Re: [PATCH V2 1/3] dma: add Qualcomm Technologies HIDMA management driver

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On 11/3/2015 5:22 AM, Andy Shevchenko wrote:
On Mon, Nov 2, 2015 at 8:07 AM, Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote:
The Qualcomm Technologies HIDMA device has been designed
to support virtualization technology. The driver has been
divided into two to follow the hardware design. The management
driver is executed in hypervisor context and is the main
management entity for all channels provided by the device.
The channel driver is executed in the hypervisor/guest OS
context.

All channel devices get probed in the hypervisor
context during power up. They show up as DMA engine
channels. Then, before starting the virtualization; each
channel device is unbound from the hypervisor by VFIO
and assigned to the guest machine for control.

This management driver will be used by the system
admin to monitor/reset the execution state of the DMA
channels. This will be the management interface.


+static ssize_t qcom_hidma_mgmt_evtena(struct file *file,
+       const char __user *user_buf, size_t count, loff_t *ppos)
+{
+       char temp_buf[16+1];

16 is a magic number. Make it defined constant.


removed it

+       struct qcom_hidma_mgmt_dev *mgmtdev = file->f_inode->i_private;
+       u32 event;
+       ssize_t ret;
+       unsigned long val;
+
+       temp_buf[16] = '\0';
+       if (copy_from_user(temp_buf, user_buf, min_t(int, count, 16)))
+               goto out;
+
+       ret = kstrtoul(temp_buf, 16, &val);

kstrtoul_from_user?

nice, simpler.


