2 * Copyright 2014 IBM Corp.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/bitmap.h>
13 #include <linux/sched.h>
14 #include <linux/pid.h>
17 #include <linux/debugfs.h>
18 #include <linux/slab.h>
19 #include <linux/idr.h>
20 #include <asm/cputable.h>
21 #include <asm/current.h>
22 #include <asm/copro.h>
27 * Allocates space for a CXL context.
29 struct cxl_context *cxl_context_alloc(void)
31 return kzalloc(sizeof(struct cxl_context), GFP_KERNEL);
35 * Initialises a CXL context.
37 int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master)
41 spin_lock_init(&ctx->sste_lock);
44 ctx->pid = NULL; /* Set in start work ioctl */
47 * Allocate the segment table before we put it in the IDR so that we
48 * can always access it when dereferenced from IDR. For the same
49 * reason, the segment table is only destroyed after the context is
50 * removed from the IDR. Access to this in the IOCTL is protected by
51 * Linux filesytem symantics (can't IOCTL until open is complete).
53 i = cxl_alloc_sst(ctx);
57 INIT_WORK(&ctx->fault_work, cxl_handle_fault);
59 init_waitqueue_head(&ctx->wq);
60 spin_lock_init(&ctx->lock);
62 ctx->irq_bitmap = NULL;
63 ctx->pending_irq = false;
64 ctx->pending_fault = false;
65 ctx->pending_afu_err = false;
68 * When we have to destroy all contexts in cxl_context_detach_all() we
69 * end up with afu_release_irqs() called from inside a
70 * idr_for_each_entry(). Hence we need to make sure that anything
71 * dereferenced from this IDR is ok before we allocate the IDR here.
72 * This clears out the IRQ ranges to ensure this.
74 for (i = 0; i < CXL_IRQ_RANGES; i++)
75 ctx->irqs.range[i] = 0;
77 mutex_init(&ctx->status_mutex);
82 * Allocating IDR! We better make sure everything's setup that
83 * dereferences from it.
85 idr_preload(GFP_KERNEL);
86 spin_lock(&afu->contexts_lock);
87 i = idr_alloc(&ctx->afu->contexts_idr, ctx, 0,
88 ctx->afu->num_procs, GFP_NOWAIT);
89 spin_unlock(&afu->contexts_lock);
95 ctx->elem = &ctx->afu->spa[i];
96 ctx->pe_inserted = false;
101 * Map a per-context mmio space into the given vma.
103 int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma)
105 u64 len = vma->vm_end - vma->vm_start;
106 len = min(len, ctx->psn_size);
108 if (ctx->afu->current_mode == CXL_MODE_DEDICATED) {
109 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
110 return vm_iomap_memory(vma, ctx->afu->psn_phys, ctx->afu->adapter->ps_size);
113 /* make sure there is a valid per process space for this AFU */
114 if ((ctx->master && !ctx->afu->psa) || (!ctx->afu->pp_psa)) {
115 pr_devel("AFU doesn't support mmio space\n");
119 /* Can't mmap until the AFU is enabled */
120 if (!ctx->afu->enabled)
123 pr_devel("%s: mmio physical: %llx pe: %i master:%i\n", __func__,
124 ctx->psn_phys, ctx->pe , ctx->master);
126 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
127 return vm_iomap_memory(vma, ctx->psn_phys, len);
131 * Detach a context from the hardware. This disables interrupts and doesn't
132 * return until all outstanding interrupts for this context have completed. The
133 * hardware should no longer access *ctx after this has returned.
135 static void __detach_context(struct cxl_context *ctx)
137 enum cxl_context_status status;
139 mutex_lock(&ctx->status_mutex);
140 status = ctx->status;
141 ctx->status = CLOSED;
142 mutex_unlock(&ctx->status_mutex);
143 if (status != STARTED)
146 WARN_ON(cxl_detach_process(ctx));
147 afu_release_irqs(ctx);
148 flush_work(&ctx->fault_work); /* Only needed for dedicated process */
149 wake_up_all(&ctx->wq);
153 * Detach the given context from the AFU. This doesn't actually
154 * free the context but it should stop the context running in hardware
155 * (ie. prevent this context from generating any further interrupts
156 * so that it can be freed).
158 void cxl_context_detach(struct cxl_context *ctx)
160 __detach_context(ctx);
164 * Detach all contexts on the given AFU.
166 void cxl_context_detach_all(struct cxl_afu *afu)
168 struct cxl_context *ctx;
172 idr_for_each_entry(&afu->contexts_idr, ctx, tmp)
174 * Anything done in here needs to be setup before the IDR is
175 * created and torn down after the IDR removed
177 __detach_context(ctx);
181 void cxl_context_free(struct cxl_context *ctx)
183 spin_lock(&ctx->afu->contexts_lock);
184 idr_remove(&ctx->afu->contexts_idr, ctx->pe);
185 spin_unlock(&ctx->afu->contexts_lock);
188 free_page((u64)ctx->sstp);