drivers/hwtracing/coresight/coresight-tmc-etr.c

   1 /*
   2  * Copyright(C) 2016 Linaro Limited. All rights reserved.
   3  * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/coresight.h>
  19 #include <linux/dma-mapping.h>
  20 #include "coresight-priv.h"
  21 #include "coresight-tmc.h"
  22
  23 void tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
  24 {
  25         u32 axictl;
  26
  27         /* Zero out the memory to help with debug */
  28         memset(drvdata->vaddr, 0, drvdata->size);
  29
  30         CS_UNLOCK(drvdata->base);
  31
  32         /* Wait for TMCSReady bit to be set */
  33         tmc_wait_for_tmcready(drvdata);
  34
  35         writel_relaxed(drvdata->size / 4, drvdata->base + TMC_RSZ);
  36         writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE);
  37
  38         axictl = readl_relaxed(drvdata->base + TMC_AXICTL);
  39         axictl |= TMC_AXICTL_WR_BURST_16;
  40         writel_relaxed(axictl, drvdata->base + TMC_AXICTL);
  41         axictl &= ~TMC_AXICTL_SCT_GAT_MODE;
  42         writel_relaxed(axictl, drvdata->base + TMC_AXICTL);
  43         axictl = (axictl &
  44                   ~(TMC_AXICTL_PROT_CTL_B0 | TMC_AXICTL_PROT_CTL_B1)) |
  45                   TMC_AXICTL_PROT_CTL_B1;
  46         writel_relaxed(axictl, drvdata->base + TMC_AXICTL);
  47
  48         writel_relaxed(drvdata->paddr, drvdata->base + TMC_DBALO);
  49         writel_relaxed(0x0, drvdata->base + TMC_DBAHI);
  50         writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI |
  51                        TMC_FFCR_FON_FLIN | TMC_FFCR_FON_TRIG_EVT |
  52                        TMC_FFCR_TRIGON_TRIGIN,
  53                        drvdata->base + TMC_FFCR);
  54         writel_relaxed(drvdata->trigger_cntr, drvdata->base + TMC_TRG);
  55         tmc_enable_hw(drvdata);
  56
  57         CS_LOCK(drvdata->base);
  58 }
  59
  60 static void tmc_etr_dump_hw(struct tmc_drvdata *drvdata)
  61 {
  62         u32 rwp, val;
  63
  64         rwp = readl_relaxed(drvdata->base + TMC_RWP);
  65         val = readl_relaxed(drvdata->base + TMC_STS);
  66
  67         /* How much memory do we still have */
  68         if (val & BIT(0))
  69                 drvdata->buf = drvdata->vaddr + rwp - drvdata->paddr;
  70         else
  71                 drvdata->buf = drvdata->vaddr;
  72 }
  73
  74 static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
  75 {
  76         CS_UNLOCK(drvdata->base);
  77
  78         tmc_flush_and_stop(drvdata);
  79         /*
  80          * When operating in sysFS mode the content of the buffer needs to be
  81          * read before the TMC is disabled.
  82          */
  83         if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
  84                 tmc_etr_dump_hw(drvdata);
  85         tmc_disable_hw(drvdata);
  86
  87         CS_LOCK(drvdata->base);
  88 }
  89
  90 static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
  91 {
  92         int ret = 0;
  93         bool used = false;
  94         long val;
  95         unsigned long flags;
  96         void __iomem *vaddr = NULL;
  97         dma_addr_t paddr;
  98         struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
  99
 100          /* This shouldn't be happening */
 101         if (WARN_ON(mode != CS_MODE_SYSFS))
 102                 return -EINVAL;
 103
 104         /*
 105          * If we don't have a buffer release the lock and allocate memory.
 106          * Otherwise keep the lock and move along.
 107          */
 108         spin_lock_irqsave(&drvdata->spinlock, flags);
 109         if (!drvdata->vaddr) {
 110                 spin_unlock_irqrestore(&drvdata->spinlock, flags);
 111
 112                 /*
 113                  * Contiguous  memory can't be allocated while a spinlock is
 114                  * held.  As such allocate memory here and free it if a buffer
 115                  * has already been allocated (from a previous session).
 116                  */
 117                 vaddr = dma_alloc_coherent(drvdata->dev, drvdata->size,
 118                                            &paddr, GFP_KERNEL);
 119                 if (!vaddr)
 120                         return -ENOMEM;
 121
 122                 /* Let's try again */
 123                 spin_lock_irqsave(&drvdata->spinlock, flags);
 124         }
 125
 126         if (drvdata->reading) {
 127                 ret = -EBUSY;
 128                 goto out;
 129         }
 130
 131         val = local_xchg(&drvdata->mode, mode);
 132         /*
 133          * In sysFS mode we can have multiple writers per sink.  Since this
 134          * sink is already enabled no memory is needed and the HW need not be
 135          * touched.
 136          */
 137         if (val == CS_MODE_SYSFS)
 138                 goto out;
 139
 140         /*
 141          * If drvdata::buf == NULL, use the memory allocated above.
 142          * Otherwise a buffer still exists from a previous session, so
 143          * simply use that.
