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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2021 Intel Corporation. All rights reserved. */
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/pci.h>
#include "cxl.h"
#include "pci.h"
/* Encode defined in CXL 2.0 8.2.5.12.7 HDM Decoder Control Register */
#define CFMWS_INTERLEAVE_WAYS(x) (1 << (x)->interleave_ways)
#define CFMWS_INTERLEAVE_GRANULARITY(x) ((x)->granularity + 8)
static unsigned long cfmws_to_decoder_flags(int restrictions)
{
unsigned long flags = 0;
if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE2)
flags |= CXL_DECODER_F_TYPE2;
if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE3)
flags |= CXL_DECODER_F_TYPE3;
if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE)
flags |= CXL_DECODER_F_RAM;
if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_PMEM)
flags |= CXL_DECODER_F_PMEM;
if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_FIXED)
flags |= CXL_DECODER_F_LOCK;
return flags;
}
static int cxl_acpi_cfmws_verify(struct device *dev,
struct acpi_cedt_cfmws *cfmws)
{
int expected_len;
if (cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_MODULO) {
dev_err(dev, "CFMWS Unsupported Interleave Arithmetic\n");
return -EINVAL;
}
if (!IS_ALIGNED(cfmws->base_hpa, SZ_256M)) {
dev_err(dev, "CFMWS Base HPA not 256MB aligned\n");
return -EINVAL;
}
if (!IS_ALIGNED(cfmws->window_size, SZ_256M)) {
dev_err(dev, "CFMWS Window Size not 256MB aligned\n");
return -EINVAL;
}
if (CFMWS_INTERLEAVE_WAYS(cfmws) > CXL_DECODER_MAX_INTERLEAVE) {
dev_err(dev, "CFMWS Interleave Ways (%d) too large\n",
CFMWS_INTERLEAVE_WAYS(cfmws));
return -EINVAL;
}
expected_len = struct_size((cfmws), interleave_targets,
CFMWS_INTERLEAVE_WAYS(cfmws));
if (cfmws->header.length < expected_len) {
dev_err(dev, "CFMWS length %d less than expected %d\n",
cfmws->header.length, expected_len);
return -EINVAL;
}
if (cfmws->header.length > expected_len)
dev_dbg(dev, "CFMWS length %d greater than expected %d\n",
cfmws->header.length, expected_len);
return 0;
}
struct cxl_cfmws_context {
struct device *dev;
struct cxl_port *root_port;
};
static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
const unsigned long end)
{
int target_map[CXL_DECODER_MAX_INTERLEAVE];
struct cxl_cfmws_context *ctx = arg;
struct cxl_port *root_port = ctx->root_port;
struct device *dev = ctx->dev;
struct acpi_cedt_cfmws *cfmws;
struct cxl_decoder *cxld;
int rc, i;
cfmws = (struct acpi_cedt_cfmws *) header;
rc = cxl_acpi_cfmws_verify(dev, cfmws);
if (rc) {
dev_err(dev, "CFMWS range %#llx-%#llx not registered\n",
cfmws->base_hpa,
cfmws->base_hpa + cfmws->window_size - 1);
return 0;
}
for (i = 0; i < CFMWS_INTERLEAVE_WAYS(cfmws); i++)
target_map[i] = cfmws->interleave_targets[i];
cxld = cxl_root_decoder_alloc(root_port, CFMWS_INTERLEAVE_WAYS(cfmws));
if (IS_ERR(cxld))
return 0;
cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions);
cxld->target_type = CXL_DECODER_EXPANDER;
cxld->platform_res = (struct resource)DEFINE_RES_MEM(cfmws->base_hpa,
cfmws->window_size);
cxld->interleave_ways = CFMWS_INTERLEAVE_WAYS(cfmws);
