From 2ec1b17f745b08526220f3c169d2eb9799a9be39 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Fri, 6 Jan 2023 09:39:49 -0700 Subject: cxl: fix cxl_report_and_clear() RAS UE addr mis-assignment 'addr' that contains RAS UE register address is re-assigned to RAS_CAP_CONTROL offset if there are multiple UE errors. Use different addr variable to avoid the reassignment mistake. Fixes: 2905cb5236cb ("cxl/pci: Add (hopeful) error handling support") Reported-by: Jonathan Cameron Signed-off-by: Dave Jiang Reviewed-by: Jonathan Cameron Reviewed-by: Ira Weiny Link: https://lore.kernel.org/r/167302318779.580155.15233596744650706167.stgit@djiang5-mobl3.local Signed-off-by: Dan Williams --- drivers/cxl/pci.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index 33083a522fd1..258004f34281 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -554,8 +554,11 @@ static bool cxl_report_and_clear(struct cxl_dev_state *cxlds) /* If multiple errors, log header points to first error from ctrl reg */ if (hweight32(status) > 1) { - addr = cxlds->regs.ras + CXL_RAS_CAP_CONTROL_OFFSET; - fe = BIT(FIELD_GET(CXL_RAS_CAP_CONTROL_FE_MASK, readl(addr))); + void __iomem *rcc_addr = + cxlds->regs.ras + CXL_RAS_CAP_CONTROL_OFFSET; + + fe = BIT(FIELD_GET(CXL_RAS_CAP_CONTROL_FE_MASK, + readl(rcc_addr))); } else { fe = status; } -- cgit v1.2.3 From 19398821b25a9cde564265262e680ae1c2351be7 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 20 Jan 2023 16:26:12 -0800 Subject: cxl/pmem: Fix nvdimm unregistration when cxl_pmem driver is absent The cxl_pmem.ko module houses the driver for both cxl_nvdimm_bridge objects and cxl_nvdimm objects. When the core creates a cxl_nvdimm it arranges for it to be autoremoved when the bridge goes down. However, if the bridge never initialized because the cxl_pmem.ko module never loaded, it sets up a the following crash scenario: BUG: kernel NULL pointer dereference, address: 0000000000000478 [..] RIP: 0010:cxl_nvdimm_probe+0x99/0x140 [cxl_pmem] [..] Call Trace: cxl_bus_probe+0x17/0x50 [cxl_core] really_probe+0xde/0x380 __driver_probe_device+0x78/0x170 driver_probe_device+0x1f/0x90 __driver_attach+0xd2/0x1c0 bus_for_each_dev+0x79/0xc0 bus_add_driver+0x1b1/0x200 driver_register+0x89/0xe0 cxl_pmem_init+0x50/0xff0 [cxl_pmem] It turns out the recent rework to simplify nvdimm probing obviated the need to unregister cxl_nvdimm objects at cxl_nvdimm_bridge ->remove() time. Leave the cxl_nvdimm device registered until the hosting cxl_memdev departs. The alternative is that the cxl_memdev needs to be reattached whenever the cxl_nvdimm_bridge attach state cycles, which is awkward and unnecessary. The only requirement is to make sure that when the cxl_nvdimm_bridge goes away any dependent cxl_nvdimm objects are shutdown. Handle that in unregister_nvdimm_bus(). With these registration entanglements removed there is no longer a need to pre-load the cxl_pmem module in cxl_acpi. Fixes: cb9cfff82f6a ("cxl/acpi: Simplify cxl_nvdimm_bridge probing") Reported-by: Gregory Price Debugged-by: Jonathan Cameron Tested-by: Jonathan Cameron Reviewed-by: Jonathan Cameron Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/167426077263.3955046.9695309346988027311.