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-rw-r--r--drivers/cxl/core/hdm.c865
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);