cxld->interleave_granularity = CFMWS_INTERLEAVE_GRANULARITY(cfmws);
rc = cxl_decoder_add(cxld, target_map);
if (rc)
put_device(&cxld->dev);
else
rc = cxl_decoder_autoremove(dev, cxld);
if (rc) {
dev_err(dev, "Failed to add decoder for %pr\n",
&cxld->platform_res);
return 0;
}
dev_dbg(dev, "add: %s node: %d range %pr\n", dev_name(&cxld->dev),
phys_to_target_node(cxld->platform_res.start),
&cxld->platform_res);
return 0;
}
__mock int match_add_root_ports(struct pci_dev *pdev, void *data)
{
resource_size_t creg = CXL_RESOURCE_NONE;
struct cxl_walk_context *ctx = data;
struct pci_bus *root_bus = ctx->root;
struct cxl_port *port = ctx->port;
int type = pci_pcie_type(pdev);
struct device *dev = ctx->dev;
struct cxl_register_map map;
u32 lnkcap, port_num;
int rc;
if (pdev->bus != root_bus)
return 0;
if (!pci_is_pcie(pdev))
return 0;
if (type != PCI_EXP_TYPE_ROOT_PORT)
return 0;
if (pci_read_config_dword(pdev, pci_pcie_cap(pdev) + PCI_EXP_LNKCAP,
&lnkcap) != PCIBIOS_SUCCESSFUL)
return 0;
/* The driver doesn't rely on component registers for Root Ports yet. */
rc = cxl_find_regblock(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
if (!rc)
dev_info(&pdev->dev, "No component register block found\n");
creg = cxl_regmap_to_base(pdev, &map);
port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap);
rc = cxl_add_dport(port, &pdev->dev, port_num, creg);
if (rc) {
ctx->error = rc;
return rc;
}
ctx->count++;
dev_dbg(dev, "add dport%d: %s\n", port_num, dev_name(&pdev->dev));
return 0;
}
static struct cxl_dport *find_dport_by_dev(struct cxl_port *port, struct device *dev)
{
struct cxl_dport *dport;
cxl_device_lock(&port->dev);
list_for_each_entry(dport, &port->dports, list)
if (dport->dport == dev) {
cxl_device_unlock(&port->dev);
return dport;
}
cxl_device_unlock(&port->dev);
return NULL;
}
__mock struct acpi_device *to_cxl_host_bridge(struct device *host,
struct device *dev)
{
struct acpi_device *adev = to_acpi_device(dev);
if (!acpi_pci_find_root(adev->handle))
return NULL;
if (strcmp(acpi_device_hid(adev), "ACPI0016") == 0)
return adev;
return NULL;
}
/*
* A host bridge is a dport to a CFMWS decode and it is a uport to the
* dport (PCIe Root Ports) in the host bridge.
*/
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_pci_root *pci_root;
struct cxl_walk_context ctx;
int single_port_map[1], rc;
struct cxl_decoder *cxld;
struct cxl_dport *dport;
struct cxl_port *port;
if (!bridge)
return 0;
dport = find_dport_by_dev(root_port, match);
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 (rc)
return rc;
port = devm_cxl_add_port(host, match, dport->component_reg_phys,
root_port);
if (IS_ERR(port))
return PTR_ERR(port);
dev_dbg(host, "%s: add: %s\n", dev_name(match), dev_name(&port->dev));
ctx = (struct cxl_walk_context){
.dev = host,
.root = pci_root->bus,
.port = port,
};
pci_walk_bus(pci_root->bus, match_add_root_ports, &ctx);
if (ctx.count == 0)
return -ENODEV;
if (ctx.error)
return ctx.error;
if (ctx.count > 1)
return 0;
/* TODO: Scan CHBCR for HDM Decoder resources */
/*
* 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.
