drivers/misc/cxl/main.c

   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/spinlock.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/device.h>
  14 #include <linux/mutex.h>
  15 #include <linux/init.h>
  16 #include <linux/list.h>
  17 #include <linux/mm.h>
  18 #include <linux/of.h>
  19 #include <linux/slab.h>
  20 #include <linux/idr.h>
  21 #include <linux/pci.h>
  22 #include <asm/cputable.h>
  23 #include <misc/cxl.h>
  24
  25 #include "cxl.h"
  26 #include "trace.h"
  27
  28 static DEFINE_SPINLOCK(adapter_idr_lock);
  29 static DEFINE_IDR(cxl_adapter_idr);
  30
  31 uint cxl_verbose;
  32 module_param_named(verbose, cxl_verbose, uint, 0600);
  33 MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
  34
  35 static inline void _cxl_slbia(struct cxl_context *ctx, struct mm_struct *mm)
  36 {
  37         struct task_struct *task;
  38         unsigned long flags;
  39         if (!(task = get_pid_task(ctx->pid, PIDTYPE_PID))) {
  40                 pr_devel("%s unable to get task %i\n",
  41                          __func__, pid_nr(ctx->pid));
  42                 return;
  43         }
  44
  45         if (task->mm != mm)
  46                 goto out_put;
  47
  48         pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__,
  49                  ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe);
  50
  51         spin_lock_irqsave(&ctx->sste_lock, flags);
  52         trace_cxl_slbia(ctx);
  53         memset(ctx->sstp, 0, ctx->sst_size);
  54         spin_unlock_irqrestore(&ctx->sste_lock, flags);
  55         mb();
  56         cxl_afu_slbia(ctx->afu);
  57 out_put:
  58         put_task_struct(task);
  59 }
  60
  61 static inline void cxl_slbia_core(struct mm_struct *mm)
  62 {
  63         struct cxl *adapter;
  64         struct cxl_afu *afu;
  65         struct cxl_context *ctx;
  66         int card, slice, id;
  67
  68         pr_devel("%s called\n", __func__);
  69
  70         spin_lock(&adapter_idr_lock);
  71         idr_for_each_entry(&cxl_adapter_idr, adapter, card) {
  72                 /* XXX: Make this lookup faster with link from mm to ctx */
  73                 spin_lock(&adapter->afu_list_lock);
  74                 for (slice = 0; slice < adapter->slices; slice++) {
  75                         afu = adapter->afu[slice];
  76                         if (!afu || !afu->enabled)
  77                                 continue;
  78                         rcu_read_lock();
  79                         idr_for_each_entry(&afu->contexts_idr, ctx, id)
  80                                 _cxl_slbia(ctx, mm);
  81                         rcu_read_unlock();
  82                 }
  83                 spin_unlock(&adapter->afu_list_lock);
  84         }
  85         spin_unlock(&adapter_idr_lock);
  86 }
  87
  88 static struct cxl_calls cxl_calls = {
  89         .cxl_slbia = cxl_slbia_core,
  90         .owner = THIS_MODULE,
  91 };
  92
  93 int cxl_alloc_sst(struct cxl_context *ctx)
  94 {
  95         unsigned long vsid;
  96         u64 ea_mask, size, sstp0, sstp1;
  97
  98         sstp0 = 0;
  99         sstp1 = 0;
 100
 101         ctx->sst_size = PAGE_SIZE;
 102         ctx->sst_lru = 0;
 103         ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL);
 104         if (!ctx->sstp) {
 105                 pr_err("cxl_alloc_sst: Unable to allocate segment table\n");
 106                 return -ENOMEM;
 107         }
 108         pr_devel("SSTP allocated at 0x%p\n", ctx->sstp);
 109
 110         vsid  = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12;
 111
 112         sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT;
