From 458ba8189cb4380aa6a6cc4d52ab067f80a64829 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Mon, 16 Oct 2023 10:57:48 -0700 Subject: cxl: Add cxl_decoders_committed() helper Add a helper to retrieve the number of decoders committed for the port. Replace all the open coding of the calculation with the helper. Link: https://lore.kernel.org/linux-cxl/651c98472dfed_ae7e729495@dwillia2-xfh.jf.intel.com.notmuch/ Suggested-by: Dan Williams Signed-off-by: Dave Jiang Reviewed-by: Jonathan Cameron Reviewed-by: Jim Harris Reviewed-by: Alison Schofield Link: https://lore.kernel.org/r/169747906849.272156.1729290904857372335.stgit@djiang5-mobl3 Signed-off-by: Dan Williams --- drivers/cxl/core/hdm.c | 7 ++++--- drivers/cxl/core/mbox.c | 2 +- drivers/cxl/core/memdev.c | 4 ++-- drivers/cxl/core/port.c | 7 +++++++ drivers/cxl/cxl.h | 1 + 5 files changed, 15 insertions(+), 6 deletions(-) (limited to 'drivers/cxl') diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index 506c9e14cdf9..7d112557c939 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -643,10 +643,11 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld) if (cxld->flags & CXL_DECODER_F_ENABLE) return 0; - if (port->commit_end + 1 != id) { + if (cxl_num_decoders_committed(port) != id) { dev_dbg(&port->dev, "%s: out of order commit, expected decoder%d.%d\n", - dev_name(&cxld->dev), port->id, port->commit_end + 1); + dev_name(&cxld->dev), port->id, + cxl_num_decoders_committed(port)); return -EBUSY; } @@ -863,7 +864,7 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, cxld->target_type = CXL_DECODER_HOSTONLYMEM; else cxld->target_type = CXL_DECODER_DEVMEM; - if (cxld->id != port->commit_end + 1) { + if (cxld->id != cxl_num_decoders_committed(port)) { dev_warn(&port->dev, "decoder%d.%d: Committed out of order\n", port->id, cxld->id); diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index b91bb9886991..b12986b968da 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -1200,7 +1200,7 @@ int cxl_mem_sanitize(struct cxl_memdev *cxlmd, u16 cmd) * Require an endpoint to be safe otherwise the driver can not * be sure that the device is unmapped. */ - if (endpoint && endpoint->commit_end == -1) + if (endpoint && cxl_num_decoders_committed(endpoint) == 0) rc = __cxl_mem_sanitize(mds, cmd); else rc = -EBUSY; diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c index fed9573cf355..fc5c2b414793 100644 --- a/drivers/cxl/core/memdev.c +++ b/drivers/cxl/core/memdev.c @@ -231,7 +231,7 @@ int cxl_trigger_poison_list(struct cxl_memdev *cxlmd) if (rc) return rc; - if (port->commit_end == -1) { + if (cxl_num_decoders_committed(port) == 0) { /* No regions mapped to this memdev */ rc = cxl_get_poison_by_memdev(cxlmd); } else { @@ -282,7 +282,7 @@ static struct cxl_region *cxl_dpa_to_region(struct cxl_memdev *cxlmd, u64 dpa) .dpa = dpa, }; port = cxlmd->endpoint; - if (port && is_cxl_endpoint(port) && port->commit_end != -1) + if (port && is_cxl_endpoint(port) && cxl_num_decoders_committed(port)) device_for_each_child(&port->dev, &ctx, __cxl_dpa_to_region); return ctx.cxlr; diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 5ba606c6e03f..d0ed98a6bade 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -37,6 +37,13 @@ DECLARE_RWSEM(cxl_region_rwsem); static DEFINE_IDA(cxl_port_ida); static DEFINE_XARRAY(cxl_root_buses); +int cxl_num_decoders_committed(struct cxl_port *port) +{ + lockdep_assert_held(&cxl_region_rwsem); + + return port->commit_end + 1; +} + static ssize_t devtype_show(struct device *dev, struct device_attribute *attr, char *buf) { diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 76d92561af29..36bd3f06dd90 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -679,6 +679,7 @@ static inline bool is_cxl_root(struct cxl_port *port) return port->uport_dev == port->dev.parent; } +int cxl_num_decoders_committed(struct cxl_port *port); bool is_cxl_port(const struct device *dev); struct cxl_port *to_cxl_port(const struct device *dev); struct pci_bus; -- cgit v1.2.3 From 05e37b2138a6deb1f23daf1282dc86b29968a1ab Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Mon, 16 Oct 2023 10:57:54 -0700 Subject: cxl: Add decoders_committed sysfs attribute to cxl_port This attribute allows cxl-cli to determine whether there are decoders committed to a memdev. This is only a snapshot of the state, and doesn't offer any protection or serialization against a concurrent disable-region operation. Reviewed-by: Jim Harris Suggested-by: Dan Williams Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/169747907439.272156.10261062080830155662.stgit@djiang5-mobl3 Signed-off-by: Dan Williams --- Documentation/ABI/testing/sysfs-bus-cxl | 15 +++++++++++++++ drivers/cxl/core/port.c | 25 +++++++++++++++++++++++++ 2 files changed, 40 insertions(+) (limited to 'drivers/cxl') diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 087f762ebfd5..432610f41aee 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -178,6 +178,21 @@ Description: hardware decoder target list. +What: /sys/bus/cxl/devices/portX/decoders_committed +Date: October, 2023 +KernelVersion: v6.7 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) A memory device is considered active when any of its + decoders are in the "committed" state (See CXL 3.0 8.2.4.19.7 + CXL HDM Decoder n Control Register). Hotplug and destructive + operations like "sanitize" are blocked while device is actively + decoding a Host Physical Address range. Note that this number + may be elevated without any regionX objects active or even + enumerated, as this may be due to decoders established by + platform firwmare or a previous kernel (kexec). + + What: /sys/bus/cxl/devices/decoderX.Y Date: June, 2021 KernelVersion: v5.14 diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index d0ed98a6bade..0adee1e406ec 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -534,8 +534,33 @@ static void cxl_port_release(struct device *dev) kfree(port); } +static ssize_t decoders_committed_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cxl_port *port = to_cxl_port(dev); + int rc; + + down_read(&cxl_region_rwsem); + rc = sysfs_emit(buf, "%d\n", cxl_num_decoders_committed(port)); + up_read(&cxl_region_rwsem); + + return rc; +} + +static DEVICE_ATTR_RO(decoders_committed); + +static struct attribute *cxl_port_attrs[] = { + &dev_attr_decoders_committed.attr, + NULL, +}; + +static struct attribute_group cxl_port_attribute_group = { + .attrs = cxl_port_attrs, +}; + static const struct attribute_group *cxl_port_attribute_groups[] = { &cxl_base_attribute_group, + &cxl_port_attribute_group, NULL, }; -- cgit v1.2.3