+       if (ret) {
+               dev_warn(&mgmtdev->pdev->dev, "unknown event\n");
+               goto out;
+       }
+
+       event = (u32)val & HW_EVENTS_CFG_MASK;
+
+       pm_runtime_get_sync(&mgmtdev->pdev->dev);
+       writel(event, mgmtdev->dev_virtaddr + HW_EVENTS_CFG_OFFSET);
+       pm_runtime_mark_last_busy(&mgmtdev->pdev->dev);
+       pm_runtime_put_autosuspend(&mgmtdev->pdev->dev);
+out:
+       return count;
+}
+
+static const struct file_operations qcom_hidma_mgmt_evtena_fops = {
+       .write = qcom_hidma_mgmt_evtena,
+};
+
+struct fileinfo {
+       char *name;
+       int mode;
+       const struct file_operations *ops;
+};
+
+static struct fileinfo files[] = {
+       {"info", S_IRUGO, &qcom_hidma_mgmt_fops},
+       {"err", S_IRUGO,  &qcom_hidma_mgmt_err_fops},
+       {"mhiderrclr", S_IWUSR, &qcom_hidma_mgmt_mhiderr_clrfops},
+       {"evterrclr", S_IWUSR, &qcom_hidma_mgmt_evterr_clrfops},
+       {"ideerrclr", S_IWUSR, &qcom_hidma_mgmt_ideerr_clrfops},
+       {"odeerrclr", S_IWUSR, &qcom_hidma_mgmt_odeerr_clrfops},
+       {"msierrclr", S_IWUSR, &qcom_hidma_mgmt_msierr_clrfops},
+       {"treerrclr", S_IWUSR, &qcom_hidma_mgmt_treerr_clrfops},
+       {"evtena", S_IWUSR, &qcom_hidma_mgmt_evtena_fops},
+};
+
+static void qcom_hidma_mgmt_debug_uninit(struct qcom_hidma_mgmt_dev *mgmtdev)
+{
+       debugfs_remove_recursive(mgmtdev->debugfs);
+}
+
+static int qcom_hidma_mgmt_debug_init(struct qcom_hidma_mgmt_dev *mgmtdev)
+{
+       int rc = 0;
+       u32 i;
+       struct dentry   *fs_entry;
+
+       mgmtdev->debugfs = debugfs_create_dir(dev_name(&mgmtdev->pdev->dev),
+                                               NULL);
+       if (!mgmtdev->debugfs) {
+               rc = -ENODEV;
+               return rc;
+       }
+
+       for (i = 0; i < ARRAY_SIZE(files); i++) {
+               fs_entry = debugfs_create_file(files[i].name,
+                                       files[i].mode, mgmtdev->debugfs,
+                                       mgmtdev, files[i].ops);
+               if (!fs_entry) {
+                       rc = -ENOMEM;
+                       goto cleanup;
+               }
+       }
+
+       return 0;
+cleanup:
+       qcom_hidma_mgmt_debug_uninit(mgmtdev);
+       return rc;
+}
+#else
+static void qcom_hidma_mgmt_debug_uninit(struct qcom_hidma_mgmt_dev *mgmtdev)
+{
+}
+static int qcom_hidma_mgmt_debug_init(struct qcom_hidma_mgmt_dev *mgmtdev)
+{
+       return 0;
+}
+#endif
+
+static int qcom_hidma_mgmt_setup(struct qcom_hidma_mgmt_dev *mgmtdev)
+{
+       u32 val;
+       u32 i;
+
+       val = readl(mgmtdev->dev_virtaddr + MAX_BUS_REQ_LEN_OFFSET);
+       val = val &
+               ~(MAX_BUS_REQ_LEN_MASK << MAX_BUS_WR_REQ_BIT_POS);
+       val = val |
+               (mgmtdev->max_write_request << MAX_BUS_WR_REQ_BIT_POS);
+       val = val & ~(MAX_BUS_REQ_LEN_MASK);
+       val = val | (mgmtdev->max_read_request);
+       writel(val, mgmtdev->dev_virtaddr + MAX_BUS_REQ_LEN_OFFSET);
+
+       val = readl(mgmtdev->dev_virtaddr + MAX_XACTIONS_OFFSET);
+       val = val &
+               ~(MAX_WR_XACTIONS_MASK << MAX_WR_XACTIONS_BIT_POS);
+       val = val |
+               (mgmtdev->max_wr_xactions << MAX_WR_XACTIONS_BIT_POS);
+       val = val & ~(MAX_RD_XACTIONS_MASK);
+       val = val | (mgmtdev->max_rd_xactions);
+       writel(val, mgmtdev->dev_virtaddr + MAX_XACTIONS_OFFSET);
+
+       mgmtdev->sw_version = readl(mgmtdev->dev_virtaddr + SW_VERSION_OFFSET);
+
+       for (i = 0; i < mgmtdev->dma_channels; i++) {
+               val = readl(mgmtdev->dev_virtaddr + QOS_N_OFFSET + (4 * i));
+               val = val & ~(1 << PRIORITY_BIT_POS);
+               val = val |
+                       ((mgmtdev->priority[i] & 0x1) << PRIORITY_BIT_POS);
+               val = val & ~(WEIGHT_MASK << WRR_BIT_POS);
+               val = val
+                       | ((mgmtdev->weight[i] & WEIGHT_MASK) << WRR_BIT_POS);
+               writel(val, mgmtdev->dev_virtaddr + QOS_N_OFFSET + (4 * i));
+       }
+
+       val = readl(mgmtdev->dev_virtaddr + CHRESET_TIMEOUT_OFFSET);
+       val = val & ~CHRESET_TIMEOUUT_MASK;
+       val = val | (mgmtdev->chreset_timeout & CHRESET_TIMEOUUT_MASK);
+       writel(val, mgmtdev->dev_virtaddr + CHRESET_TIMEOUT_OFFSET);
+
+       val = readl(mgmtdev->dev_virtaddr + CFG_OFFSET);
+       val = val | 1;
+       writel(val, mgmtdev->dev_virtaddr + CFG_OFFSET);
+
+       return 0;
+}
+
+static int qcom_hidma_mgmt_probe(struct platform_device *pdev)
+{
+       struct resource *dma_resource;
+       int irq;
+       int rc;
+       u32 i;
+       struct qcom_hidma_mgmt_dev *mgmtdev;

Better move this line to the top of definition block.

