *trigger_addr = addr; + return 0; +} + +void ocxl_link_free_irq(void *link_handle, int hw_irq) +{ + struct link *link = (struct link *) link_handle; + + pnv_ocxl_free_xive_irq(hw_irq); + atomic_inc(&link->irq_available); +} diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h index 04fc160c7bd5..a89b88ac67eb 100644 --- a/drivers/misc/ocxl/ocxl_internal.h +++ b/drivers/misc/ocxl/ocxl_internal.h @@ -190,4 +190,11 @@ extern void ocxl_context_free(struct ocxl_context *ctx); extern int ocxl_sysfs_add_afu(struct ocxl_afu *afu); extern void ocxl_sysfs_remove_afu(struct ocxl_afu *afu); +extern int ocxl_afu_irq_alloc(struct ocxl_context *ctx, u64 *irq_offset); +extern int ocxl_afu_irq_free(struct ocxl_context *ctx, u64 irq_offset); +extern void ocxl_afu_irq_free_all(struct ocxl_context *ctx); +extern int ocxl_afu_irq_set_fd(struct ocxl_context *ctx, u64 irq_offset, + int eventfd); +extern u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, u64 irq_offset); + #endif /* _OCXL_INTERNAL_H_ */ diff --git a/include/uapi/misc/ocxl.h b/include/uapi/misc/ocxl.h index a37e34edf52f..4b0b0b756f3e 100644 --- a/include/uapi/misc/ocxl.h +++ b/include/uapi/misc/ocxl.h @@ -32,9 +32,18 @@ struct ocxl_ioctl_attach { __u64 reserved3; }; +struct ocxl_ioctl_irq_fd { + __u64 irq_offset; + __s32 eventfd; + __u32 reserved; +}; + /* ioctl numbers */ #define OCXL_MAGIC 0xCA /* AFU devices */ #define OCXL_IOCTL_ATTACH _IOW(OCXL_MAGIC, 0x10, struct ocxl_ioctl_attach) +#define OCXL_IOCTL_IRQ_ALLOC _IOR(OCXL_MAGIC, 0x11, __u64) +#define OCXL_IOCTL_IRQ_FREE _IOW(OCXL_MAGIC, 0x12, __u64) +#define OCXL_IOCTL_IRQ_SET_FD _IOW(OCXL_MAGIC, 0x13, struct ocxl_ioctl_irq_fd) #endif /* _UAPI_MISC_OCXL_H */ -- 2.39.5