On Wed, 12 Aug 2015 10:48:18 +1000 Daniel Axtens <d...@axtens.net> wrote:
> 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. > Looks much better without all the #ifdefs!! Reviewed-by: Cyril Bur <cyril...@gmail.com> > Signed-off-by: Daniel Axtens <d...@axtens.net> > --- > Documentation/ABI/testing/sysfs-class-cxl | 10 ++++++++++ > drivers/misc/cxl/api.c | 7 +++++++ > drivers/misc/cxl/cxl.h | 1 + > drivers/misc/cxl/pci.c | 7 +++++++ > drivers/misc/cxl/sysfs.c | 26 ++++++++++++++++++++++++++ > include/misc/cxl.h | 10 ++++++++++ > 6 files changed, 61 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-class-cxl > b/Documentation/ABI/testing/sysfs-class-cxl > index acfe9df83139..b07e86d4597f 100644 > --- a/Documentation/ABI/testing/sysfs-class-cxl > +++ b/Documentation/ABI/testing/sysfs-class-cxl > @@ -223,3 +223,13 @@ Description: write only > Writing 1 will issue a PERST to card which may cause the card > to reload the FPGA depending on load_image_on_perst. > Users: https://github.com/ibm-capi/libcxl > + > +What: /sys/class/cxl/<card>/perst_reloads_same_image > +Date: July 2015 > +Contact: linuxppc-dev@lists.ozlabs.org > +Description: read/write > + Trust that when an image is reloaded via PERST, it will not > + have changed. > + 0 = don't trust, the image may be different (default) > + 1 = trust that the image will not change. > +Users: https://github.com/ibm-capi/libcxl > 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 023a2086830b..b4a68a896a33 100644 > --- a/drivers/misc/cxl/pci.c > +++ b/drivers/misc/cxl/pci.c > @@ -874,6 +874,12 @@ 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 > @@ -1148,6 +1154,7 @@ 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), > }; > > diff --git a/include/misc/cxl.h b/include/misc/cxl.h > index 7a6c1d6cc173..f2ffe5bd720d 100644 > --- a/include/misc/cxl.h > +++ b/include/misc/cxl.h > @@ -200,4 +200,14 @@ unsigned int cxl_fd_poll(struct file *file, struct > poll_table_struct *poll); > ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count, > loff_t *off); > > +/* > + * For EEH, a driver may want to assert a PERST will reload the same image > + * from flash into the FPGA. > + * > + * This is a property of the entire adapter, not a single AFU, so drivers > + * should set this property with care! > + */ > +void cxl_perst_reloads_same_image(struct cxl_afu *afu, > + bool perst_reloads_same_image); > + > #endif /* _MISC_CXL_H */ _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
