| /* |
| * Copyright 2014 IBM Corp. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/bitmap.h> |
| #include <linux/sched.h> |
| #include <linux/pid.h> |
| #include <linux/fs.h> |
| #include <linux/mm.h> |
| #include <linux/debugfs.h> |
| #include <linux/slab.h> |
| #include <linux/idr.h> |
| #include <asm/cputable.h> |
| #include <asm/current.h> |
| #include <asm/copro.h> |
| |
| #include "cxl.h" |
| |
| /* |
| * Allocates space for a CXL context. |
| */ |
| struct cxl_context *cxl_context_alloc(void) |
| { |
| return kzalloc(sizeof(struct cxl_context), GFP_KERNEL); |
| } |
| |
| /* |
| * Initialises a CXL context. |
| */ |
| int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, |
| struct address_space *mapping) |
| { |
| int i; |
| |
| spin_lock_init(&ctx->sste_lock); |
| ctx->afu = afu; |
| ctx->master = master; |
| ctx->pid = NULL; /* Set in start work ioctl */ |
| mutex_init(&ctx->mapping_lock); |
| ctx->mapping = mapping; |
| |
| /* |
| * Allocate the segment table before we put it in the IDR so that we |
| * can always access it when dereferenced from IDR. For the same |
| * reason, the segment table is only destroyed after the context is |
| * removed from the IDR. Access to this in the IOCTL is protected by |
| * Linux filesytem symantics (can't IOCTL until open is complete). |
| */ |
| i = cxl_alloc_sst(ctx); |
| if (i) |
| return i; |
| |
| INIT_WORK(&ctx->fault_work, cxl_handle_fault); |
| |
| init_waitqueue_head(&ctx->wq); |
| spin_lock_init(&ctx->lock); |
| |
| ctx->irq_bitmap = NULL; |
| ctx->pending_irq = false; |
| ctx->pending_fault = false; |
| ctx->pending_afu_err = false; |
| |
| /* |
| * When we have to destroy all contexts in cxl_context_detach_all() we |
| * end up with afu_release_irqs() called from inside a |
| * idr_for_each_entry(). Hence we need to make sure that anything |
| * dereferenced from this IDR is ok before we allocate the IDR here. |
| * This clears out the IRQ ranges to ensure this. |
| */ |
| for (i = 0; i < CXL_IRQ_RANGES; i++) |
| ctx->irqs.range[i] = 0; |
| |
| mutex_init(&ctx->status_mutex); |
| |
| ctx->status = OPENED; |
| |
| /* |
| * Allocating IDR! We better make sure everything's setup that |
| * dereferences from it. |
| */ |
| mutex_lock(&afu->contexts_lock); |
| idr_preload(GFP_KERNEL); |
| i = idr_alloc(&ctx->afu->contexts_idr, ctx, 0, |
| ctx->afu->num_procs, GFP_NOWAIT); |
| idr_preload_end(); |
| mutex_unlock(&afu->contexts_lock); |
| if (i < 0) |
| return i; |
| |
| ctx->pe = i; |
| ctx->elem = &ctx->afu->spa[i]; |
| ctx->pe_inserted = false; |
| return 0; |
| } |
| |
| static int cxl_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
| { |
| struct cxl_context *ctx = vma->vm_file->private_data; |
| unsigned long address = (unsigned long)vmf->virtual_address; |
| u64 area, offset; |
| |
| offset = vmf->pgoff << PAGE_SHIFT; |
| |
| pr_devel("%s: pe: %i address: 0x%lx offset: 0x%llx\n", |
| __func__, ctx->pe, address, offset); |
| |
| if (ctx->afu->current_mode == CXL_MODE_DEDICATED) { |
| area = ctx->afu->psn_phys; |
| if (offset >= ctx->afu->adapter->ps_size) |
| return VM_FAULT_SIGBUS; |
| } else { |
| area = ctx->psn_phys; |
| if (offset >= ctx->psn_size) |
| return VM_FAULT_SIGBUS; |
| } |
| |