*/
cxld = cxl_switch_decoder_alloc(port, 1);
if (IS_ERR(cxld))
return PTR_ERR(cxld);
cxl_device_lock(&port->dev);
dport = list_first_entry(&port->dports, typeof(*dport), list);
cxl_device_unlock(&port->dev);
single_port_map[0] = dport->port_id;
rc = cxl_decoder_add(cxld, single_port_map);
if (rc)
put_device(&cxld->dev);
else
rc = cxl_decoder_autoremove(host, cxld);
if (rc == 0)
dev_dbg(host, "add: %s\n", dev_name(&cxld->dev));
return rc;
}
struct cxl_chbs_context {
struct device *dev;
unsigned long long uid;
resource_size_t chbcr;
};
static int cxl_get_chbcr(union acpi_subtable_headers *header, void *arg,
const unsigned long end)
{
struct cxl_chbs_context *ctx = arg;
struct acpi_cedt_chbs *chbs;
if (ctx->chbcr)
return 0;
chbs = (struct acpi_cedt_chbs *) header;
if (ctx->uid != chbs->uid)
return 0;
ctx->chbcr = chbs->base;
return 0;
}
static int add_host_bridge_dport(struct device *match, void *arg)
{
int rc;
acpi_status status;
unsigned long long uid;
struct cxl_chbs_context ctx;
struct cxl_port *root_port = arg;
struct device *host = root_port->dev.parent;
struct acpi_device *bridge = to_cxl_host_bridge(host, match);
if (!bridge)
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));
return -ENODEV;
}
ctx = (struct cxl_chbs_context) {
.dev = host,
.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));
return 0;
}
rc = cxl_add_dport(root_port, match, uid, ctx.chbcr);
if (rc) {
dev_err(host, "failed to add downstream port: %s\n",
dev_name(match));
return rc;
}
dev_dbg(host, "add dport%llu: %s\n", uid, dev_name(match));
return 0;
}
static int add_root_nvdimm_bridge(struct device *match, void *data)
{
struct cxl_decoder *cxld;
struct cxl_port *root_port = data;
struct cxl_nvdimm_bridge *cxl_nvb;
struct device *host = root_port->dev.parent;
if (!is_root_decoder(match))
return 0;
cxld = to_cxl_decoder(match);
if (!(cxld->flags & CXL_DECODER_F_PMEM))
return 0;
cxl_nvb = devm_cxl_add_nvdimm_bridge(host, root_port);
if (IS_ERR(cxl_nvb)) {
dev_dbg(host, "failed to register pmem\n");
return PTR_ERR(cxl_nvb);
}
dev_dbg(host, "%s: add: %s\n", dev_name(&root_port->dev),
dev_name(&cxl_nvb->dev));
return 1;
}
static int cxl_acpi_probe(struct platform_device *pdev)
{
int rc;
struct cxl_port *root_port;
struct device *host = &pdev->dev;
struct acpi_device *adev = ACPI_COMPANION(host);
struct cxl_cfmws_context ctx;
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);
if (rc < 0)
return rc;
ctx = (struct cxl_cfmws_context) {
.dev = host,
.root_port = root_port,
};
acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, cxl_parse_cfmws, &ctx);
/*
* Root level scanned with host-bridge as dports, now scan host-bridges
* for their role as CXL uports to their CXL-capable PCIe Root Ports.
*/
rc = bus_for_each_dev(adev->dev.bus, NULL, root_port,
add_host_bridge_uport);
if (rc < 0)
return rc;
if (IS_ENABLED(CONFIG_CXL_PMEM))
rc = device_for_each_child(&root_port->dev, root_port,
add_root_nvdimm_bridge);
if (rc < 0)
return rc;
return 0;
}
static const struct acpi_device_id cxl_acpi_ids[] = {
{ "ACPI0017" },
{ },
};
MODULE_DEVICE_TABLE(acpi, cxl_acpi_ids);
static struct platform_driver cxl_acpi_driver = {
.probe = cxl_acpi_probe,
.driver = {
.name = KBUILD_MODNAME,
.acpi_match_table = cxl_acpi_ids,
},
};
module_platform_driver(cxl_acpi_driver);
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(CXL);
MODULE_IMPORT_NS(ACPI);
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