diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-cxl | 37 | ||||
| -rw-r--r-- | drivers/cxl/core/core.h | 7 | ||||
| -rw-r--r-- | drivers/cxl/core/hdm.c | 180 | ||||
| -rw-r--r-- | drivers/cxl/core/port.c | 73 |
4 files changed, 295 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 0b672248d126..1ab69aca6152 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -197,7 +197,7 @@ Date: May, 2022 KernelVersion: v5.20 Contact: linux-cxl@vger.kernel.org Description: - (RO) When a CXL decoder is of devtype "cxl_decoder_endpoint" it + (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it translates from a host physical address range, to a device local address range. Device-local address ranges are further split into a 'ram' (volatile memory) range and 'pmem' (persistent @@ -206,3 +206,38 @@ Description: when a decoder straddles the volatile/persistent partition boundary, and 'none' indicates the decoder is not actively decoding, or no DPA allocation policy has been set. + + 'mode' can be written, when the decoder is in the 'disabled' + state, with either 'ram' or 'pmem' to set the boundaries for the + next allocation. + + +What: /sys/bus/cxl/devices/decoderX.Y/dpa_resource +Date: May, 2022 +KernelVersion: v5.20 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) When a CXL decoder is of devtype "cxl_decoder_endpoint", + and its 'dpa_size' attribute is non-zero, this attribute + indicates the device physical address (DPA) base address of the + allocation. + + +What: /sys/bus/cxl/devices/decoderX.Y/dpa_size +Date: May, 2022 +KernelVersion: v5.20 +Contact: linux-cxl@vger.kernel.org +Description: + (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it + translates from a host physical address range, to a device local + address range. The range, base address plus length in bytes, of + DPA allocated to this decoder is conveyed in these 2 attributes. + Allocations can be mutated as long as the decoder is in the + disabled state. A write to 'dpa_size' releases the previous DPA + allocation and then attempts to allocate from the free capacity + in the device partition referred to by 'decoderX.Y/mode'. + Allocate and free requests can only be performed on the highest + instance number disabled decoder with non-zero size. I.e. + allocations are enforced to occur in increasing 'decoderX.Y/id' + order and frees are enforced to occur in decreasing + 'decoderX.Y/id' order. diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index a0808cdaffba..5551b82b2da0 100644 --- a/drivers/cxl/core/core.h +++ b/drivers/cxl/core/core.h @@ -18,6 +18,13 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr, resource_size_t length); struct dentry *cxl_debugfs_create_dir(const char *dir); +int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, + enum cxl_decoder_mode mode); +int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size); +int cxl_dpa_free(struct cxl_endpoint_decoder *cxled); +resource_size_t cxl_dpa_size(struct cxl_endpoint_decoder *cxled); +resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled); + int cxl_memdev_init(void); void cxl_memdev_exit(void); void cxl_mbox_init(void); diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c index 14354f4cd92e..960a77864f33 100644 --- a/drivers/cxl/core/hdm.c +++ b/drivers/cxl/core/hdm.c @@ -184,6 +184,19 @@ static void cxl_dpa_release(void *cxled) up_write(&cxl_dpa_rwsem); } +/* + * Must be called from context that will not race port device + * unregistration, like decoder sysfs attribute methods + */ +static void devm_cxl_dpa_release(struct cxl_endpoint_decoder *cxled) +{ + struct cxl_port *port = cxled_to_port(cxled); + + lockdep_assert_held_write(&cxl_dpa_rwsem); + devm_remove_action(&port->dev, cxl_dpa_release, cxled); + __cxl_dpa_release(cxled); +} + static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, resource_size_t base, resource_size_t len, resource_size_t skipped) @@ -271,6 +284,173 @@ static int devm_cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled); } +resource_size_t cxl_dpa_size(struct cxl_endpoint_decoder *cxled) +{ + resource_size_t size = 0; + + down_read(&cxl_dpa_rwsem); + if (cxled->dpa_res) + size = resource_size(cxled->dpa_res); + up_read(&cxl_dpa_rwsem); + + return size; +} + +resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled) +{ + resource_size_t base = -1; + + down_read(&cxl_dpa_rwsem); + if (cxled->dpa_res) + base = cxled->dpa_res->start; + up_read(&cxl_dpa_rwsem); + + return base; +} + +int cxl_dpa_free(struct cxl_endpoint_decoder *cxled) +{ + struct cxl_port *port = cxled_to_port(cxled); + struct device *dev = &cxled->cxld.dev; + int rc; + + down_write(&cxl_dpa_rwsem); + if (!cxled->dpa_res) { + rc = 0; + goto out; + } + if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) { + dev_dbg(dev, "decoder enabled\n"); + rc = -EBUSY; + goto out; + } + if (cxled->cxld.id != port->hdm_end) { + dev_dbg(dev, "expected decoder%d.