diff options
Diffstat (limited to 'drivers/cxl/core/hdm.c')
| -rw-r--r-- | drivers/cxl/core/hdm.c | 865 |
1 files changed, 865 insertions, 0 deletions
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c new file mode 100644 index 000000000..8c1db4e1b --- /dev/null +++ b/drivers/cxl/core/hdm.c @@ -0,0 +1,865 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright(c) 2022 Intel Corporation. All rights reserved. */ +#include <linux/io-64-nonatomic-hi-lo.h> +#include <linux/seq_file.h> +#include <linux/device.h> +#include <linux/delay.h> + +#include "cxlmem.h" +#include "core.h" + +/** + * DOC: cxl core hdm + * + * Compute Express Link Host Managed Device Memory, starting with the + * CXL 2.0 specification, is managed by an array of HDM Decoder register + * instances per CXL port and per CXL endpoint. Define common helpers + * for enumerating these registers and capabilities. + */ + +DECLARE_RWSEM(cxl_dpa_rwsem); + +static int add_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, + int *target_map) +{ + int rc; + + rc = cxl_decoder_add_locked(cxld, target_map); + if (rc) { + put_device(&cxld->dev); + dev_err(&port->dev, "Failed to add decoder\n"); + return rc; + } + + rc = cxl_decoder_autoremove(&port->dev, cxld); + if (rc) + return rc; + + dev_dbg(&cxld->dev, "Added to port %s\n", dev_name(&port->dev)); + + return 0; +} + +/* + * Per the CXL specification (8.2.5.12 CXL HDM Decoder Capability Structure) + * single ported host-bridges need not publish a decoder capability when a + * passthrough decode can be assumed, i.e. all transactions that the uport sees + * are claimed and passed to the single dport. Disable the range until the first + * CXL region is enumerated / activated. + */ +int devm_cxl_add_passthrough_decoder(struct cxl_port *port) +{ + struct cxl_switch_decoder *cxlsd; + struct cxl_dport *dport = NULL; + int single_port_map[1]; + unsigned long index; + + cxlsd = cxl_switch_decoder_alloc(port, 1); + if (IS_ERR(cxlsd)) + return PTR_ERR(cxlsd); + + device_lock_assert(&port->dev); + + xa_for_each(&port->dports, index, dport) + break; + single_port_map[0] = dport->port_id; + + return add_hdm_decoder(port, &cxlsd->cxld, single_port_map); +} +EXPORT_SYMBOL_NS_GPL(devm_cxl_add_passthrough_decoder, CXL); + +static void parse_hdm_decoder_caps(struct cxl_hdm *cxlhdm) +{ + u32 hdm_cap; + + hdm_cap = readl(cxlhdm->regs.hdm_decoder + CXL_HDM_DECODER_CAP_OFFSET); + cxlhdm->decoder_count = cxl_hdm_decoder_count(hdm_cap); + cxlhdm->target_count = + FIELD_GET(CXL_HDM_DECODER_TARGET_COUNT_MASK, hdm_cap); + if (FIELD_GET(CXL_HDM_DECODER_INTERLEAVE_11_8, hdm_cap)) + cxlhdm->interleave_mask |= GENMASK(11, 8); + if (FIELD_GET(CXL_HDM_DECODER_INTERLEAVE_14_12, hdm_cap)) + cxlhdm->interleave_mask |= GENMASK(14, 12); +} + +static void __iomem *map_hdm_decoder_regs(struct cxl_port *port, + void __iomem *crb) +{ + struct cxl_component_reg_map map; + + cxl_probe_component_regs(&port->dev, crb, &map); + if (!map.hdm_decoder.valid) { + dev_err(&port->dev, "HDM decoder registers invalid\n"); + return IOMEM_ERR_PTR(-ENXIO); + } + + return crb + map.hdm_decoder.offset; +} + +/** + * devm_cxl_setup_hdm - map HDM decoder component registers + * @port: cxl_port to map + */ +struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port) +{ + struct device *dev = &port->dev; + void __iomem *crb, *hdm; + struct cxl_hdm *cxlhdm; + + cxlhdm = devm_kzalloc(dev, sizeof(*cxlhdm), GFP_KERNEL); + if (!cxlhdm) + return ERR_PTR(-ENOMEM); + + cxlhdm->port = port; + crb = devm_cxl_iomap_block(dev, port->component_reg_phys, + CXL_COMPONENT_REG_BLOCK_SIZE); + if (!crb) { + dev_err(dev, "No component registers mapped\n"); + return ERR_PTR(-ENXIO); + } + + hdm = map_hdm_decoder_regs(port, crb); + if (IS_ERR(hdm)) + return ERR_CAST(hdm); + cxlhdm->regs.hdm_decoder = hdm; + + parse_hdm_decoder_caps(cxlhdm); + if (cxlhdm->decoder_count == 0) { + dev_err(dev, "Spec violation. Caps invalid\n"); + return