done

+
+       pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
+       pm_runtime_use_autosuspend(&pdev->dev);
+       pm_runtime_set_active(&pdev->dev);
+       pm_runtime_enable(&pdev->dev);
+       dma_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!dma_resource) {
+               dev_err(&pdev->dev, "No memory resources found\n");
+               rc = -ENODEV;
+               goto out;
+       }

Consolidate with devm_ioremap_resource()


OK

+
+       irq = platform_get_irq(pdev, 0);
+       if (irq < 0) {
+               dev_err(&pdev->dev, "irq resources not found\n");
+               rc = -ENODEV;
+               goto out;
+       }
+
+       mgmtdev = devm_kzalloc(&pdev->dev, sizeof(*mgmtdev), GFP_KERNEL);
+       if (!mgmtdev) {
+               rc = -ENOMEM;
+               goto out;
+       }
+
+       mgmtdev->pdev = pdev;
+
+       pm_runtime_get_sync(&mgmtdev->pdev->dev);
+       mgmtdev->dev_addrsize = resource_size(dma_resource);
+       mgmtdev->dev_virtaddr = devm_ioremap_resource(&pdev->dev,
+                                                       dma_resource);
+       if (IS_ERR(mgmtdev->dev_virtaddr)) {
+               dev_err(&pdev->dev, "can't map i/o memory at %pa\n",
+                       &dma_resource->start);
+               rc = -ENOMEM;
+               goto out;
+       }
+
+       if (device_property_read_u32(&pdev->dev, "dma-channels",
+               &mgmtdev->dma_channels)) {
+               dev_err(&pdev->dev, "number of channels missing\n");
+               rc = -EINVAL;
+               goto out;
+       }
+
+       if (device_property_read_u32(&pdev->dev, "channel-reset-timeout",
+               &mgmtdev->chreset_timeout)) {
+               dev_err(&pdev->dev, "channel reset timeout missing\n");
+               rc = -EINVAL;
+               goto out;
+       }
+
+       if (device_property_read_u32(&pdev->dev, "max-write-burst-bytes",
+               &mgmtdev->max_write_request)) {
+               dev_err(&pdev->dev, "max-write-burst-bytes missing\n");
+               rc = -EINVAL;
+               goto out;
+       }
+       if ((mgmtdev->max_write_request != 128) &&
+               (mgmtdev->max_write_request != 256) &&
+               (mgmtdev->max_write_request != 512) &&
+               (mgmtdev->max_write_request != 1024)) {

is_power_of_2()  && min/max ?

ok

+               dev_err(&pdev->dev, "invalid write request %d\n",
+                       mgmtdev->max_write_request);
+               rc = -EINVAL;
+               goto out;
+       }
+
+       if (device_property_read_u32(&pdev->dev, "max-read-burst-bytes",
+               &mgmtdev->max_read_request)) {
+               dev_err(&pdev->dev, "max-read-burst-bytes missing\n");
+               rc = -EINVAL;
+               goto out;
+       }
+
+       if ((mgmtdev->max_read_request != 128) &&
+               (mgmtdev->max_read_request != 256) &&
+               (mgmtdev->max_read_request != 512) &&
+               (mgmtdev->max_read_request != 1024)) {

Ditto.

