1 /* 2 * Copyright 2014 IBM Corp. 3 * 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. 8 */ 9 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> 15 #include <linux/fs.h> 16 #include <linux/mm.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> 23 24 #include "cxl.h" 25 26 /* 27 * Allocates space for a CXL context. 28 */ 29 struct cxl_context *cxl_context_alloc(void) 30 { 31 return kzalloc(sizeof(struct cxl_context), GFP_KERNEL); 32 } 33 34 /* 35 * Initialises a CXL context. 36 */ 37 int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, 38 struct address_space *mapping) 39 { 40 int i; 41 42 spin_lock_init(&ctx->sste_lock); 43 ctx->afu = afu; 44 ctx->master = master; 45 ctx->pid = NULL; /* Set in start work ioctl */ 46 mutex_init(&ctx->mapping_lock); 47 ctx->mapping = mapping; 48 49 /* 50 * Allocate the segment table before we put it in the IDR so that we 51 * can always access it when dereferenced from IDR. For the same 52 * reason, the segment table is only destroyed after the context is 53 * removed from the IDR. Access to this in the IOCTL is protected by 54 * Linux filesytem symantics (can't IOCTL until open is complete). 55 */ 56 i = cxl_alloc_sst(ctx); 57 if (i) 58 return i; 59 60 INIT_WORK(&ctx->fault_work, cxl_handle_fault); 61 62 init_waitqueue_head(&ctx->wq); 63 spin_lock_init(&ctx->lock); 64 65 ctx->irq_bitmap = NULL; 66 ctx->pending_irq = false; 67 ctx->pending_fault = false; 68 ctx->pending_afu_err = false; 69 70 /* 71 * When we have to destroy all contexts in cxl_context_detach_all() we 72 * end up with afu_release_irqs() called from inside a 73 * idr_for_each_entry(). Hence we need to make sure that anything 74 * dereferenced from this IDR is ok before we allocate the IDR here. 75 * This clears out the IRQ ranges to ensure this. 76 */ 77 for (i = 0; i < CXL_IRQ_RANGES; i++) 78 ctx->irqs.range[i] = 0; 79 80 mutex_init(&ctx->status_mutex); 81 82 ctx->status = OPENED; 83 84 /* 85 * Allocating IDR! We better make sure everything's setup that 86 * dereferences from it. 87 */ 88 mutex_lock(&afu->contexts_lock); 89 idr_preload(GFP_KERNEL); 90 i = idr_alloc(&ctx->afu->contexts_idr, ctx, 0, 91 ctx->afu->num_procs, GFP_NOWAIT); 92 idr_preload_end(); 93 mutex_unlock(&afu->contexts_lock); 94 if (i < 0) 95 return i; 96 97 ctx->pe = i; 98 ctx->elem = &ctx->afu->spa[i]; 99 ctx->pe_inserted = false; 100 return 0; 101 } 102 103 /* 104 * Map a per-context mmio space into the given vma. 105 */ 106 int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma) 107 { 108 u64 len = vma->vm_end - vma->vm_start; 109 len = min(len, ctx->psn_size); 110 111 if (ctx->afu->current_mode == CXL_MODE_DEDICATED) { 112 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 113 return vm_iomap_memory(vma, ctx->afu->psn_phys, ctx->afu->adapter->ps_size); 114 } 115 116 /* make sure there is a valid per process space for this AFU */ 117 if ((ctx->master && !ctx->afu->psa) || (!ctx->afu->pp_psa)) { 118 pr_devel("AFU doesn't support mmio space\n"); 119 return -EINVAL; 120 } 121 122 /* Can't mmap until the AFU is enabled */ 123 if (!ctx->afu->enabled) 124 return -EBUSY; 125 126 pr_devel("%s: mmio physical: %llx pe: %i master:%i\n", __func__, 127 ctx->psn_phys, ctx->pe , ctx->master); 128 129 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 130 return vm_iomap_memory(vma, ctx->psn_phys, len); 131 } 132 133 /* 134 * Detach a context from the hardware. This disables interrupts and doesn't 135 * return until all outstanding interrupts for this context have completed. The 136 * hardware should no longer access *ctx after this has returned. 137 */ 138 static void __detach_context(struct cxl_context *ctx) 139 { 140 enum cxl_context_status status; 141 142 mutex_lock(&ctx->status_mutex); 143 status = ctx->status; 144 ctx->status = CLOSED; 145 mutex_unlock(&ctx->status_mutex); 146 if (status != STARTED) 147 return; 148 149 WARN_ON(cxl_detach_process(ctx)); 150 afu_release_irqs(ctx); 151 flush_work(&ctx->fault_work); /* Only needed for dedicated process */ 152 wake_up_all(&ctx->wq); 153 154 /* Release Problem State Area mapping */ 155 mutex_lock(&ctx->mapping_lock); 156 if (ctx->mapping) 157 unmap_mapping_range(ctx->mapping, 0, 0, 1); 158 mutex_unlock(&ctx->mapping_lock); 159 } 160 161 /* 162 * Detach the given context from the AFU. This doesn't actually 163 * free the context but it should stop the context running in hardware 164 * (ie. prevent this context from generating any further interrupts 165 * so that it can be freed). 166 */ 167 void cxl_context_detach(struct cxl_context *ctx) 168 { 169 __detach_context(ctx); 170 } 171 172 /* 173 * Detach all contexts on the given AFU. 174 */ 175 void cxl_context_detach_all(struct cxl_afu *afu) 176 { 177 struct cxl_context *ctx; 178 int tmp; 179 180 mutex_lock(&afu->contexts_lock); 181 idr_for_each_entry(&afu->contexts_idr, ctx, tmp) { 182 /* 183 * Anything done in here needs to be setup before the IDR is 184 * created and torn down after the IDR removed 185 */ 186 __detach_context(ctx); 187 } 188 mutex_unlock(&afu->contexts_lock); 189 } 190 191 void cxl_context_free(struct cxl_context *ctx) 192 { 193 mutex_lock(&ctx->afu->contexts_lock); 194 idr_remove(&ctx->afu->contexts_idr, ctx->pe); 195 mutex_unlock(&ctx->afu->contexts_lock); 196 synchronize_rcu(); 197 198 free_page((u64)ctx->sstp); 199 ctx->sstp = NULL; 200 201 put_pid(ctx->pid); 202 kfree(ctx); 203 } 204