ERR_PTR(-ENXIO); + } + + dev_set_drvdata(dev, cxlhdm); + + return cxlhdm; +} +EXPORT_SYMBOL_NS_GPL(devm_cxl_setup_hdm, CXL); + +static void __cxl_dpa_debug(struct seq_file *file, struct resource *r, int depth) +{ + unsigned long long start = r->start, end = r->end; + + seq_printf(file, "%*s%08llx-%08llx : %s\n", depth * 2, "", start, end, + r->name); +} + +void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds) +{ + struct resource *p1, *p2; + + down_read(&cxl_dpa_rwsem); + for (p1 = cxlds->dpa_res.child; p1; p1 = p1->sibling) { + __cxl_dpa_debug(file, p1, 0); + for (p2 = p1->child; p2; p2 = p2->sibling) + __cxl_dpa_debug(file, p2, 1); + } + up_read(&cxl_dpa_rwsem); +} +EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, CXL); + +/* + * Must be called in a context that synchronizes against this decoder's + * port ->remove() callback (like an endpoint decoder sysfs attribute) + */ +static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_port *port = cxled_to_port(cxled); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct resource *res = cxled->dpa_res; + resource_size_t skip_start; + + lockdep_assert_held_write(&cxl_dpa_rwsem); + + /* save @skip_start, before @res is released */ + skip_start = res->start - cxled->skip; + __release_region(&cxlds->dpa_res, res->start, resource_size(res)); + if (cxled->skip) + __release_region(&cxlds->dpa_res, skip_start, cxled->skip); + cxled->skip = 0; + cxled->dpa_res = NULL; + put_device(&cxled->cxld.dev); + port->hdm_end--; +} + +static void cxl_dpa_release(void *cxled) +{ + down_write(&cxl_dpa_rwsem); + __cxl_dpa_release(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) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_port *port = cxled_to_port(cxled); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct device *dev = &port->dev; + struct resource *res; + + lockdep_assert_held_write(&cxl_dpa_rwsem); + + if (!len) { + dev_warn(dev, "decoder%d.%d: empty reservation attempted\n", + port->id, cxled->cxld.id); + return -EINVAL; + } + + if (cxled->dpa_res) { + dev_dbg(dev, "decoder%d.%d: existing allocation %pr assigned\n", + port->id, cxled->cxld.id, cxled->dpa_res); + return -EBUSY; + } + + if (port->hdm_end + 1 != cxled->cxld.id) { + /* + * Assumes alloc and commit order is always in hardware instance + * order per expectations from 8.2.5.12.20 Committing Decoder + * Programming that enforce decoder[m] committed before + * decoder[m+1] commit start. + */ + dev_dbg(dev, "decoder%d.%d: expected decoder%d.%d\n", port->id, + cxled->cxld.id, port->id, port->hdm_end + 1); + return -EBUSY; + } + + if (skipped) { + res = __request_region(&cxlds->dpa_res, base - skipped, skipped, + dev_name(&cxled->cxld.dev), 0); + if (!res) { + dev_dbg(dev, + "decoder%d.%d: failed to reserve skipped space\n", + port->id, cxled->cxld.id); + return -EBUSY; + } + } + res = __request_region(&cxlds->dpa_res, base, len, + dev_name(&cxled->cxld.dev), 0); + if (!res) { + dev_dbg(dev, "decoder%d.%d: failed to reserve allocation\n", + port->id, cxled->cxld.id); + if (skipped) + __release_region(&cxlds->dpa_res, base - skipped, + skipped); + return -EBUSY; + } + cxled->dpa_res = res; + cxled->skip = skipped; + + if (resource_contains(&cxlds->pmem_res, res)) + cxled->mode = CXL_DECODER_PMEM; + else if (resource_contains(&cxlds->ram_res, res)) + cxled->mode = CXL_DECODER_RAM; + else { + dev_dbg(dev, "decoder%d.