 113         sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50;
 114
 115         size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT;
 116         if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) {
 117                 WARN(1, "Impossible segment table size\n");
 118                 return -EINVAL;
 119         }
 120         sstp0 |= size;
 121
 122         if (mmu_kernel_ssize == MMU_SEGSIZE_256M)
 123                 ea_mask = 0xfffff00ULL;
 124         else
 125                 ea_mask = 0xffffffff00ULL;
 126
 127         sstp0 |=  vsid >>     (50-14);  /*   Top 14 bits of VSID */
 128         sstp1 |= (vsid << (64-(50-14))) & ~ea_mask;
 129         sstp1 |= (u64)ctx->sstp & ea_mask;
 130         sstp1 |= CXL_SSTP1_An_V;
 131
 132         pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n",
 133                         (u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1);
 134
 135         /* Store calculated sstp hardware points for use later */
 136         ctx->sstp0 = sstp0;
 137         ctx->sstp1 = sstp1;
 138
 139         return 0;
 140 }
 141
 142 /* Find a CXL adapter by it's number and increase it's refcount */
 143 struct cxl *get_cxl_adapter(int num)
 144 {
 145         struct cxl *adapter;
 146
 147         spin_lock(&adapter_idr_lock);
 148         if ((adapter = idr_find(&cxl_adapter_idr, num)))
 149                 get_device(&adapter->dev);
 150         spin_unlock(&adapter_idr_lock);
 151
 152         return adapter;
 153 }
 154
 155 int cxl_alloc_adapter_nr(struct cxl *adapter)
 156 {
 157         int i;
 158
 159         idr_preload(GFP_KERNEL);
 160         spin_lock(&adapter_idr_lock);
 161         i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT);
 162         spin_unlock(&adapter_idr_lock);
 163         idr_preload_end();
 164         if (i < 0)
 165                 return i;
 166
 167         adapter->adapter_num = i;
 168
 169         return 0;
 170 }
 171
 172 void cxl_remove_adapter_nr(struct cxl *adapter)
 173 {
 174         idr_remove(&cxl_adapter_idr, adapter->adapter_num);
 175 }
 176
 177 int cxl_afu_select_best_mode(struct cxl_afu *afu)
 178 {
 179         if (afu->modes_supported & CXL_MODE_DIRECTED)
 180                 return cxl_afu_activate_mode(afu, CXL_MODE_DIRECTED);
 181
 182         if (afu->modes_supported & CXL_MODE_DEDICATED)
 183                 return cxl_afu_activate_mode(afu, CXL_MODE_DEDICATED);
 184
 185         dev_warn(&afu->dev, "No supported programming modes available\n");
 186         /* We don't fail this so the user can inspect sysfs */
 187         return 0;
 188 }
 189
 190 static int __init init_cxl(void)
 191 {
 192         int rc = 0;
 193
 194         if (!cpu_has_feature(CPU_FTR_HVMODE))
 195                 return -EPERM;
 196
 197         if ((rc = cxl_file_init()))
 198                 return rc;
 199
 200         cxl_debugfs_init();
 201
 202         if ((rc = register_cxl_calls(&cxl_calls)))
 203                 goto err;
 204
 205         if ((rc = pci_register_driver(&cxl_pci_driver)))
 206                 goto err1;
 207
 208         return 0;
 209 err1:
 210         unregister_cxl_calls(&cxl_calls);
 211 err:
 212         cxl_debugfs_exit();
 213         cxl_file_exit();
 214
 215         return rc;
 216 }
 217
 218 static void exit_cxl(void)
 219 {
 220         pci_unregister_driver(&cxl_pci_driver);
 221
 222         cxl_debugfs_exit();
 223         cxl_file_exit();
 224         unregister_cxl_calls(&cxl_calls);
 225 }
 226
 227 module_init(init_cxl);
 228 module_exit(exit_cxl);
 229
 230 MODULE_DESCRIPTION("IBM Coherent Accelerator");
 231 MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>");
 232 MODULE_LICENSE("GPL");