Messages in this thread | | | From | Dan Williams <> | Date | Fri, 11 Jun 2021 17:34:06 -0700 | Subject | Re: [PATCH 5/5] cxl/pmem: Register 'pmem' / cxl_nvdimm devices |
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On Fri, Jun 11, 2021 at 5:57 AM Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: > > On Thu, 10 Jun 2021 15:26:26 -0700 > Dan Williams <dan.j.williams@intel.com> wrote: > > > While a memX device on /sys/bus/cxl represents a CXL memory expander > > control interface, a pmemX device represents the persistent memory > > sub-functionality. It bridges the CXL subystem to the libnvdimm nmemX > > control interface. > > > > With this skeleton ndctl can now see persistent memory devices on a > > "CXL" bus. Later patches add support for translating libnvdimm native > > commands to CXL commands. > > > > # ndctl list -BDiu -b CXL > > { > > "provider":"CXL", > > "dev":"ndbus1", > > "dimms":[ > > { > > "dev":"nmem1", > > "state":"disabled" > > }, > > { > > "dev":"nmem0", > > "state":"disabled" > > } > > ] > > } > > > > Given nvdimm_bus_unregister() removes all devices on an ndbus0 the > > cxl_pmem infrastructure needs to arrange ->remove() to be triggered on > > cxl_nvdimm devices to keep their enabled state synchronized with the > > registration state of their corresponding device on the nvdimm_bus. In > > other words, always arrange for cxl_nvdimm_driver.remove() to unregister > > nvdimms from an nvdimm_bus ahead of the bus being unregistered. > > > > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > Being my usual fussy self, I've highlighed a few header changes that > as far as I can see are unrelated to this specific patch. > > Otherwise, one request for a local variable name change and > a bit of trivial editorial stuff. > > Thanks, > > Jonathan > > > > --- > > drivers/cxl/core.c | 86 ++++++++++++++++++++++++++++++++++++++++ > > drivers/cxl/cxl.h | 13 ++++++ > > drivers/cxl/mem.h | 2 + > > drivers/cxl/pci.c | 23 ++++++++--- > > drivers/cxl/pmem.c | 111 +++++++++++++++++++++++++++++++++++++++++++++++----- > > 5 files changed, 217 insertions(+), 18 deletions(-) > > > > diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c > > index f0305c9c91c8..6db660249cea 100644 > > --- a/drivers/cxl/core.c > > +++ b/drivers/cxl/core.c > > @@ -7,6 +7,7 @@ > > #include <linux/slab.h> > > #include <linux/idr.h> > > #include "cxl.h" > > +#include "mem.h"
Looks like this can go too...
> > > > /** > > * DOC: cxl core > > @@ -731,6 +732,89 @@ struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host, > > } > > EXPORT_SYMBOL_GPL(devm_cxl_add_nvdimm_bridge); > > > > +static void cxl_nvdimm_release(struct device *dev) > > +{ > > + struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev); > > + > > + kfree(cxl_nvd); > > +} > > + > > +static const struct attribute_group *cxl_nvdimm_attribute_groups[] = { > > + &cxl_base_attribute_group, > > + NULL, > > +}; > > + > > +static const struct device_type cxl_nvdimm_type = { > > + .name = "cxl_nvdimm", > > + .release = cxl_nvdimm_release, > > + .groups = cxl_nvdimm_attribute_groups, > > +}; > > + > > +bool is_cxl_nvdimm(struct device *dev) > > +{ > > + return dev->type == &cxl_nvdimm_type; > > +} > > +EXPORT_SYMBOL_GPL(is_cxl_nvdimm); > > + > > +struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev) > > +{ > > + if (dev_WARN_ONCE(dev, !is_cxl_nvdimm(dev), > > + "not a cxl_nvdimm device\n")) > > + return NULL; > > + return container_of(dev, struct cxl_nvdimm, dev); > > +} > > +EXPORT_SYMBOL_GPL(to_cxl_nvdimm); > > + > > +static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_memdev *cxlmd) > > +{ > > + struct cxl_nvdimm *cxl_nvd; > > + struct device *dev; > > + > > + cxl_nvd = kzalloc(sizeof(*cxl_nvd), GFP_KERNEL); > > + if (!cxl_nvd) > > + return ERR_PTR(-ENOMEM); > > + > > + dev = &cxl_nvd->dev; > > + cxl_nvd->cxlmd = cxlmd; > > + device_initialize(dev); > > + device_set_pm_not_required(dev); > > + dev->parent = &cxlmd->dev; > > + dev->bus = &cxl_bus_type; > > + dev->type = &cxl_nvdimm_type; > > + > > + return cxl_nvd; > > +} > > + > > +int devm_cxl_add_nvdimm(struct device *host, struct cxl_memdev *cxlmd) > > +{ > > + struct cxl_nvdimm *cxl_nvd; > > + struct device *dev; > > + int rc; > > + > > + cxl_nvd = cxl_nvdimm_alloc(cxlmd); > > + if (IS_ERR(cxl_nvd)) > > + return PTR_ERR(cxl_nvd); > > + > > + dev = &cxl_nvd->dev; > > + rc = dev_set_name(dev, "pmem%d", cxlmd->id); > > + if (rc) > > + goto err; > > + > > + rc = device_add(dev); > > + if (rc) > > + goto err; > > + > > + dev_dbg(host, "%s: register %s\n", dev_name(dev->parent), > > + dev_name(dev)); > > + > > + return devm_add_action_or_reset(host, unregister_dev, dev); > > + > > +err: > > + put_device(dev); > > + return rc; > > +} > > +EXPORT_SYMBOL_GPL(devm_cxl_add_nvdimm); > > + > > /** > > * cxl_probe_device_regs() - Detect CXL Device register blocks > > * @dev: Host device of the @base mapping > > @@ -930,6 +1014,8 @@ static int cxl_device_id(struct device *dev) > > { > > if (dev->type == &cxl_nvdimm_bridge_type) > > return CXL_DEVICE_NVDIMM_BRIDGE; > > + if (dev->type == &cxl_nvdimm_type) > > + return CXL_DEVICE_NVDIMM; > > return 0; > > } > > > > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > > index 47fcb7ad5978..3f9a6f7b05db 100644 > > --- a/drivers/cxl/cxl.h > > +++ b/drivers/cxl/cxl.h > > @@ -213,6 +213,13 @@ struct cxl_nvdimm_bridge { > > enum cxl_nvdimm_brige_state state; > > }; > > > > +struct cxl_mem; > > Above looks unrelated as you've not added any uses of cxl_mem
I think it was a refactoring leftover from an abandoned approach.
Gone now.
> > > +struct cxl_nvdimm { > > + struct device dev; > > + struct cxl_memdev *cxlmd; > > + struct nvdimm *nvdimm; > > +}; > > + > > /** > > * struct cxl_port - logical collection of upstream port devices and > > * downstream port devices to construct a CXL memory > > @@ -299,7 +306,8 @@ int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner, > > #define cxl_driver_register(x) __cxl_driver_register(x, THIS_MODULE, KBUILD_MODNAME) > > void cxl_driver_unregister(struct cxl_driver *cxl_drv); > > > > -#define CXL_DEVICE_NVDIMM_BRIDGE 1 > > +#define CXL_DEVICE_NVDIMM_BRIDGE 1 > > +#define CXL_DEVICE_NVDIMM 2 > > > > #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*") > > #define CXL_MODALIAS_FMT "cxl:t%d" > > @@ -307,4 +315,7 @@ void cxl_driver_unregister(struct cxl_driver *cxl_drv); > > struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev); > > struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host, > > struct cxl_port *port); > > +struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev); > > +bool is_cxl_nvdimm(struct device *dev); > > +int devm_cxl_add_nvdimm(struct device *host, struct cxl_memdev *cxlmd); > > #endif /* __CXL_H__ */ > > diff --git a/drivers/cxl/mem.h b/drivers/cxl/mem.h > > index 13868ff7cadf..8f02d02b26b4 100644 > > --- a/drivers/cxl/mem.h > > +++ b/drivers/cxl/mem.h > > @@ -2,6 +2,8 @@ > > /* Copyright(c) 2020-2021 Intel Corporation. */ > > #ifndef __CXL_MEM_H__ > > #define __CXL_MEM_H__ > > +#include <linux/cdev.h> > > Unrelated to rest of patch. Good to add this, but not hidden in this > patch.
Yup.
