Merge tag 'cxl-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull cxl updates from Dan Williams:
 "Compute Express Link (CXL) updates for 6.2.

  While it may seem backwards, the CXL update this time around includes
  some focus on CXL 1.x enabling where the work to date had been with
  CXL 2.0 (VH topologies) in mind.

  First generation CXL can mostly be supported via BIOS, similar to DDR,
  however it became clear there are use cases for OS native CXL error
  handling and some CXL 3.0 endpoint features can be deployed on CXL 1.x
  hosts (Restricted CXL Host (RCH) topologies). So, this update brings
  RCH topologies into the Linux CXL device model.

  In support of the ongoing CXL 2.0+ enabling two new core kernel
  facilities are added.

  One is the ability for the kernel to flag collisions between userspace
  access to PCI configuration registers and kernel accesses. This is
  brought on by the PCIe Data-Object-Exchange (DOE) facility, a hardware
  mailbox over config-cycles.

  The other is a cpu_cache_invalidate_memregion() API that maps to
  wbinvd_on_all_cpus() on x86. To prevent abuse it is disabled in guest
  VMs and architectures that do not support it yet. The CXL paths that
  need it, dynamic memory region creation and security commands (erase /
  unlock), are disabled when it is not present.

  As for the CXL 2.0+ this cycle the subsystem gains support Persistent
  Memory Security commands, error handling in response to PCIe AER
  notifications, and support for the "XOR" host bridge interleave
  algorithm.

  Summary:

   - Add the cpu_cache_invalidate_memregion() API for cache flushing in
     response to physical memory reconfiguration, or memory-side data
     invalidation from operations like secure erase or memory-device
     unlock.

   - Add a facility for the kernel to warn about collisions between
     kernel and userspace access to PCI configuration registers

   - Add support for Restricted CXL Host (RCH) topologies (formerly CXL
     1.1)

   - Add handling and reporting of CXL errors reported via the PCIe AER
     mechanism

   - Add support for CXL Persistent Memory Security commands

   - Add support for the "XOR" algorithm for CXL host bridge interleave

   - Rework / simplify CXL to NVDIMM interactions

   - Miscellaneous cleanups and fixes"

* tag 'cxl-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (71 commits)
  cxl/region: Fix memdev reuse check
  cxl/pci: Remove endian confusion
  cxl/pci: Add some type-safety to the AER trace points
  cxl/security: Drop security command ioctl uapi
  cxl/mbox: Add variable output size validation for internal commands
  cxl/mbox: Enable cxl_mbox_send_cmd() users to validate output size
  cxl/security: Fix Get Security State output payload endian handling
  cxl: update names for interleave ways conversion macros
  cxl: update names for interleave granularity conversion macros
  cxl/acpi: Warn about an invalid CHBCR in an existing CHBS entry
  tools/testing/cxl: Require cache invalidation bypass
  cxl/acpi: Fail decoder add if CXIMS for HBIG is missing
  cxl/region: Fix spelling mistake "memergion" -> "memregion"
  cxl/regs: Fix sparse warning
  cxl/acpi: Set ACPI's CXL _OSC to indicate RCD mode support
  tools/testing/cxl: Add an RCH topology
  cxl/port: Add RCD endpoint port enumeration
  cxl/mem: Move devm_cxl_add_endpoint() from cxl_core to cxl_mem
  tools/testing/cxl: Add XOR Math support to cxl_test
  cxl/acpi: Support CXL XOR Interleave Math (CXIMS)
  ...

