> -----Original Message----- > From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > Sent: 01 July 2024 16:40 > To: Shradha Todi <shradha.t@xxxxxxxxxxx> > Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; > manivannan.sadhasivam@xxxxxxxxxx; lpieralisi@xxxxxxxxxx; kw@xxxxxxxxx; > robh@xxxxxxxxxx; bhelgaas@xxxxxxxxxx; jingoohan1@xxxxxxxxx; > fancer.lancer@xxxxxxxxx; yoshihiro.shimoda.uh@xxxxxxxxxxx; > conor.dooley@xxxxxxxxxxxxx; pankaj.dubey@xxxxxxxxxxx; > gost.dev@xxxxxxxxxxx > Subject: Re: [PATCH 2/3] PCI: debugfs: Add support for RASDES framework in DWC > > On Tue, 25 Jun 2024 15:08:12 +0530 > Shradha Todi <shradha.t@xxxxxxxxxxx> wrote: > > > Add support to use the RASDES feature of DesignWare PCIe controller > > using debugfs entries. > > > > RASDES is a vendor specific extended PCIe capability which reads the > > current hardware internal state of PCIe device. Following primary > > features are provided to userspace via debugfs: > > - Debug registers > > - Error injection > > - Statistical counters > > > > Signed-off-by: Shradha Todi <shradha.t@xxxxxxxxxxx> > > A few minor things inline. > > > + > > +struct rasdes_info { > > + /* to store rasdes capability offset */ > > + u32 ras_cap; > > + struct mutex dbg_mutex; > > Add a comment on what data this mutex protects. > > > + struct dentry *rasdes; > > +}; > > > +struct err_inj { > Very generic name is likely to bite in future if similar gets defined in a header. I'd at > least prefix with dw_ > > > + const char *name; > > + /* values can be from group 0 - 6 */ > > + u32 err_inj_group; > > + /* within each group there can be types */ > > + u32 err_inj_type; > > + /* More details about the error */ > > + u32 err_inj_12_31; > > +}; > > > > + > > +int dwc_pcie_rasdes_debugfs_init(struct dw_pcie *pci) { > > + struct device *dev = pci->dev; > > + int ras_cap; > > + struct rasdes_info *dump_info; > > + char dirname[DWC_DEBUGFS_MAX]; > > + struct dentry *dir, *rasdes_debug, *rasdes_err_inj; > > + struct dentry *rasdes_event_counter, *rasdes_events; > > + int i; > > Perhaps combine with int ras_cap above. > > From a quick look, I think this can get called from resume paths as well as initial > setup which doesn't look like a safe thing to do. > imx6_pcie_resume_irq() > dw_pcie_setup_rc() > dw_pcie_setup() > dwc_pcie_rasdes_debugfs_init() > > Thanks for review. I'm going to post the next version soon with all your comments addressed. Yes, I guess this is a fair point that calling it during resume path + setup is not a safe thing to do. I was thinking we leave it up to platform drivers to call it and drop patch 3 altogether as I realised that there is also no ep_deinit to call the "dwc_pcie_rasdes_debugfs_deinit(pci)" from. Would love to know your opinion on this before I proceed to post the changes. > > + struct rasdes_priv *priv_tmp; > > + > > + ras_cap = dw_pcie_find_vsec_capability(pci, DW_PCIE_RAS_DES_CAP); > > + if (!ras_cap) { > > + dev_err(dev, "No RASDES capability available\n"); > > + return -ENODEV; > > + } > > + > > + dump_info = devm_kzalloc(dev, sizeof(*dump_info), GFP_KERNEL); > > + if (!dump_info) > > + return -ENOMEM; > > + > > + /* Create main directory for each platform driver */ > > + sprintf(dirname, "pcie_dwc_%s", dev_name(dev)); > > dev_name could in theory be huge. I'd use snprintf() and check the result as more > obviously correct. > > > + dir = debugfs_create_dir(dirname, NULL); > > Check for errors in all these. > > > + > > + /* Create subdirectories for Debug, Error injection, Statistics */ > > + rasdes_debug = debugfs_create_dir("rasdes_debug", dir); > > + rasdes_err_inj = debugfs_create_dir("rasdes_err_inj", dir); > > + rasdes_event_counter = debugfs_create_dir("rasdes_event_counter", > > +dir); > > + > > + mutex_init(&dump_info->dbg_mutex); > > + dump_info->ras_cap = ras_cap; > > + dump_info->rasdes = dir; > > + pci->dump_info = dump_info; > > + > > + /* Create debugfs files for Debug subdirectory */ > > + dwc_debugfs_create(lane_detect); > > + dwc_debugfs_create(rx_valid); > > + > > + /* Create debugfs files for Error injection subdirectory */ > > + for (i = 0; i < ARRAY_SIZE(err_inj_list); i++) { > > + priv_tmp = devm_kzalloc(dev, sizeof(*priv_tmp), GFP_KERNEL); > > + if (!priv_tmp) > > + goto err; > > + > > + priv_tmp->idx = i; > > + priv_tmp->pci = pci; > > + debugfs_create_file(err_inj_list[i].name, 0200, > > + rasdes_err_inj, priv_tmp, &err_inj_ops); > > + } > > + > > + /* Create debugfs files for Statistical counter subdirectory */ > > + for (i = 0; i < ARRAY_SIZE(event_counters); i++) { > > + priv_tmp = devm_kzalloc(dev, sizeof(*priv_tmp), GFP_KERNEL); > > + if (!priv_tmp) > > + goto err; > > + > > + priv_tmp->idx = i; > > + priv_tmp->pci = pci; > > + rasdes_events = debugfs_create_dir(event_counters[i].name, > > + rasdes_event_counter); > > + if (event_counters[i].group_no == 0) { > > + debugfs_create_file("lane_select", 0644, rasdes_events, > > + priv_tmp, &cnt_lane_ops); > > + } > > + debugfs_create_file("counter_value", 0444, rasdes_events, > priv_tmp, > > + &cnt_val_ops); > > + debugfs_create_file("counter_enable", 0644, rasdes_events, > priv_tmp, > > + &cnt_en_ops); > > + } > > + > > + return 0; > > +err: > > + dwc_pcie_rasdes_debugfs_deinit(pci); > > + return -ENOMEM; > > +} > > diff --git a/drivers/pci/controller/dwc/pcie-designware-debugfs.h > > b/drivers/pci/controller/dwc/pcie-designware-debugfs.h > > new file mode 100644 > > index 000000000000..e69de29bb2d1 > > diff --git a/drivers/pci/controller/dwc/pcie-designware.h > > b/drivers/pci/controller/dwc/pcie-designware.h > > index 77686957a30d..9fa9f33e4ddb 100644 > > --- a/drivers/pci/controller/dwc/pcie-designware.h > > +++ b/drivers/pci/controller/dwc/pcie-designware.h > > @@ -223,6 +223,8 @@ > > > > #define PCIE_RAS_DES_EVENT_COUNTER_DATA 0xc > > > > +#define DW_PCIE_RAS_DES_CAP 0x2 > > I'd be tempted to try and name that in a fashion that makes it clear it is a vsec > capability ID. Currently it sounds like a top level capability ID. > > > + > > /* > > * The default address offset between dbi_base and atu_base. Root controller > > * drivers are not required to initialize atu_base if the offset > > matches this @@ -410,6 +412,7 @@ struct dw_pcie { > > struct reset_control_bulk_data core_rsts[DW_PCIE_NUM_CORE_RSTS]; > > struct gpio_desc *pe_rst; > > bool suspended; > > + void *dump_info; > > }; >