> > > +#include "cxl.h" > > > > /* CXL 2.0 8.2.8.5.1.1 Memory Device Status Register */ > > #define CXLMDEV_STATUS_OFFSET 0x0 > > diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c > > index 5a1705b52278..83e81b44c8f5 100644 > > --- a/drivers/cxl/pci.c > > +++ b/drivers/cxl/pci.c > > @@ -1313,7 +1313,8 @@ static struct cxl_memdev *cxl_memdev_alloc(struct cxl_mem *cxlm) > > return ERR_PTR(rc); > > } > > > > -static int cxl_mem_add_memdev(struct cxl_mem *cxlm) > > +static struct cxl_memdev *devm_cxl_add_memdev(struct device *host, > > + struct cxl_mem *cxlm) > > { > > struct cxl_memdev *cxlmd; > > struct device *dev; > > @@ -1322,7 +1323,7 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) > > > > cxlmd = cxl_memdev_alloc(cxlm); > > if (IS_ERR(cxlmd)) > > - return PTR_ERR(cxlmd); > > + return cxlmd; > > > > dev = &cxlmd->dev; > > rc = dev_set_name(dev, "mem%d", cxlmd->id); > > @@ -1340,8 +1341,10 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) > > if (rc) > > goto err; > > > > - return devm_add_action_or_reset(dev->parent, cxl_memdev_unregister, > > - cxlmd); > > + rc = devm_add_action_or_reset(host, cxl_memdev_unregister, cxlmd); > > + if (rc) > > + return ERR_PTR(rc); > > + return cxlmd; > > > > err: > > /* > > @@ -1350,7 +1353,7 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm) > > */ > > cxl_memdev_shutdown(cxlmd); > > put_device(dev); > > - return rc; > > + return ERR_PTR(rc); > > } > > > > static int cxl_xfer_log(struct cxl_mem *cxlm, uuid_t *uuid, u32 size, u8 *out) > > @@ -1561,6 +1564,7 @@ static int cxl_mem_identify(struct cxl_mem *cxlm) > > > > static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > { > > + struct cxl_memdev *cxlmd; > > struct cxl_mem *cxlm; > > int rc; > > > > @@ -1588,7 +1592,14 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > if (rc) > > return rc; > > > > - return cxl_mem_add_memdev(cxlm); > > + cxlmd = devm_cxl_add_memdev(&pdev->dev, cxlm); > > + if (IS_ERR(cxlmd)) > > + return PTR_ERR(cxlmd); > > + > > + if (range_len(&cxlm->pmem_range) && IS_ENABLED(CONFIG_CXL_PMEM)) > > + rc = devm_cxl_add_nvdimm(&pdev->dev, cxlmd); > > + > > + return rc; > > } > > > > static const struct pci_device_id cxl_mem_pci_tbl[] = { > > diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c > > index 0067bd734559..1ed19e213157 100644 > > --- a/drivers/cxl/pmem.c > > +++ b/drivers/cxl/pmem.c > > @@ -3,7 +3,10 @@ > > #include <linux/libnvdimm.h> > > #include <linux/device.h> > > #include <linux/module.h> > > +#include <linux/ndctl.h> > > +#include <linux/async.h> > > #include <linux/slab.h> > > +#include "mem.h" > > #include "cxl.h" > > > > /* > > @@ -13,6 +16,64 @@ > > */ > > static struct workqueue_struct *cxl_pmem_wq; > > > > +static void unregister_nvdimm(void *nvdimm) > > +{ > > + nvdimm_delete(nvdimm); > > +} > > + > > +static int match_nvdimm_bridge(struct device *dev, const void *data) > > +{ > > + return strcmp(dev_name(dev), "nvdimm-bridge") == 0; > > +} > > + > > +static struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(void) > > +{ > > + struct device *dev; > > + > > + dev = bus_find_device(&cxl_bus_type, NULL, NULL, match_nvdimm_bridge); > > Hmm. It's a singleton, so you could just stash the pointer somewhere > appropriate, but I guess this avoids adding extra infrastructure around > that, so fair enough.
Yeah, it's a singleton only by convention. If you want to have multiple CXL nvdimm buses the core won't prevent it.
> > > + if (!dev) > > + return NULL; > > + return to_cxl_nvdimm_bridge(dev); > > +} > > + > > +static int cxl_nvdimm_probe(struct device *dev) > > +{ > > + struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev); > > + struct cxl_nvdimm_bridge *cxl_nvb; > > + unsigned long flags = 0; > > + struct nvdimm *nvdimm; > > + int rc = -ENXIO; > > + > > + cxl_nvb = cxl_find_nvdimm_bridge(); > > + if (!cxl_nvb) > > + return -ENXIO; > > + > > + device_lock(&cxl_nvb->dev); > > + if (!cxl_nvb->nvdimm_bus) > > + goto out; > > + > > + set_bit(NDD_LABELING, &flags); > > + nvdimm = nvdimm_create(cxl_nvb->nvdimm_bus, cxl_nvd, NULL, flags, 0, 0, > > + NULL); > > + if (!nvdimm) > > + goto out; > > + > > + dev_set_drvdata(dev, nvdimm); > > Why? No harm done, but I wanted to check this was only used to get the > nvdimm, but can't find where it's used at all.