1 files changed, 236 insertions, 39 deletions

diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index fb649683dd3a..ad0849af42d7 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -6,9 +6,120 @@
 #include <linux/kernel.h>
 #include <linux/acpi.h>
 #include <linux/pci.h>
+#include <asm/div64.h>
 #include "cxlpci.h"
 #include "cxl.h"
 
+#define CXL_RCRB_SIZE	SZ_8K
+
+struct cxl_cxims_data {
+	int nr_maps;
+	u64 xormaps[];
+};
+
+/*
+ * Find a targets entry (n) in the host bridge interleave list.
+ * CXL Specfication 3.0 Table 9-22
+ */
+static int cxl_xor_calc_n(u64 hpa, struct cxl_cxims_data *cximsd, int iw,
+			  int ig)
+{
+	int i = 0, n = 0;
+	u8 eiw;
+
+	/* IW: 2,4,6,8,12,16 begin building 'n' using xormaps */
+	if (iw != 3) {
+		for (i = 0; i < cximsd->nr_maps; i++)
+			n |= (hweight64(hpa & cximsd->xormaps[i]) & 1) << i;
+	}
+	/* IW: 3,6,12 add a modulo calculation to 'n' */
+	if (!is_power_of_2(iw)) {
+		if (ways_to_eiw(iw, &eiw))
+			return -1;
+		hpa &= GENMASK_ULL(51, eiw + ig);
+		n |= do_div(hpa, 3) << i;
+	}
+	return n;
+}
+
+static struct cxl_dport *cxl_hb_xor(struct cxl_root_decoder *cxlrd, int pos)
+{
+	struct cxl_cxims_data *cximsd = cxlrd->platform_data;
+	struct cxl_switch_decoder *cxlsd = &cxlrd->cxlsd;
+	struct cxl_decoder *cxld = &cxlsd->cxld;
+	int ig = cxld->interleave_granularity;
+	int iw = cxld->interleave_ways;
+	int n = 0;
+	u64 hpa;
+
+	if (dev_WARN_ONCE(&cxld->dev,
+			  cxld->interleave_ways != cxlsd->nr_targets,
+			  "misconfigured root decoder\n"))
+		return NULL;
+
+	hpa = cxlrd->res->start + pos * ig;
+
+	/* Entry (n) is 0 for no interleave (iw == 1) */
+	if (iw != 1)
+		n = cxl_xor_calc_n(hpa, cximsd, iw, ig);
+
+	if (n < 0)
+		return NULL;
+
+	return cxlrd->cxlsd.target[n];
+}
+
+struct cxl_cxims_context {
+	struct device *dev;
+	struct cxl_root_decoder *cxlrd;
+};
+
+static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg,
+			   const unsigned long end)
+{
+	struct acpi_cedt_cxims *cxims = (struct acpi_cedt_cxims *)header;
+	struct cxl_cxims_context *ctx = arg;
+	struct cxl_root_decoder *cxlrd = ctx->cxlrd;
+	struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
+	struct device *dev = ctx->dev;
+	struct cxl_cxims_data *cximsd;
+	unsigned int hbig, nr_maps;
+	int rc;
+
+	rc = eig_to_granularity(cxims->hbig, &hbig);
+	if (rc)
+		return rc;
+
+	/* Does this CXIMS entry apply to the given CXL Window? */
+	if (hbig != cxld->interleave_granularity)
+		return 0;
+
+	/* IW 1,3 do not use xormaps and skip this parsing entirely */
+	if (is_power_of_2(cxld->interleave_ways))
+		/* 2, 4, 8, 16 way */
+		nr_maps = ilog2(cxld->interleave_ways);
+	else
+		/* 6, 12 way */
+		nr_maps = ilog2(cxld->interleave_ways / 3);
+
+	if (cxims->nr_xormaps < nr_maps) {
+		dev_dbg(dev, "CXIMS nr_xormaps[%d] expected[%d]\n",
+			cxims->nr_xormaps, nr_maps);
+		return -ENXIO;
+	}
+
+	cximsd = devm_kzalloc(dev, struct_size(cximsd, xormaps, nr_maps),
+			      GFP_KERNEL);
+	if (!cximsd)
+		return -ENOMEM;
+	memcpy(cximsd->xormaps, cxims->xormap_list,
+	       nr_maps * sizeof(*cximsd->xormaps));
+	cximsd->nr_maps = nr_maps;
+	cxlrd->platform_data = cximsd;
+
+	return 0;
+}
+
 static unsigned long cfmws_to_decoder_flags(int restrictions)
 {
 	unsigned long flags = CXL_DECODER_F_ENABLE;
@@ -33,8 +144,10 @@ static int cxl_acpi_cfmws_verify(struct device *dev,
 	int rc, expected_len;
 	unsigned int ways;
 
