dmaengine: qcom_hidma: add debugfs hooks

Add debugfs hooks for debugging the execution behavior of the DMA
channel. The debugfs hooks get initialized by the probe function and
uninitialized by the remove function.

A stats file is created in debugfs. The stats file will show the
information about each HIDMA channel as well as each asynchronous job
queued and completed at a given time.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

4 files changed, 224 insertions, 2 deletions

diff --git a/drivers/dma/qcom/Makefile b/drivers/dma/qcom/Makefile
index 6bf9267e6387..4bfc38b45220 100644
--- a/drivers/dma/qcom/Makefile
+++ b/drivers/dma/qcom/Makefile
@@ -2,4 +2,4 @@ obj-$(CONFIG_QCOM_BAM_DMA) += bam_dma.o
 obj-$(CONFIG_QCOM_HIDMA_MGMT) += hdma_mgmt.o
 hdma_mgmt-objs   := hidma_mgmt.o hidma_mgmt_sys.o
 obj-$(CONFIG_QCOM_HIDMA) +=  hdma.o
-hdma-objs        := hidma_ll.o hidma.o
+hdma-objs        := hidma_ll.o hidma.o hidma_dbg.o
diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c
index af5e542f453b..1ad27c28d00c 100644
--- a/drivers/dma/qcom/hidma.c
+++ b/drivers/dma/qcom/hidma.c
@@ -1,7 +1,7 @@
 /*
  * Qualcomm Technologies HIDMA DMA engine interface
  *
- * Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -644,6 +644,7 @@ static int hidma_probe(struct platform_device *pdev)
 
         dmadev->irq = chirq;
         tasklet_init(&dmadev->task, hidma_issue_task, (unsigned long)dmadev);
+        hidma_debug_init(dmadev);
         dev_info(&pdev->dev, "HI-DMA engine driver registration complete\n");
         platform_set_drvdata(pdev, dmadev);
         pm_runtime_mark_last_busy(dmadev->ddev.dev);
@@ -651,6 +652,7 @@ static int hidma_probe(struct platform_device *pdev)
         return 0;
 
 uninit:
+        hidma_debug_uninit(dmadev);
         hidma_ll_uninit(dmadev->lldev);
 dmafree:
         if (dmadev)
@@ -668,6 +670,7 @@ static int hidma_remove(struct platform_device *pdev)
         pm_runtime_get_sync(dmadev->ddev.dev);
         dma_async_device_unregister(&dmadev->ddev);
         devm_free_irq(dmadev->ddev.dev, dmadev->irq, dmadev->lldev);
+        hidma_debug_uninit(dmadev);
         hidma_ll_uninit(dmadev->lldev);
         hidma_free(dmadev);
 
