From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/misc/ocxl/context.c | 296 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 296 insertions(+) create mode 100644 drivers/misc/ocxl/context.c (limited to 'drivers/misc/ocxl/context.c') diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c new file mode 100644 index 000000000..9eb0d93b0 --- /dev/null +++ b/drivers/misc/ocxl/context.c @@ -0,0 +1,296 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright 2017 IBM Corp. +#include +#include "trace.h" +#include "ocxl_internal.h" + +int ocxl_context_alloc(struct ocxl_context **context, struct ocxl_afu *afu, + struct address_space *mapping) +{ + int pasid; + struct ocxl_context *ctx; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + ctx->afu = afu; + mutex_lock(&afu->contexts_lock); + pasid = idr_alloc(&afu->contexts_idr, ctx, afu->pasid_base, + afu->pasid_base + afu->pasid_max, GFP_KERNEL); + if (pasid < 0) { + mutex_unlock(&afu->contexts_lock); + kfree(ctx); + return pasid; + } + afu->pasid_count++; + mutex_unlock(&afu->contexts_lock); + + ctx->pasid = pasid; + ctx->status = OPENED; + mutex_init(&ctx->status_mutex); + ctx->mapping = mapping; + 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); + ctx->tidr = 0; + + /* + * Keep a reference on the AFU to make sure it's valid for the + * duration of the life of the context + */ + ocxl_afu_get(afu); + *context = ctx; + return 0; +} +EXPORT_SYMBOL_GPL(ocxl_context_alloc); + +/* + * Callback for when a translation fault triggers an error + * data: a pointer to the context which triggered the fault + * addr: the address that triggered the error + * dsisr: the value of the PPC64 dsisr register + */ +static void xsl_fault_error(void *data, u64 addr, u64 dsisr) +{ + struct ocxl_context *ctx = (struct ocxl_context *) data; + + mutex_lock(&ctx->xsl_error_lock); + ctx->xsl_error.addr = addr; + ctx->xsl_error.dsisr = dsisr; + ctx->xsl_error.count++; + mutex_unlock(&ctx->xsl_error_lock); + + wake_up_all(&ctx->events_wq); +} + +int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm) +{ + int rc; + unsigned long pidr = 0; + struct pci_dev *dev; + + // Locks both status & tidr + mutex_lock(&ctx->status_mutex); + if (ctx->status != OPENED) { + rc = -EIO; + goto out; + } + + if (mm) + pidr = mm->context.id; + + dev = to_pci_dev(ctx->afu->fn->dev.parent); + rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, pidr, ctx->tidr, + amr, pci_dev_id(dev), mm, xsl_fault_error, ctx); + if (rc) + goto out; + + ctx->status = ATTACHED; +out: + mutex_unlock(&ctx->status_mutex); + return rc; +} +EXPORT_SYMBOL_GPL(ocxl_context_attach); + +static vm_fault_t map_afu_irq(struct vm_area_struct *vma, unsigned long address, + u64 offset, struct ocxl_context *ctx) +{ + u64 trigger_addr; + int irq_id = ocxl_irq_offset_to_id(ctx, offset); + + trigger_addr = ocxl_afu_irq_get_addr(ctx, irq_id); + if (!trigger_addr) + return VM_FAULT_SIGBUS; + + return vmf_insert_pfn(vma, address, trigger_addr >> PAGE_SHIFT); +} + +static vm_fault_t map_pp_mmio(struct vm_area_struct *vma, unsigned long address, + u64 offset, struct ocxl_context *ctx) +{ + u64 pp_mmio_addr; + int pasid_off; + vm_fault_t ret; + + if (offset >= ctx->afu->config.pp_mmio_stride) + return VM_FAULT_SIGBUS; + + mutex_lock(&ctx->status_mutex); + if (ctx->status != ATTACHED) { + mutex_unlock(&ctx->status_mutex); + pr_debug("%s: Context not attached, failing mmio mmap\n", + __func__); + return VM_FAULT_SIGBUS; + } + + pasid_off = ctx->pasid - ctx->afu->pasid_base; + pp_mmio_addr = ctx->afu->pp_mmio_start + + pasid_off * ctx->afu->config.pp_mmio_stride + + offset; + + ret = vmf_insert_pfn(vma, address, pp_mmio_addr >> PAGE_SHIFT); + mutex_unlock(&ctx->status_mutex); + return ret; +} + +static vm_fault_t ocxl_mmap_fault(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + struct ocxl_context *ctx = vma->vm_file->private_data; + u64 offset; + vm_fault_t ret; + + offset = vmf->pgoff << PAGE_SHIFT; + pr_debug("%s: pasid %d address 0x%lx offset 0x%llx\n", __func__, + ctx->pasid, vmf->address, offset); + + if (offset < ctx->afu->irq_base_offset) + ret = map_pp_mmio(vma, vmf->address, offset, ctx); + else + ret = map_afu_irq(vma, vmf->address, offset, ctx); + return ret; +} + +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) +{ + int irq_id = ocxl_irq_offset_to_id(ctx, vma->vm_pgoff << PAGE_SHIFT); + + /* only one page */ + if (vma_pages(vma) != 1) + return -EINVAL; + + /* check offset validty */ + if (!ocxl_afu_irq_get_addr(ctx, irq_id)) + 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) +{ + if ((vma_pages(vma) + vma->vm_pgoff) > + (ctx->afu->config.pp_mmio_stride >> PAGE_SHIFT)) + return -EINVAL; + return 0; +} + +int ocxl_context_mmap(struct ocxl_context *ctx, struct vm_area_struct *vma) +{ + int rc; + + 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; + + vma->vm_flags |= VM_IO | VM_PFNMAP; + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + vma->vm_ops = &ocxl_vmops; + return 0; +} + +int ocxl_context_detach(struct ocxl_context *ctx) +{ + struct pci_dev *dev; + int afu_control_pos; + enum ocxl_context_status status; + int rc; + + mutex_lock(&ctx->status_mutex); + status = ctx->status; + ctx->status = CLOSED; + mutex_unlock(&ctx->status_mutex); + if (status != ATTACHED) + return 0; + + dev = to_pci_dev(ctx->afu->fn->dev.parent); + afu_control_pos = ctx->afu->config.dvsec_afu_control_pos; + + mutex_lock(&ctx->afu->afu_control_lock); + rc = ocxl_config_terminate_pasid(dev, afu_control_pos, ctx->pasid); + mutex_unlock(&ctx->afu->afu_control_lock); + trace_ocxl_terminate_pasid(ctx->pasid, rc); + if (rc) { + /* + * If we timeout waiting for the AFU to terminate the + * pasid, then it's dangerous to clean up the Process + * Element entry in the SPA, as it may be referenced + * in the future by the AFU. In which case, we would + * checkstop because of an invalid PE access (FIR + * register 2, bit 42). So leave the PE + * defined. Caller shouldn't free the context so that + * PASID remains allocated. + * + * A link reset will be required to cleanup the AFU + * and the SPA. + */ + if (rc == -EBUSY) + return rc; + } + rc = ocxl_link_remove_pe(ctx->afu->fn->link, ctx->pasid); + if (rc) { + dev_warn(&dev->dev, + "Couldn't remove PE entry cleanly: %d\n", rc); + } + return 0; +} +EXPORT_SYMBOL_GPL(ocxl_context_detach); + +void ocxl_context_detach_all(struct ocxl_afu *afu) +{ + struct ocxl_context *ctx; + int tmp; + + mutex_lock(&afu->contexts_lock); + idr_for_each_entry(&afu->contexts_idr, ctx, tmp) { + ocxl_context_detach(ctx); + /* + * We are force detaching - remove any active mmio + * mappings so userspace cannot interfere with the + * card if it comes back. Easiest way to exercise + * this is to unbind and rebind the driver via sysfs + * while it is in use. + */ + mutex_lock(&ctx->mapping_lock); + if (ctx->mapping) + unmap_mapping_range(ctx->mapping, 0, 0, 1); + mutex_unlock(&ctx->mapping_lock); + } + mutex_unlock(&afu->contexts_lock); +} + +void ocxl_context_free(struct ocxl_context *ctx) +{ + mutex_lock(&ctx->afu->contexts_lock); + ctx->afu->pasid_count--; + 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_alloc() */ + ocxl_afu_put(ctx->afu); + kfree(ctx); +} +EXPORT_SYMBOL_GPL(ocxl_context_free); -- cgit v1.2.3