-	if (cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_MODULO) {
-		dev_err(dev, "CFMWS Unsupported Interleave Arithmetic\n");
+	if (cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_MODULO &&
+	    cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
+		dev_err(dev, "CFMWS Unknown Interleave Arithmetic: %d\n",
+			cfmws->interleave_arithmetic);
 		return -EINVAL;
 	}
 
@@ -48,7 +161,7 @@ static int cxl_acpi_cfmws_verify(struct device *dev,
 		return -EINVAL;
 	}
 
-	rc = cxl_to_ways(cfmws->interleave_ways, &ways);
+	rc = eiw_to_ways(cfmws->interleave_ways, &ways);
 	if (rc) {
 		dev_err(dev, "CFMWS Interleave Ways (%d) invalid\n",
 			cfmws->interleave_ways);
@@ -70,6 +183,10 @@ static int cxl_acpi_cfmws_verify(struct device *dev,
 	return 0;
 }
 
+/*
+ * Note, @dev must be the first member, see 'struct cxl_chbs_context'
+ * and mock_acpi_table_parse_cedt()
+ */
 struct cxl_cfmws_context {
 	struct device *dev;
 	struct cxl_port *root_port;
@@ -84,9 +201,11 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
 	struct cxl_cfmws_context *ctx = arg;
 	struct cxl_port *root_port = ctx->root_port;
 	struct resource *cxl_res = ctx->cxl_res;
+	struct cxl_cxims_context cxims_ctx;
 	struct cxl_root_decoder *cxlrd;
 	struct device *dev = ctx->dev;
 	struct acpi_cedt_cfmws *cfmws;
+	cxl_calc_hb_fn cxl_calc_hb;
 	struct cxl_decoder *cxld;
 	unsigned int ways, i, ig;
 	struct resource *res;
@@ -102,10 +221,10 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
 		return 0;
 	}
 
-	rc = cxl_to_ways(cfmws->interleave_ways, &ways);
+	rc = eiw_to_ways(cfmws->interleave_ways, &ways);
 	if (rc)
 		return rc;
-	rc = cxl_to_granularity(cfmws->granularity, &ig);
+	rc = eig_to_granularity(cfmws->granularity, &ig);
 	if (rc)
 		return rc;
 	for (i = 0; i < ways; i++)
@@ -128,7 +247,12 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
 	if (rc)
 		goto err_insert;
 
-	cxlrd = cxl_root_decoder_alloc(root_port, ways);
+	if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_MODULO)
+		cxl_calc_hb = cxl_hb_modulo;
+	else
+		cxl_calc_hb = cxl_hb_xor;
+
+	cxlrd = cxl_root_decoder_alloc(root_port, ways, cxl_calc_hb);
 	if (IS_ERR(cxlrd))
 		return 0;
 
@@ -148,7 +272,25 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
 		ig = CXL_DECODER_MIN_GRANULARITY;
 	cxld->interleave_granularity = ig;
 
+	if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
+		if (ways != 1 && ways != 3) {
+			cxims_ctx = (struct cxl_cxims_context) {
+				.dev = dev,
+				.cxlrd = cxlrd,
+			};
+			rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CXIMS,
+						   cxl_parse_cxims, &cxims_ctx);
+			if (rc < 0)
+				goto err_xormap;
+			if (!cxlrd->platform_data) {
+				dev_err(dev, "No CXIMS for HBIG %u\n", ig);
+				rc = -EINVAL;
+				goto err_xormap;
+			}
+		}
+	}
 	rc = cxl_decoder_add(cxld, target_map);
+err_xormap:
 	if (rc)
 		put_device(&cxld->dev);
 	else
@@ -193,34 +335,39 @@ static int add_host_bridge_uport(struct device *match, void *arg)
 {
 	struct cxl_port *root_port = arg;
 	struct device *host = root_port->dev.parent;
-	struct acpi_device *bridge = to_cxl_host_bridge(host, match);
+	struct acpi_device *hb = to_cxl_host_bridge(host, match);
 	struct acpi_pci_root *pci_root;
 	struct cxl_dport *dport;
 	struct cxl_port *port;
+	struct device *bridge;
 	int rc;
 