diff --git a/drivers/dma/qcom/hidma.h b/drivers/dma/qcom/hidma.h
index b1362ef7b747..db413a5efc4e 100644
--- a/drivers/dma/qcom/hidma.h
+++ b/drivers/dma/qcom/hidma.h
@@ -153,4 +153,6 @@ int hidma_ll_uninit(struct hidma_lldev *llhndl);
 irqreturn_t hidma_ll_inthandler(int irq, void *arg);
 void hidma_cleanup_pending_tre(struct hidma_lldev *llhndl, u8 err_info,
                                 u8 err_code);
+int hidma_debug_init(struct hidma_dev *dmadev);
+void hidma_debug_uninit(struct hidma_dev *dmadev);
 #endif
diff --git a/drivers/dma/qcom/hidma_dbg.c b/drivers/dma/qcom/hidma_dbg.c
new file mode 100644
index 000000000000..fa827e5ffd68
--- /dev/null
+++ b/drivers/dma/qcom/hidma_dbg.c
@@ -0,0 +1,217 @@
+/*
+ * Qualcomm Technologies HIDMA debug file
+ *
+ * Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/pm_runtime.h>
+
+#include "hidma.h"
+
+static void hidma_ll_chstats(struct seq_file *s, void *llhndl, u32 tre_ch)
+{
+        struct hidma_lldev *lldev = llhndl;
+        struct hidma_tre *tre;
+        u32 length;
+        dma_addr_t src_start;
+        dma_addr_t dest_start;
+        u32 *tre_local;
+
+        if (tre_ch >= lldev->nr_tres) {
+                dev_err(lldev->dev, "invalid TRE number in chstats:%d", tre_ch);
+                return;
+        }
+        tre = &lldev->trepool[tre_ch];
+        seq_printf(s, "------Channel %d -----\n", tre_ch);
+        seq_printf(s, "allocated=%d\n", atomic_read(&tre->allocated));
+        seq_printf(s, "queued = 0x%x\n", tre->queued);
+        seq_printf(s, "err_info = 0x%x\n", tre->err_info);
+        seq_printf(s, "err_code = 0x%x\n", tre->err_code);
+        seq_printf(s, "status = 0x%x\n", tre->status);
+        seq_printf(s, "idx = 0x%x\n", tre->idx);
+        seq_printf(s, "dma_sig = 0x%x\n", tre->dma_sig);
+        seq_printf(s, "dev_name=%s\n", tre->dev_name);
+        seq_printf(s, "callback=%p\n", tre->callback);
+        seq_printf(s, "data=%p\n", tre->data);
+        seq_printf(s, "tre_index = 0x%x\n", tre->tre_index);
+
+        tre_local = &tre->tre_local[0];
+        src_start = tre_local[HIDMA_TRE_SRC_LOW_IDX];
+        src_start = ((u64) (tre_local[HIDMA_TRE_SRC_HI_IDX]) << 32) + src_start;
+        dest_start = tre_local[HIDMA_TRE_DEST_LOW_IDX];
+        dest_start += ((u64) (tre_local[HIDMA_TRE_DEST_HI_IDX]) << 32);
+        length = tre_local[HIDMA_TRE_LEN_IDX];
+
+        seq_printf(s, "src=%pap\n", &src_start);
+        seq_printf(s, "dest=%pap\n", &dest_start);
+        seq_printf(s, "length = 0x%x\n", length);
+}
+
+static void hidma_ll_devstats(struct seq_file *s, void *llhndl)
+{
+        struct hidma_lldev *lldev = llhndl;
+
+        seq_puts(s, "------Device -----\n");
+        seq_printf(s, "lldev init = 0x%x\n", lldev->initialized);
+        seq_printf(s, "trch_state = 0x%x\n", lldev->trch_state);
+        seq_printf(s, "evch_state = 0x%x\n", lldev->evch_state);
+        seq_printf(s, "chidx = 0x%x\n", lldev->chidx);
+        seq_printf(s, "nr_tres = 0x%x\n", lldev->nr_tres);
+        seq_printf(s, "trca=%p\n", lldev->trca);
+        seq_printf(s, "tre_ring=%p\n", lldev->tre_ring);
+        seq_printf(s, "tre_ring_handle=%pap\n", &lldev->tre_dma);
+        seq_printf(s, "tre_ring_size = 0x%x\n", lldev->tre_ring_size);
+        seq_printf(s, "tre_processed_off = 0x%x\n", lldev->tre_processed_off);
+        seq_printf(s, "pending_tre_count=%d\n", lldev->pending_tre_count);
+        seq_printf(s, "evca=%p\n", lldev->evca);
+        seq_printf(s, "evre_ring=%p\n", lldev->evre_ring);
+        seq_printf(s, "evre_ring_handle=%pap\n", &lldev->evre_dma);
+        seq_printf(s, "evre_ring_size = 0x%x\n", lldev->evre_ring_size);
+        seq_printf(s, "evre_processed_off = 0x%x\n", lldev->evre_processed_off);
+        seq_printf(s, "tre_write_offset = 0x%x\n", lldev->tre_write_offset);
+}
+
+/*
+ * hidma_chan_stats: display HIDMA channel statistics
+ *
+ * Display the statistics for the current HIDMA virtual channel device.
+ */
+static int hidma_chan_stats(struct seq_file *s, void *unused)
+{
+        struct hidma_chan *mchan = s->private;
+        struct hidma_desc *mdesc;
+        struct hidma_dev *dmadev = mchan->dmadev;