 144          */
 145         if (drvdata->buf == NULL) {
 146                 used = true;
 147                 drvdata->vaddr = vaddr;
 148                 drvdata->paddr = paddr;
 149                 drvdata->buf = drvdata->vaddr;
 150         }
 151
 152         memset(drvdata->vaddr, 0, drvdata->size);
 153
 154         tmc_etr_enable_hw(drvdata);
 155 out:
 156         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 157
 158         /* Free memory outside the spinlock if need be */
 159         if (!used && vaddr)
 160                 dma_free_coherent(drvdata->dev, drvdata->size, vaddr, paddr);
 161
 162         if (!ret)
 163                 dev_info(drvdata->dev, "TMC-ETR enabled\n");
 164
 165         return ret;
 166 }
 167
 168 static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
 169 {
 170         int ret = 0;
 171         long val;
 172         unsigned long flags;
 173         struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 174
 175          /* This shouldn't be happening */
 176         if (WARN_ON(mode != CS_MODE_PERF))
 177                 return -EINVAL;
 178
 179         spin_lock_irqsave(&drvdata->spinlock, flags);
 180         if (drvdata->reading) {
 181                 ret = -EINVAL;
 182                 goto out;
 183         }
 184
 185         val = local_xchg(&drvdata->mode, mode);
 186         /*
 187          * In Perf mode there can be only one writer per sink.  There
 188          * is also no need to continue if the ETR is already operated
 189          * from sysFS.
 190          */
 191         if (val != CS_MODE_DISABLED) {
 192                 ret = -EINVAL;
 193                 goto out;
 194         }
 195
 196         tmc_etr_enable_hw(drvdata);
 197 out:
 198         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 199
 200         return ret;
 201 }
 202
 203 static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
 204 {
 205         switch (mode) {
 206         case CS_MODE_SYSFS:
 207                 return tmc_enable_etr_sink_sysfs(csdev, mode);
 208         case CS_MODE_PERF:
 209                 return tmc_enable_etr_sink_perf(csdev, mode);
 210         }
 211
 212         /* We shouldn't be here */
 213         return -EINVAL;
 214 }
 215
 216 static void tmc_disable_etr_sink(struct coresight_device *csdev)
 217 {
 218         long val;
 219         unsigned long flags;
 220         struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 221
 222         spin_lock_irqsave(&drvdata->spinlock, flags);
 223         if (drvdata->reading) {
 224                 spin_unlock_irqrestore(&drvdata->spinlock, flags);
 225                 return;
 226         }
 227
 228         val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
 229         /* Disable the TMC only if it needs to */
 230         if (val != CS_MODE_DISABLED)
 231                 tmc_etr_disable_hw(drvdata);
 232
 233         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 234
 235         dev_info(drvdata->dev, "TMC-ETR disabled\n");
 236 }
 237
 238 static const struct coresight_ops_sink tmc_etr_sink_ops = {
 239         .enable         = tmc_enable_etr_sink,
 240         .disable        = tmc_disable_etr_sink,
 241 };
 242
 243 const struct coresight_ops tmc_etr_cs_ops = {
 244         .sink_ops       = &tmc_etr_sink_ops,
 245 };
 246
 247 int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
 248 {
 249         int ret = 0;
 250         long val;
 251         unsigned long flags;
 252
 253         /* config types are set a boot time and never change */
 254         if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
 255                 return -EINVAL;
 256
 257         spin_lock_irqsave(&drvdata->spinlock, flags);
 258         if (drvdata->reading) {
 259                 ret = -EBUSY;
 260                 goto out;
 261         }
 262
 263         val = local_read(&drvdata->mode);
 264         /* Don't interfere if operated from Perf */
 265         if (val == CS_MODE_PERF) {
 266                 ret = -EINVAL;
 267                 goto out;
 268         }
 269
 270         /* If drvdata::buf is NULL the trace data has been read already */
 271         if (drvdata->buf == NULL) {
 272                 ret = -EINVAL;
 273                 goto out;
 274         }
 275
 276         /* Disable the TMC if need be */
 277         if (val == CS_MODE_SYSFS)
 278                 tmc_etr_disable_hw(drvdata);
 279
 280         drvdata->reading = true;
 281 out:
 282         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 283
 284         return ret;
 285 }
 286
 287 int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
 288 {
 289         unsigned long flags;
 290         dma_addr_t paddr;
 291         void __iomem *vaddr = NULL;
 292
 293         /* config types are set a boot time and never change */
 294         if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
 295                 return -EINVAL;
 296
 297         spin_lock_irqsave(&drvdata->spinlock, flags);
 298
 299         /* RE-enable the TMC if need be */
 300         if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
 301                 /*
 302                  * The trace run will continue with the same allocated trace
 303                  * buffer. As such zero-out the buffer so that we don't end
 304                  * up with stale data.
 305                  *
 306                  * Since the tracer is still enabled drvdata::buf
 307                  * can't be NULL.
 308                  */
 309                 memset(drvdata->buf, 0, drvdata->size);
 310                 tmc_etr_enable_hw(drvdata);
 311         } else {
 312                 /*
 313                  * The ETR is not tracing and the buffer was just read.
 314                  * As such prepare to free the trace buffer.
 315                  */
 316                 vaddr = drvdata->vaddr;
 317                 paddr = drvdata->paddr;
 318                 drvdata->buf = NULL;
 319         }
 320
 321         drvdata->reading = false;
 322         spin_unlock_irqrestore(&drvdata->spinlock, flags);
 323
 324         /* Free allocated memory out side of the spinlock */
 325         if (vaddr)
 326                 dma_free_coherent(drvdata->dev, drvdata->size, vaddr, paddr);
 327
 328         return 0;
 329 }