-	if (!bridge)
+	if (!hb)
 		return 0;
 
-	dport = cxl_find_dport_by_dev(root_port, match);
+	pci_root = acpi_pci_find_root(hb->handle);
+	bridge = pci_root->bus->bridge;
+	dport = cxl_find_dport_by_dev(root_port, bridge);
 	if (!dport) {
 		dev_dbg(host, "host bridge expected and not found\n");
 		return 0;
 	}
 
-	/*
-	 * Note that this lookup already succeeded in
-	 * to_cxl_host_bridge(), so no need to check for failure here
-	 */
-	pci_root = acpi_pci_find_root(bridge->handle);
-	rc = devm_cxl_register_pci_bus(host, match, pci_root->bus);
+	if (dport->rch) {
+		dev_info(bridge, "host supports CXL (restricted)\n");
+		return 0;
+	}
+
+	rc = devm_cxl_register_pci_bus(host, bridge, pci_root->bus);
 	if (rc)
 		return rc;
 
-	port = devm_cxl_add_port(host, match, dport->component_reg_phys, dport);
+	port = devm_cxl_add_port(host, bridge, dport->component_reg_phys,
+				 dport);
 	if (IS_ERR(port))
 		return PTR_ERR(port);
-	dev_dbg(host, "%s: add: %s\n", dev_name(match), dev_name(&port->dev));
+
+	dev_info(bridge, "host supports CXL\n");
 
 	return 0;
 }
@@ -228,7 +375,9 @@ static int add_host_bridge_uport(struct device *match, void *arg)
 struct cxl_chbs_context {
 	struct device *dev;
 	unsigned long long uid;
+	resource_size_t rcrb;
 	resource_size_t chbcr;
+	u32 cxl_version;
 };
 
 static int cxl_get_chbcr(union acpi_subtable_headers *header, void *arg,
@@ -244,51 +393,86 @@ static int cxl_get_chbcr(union acpi_subtable_headers *header, void *arg,
 
 	if (ctx->uid != chbs->uid)
 		return 0;
-	ctx->chbcr = chbs->base;
+
+	ctx->cxl_version = chbs->cxl_version;
+	ctx->rcrb = CXL_RESOURCE_NONE;
+	ctx->chbcr = CXL_RESOURCE_NONE;
+
+	if (!chbs->base)
+		return 0;
+
+	if (chbs->cxl_version != ACPI_CEDT_CHBS_VERSION_CXL11) {
+		ctx->chbcr = chbs->base;
+		return 0;
+	}
+
+	if (chbs->length != CXL_RCRB_SIZE)
+		return 0;
+
+	ctx->rcrb = chbs->base;
+	ctx->chbcr = cxl_rcrb_to_component(ctx->dev, chbs->base,
+					   CXL_RCRB_DOWNSTREAM);
 
 	return 0;
 }
 
 static int add_host_bridge_dport(struct device *match, void *arg)
 {
-	acpi_status status;
+	acpi_status rc;
+	struct device *bridge;
 	unsigned long long uid;
 	struct cxl_dport *dport;
 	struct cxl_chbs_context ctx;
+	struct acpi_pci_root *pci_root;
 	struct cxl_port *root_port = arg;
 	struct device *host = root_port->dev.parent;
-	struct acpi_device *bridge = to_cxl_host_bridge(host, match);
+	struct acpi_device *hb = to_cxl_host_bridge(host, match);
 
-	if (!bridge)
+	if (!hb)
 		return 0;
 