%d: %pr mixed\n", port->id, + cxled->cxld.id, cxled->dpa_res); + cxled->mode = CXL_DECODER_MIXED; + } + + port->hdm_end++; + get_device(&cxled->cxld.dev); + return 0; +} + +int devm_cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled, + resource_size_t base, resource_size_t len, + resource_size_t skipped) +{ + struct cxl_port *port = cxled_to_port(cxled); + int rc; + + down_write(&cxl_dpa_rwsem); + rc = __cxl_dpa_reserve(cxled, base, len, skipped); + up_write(&cxl_dpa_rwsem); + + if (rc) + return rc; + + return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled); +} +EXPORT_SYMBOL_NS_GPL(devm_cxl_dpa_reserve, CXL); + +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.region) { + dev_dbg(dev, "decoder assigned to: %s\n", + dev_name(&cxled->cxld.region->dev)); + rc = -EBUSY; + 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.region) { + dev_dbg(dev, "decoder attached to %s\n", + dev_name(&cxled->cxld.region->dev)); + rc = -EBUSY; + goto out; + } + + 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; + + /* + * If some pmem is already allocated, then that allocation + * already handled the skip. + */ + if (cxlds->pmem_res.child && + skip_start == cxlds->pmem_res.child->start) + skip_end = skip_start - 1; + else + 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 void cxld_set_interleave(struct cxl_decoder *cxld, u32 *ctrl) +{ + u16 eig; + u8 eiw; + + /* + * Input validation ensures these warns never fire, but otherwise + * suppress unititalized variable usage warnings. + */ + if (WARN_ONCE(ways_to_cxl(cxld->interleave_ways, &eiw), + "invalid interleave_ways: %d\n", cxld->interleave_ways)) + return; + if (WARN_ONCE(granularity_to_cxl(cxld->interleave_granularity, &eig), + "invalid interleave_granularity: %d\n", + cxld->interleave_granularity)) + return; + + u32p_replace_bits(ctrl, eig, CXL_HDM_DECODER0_CTRL_IG_MASK); + u32p_replace_bits(ctrl, eiw, CXL_HDM_DECODER0_CTRL_IW_MASK); + *ctrl |= CXL_HDM_DECODER0_CTRL_COMMIT; +} + +static void cxld_set_type(struct cxl_decoder *cxld, u32 *ctrl) +{ + u32p_replace_bits(ctrl, !!(cxld->target_type == 3), + CXL_HDM_DECODER0_CTRL_TYPE); +} + +static int cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt) +{ + struct cxl_dport **t = &cxlsd->target[0]; + int ways = cxlsd->cxld.interleave_ways; + + if (dev_WARN_ONCE(&cxlsd->cxld.dev, + ways > 8 || ways > cxlsd->nr_targets, + "ways: %d overflows targets: %d\n", ways, + cxlsd->nr_targets)) + return -ENXIO; + + *tgt = FIELD_PREP(GENMASK(7, 0), t[0]->port_id); + if (ways > 1) + *tgt |= FIELD_PREP(GENMASK(15, 8), t[1]->port_id); + if (ways > 2) + *tgt |= FIELD_PREP(GENMASK(23, 16), t[2]->port_id); + if (ways > 3) + *tgt |= FIELD_PREP(GENMASK(31, 24), t[3]->port_id); + if (ways > 4) + *tgt |= FIELD_PREP(GENMASK_ULL(39, 32), t[4]->port_id); + if (ways > 5) + *tgt |= FIELD_PREP(GENMASK_ULL(47, 40), t[5]->port_id); + if (ways > 6) + *tgt |= FIELD_PREP(GENMASK_ULL(55, 48), t[6]->port_id); + if (ways > 7) + *tgt |= FIELD_PREP(GENMASK_ULL(63, 56), t[7]->port_id); + + return 0; +} + +/* + * Per CXL 2.0 8.2.5.12.20 Committing Decoder Programming, hardware must set + * committed or error within 10ms, but just be generous with 20ms to account for + * clock skew and other marginal behavior + */ +#define COMMIT_TIMEOUT_MS 20 +static int cxld_await_commit(void __iomem *hdm, int id) +{ + u32 ctrl; + int i; + + for (i = 0; i < COMMIT_TIMEOUT_MS; i++) { + ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id)); + if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMIT_ERROR, ctrl)) { + ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT; + writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id)); + return -EIO; + } + if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl)) + return 0; + fsleep(1000); + } + + return -ETIMEDOUT; +} + +static int cxl_decoder_commit(struct cxl_decoder *cxld) +{ + struct cxl_port *port = to_cxl_port(cxld->dev.parent); + struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev); + void __iomem *hdm = cxlhdm->regs.hdm_decoder; + int id = cxld->id, rc; + u64 base, size; + u32 ctrl; + + if (cxld->flags & CXL_DECODER_F_ENABLE) + return 0; + + if (port->commit_end + 1 != 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); + return -EBUSY; + } + + down_read(&cxl_dpa_rwsem); + /* common decoder settings */ + ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id)); + cxld_set_interleave(cxld, &ctrl); + cxld_set_type(cxld, &ctrl); + base = cxld->hpa_range.start; + size = range_len(&cxld->hpa_range); + + writel(upper_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id)); + writel(lower_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id)); + writel(upper_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id)); + writel(lower_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id)); + + if (is_switch_decoder(&cxld->dev)) { + struct cxl_switch_decoder *cxlsd = + to_cxl_switch_decoder(&cxld->dev); + void __iomem *tl_hi = hdm + CXL_HDM_DECODER0_TL_HIGH(id); + void __iomem *tl_lo = hdm + CXL_HDM_DECODER0_TL_LOW(id); + u64 targets; + + rc = cxlsd_set_targets(cxlsd, &targets); + if (rc) { + dev_dbg(&port->dev, "%s: target configuration error\n", + dev_name(&cxld->dev)); + goto err; + } + + writel(upper_32_bits(targets), tl_hi); + writel(lower_32_bits(targets), tl_lo); + } else { + struct cxl_endpoint_decoder *cxled = + to_cxl_endpoint_decoder(&cxld->dev); + void __iomem *sk_hi = hdm + CXL_HDM_DECODER0_SKIP_HIGH(id); + void __iomem *sk_lo = hdm + CXL_HDM_DECODER0_SKIP_LOW(id); + + writel(upper_32_bits(cxled->skip), sk_hi); + writel(lower_32_bits(cxled->skip), sk_lo); + } + + writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id)); + up_read(&cxl_dpa_rwsem); + + port->commit_end++; + rc = cxld_await_commit(hdm, cxld->id); +err: + if (rc) { + dev_dbg(&port->dev, "%s: error %d committing decoder\n", + dev_name(&cxld->dev), rc); + cxld->reset(cxld); + return rc; + } + cxld->flags |= CXL_DECODER_F_ENABLE; + + return 0; +} + +static int cxl_decoder_reset(struct cxl_decoder *cxld) +{ + struct cxl_port *port = to_cxl_port(cxld->dev.parent); + struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev); + void __iomem *hdm = cxlhdm->regs.hdm_decoder; + int id = cxld->id; + u32 ctrl; + + if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0) + return 0; + + if (port->commit_end != id) { + dev_dbg(&port->dev, + "%s: out of order reset, expected decoder%d.%d\n", + dev_name(&cxld->dev), port->id, port->commit_end); + return -EBUSY; + } + + down_read(&cxl_dpa_rwsem); + ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id)); + ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT; + writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id)); + + writel(0, hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id)); + writel(0, hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id)); + writel(0, hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id)); + writel(0, hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id)); + up_read(&cxl_dpa_rwsem); + + port->commit_end--; + cxld->flags &= ~CXL_DECODER_F_ENABLE; + + return 0; +} + +static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld, + int *target_map, void __iomem *hdm, int which, + u64 *dpa_base) +{ + struct cxl_endpoint_decoder *cxled = NULL; + u64 size, base, skip, dpa_size; + bool committed; + u32 remainder; + int i, rc; + u32 ctrl; + union { + u64 value; + unsigned char target_id[8]; + } target_list; + + if (is_endpoint_decoder(&cxld->dev)) + cxled = to_cxl_endpoint_decoder(&cxld->dev); + + ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which)); + base = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(which)); + size = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(which)); + committed = !!(ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED); + cxld->commit = cxl_decoder_commit; + cxld->reset = cxl_decoder_reset; + + if (!committed) + size = 0; + if (base == U64_MAX || size == U64_MAX) { + dev_warn(&port->dev, "decoder%d.%d: Invalid resource range\n", + port->id, cxld->id); + return -ENXIO; + } + + cxld->hpa_range = (struct range) { + .start = base, + .end = base + size - 1, + }; + + /* decoders are enabled if committed */ + if (committed) { + cxld->flags |= CXL_DECODER_F_ENABLE; + if (ctrl & CXL_HDM_DECODER0_CTRL_LOCK) + cxld->flags |= CXL_DECODER_F_LOCK; + if (FIELD_GET(CXL_HDM_DECODER0_CTRL_TYPE, ctrl)) + cxld->target_type = CXL_DECODER_EXPANDER; + else + cxld->target_type = CXL_DECODER_ACCELERATOR; + if (cxld->id != port->commit_end + 1) { + dev_warn(&port->dev, + "decoder%d.