From 13e68d8bd05c998cae452a4f3400af1e8edd852e Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Fri, 14 Aug 2015 17:41:25 +1000 Subject: cxl: Allow the kernel to trust that an image won't change on PERST. Provide a kernel API and a sysfs entry which allow a user to specify that when a card is PERSTed, it's image will stay the same, allowing it to participate in EEH. cxl_reset is used to reflash the card. In that case, we cannot safely assert that the image will not change. Therefore, disallow cxl_reset if the flag is set. Signed-off-by: Daniel Axtens Signed-off-by: Michael Ellerman --- drivers/misc/cxl/api.c | 7 +++++++ drivers/misc/cxl/cxl.h | 1 + drivers/misc/cxl/pci.c | 7 +++++++ drivers/misc/cxl/sysfs.c | 26 ++++++++++++++++++++++++++ 4 files changed, 41 insertions(+) (limited to 'drivers/misc') diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index 729e0851167d..6a768a9ad22f 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -327,3 +327,10 @@ int cxl_afu_reset(struct cxl_context *ctx) return cxl_afu_check_and_enable(afu); } EXPORT_SYMBOL_GPL(cxl_afu_reset); + +void cxl_perst_reloads_same_image(struct cxl_afu *afu, + bool perst_reloads_same_image) +{ + afu->adapter->perst_same_image = perst_reloads_same_image; +} +EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image); diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index d540542f9931..cda02412b01e 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -493,6 +493,7 @@ struct cxl { bool user_image_loaded; bool perst_loads_image; bool perst_select_user; + bool perst_same_image; }; int cxl_alloc_one_irq(struct cxl *adapter); diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 2b61cb1ee62c..bfbd6478c0c5 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -878,6 +878,12 @@ int cxl_reset(struct cxl *adapter) int i; u32 val; + if (adapter->perst_same_image) { + dev_warn(&dev->dev, + "cxl: refusing to reset/reflash when perst_reloads_same_image is set.\n"); + return -EINVAL; + } + dev_info(&dev->dev, "CXL reset\n"); /* pcie_warm_reset requests a fundamental pci reset which includes a @@ -1151,6 +1157,7 @@ static struct cxl *cxl_init_adapter(struct pci_dev *dev) * configure/reconfigure */ adapter->perst_loads_image = true; + adapter->perst_same_image = false; rc = cxl_configure_adapter(adapter, dev); if (rc) { diff --git a/drivers/misc/cxl/sysfs.c b/drivers/misc/cxl/sysfs.c index 31f38bc71a3d..6619cf1f6e1f 100644 --- a/drivers/misc/cxl/sysfs.c +++ b/drivers/misc/cxl/sysfs.c @@ -112,12 +112,38 @@ static ssize_t load_image_on_perst_store(struct device *device, return count; } +static ssize_t perst_reloads_same_image_show(struct device *device, + struct device_attribute *attr, + char *buf) +{ + struct cxl *adapter = to_cxl_adapter(device); + + return scnprintf(buf, PAGE_SIZE, "%i\n", adapter->perst_same_image); +} + +static ssize_t perst_reloads_same_image_store(struct device *device, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct cxl *adapter = to_cxl_adapter(device); + int rc; + int val; + + rc = sscanf(buf, "%i", &val); + if ((rc != 1) || !(val == 1 || val == 0)) + return -EINVAL; + + adapter->perst_same_image = (val == 1 ? true : false); + return count; +} + static struct device_attribute adapter_attrs[] = { __ATTR_RO(caia_version), __ATTR_RO(psl_revision), __ATTR_RO(base_image), __ATTR_RO(image_loaded), __ATTR_RW(load_image_on_perst), + __ATTR_RW(perst_reloads_same_image), __ATTR(reset, S_IWUSR, NULL, reset_adapter_store), }; -- cgit v1.2.3