From 87db7579ebd5ded337056eb765542eb2608f16e3 Mon Sep 17 00:00:00 2001 From: Philippe Bergheaud Date: Fri, 19 Jun 2020 16:04:39 +0200 Subject: [PATCH] ocxl: control via sysfs whether the FPGA is reloaded on a link reset Some opencapi FPGA images allow to control if the FPGA should be reloaded on the next adapter reset. If it is supported, the image specifies it through a Vendor Specific DVSEC in the config space of function 0. Signed-off-by: Philippe Bergheaud Signed-off-by: Frederic Barrat Reviewed-by: Andrew Donnellan Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200619140439.153962-1-fbarrat@linux.ibm.com --- Documentation/ABI/testing/sysfs-class-ocxl | 11 +++ drivers/misc/ocxl/config.c | 81 ++++++++++++++++++++-- drivers/misc/ocxl/ocxl_internal.h | 6 ++ drivers/misc/ocxl/sysfs.c | 35 ++++++++++ include/misc/ocxl-config.h | 1 + 5 files changed, 129 insertions(+), 5 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-class-ocxl b/Documentation/ABI/testing/sysfs-class-ocxl index b5b1fa197592..ae1276efa45a 100644 --- a/Documentation/ABI/testing/sysfs-class-ocxl +++ b/Documentation/ABI/testing/sysfs-class-ocxl @@ -33,3 +33,14 @@ Date: January 2018 Contact: linuxppc-dev@lists.ozlabs.org Description: read/write Give access the global mmio area for the AFU + +What: /sys/class/ocxl//reload_on_reset +Date: February 2020 +Contact: linuxppc-dev@lists.ozlabs.org +Description: read/write + Control whether the FPGA is reloaded on a link reset. Enabled + through a vendor-specific logic block on the FPGA. + 0 Do not reload FPGA image from flash + 1 Reload FPGA image from flash + unavailable + The device does not support this capability diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c index c8e19bfb5ef9..42f7a1298775 100644 --- a/drivers/misc/ocxl/config.c +++ b/drivers/misc/ocxl/config.c @@ -71,6 +71,20 @@ static int find_dvsec_afu_ctrl(struct pci_dev *dev, u8 afu_idx) return 0; } +/** + * get_function_0() - Find a related PCI device (function 0) + * @device: PCI device to match + * + * Returns a pointer to the related device, or null if not found + */ +static struct pci_dev *get_function_0(struct pci_dev *dev) +{ + unsigned int devfn = PCI_DEVFN(PCI_SLOT(dev->devfn), 0); + + return pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus), + dev->bus->number, devfn); +} + static void read_pasid(struct pci_dev *dev, struct ocxl_fn_config *fn) { u16 val; @@ -159,14 +173,15 @@ static int read_dvsec_afu_info(struct pci_dev *dev, struct ocxl_fn_config *fn) static int read_dvsec_vendor(struct pci_dev *dev) { int pos; - u32 cfg, tlx, dlx; + u32 cfg, tlx, dlx, reset_reload; /* - * vendor specific DVSEC is optional + * vendor specific DVSEC, for IBM images only. Some older + * images may not have it * - * It's currently only used on function 0 to specify the - * version of some logic blocks. Some older images may not - * even have it so we ignore any errors + * It's only used on function 0 to specify the version of some + * logic blocks and to give access to special registers to + * enable host-based flashing. */ if (PCI_FUNC(dev->devfn) != 0) return 0; @@ -178,11 +193,67 @@ static int read_dvsec_vendor(struct pci_dev *dev) pci_read_config_dword(dev, pos + OCXL_DVSEC_VENDOR_CFG_VERS, &cfg); pci_read_config_dword(dev, pos + OCXL_DVSEC_VENDOR_TLX_VERS, &tlx); pci_read_config_dword(dev, pos + OCXL_DVSEC_VENDOR_DLX_VERS, &dlx); + pci_read_config_dword(dev, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD, + &reset_reload); dev_dbg(&dev->dev, "Vendor specific DVSEC:\n"); dev_dbg(&dev->dev, " CFG version = 0x%x\n", cfg); dev_dbg(&dev->dev, " TLX