Yup, vestigial. I thought I would use it in the release action, but now it's just passed directly to unregister_nvdimm().
> > > + > > + rc = devm_add_action_or_reset(dev, unregister_nvdimm, nvdimm); > > +out: > > + device_unlock(&cxl_nvb->dev); > > + put_device(&cxl_nvb->dev); > > + > > + return rc; > > +} > > + > > +static struct cxl_driver cxl_nvdimm_driver = { > > + .name = "cxl_nvdimm", > > + .probe = cxl_nvdimm_probe, > > + .id = CXL_DEVICE_NVDIMM, > > +}; > > + > > static int cxl_pmem_ctl(struct nvdimm_bus_descriptor *nd_desc, > > struct nvdimm *nvdimm, unsigned int cmd, void *buf, > > unsigned int buf_len, int *cmd_rc) > > @@ -28,19 +89,31 @@ static void online_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb) > > nvdimm_bus_register(&cxl_nvb->dev, &cxl_nvb->nd_desc); > > } > > > > -static void offline_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb) > > +static int cxl_nvdimm_release_driver(struct device *dev, void *data) > > { > > - if (!cxl_nvb->nvdimm_bus) > > - return; > > - nvdimm_bus_unregister(cxl_nvb->nvdimm_bus); > > - cxl_nvb->nvdimm_bus = NULL; > > + if (!is_cxl_nvdimm(dev)) > > + return 0; > > + device_release_driver(dev); > > + return 0; > > +} > > + > > +static void offline_nvdimm_bus(struct nvdimm_bus *nvdimm_bus) > > +{ > > + /* > > + * Set the state of cxl_nvdimm devices to unbound / idle before > > + * nvdimm_bus_unregister() rips the nvdimm objects out from > > + * underneath them. > > + */ > > + bus_for_each_dev(&cxl_bus_type, NULL, NULL, cxl_nvdimm_release_driver); > > + nvdimm_bus_unregister(nvdimm_bus); > > } > > > > static void cxl_nvb_update_state(struct work_struct *work) > > { > > struct cxl_nvdimm_bridge *cxl_nvb = > > container_of(work, typeof(*cxl_nvb), state_work); > > - bool release = false; > > + struct nvdimm_bus *nvdimm_bus = NULL; > > + bool release = false, rescan = false; > > > > device_lock(&cxl_nvb->dev); > > switch (cxl_nvb->state) { > > @@ -50,11 +123,13 @@ static void cxl_nvb_update_state(struct work_struct *work) > > dev_err(&cxl_nvb->dev, > > "failed to establish nvdimm bus\n"); > > release = true; > > - } > > + } else > > + rescan = true; > > break; > > case CXL_NVB_OFFLINE: > > case CXL_NVB_DEAD: > > - offline_nvdimm_bus(cxl_nvb); > > + nvdimm_bus = cxl_nvb->nvdimm_bus; > > Perhaps rename this to make it clear that it only exists as a means > to offline it later? I wondered briefly why you were offlining > any bus that existed (e.g. in the online case) > > nvdimm_bus_to_offline = ... >
Good point, although I renamed it to "victim_bus", and made offline_nvdimm_bus() handle the NULL bus case, so now it reads with no conditional.
offline_nvdimm_bus(victim_bus);
> > + cxl_nvb->nvdimm_bus = NULL; > > break; > > default: > > break; > > @@ -63,6 +138,13 @@ static void cxl_nvb_update_state(struct work_struct *work) > > > > if (release) > > device_release_driver(&cxl_nvb->dev); > > + if (rescan) { > > + int rc = bus_rescan_devices(&cxl_bus_type); > > + > > + dev_dbg(&cxl_nvb->dev, "rescan: %d\n", rc); > > + } > > + if (nvdimm_bus) > > + offline_nvdimm_bus(nvdimm_bus); > > > > put_device(&cxl_nvb->dev); > > } > > @@ -113,23 +195,29 @@ static __init int cxl_pmem_init(void) > > int rc; > > > > cxl_pmem_wq = alloc_ordered_workqueue("cxl_pmem", 0); > > - > > Shouldn't be here obviously. Move to earlier patch.
Yup.
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