done

+               dev_err(&pdev->dev, "invalid read request %d\n",
+                       mgmtdev->max_read_request);
+               rc = -EINVAL;
+               goto out;
+       }
+
+       if (device_property_read_u32(&pdev->dev, "max-write-transactions",
+               &mgmtdev->max_wr_xactions)) {
+               dev_err(&pdev->dev, "max-write-transactions missing\n");
+               rc = -EINVAL;
+               goto out;
+       }
+
+       if (device_property_read_u32(&pdev->dev, "max-read-transactions",
+               &mgmtdev->max_rd_xactions)) {
+               dev_err(&pdev->dev, "max-read-transactions missing\n");
+               rc = -EINVAL;
+               goto out;
+       }
+
+       mgmtdev->priority = devm_kcalloc(&pdev->dev,
+               mgmtdev->dma_channels, sizeof(*mgmtdev->priority), GFP_KERNEL);
+       if (!mgmtdev->priority) {
+               rc = -ENOMEM;
+               goto out;
+       }
+
+       mgmtdev->weight = devm_kcalloc(&pdev->dev,
+               mgmtdev->dma_channels, sizeof(*mgmtdev->weight), GFP_KERNEL);
+       if (!mgmtdev->weight) {
+               rc = -ENOMEM;
+               goto out;
+       }
+
+       if (device_property_read_u32_array(&pdev->dev, "channel-priority",
+                               mgmtdev->priority, mgmtdev->dma_channels)) {
+               dev_err(&pdev->dev, "channel-priority missing\n");
+               rc = -EINVAL;
+               goto out;
+       }
+
+       if (device_property_read_u32_array(&pdev->dev, "channel-weight",
+                               mgmtdev->weight, mgmtdev->dma_channels)) {
+               dev_err(&pdev->dev, "channel-weight missing\n");
+               rc = -EINVAL;
+               goto out;
+       }
+
+       for (i = 0; i < mgmtdev->dma_channels; i++) {
+               if (mgmtdev->weight[i] > 15) {

15 is magic.


I created a new macro called MAX_CHANNEL_WEIGHT.

+                       dev_err(&pdev->dev,
+                               "max value of weight can be 15.\n");
+                       rc = -EINVAL;
+                       goto out;
+               }
+
+               /* weight needs to be at least one */
+               if (mgmtdev->weight[i] == 0)
+                       mgmtdev->weight[i] = 1;
+       }
+
+       rc = qcom_hidma_mgmt_setup(mgmtdev);
+       if (rc) {
+               dev_err(&pdev->dev, "setup failed\n");
+               goto out;
+       }
+
+       rc = qcom_hidma_mgmt_debug_init(mgmtdev);
+       if (rc) {
+               dev_err(&pdev->dev, "debugfs init failed\n");
+               goto out;
+       }
+
+       dev_info(&pdev->dev,
+               "HI-DMA engine management driver registration complete\n");

You may put some useful information here, otherwise looks like a debug message.

ok, I did now. I copied the syntax from another driver to here.

+       platform_set_drvdata(pdev, mgmtdev);
+       pm_runtime_mark_last_busy(&mgmtdev->pdev->dev);
+       pm_runtime_put_autosuspend(&mgmtdev->pdev->dev);
+       return 0;
+out:
+       pm_runtime_disable(&pdev->dev);
+       pm_runtime_put_sync_suspend(&pdev->dev);
+       return rc;
+}
+
+static int qcom_hidma_mgmt_remove(struct platform_device *pdev)
+{
+       struct qcom_hidma_mgmt_dev *mgmtdev = platform_get_drvdata(pdev);
+
+       pm_runtime_get_sync(&mgmtdev->pdev->dev);
+       qcom_hidma_mgmt_debug_uninit(mgmtdev);
+       pm_runtime_put_sync_suspend(&pdev->dev);
+       pm_runtime_disable(&pdev->dev);
+
+       dev_info(&pdev->dev, "HI-DMA engine management driver removed\n");

Useless message.

removed .


+       return 0;
+}
+
+#if IS_ENABLED(CONFIG_ACPI)
+static const struct acpi_device_id qcom_hidma_mgmt_acpi_ids[] = {
+       {"QCOM8060"},
+       {},
+};
+#endif
+
+static const struct of_device_id qcom_hidma_mgmt_match[] = {
+       { .compatible = "qcom,hidma-mgmt-1.0", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, qcom_hidma_mgmt_match);
+
+static struct platform_driver qcom_hidma_mgmt_driver = {
+       .probe = qcom_hidma_mgmt_probe,
+       .remove = qcom_hidma_mgmt_remove,
+       .driver = {
+               .name = "hidma-mgmt",
+               .of_match_table = qcom_hidma_mgmt_match,
+               .acpi_match_table = ACPI_PTR(qcom_hidma_mgmt_acpi_ids),
+       },
+};
+module_platform_driver(qcom_hidma_mgmt_driver);
+MODULE_LICENSE("GPL v2");
--
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project

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--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
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