%d: Committed out of order\n", + port->id, cxld->id); + return -ENXIO; + } + + if (size == 0) { + dev_warn(&port->dev, + "decoder%d.%d: Committed with zero size\n", + port->id, cxld->id); + return -ENXIO; + } + port->commit_end = cxld->id; + } else { + /* unless / until type-2 drivers arrive, assume type-3 */ + if (FIELD_GET(CXL_HDM_DECODER0_CTRL_TYPE, ctrl) == 0) { + ctrl |= CXL_HDM_DECODER0_CTRL_TYPE; + writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which)); + } + cxld->target_type = CXL_DECODER_EXPANDER; + } + rc = cxl_to_ways(FIELD_GET(CXL_HDM_DECODER0_CTRL_IW_MASK, ctrl), + &cxld->interleave_ways); + if (rc) { + dev_warn(&port->dev, + "decoder%d.%d: Invalid interleave ways (ctrl: %#x)\n", + port->id, cxld->id, ctrl); + return rc; + } + rc = cxl_to_granularity(FIELD_GET(CXL_HDM_DECODER0_CTRL_IG_MASK, ctrl), + &cxld->interleave_granularity); + if (rc) + return rc; + + if (!cxled) { + target_list.value = + ioread64_hi_lo(hdm + CXL_HDM_DECODER0_TL_LOW(which)); + for (i = 0; i < cxld->interleave_ways; i++) + target_map[i] = target_list.target_id[i]; + + return 0; + } + + if (!committed) + return 0; + + dpa_size = div_u64_rem(size, cxld->interleave_ways, &remainder); + if (remainder) { + dev_err(&port->dev, + "decoder%d.%d: invalid committed configuration size: %#llx ways: %d\n", + port->id, cxld->id, size, cxld->interleave_ways); + return -ENXIO; + } + skip = ioread64_hi_lo(hdm + CXL_HDM_DECODER0_SKIP_LOW(which)); + rc = devm_cxl_dpa_reserve(cxled, *dpa_base + skip, dpa_size, skip); + if (rc) { + dev_err(&port->dev, + "decoder%d.%d: Failed to reserve DPA range %#llx - %#llx\n (%d)", + port->id, cxld->id, *dpa_base, + *dpa_base + dpa_size + skip - 1, rc); + return rc; + } + *dpa_base += dpa_size + skip; + return 0; +} + +/** + * devm_cxl_enumerate_decoders - add decoder objects per HDM register set + * @cxlhdm: Structure to populate with HDM capabilities + */ +int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm) +{ + void __iomem *hdm = cxlhdm->regs.hdm_decoder; + struct cxl_port *port = cxlhdm->port; + int i, committed; + u64 dpa_base = 0; + u32 ctrl; + + /* + * Since the register resource was recently claimed via request_region() + * be careful about trusting the "not-committed" status until the commit + * timeout has elapsed. The commit timeout is 10ms (CXL 2.0 + * 8.2.5.12.20), but double it to be tolerant of any clock skew between + * host and target. + */ + for (i = 0, committed = 0; i < cxlhdm->decoder_count; i++) { + ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(i)); + if (ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED) + committed++; + } + + /* ensure that future checks of committed can be trusted */ + if (committed != cxlhdm->decoder_count) + msleep(20); + + for (i = 0; i < cxlhdm->decoder_count; i++) { + int target_map[CXL_DECODER_MAX_INTERLEAVE] = { 0 }; + int rc, target_count = cxlhdm->target_count; + struct cxl_decoder *cxld; + + if (is_cxl_endpoint(port)) { + struct cxl_endpoint_decoder *cxled; + + cxled = cxl_endpoint_decoder_alloc(port); + if (IS_ERR(cxled)) { + dev_warn(&port->dev, + "Failed to allocate the decoder\n"); + return PTR_ERR(cxled); + } + cxld = &cxled->cxld; + } else { + struct cxl_switch_decoder *cxlsd; + + cxlsd = cxl_switch_decoder_alloc(port, target_count); + if (IS_ERR(cxlsd)) { + dev_warn(&port->dev, + "Failed to allocate the decoder\n"); + return PTR_ERR(cxlsd); + } + cxld = &cxlsd->cxld; + } + + rc = init_hdm_decoder(port, cxld, target_map, hdm, i, &dpa_base); + if (rc) { + put_device(&cxld->dev); + return rc; + } + rc = add_hdm_decoder(port, cxld, target_map); + if (rc) { + dev_warn(&port->dev, + "Failed to add decoder to port\n"); + return rc; + } + } + + return 0; +} +EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_decoders, CXL); |