version = 0x%x\n", tlx); dev_dbg(&dev->dev, " DLX version = 0x%x\n", dlx); + dev_dbg(&dev->dev, " ResetReload = 0x%x\n", reset_reload); + return 0; +} + +static int get_dvsec_vendor0(struct pci_dev *dev, struct pci_dev **dev0, + int *out_pos) +{ + int pos; + + if (PCI_FUNC(dev->devfn) != 0) { + dev = get_function_0(dev); + if (!dev) + return -1; + } + pos = find_dvsec(dev, OCXL_DVSEC_VENDOR_ID); + if (!pos) + return -1; + *dev0 = dev; + *out_pos = pos; + return 0; +} + +int ocxl_config_get_reset_reload(struct pci_dev *dev, int *val) +{ + struct pci_dev *dev0; + u32 reset_reload; + int pos; + + if (get_dvsec_vendor0(dev, &dev0, &pos)) + return -1; + + pci_read_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD, + &reset_reload); + *val = !!(reset_reload & BIT(0)); + return 0; +} + +int ocxl_config_set_reset_reload(struct pci_dev *dev, int val) +{ + struct pci_dev *dev0; + u32 reset_reload; + int pos; + + if (get_dvsec_vendor0(dev, &dev0, &pos)) + return -1; + + pci_read_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD, + &reset_reload); + if (val) + reset_reload |= BIT(0); + else + reset_reload &= ~BIT(0); + pci_write_config_dword(dev0, pos + OCXL_DVSEC_VENDOR_RESET_RELOAD, + reset_reload); return 0; } diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h index 345bf843a38e..af9a84aeee6f 100644 --- a/drivers/misc/ocxl/ocxl_internal.h +++ b/drivers/misc/ocxl/ocxl_internal.h @@ -112,6 +112,12 @@ void ocxl_actag_afu_free(struct ocxl_fn *fn, u32 start, u32 size); */ int ocxl_config_get_pasid_info(struct pci_dev *dev, int *count); +/* + * Control whether the FPGA is reloaded on a link reset + */ +int ocxl_config_get_reset_reload(struct pci_dev *dev, int *val); +int ocxl_config_set_reset_reload(struct pci_dev *dev, int val); + /* * Check if an AFU index is valid for the given function. * diff --git a/drivers/misc/ocxl/sysfs.c b/drivers/misc/ocxl/sysfs.c index 58f1ba264206..25c78df8055d 100644 --- a/drivers/misc/ocxl/sysfs.c +++ b/drivers/misc/ocxl/sysfs.c @@ -51,11 +51,46 @@ static ssize_t contexts_show(struct device *device, afu->pasid_count, afu->pasid_max); } +static ssize_t reload_on_reset_show(struct device *device, + struct device_attribute *attr, + char *buf) +{ + struct ocxl_afu *afu = to_afu(device); + struct ocxl_fn *fn = afu->fn; + struct pci_dev *pci_dev = to_pci_dev(fn->dev.parent); + int val; + + if (ocxl_config_get_reset_reload(pci_dev, &val)) + return scnprintf(buf, PAGE_SIZE, "unavailable\n"); + + return scnprintf(buf, PAGE_SIZE, "%d\n", val); +} + +static ssize_t reload_on_reset_store(struct device *device, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct ocxl_afu *afu = to_afu(device); + struct ocxl_fn *fn = afu->fn; + struct pci_dev *pci_dev = to_pci_dev(fn->dev.parent); + int rc, val; + + rc = kstrtoint(buf, 0, &val); + if (rc || (val != 0 && val != 1)) + return -EINVAL; + + if (ocxl_config_set_reset_reload(pci_dev, val)) + return -ENODEV; + + return count; +} + static struct device_attribute afu_attrs[] = { __ATTR_RO(global_mmio_size), __ATTR_RO(pp_mmio_size), __ATTR_RO(afu_version), __ATTR_RO(contexts), + __ATTR_RW(reload_on_reset), }; static ssize_t global_mmio_read(struct file *filp, struct kobject *kobj, diff --git a/include/misc/ocxl-config.h b/include/misc/ocxl-config.h index 3526fa996a22..ccfd3b463517 100644 --- a/include/misc/ocxl-config.h +++ b/include/misc/ocxl-config.h @@ -41,5 +41,6 @@ #define OCXL_DVSEC_VENDOR_CFG_VERS 0x0C #define OCXL_DVSEC_VENDOR_TLX_VERS 0x10 #define OCXL_DVSEC_VENDOR_DLX_VERS 0x20 +#define OCXL_DVSEC_VENDOR_RESET_RELOAD 0x38 #endif /* _OCXL_CONFIG_H_ */ -- 2.39.5