-	status = acpi_evaluate_integer(bridge->handle, METHOD_NAME__UID, NULL,
-				       &uid);
-	if (status != AE_OK) {
-		dev_err(host, "unable to retrieve _UID of %s\n",
-			dev_name(match));
+	rc = acpi_evaluate_integer(hb->handle, METHOD_NAME__UID, NULL, &uid);
+	if (rc != AE_OK) {
+		dev_err(match, "unable to retrieve _UID\n");
 		return -ENODEV;
 	}
 
+	dev_dbg(match, "UID found: %lld\n", uid);
+
 	ctx = (struct cxl_chbs_context) {
-		.dev = host,
+		.dev = match,
 		.uid = uid,
 	};
 	acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, cxl_get_chbcr, &ctx);
 
-	if (ctx.chbcr == 0) {
-		dev_warn(host, "No CHBS found for Host Bridge: %s\n",
-			 dev_name(match));
+	if (!ctx.chbcr) {
+		dev_warn(match, "No CHBS found for Host Bridge (UID %lld)\n",
+			 uid);
 		return 0;
 	}
 
-	dport = devm_cxl_add_dport(root_port, match, uid, ctx.chbcr);
-	if (IS_ERR(dport)) {
-		dev_err(host, "failed to add downstream port: %s\n",
-			dev_name(match));
-		return PTR_ERR(dport);
+	if (ctx.rcrb != CXL_RESOURCE_NONE)
+		dev_dbg(match, "RCRB found for UID %lld: %pa\n", uid, &ctx.rcrb);
+
+	if (ctx.chbcr == CXL_RESOURCE_NONE) {
+		dev_warn(match, "CHBCR invalid for Host Bridge (UID %lld)\n",
+			 uid);
+		return 0;
 	}
-	dev_dbg(host, "add dport%llu: %s\n", uid, dev_name(match));
+
+	dev_dbg(match, "CHBCR found: %pa\n", &ctx.chbcr);
+
+	pci_root = acpi_pci_find_root(hb->handle);
+	bridge = pci_root->bus->bridge;
+	if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11)
+		dport = devm_cxl_add_rch_dport(root_port, bridge, uid,
+					       ctx.chbcr, ctx.rcrb);
+	else
+		dport = devm_cxl_add_dport(root_port, bridge, uid,
+					   ctx.chbcr);
+	if (IS_ERR(dport))
+		return PTR_ERR(dport);
+
 	return 0;
 }
 
@@ -466,7 +650,6 @@ static int cxl_acpi_probe(struct platform_device *pdev)
 	root_port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL);
 	if (IS_ERR(root_port))
 		return PTR_ERR(root_port);
-	dev_dbg(host, "add: %s\n", dev_name(&root_port->dev));
 
 	rc = bus_for_each_dev(adev->dev.bus, NULL, root_port,
 			      add_host_bridge_dport);
@@ -512,7 +695,8 @@ static int cxl_acpi_probe(struct platform_device *pdev)
 		return rc;
 
 	/* In case PCI is scanned before ACPI re-trigger memdev attach */
-	return cxl_bus_rescan();
+	cxl_bus_rescan();
+	return 0;
 }
 
 static const struct acpi_device_id cxl_acpi_ids[] = {
@@ -536,7 +720,20 @@ static struct platform_driver cxl_acpi_driver = {
 	.id_table = cxl_test_ids,
 };
 
-module_platform_driver(cxl_acpi_driver);
+static int __init cxl_acpi_init(void)
+{
+	return platform_driver_register(&cxl_acpi_driver);
+}
+
+static void __exit cxl_acpi_exit(void)
+{
+	platform_driver_unregister(&cxl_acpi_driver);
+	cxl_bus_drain();
+}
+
+module_init(cxl_acpi_init);
+module_exit(cxl_acpi_exit);
 MODULE_LICENSE("GPL v2");
 MODULE_IMPORT_NS(CXL);
 MODULE_IMPORT_NS(ACPI);
+MODULE_SOFTDEP("pre: cxl_pmem");