+
+        pm_runtime_get_sync(dmadev->ddev.dev);
+        seq_printf(s, "paused=%u\n", mchan->paused);
+        seq_printf(s, "dma_sig=%u\n", mchan->dma_sig);
+        seq_puts(s, "prepared\n");
+        list_for_each_entry(mdesc, &mchan->prepared, node)
+                hidma_ll_chstats(s, mchan->dmadev->lldev, mdesc->tre_ch);
+
+        seq_puts(s, "active\n");
+        list_for_each_entry(mdesc, &mchan->active, node)
+                hidma_ll_chstats(s, mchan->dmadev->lldev, mdesc->tre_ch);
+
+        seq_puts(s, "completed\n");
+        list_for_each_entry(mdesc, &mchan->completed, node)
+                hidma_ll_chstats(s, mchan->dmadev->lldev, mdesc->tre_ch);
+
+        hidma_ll_devstats(s, mchan->dmadev->lldev);
+        pm_runtime_mark_last_busy(dmadev->ddev.dev);
+        pm_runtime_put_autosuspend(dmadev->ddev.dev);
+        return 0;
+}
+
+/*
+ * hidma_dma_info: display HIDMA device info
+ *
+ * Display the info for the current HIDMA device.
+ */
+static int hidma_dma_info(struct seq_file *s, void *unused)
+{
+        struct hidma_dev *dmadev = s->private;
+        resource_size_t sz;
+
+        seq_printf(s, "nr_descriptors=%d\n", dmadev->nr_descriptors);
+        seq_printf(s, "dev_trca=%p\n", &dmadev->dev_trca);
+        seq_printf(s, "dev_trca_phys=%pa\n", &dmadev->trca_resource->start);
+        sz = resource_size(dmadev->trca_resource);
+        seq_printf(s, "dev_trca_size=%pa\n", &sz);
+        seq_printf(s, "dev_evca=%p\n", &dmadev->dev_evca);
+        seq_printf(s, "dev_evca_phys=%pa\n", &dmadev->evca_resource->start);
+        sz = resource_size(dmadev->evca_resource);
+        seq_printf(s, "dev_evca_size=%pa\n", &sz);
+        return 0;
+}
+
+static int hidma_chan_stats_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, hidma_chan_stats, inode->i_private);
+}
+
+static int hidma_dma_info_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, hidma_dma_info, inode->i_private);
+}
+
+static const struct file_operations hidma_chan_fops = {
+        .open = hidma_chan_stats_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = single_release,
+};
+
+static const struct file_operations hidma_dma_fops = {
+        .open = hidma_dma_info_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = single_release,
+};
+
+void hidma_debug_uninit(struct hidma_dev *dmadev)
+{
+        debugfs_remove_recursive(dmadev->debugfs);
+        debugfs_remove_recursive(dmadev->stats);
+}
+
+int hidma_debug_init(struct hidma_dev *dmadev)
+{
+        int rc = 0;
+        int chidx = 0;
+        struct list_head *position = NULL;
+
+        dmadev->debugfs = debugfs_create_dir(dev_name(dmadev->ddev.dev), NULL);
+        if (!dmadev->debugfs) {
+                rc = -ENODEV;
+                return rc;
+        }
+
+        /* walk through the virtual channel list */
+        list_for_each(position, &dmadev->ddev.channels) {
+                struct hidma_chan *chan;
+
+                chan = list_entry(position, struct hidma_chan,
+                                  chan.device_node);
+                sprintf(chan->dbg_name, "chan%d", chidx);
+                chan->debugfs = debugfs_create_dir(chan->dbg_name,
+                                                   dmadev->debugfs);
+                if (!chan->debugfs) {
+                        rc = -ENOMEM;
+                        goto cleanup;
+                }
+                chan->stats = debugfs_create_file("stats", S_IRUGO,
+                                                  chan->debugfs, chan,
+                                                  &hidma_chan_fops);
+                if (!chan->stats) {
+                        rc = -ENOMEM;
+                        goto cleanup;
+                }
+                chidx++;
+        }
+
+        dmadev->stats = debugfs_create_file("stats", S_IRUGO,
+                                            dmadev->debugfs, dmadev,
+                                            &hidma_dma_fops);
+        if (!dmadev->stats) {
+                rc = -ENOMEM;
+                goto cleanup;
+        }
+
+        return 0;
+cleanup:
+        hidma_debug_uninit(dmadev);
+        return rc;
+}