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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/misc/ocxl/context.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/misc/ocxl/context.c')
| -rw-r--r-- | drivers/misc/ocxl/context.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c new file mode 100644 index 000000000..33f25be46 --- /dev/null +++ b/drivers/misc/ocxl/context.c @@ -0,0 +1,296 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright 2017 IBM Corp. +#include <linux/sched/mm.h> +#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_obj(*ctx); + 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 = 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; + vm_flags_clear(vma, 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; + + vm_flags_set(vma, 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); |