%d\n", port->id, + port->hdm_end); + rc = -EBUSY; + goto out; + } + devm_cxl_dpa_release(cxled); + rc = 0; +out: + up_write(&cxl_dpa_rwsem); + return rc; +} + +int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled, + enum cxl_decoder_mode mode) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct device *dev = &cxled->cxld.dev; + int rc; + + switch (mode) { + case CXL_DECODER_RAM: + case CXL_DECODER_PMEM: + break; + default: + dev_dbg(dev, "unsupported mode: %d\n", mode); + return -EINVAL; + } + + down_write(&cxl_dpa_rwsem); + if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) { + rc = -EBUSY; + goto out; + } + + /* + * Only allow modes that are supported by the current partition + * configuration + */ + if (mode == CXL_DECODER_PMEM && !resource_size(&cxlds->pmem_res)) { + dev_dbg(dev, "no available pmem capacity\n"); + rc = -ENXIO; + goto out; + } + if (mode == CXL_DECODER_RAM && !resource_size(&cxlds->ram_res)) { + dev_dbg(dev, "no available ram capacity\n"); + rc = -ENXIO; + goto out; + } + + cxled->mode = mode; + rc = 0; +out: + up_write(&cxl_dpa_rwsem); + + return rc; +} + +int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + resource_size_t free_ram_start, free_pmem_start; + struct cxl_port *port = cxled_to_port(cxled); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct device *dev = &cxled->cxld.dev; + resource_size_t start, avail, skip; + struct resource *p, *last; + int rc; + + down_write(&cxl_dpa_rwsem); + if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) { + dev_dbg(dev, "decoder enabled\n"); + rc = -EBUSY; + goto out; + } + + for (p = cxlds->ram_res.child, last = NULL; p; p = p->sibling) + last = p; + if (last) + free_ram_start = last->end + 1; + else + free_ram_start = cxlds->ram_res.start; + + for (p = cxlds->pmem_res.child, last = NULL; p; p = p->sibling) + last = p; + if (last) + free_pmem_start = last->end + 1; + else + free_pmem_start = cxlds->pmem_res.start; + + if (cxled->mode == CXL_DECODER_RAM) { + start = free_ram_start; + avail = cxlds->ram_res.end - start + 1; + skip = 0; + } else if (cxled->mode == CXL_DECODER_PMEM) { + resource_size_t skip_start, skip_end; + + start = free_pmem_start; + avail = cxlds->pmem_res.end - start + 1; + skip_start = free_ram_start; + skip_end = start - 1; + skip = skip_end - skip_start + 1; + } else { + dev_dbg(dev, "mode not set\n"); + rc = -EINVAL; + goto out; + } + + if (size > avail) { + dev_dbg(dev, "%pa exceeds available %s capacity: %pa\n", &size, + cxled->mode == CXL_DECODER_RAM ? "ram" : "pmem", + &avail); + rc = -ENOSPC; + goto out; + } + + rc = __cxl_dpa_reserve(cxled, start, size, skip); +out: + up_write(&cxl_dpa_rwsem); + + if (rc) + return rc; + + return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled); +} + static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, int *target_map, void __iomem *hdm, int which, u64 *dpa_base) diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 635d63e2f8a8..e301cf7e5141 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -189,7 +189,76 @@ static ssize_t mode_show(struct device *dev, struct device_attribute *attr, return sysfs_emit(buf, "mixed\n"); } } -static DEVICE_ATTR_RO(mode); + +static ssize_t mode_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev); + enum cxl_decoder_mode mode; + ssize_t rc; + + if (sysfs_streq(buf, "pmem")) + mode = CXL_DECODER_PMEM; + else if (sysfs_streq(buf, "ram")) + mode = CXL_DECODER_RAM; + else + return -EINVAL; + + rc = cxl_dpa_set_mode(cxled, mode); + if (rc) + return rc; + + return len; +} +static DEVICE_ATTR_RW(mode); + +static ssize_t dpa_resource_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev); + u64 base = cxl_dpa_resource_start(cxled); + + return sysfs_emit(buf, "%#llx\n", base); +} +static DEVICE_ATTR_RO(dpa_resource); + +static ssize_t dpa_size_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev); + resource_size_t size = cxl_dpa_size(cxled); + + return sysfs_emit(buf, "%pa\n", &size); +} + +static ssize_t dpa_size_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev); + unsigned long long size; + ssize_t rc; + + rc = kstrtoull(buf, 0, &size); + if (rc) + return rc; + + if (!IS_ALIGNED(size, SZ_256M)) + return -EINVAL; + + rc = cxl_dpa_free(cxled); + if (rc) + return rc; + + if (size == 0) + return len; + + rc = cxl_dpa_alloc(cxled, size); + if (rc) + return rc; + + return len; +} +static DEVICE_ATTR_RW(dpa_size); static struct attribute *cxl_decoder_base_attrs[] = { &dev_attr_start.attr, @@ -242,6 +311,8 @@ static const struct attribute_group *cxl_decoder_switch_attribute_groups[] = { static struct attribute *cxl_decoder_endpoint_attrs[] = { &dev_attr_target_type.attr, &dev_attr_mode.attr, + &dev_attr_dpa_size.attr, + &dev_attr_dpa_resource.attr, NULL, }; |