| mutex_lock(&ctx->status_mutex); |
| |
| if (ctx->status != STARTED) { |
| mutex_unlock(&ctx->status_mutex); |
| pr_devel("%s: Context not started, failing problem state access\n", __func__); |
| return VM_FAULT_SIGBUS; |
| } |
| |
| vm_insert_pfn(vma, address, (area + offset) >> PAGE_SHIFT); |
| |
| mutex_unlock(&ctx->status_mutex); |
| |
| return VM_FAULT_NOPAGE; |
| } |
| |
| static const struct vm_operations_struct cxl_mmap_vmops = { |
| .fault = cxl_mmap_fault, |
| }; |
| |
| /* |
| * Map a per-context mmio space into the given vma. |
| */ |
| int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma) |
| { |
| u64 len = vma->vm_end - vma->vm_start; |
| len = min(len, ctx->psn_size); |
| |
| if (ctx->afu->current_mode != CXL_MODE_DEDICATED) { |
| /* make sure there is a valid per process space for this AFU */ |
| if ((ctx->master && !ctx->afu->psa) || (!ctx->afu->pp_psa)) { |
| pr_devel("AFU doesn't support mmio space\n"); |
| return -EINVAL; |
| } |
| |
| /* Can't mmap until the AFU is enabled */ |
| if (!ctx->afu->enabled) |
| return -EBUSY; |
| } |
| |
| pr_devel("%s: mmio physical: %llx pe: %i master:%i\n", __func__, |
| ctx->psn_phys, ctx->pe , ctx->master); |
| |
| vma->vm_flags |= VM_IO | VM_PFNMAP; |
| vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
| vma->vm_ops = &cxl_mmap_vmops; |
| return 0; |
| } |
| |
| /* |
| * Detach a context from the hardware. This disables interrupts and doesn't |
| * return until all outstanding interrupts for this context have completed. The |
| * hardware should no longer access *ctx after this has returned. |
| */ |
| static void __detach_context(struct cxl_context *ctx) |
| { |
| enum cxl_context_status status; |
| |
| mutex_lock(&ctx->status_mutex); |
| status = ctx->status; |
| ctx->status = CLOSED; |
| mutex_unlock(&ctx->status_mutex); |
| if (status != STARTED) |
| return; |
| |
| WARN_ON(cxl_detach_process(ctx)); |
| afu_release_irqs(ctx); |
| flush_work(&ctx->fault_work); /* Only needed for dedicated process */ |
| wake_up_all(&ctx->wq); |
| } |
| |
| /* |
| * Detach the given context from the AFU. This doesn't actually |
| * free the context but it should stop the context running in hardware |
| * (ie. prevent this context from generating any further interrupts |
| * so that it can be freed). |
| */ |
| void cxl_context_detach(struct cxl_context *ctx) |
| { |
| __detach_context(ctx); |
| } |
| |
| /* |
| * Detach all contexts on the given AFU. |
| */ |
| void cxl_context_detach_all(struct cxl_afu *afu) |
| { |
| struct cxl_context *ctx; |
| int tmp; |
| |
| mutex_lock(&afu->contexts_lock); |
| idr_for_each_entry(&afu->contexts_idr, ctx, tmp) { |
| /* |
| * Anything done in here needs to be setup before the IDR is |
| * created and torn down after the IDR removed |
| */ |
| __detach_context(ctx); |
| |
| /* |
| * We are force detaching - remove any active PSA 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 cxl_context_free(struct cxl_context *ctx) |
| { |
| mutex_lock(&ctx->afu->contexts_lock); |
| idr_remove(&ctx->afu->contexts_idr, ctx->pe); |
| mutex_unlock(&ctx->afu->contexts_lock); |
| synchronize_rcu(); |
| |
| free_page((u64)ctx->sstp); |
| ctx->sstp = NULL; |
| |
| put_pid(ctx->pid); |
| kfree(ctx); |
| } |