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams --- drivers/cxl/acpi.c | 1 - drivers/cxl/core/pmem.c | 42 ++++-------------------------------------- drivers/cxl/pmem.c | 24 ++++++++++++++++++++++++ 3 files changed, 28 insertions(+), 39 deletions(-) diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index ad0849af42d7..13cde44c6086 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -736,4 +736,3 @@ module_exit(cxl_acpi_exit); MODULE_LICENSE("GPL v2"); MODULE_IMPORT_NS(CXL); MODULE_IMPORT_NS(ACPI); -MODULE_SOFTDEP("pre: cxl_pmem"); diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c index f3d2169b6731..c2e4b1093788 100644 --- a/drivers/cxl/core/pmem.c +++ b/drivers/cxl/core/pmem.c @@ -227,34 +227,16 @@ static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_nvdimm_bridge *cxl_nvb, return cxl_nvd; } -static void cxl_nvd_unregister(void *_cxl_nvd) +static void cxlmd_release_nvdimm(void *_cxlmd) { - struct cxl_nvdimm *cxl_nvd = _cxl_nvd; - struct cxl_memdev *cxlmd = cxl_nvd->cxlmd; + struct cxl_memdev *cxlmd = _cxlmd; + struct cxl_nvdimm *cxl_nvd = cxlmd->cxl_nvd; struct cxl_nvdimm_bridge *cxl_nvb = cxlmd->cxl_nvb; - /* - * Either the bridge is in ->remove() context under the device_lock(), - * or cxlmd_release_nvdimm() is cancelling the bridge's release action - * for @cxl_nvd and doing it itself (while manually holding the bridge - * lock). - */ - device_lock_assert(&cxl_nvb->dev); cxl_nvd->cxlmd = NULL; cxlmd->cxl_nvd = NULL; + cxlmd->cxl_nvb = NULL; device_unregister(&cxl_nvd->dev); -} - -static void cxlmd_release_nvdimm(void *_cxlmd) -{ - struct cxl_memdev *cxlmd = _cxlmd; - struct cxl_nvdimm_bridge *cxl_nvb = cxlmd->cxl_nvb; - - device_lock(&cxl_nvb->dev); - if (cxlmd->cxl_nvd) - devm_release_action(&cxl_nvb->dev, cxl_nvd_unregister, - cxlmd->cxl_nvd); - device_unlock(&cxl_nvb->dev); put_device(&cxl_nvb->dev); } @@ -293,22 +275,6 @@ int devm_cxl_add_nvdimm(struct cxl_memdev *cxlmd) dev_dbg(&cxlmd->dev, "register %s\n", dev_name(dev)); - /* - * The two actions below arrange for @cxl_nvd to be deleted when either - * the top-level PMEM bridge goes down, or the endpoint device goes - * through ->remove(). - */ - device_lock(&cxl_nvb->dev); - if (cxl_nvb->dev.driver) - rc = devm_add_action_or_reset(&cxl_nvb->dev, cxl_nvd_unregister, - cxl_nvd); - else - rc = -ENXIO; - device_unlock(&cxl_nvb->dev); - - if (rc) - goto err_alloc; - /* @cxlmd carries a reference on @cxl_nvb until cxlmd_release_nvdimm */ return devm_add_action_or_reset(&cxlmd->dev, cxlmd_release_nvdimm, cxlmd); diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c index eedefebc4283..08bbbac9a6d0 100644 --- a/drivers/cxl/pmem.c +++ b/drivers/cxl/pmem.c @@ -225,11 +225,35 @@ static int cxl_pmem_ctl(struct nvdimm_bus_descriptor *nd_desc, return cxl_pmem_nvdimm_ctl(nvdimm, cmd, buf, buf_len); } +static int detach_nvdimm(struct device *dev, void *data) +{ + struct cxl_nvdimm *cxl_nvd; + bool release = false; + + if (!is_cxl_nvdimm(dev)) + return 0; + + device_lock(dev); + if (!dev->driver) + goto out; + + cxl_nvd = to_cxl_nvdimm(dev); + if (cxl_nvd->cxlmd && cxl_nvd->cxlmd->cxl_nvb == data) + release = true; +out: + device_unlock(dev); + if (release) + device_release_driver(dev); + return 0; +} + static void unregister_nvdimm_bus(void *_cxl_nvb) { struct cxl_nvdimm_bridge *cxl_nvb = _cxl_nvb; struct nvdimm_bus *nvdimm_bus = cxl_nvb->nvdimm_bus; + bus_for_each_dev(&cxl_bus_type, NULL, cxl_nvb, detach_nvdimm); + cxl_nvb->nvdimm_bus = NULL; nvdimm_bus_unregister(nvdimm_bus); } -- cgit v1.2.3