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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 <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;
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 rc, expected_len;
unsigned int ways;
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;
}
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;
}
rc = eiw_to_ways(cfmws->interleave_ways, &ways);
if (rc) {
dev_err(dev, "CFMWS Interleave Ways (%d) invalid\n",
cfmws->interleave_ways);
return -EINVAL;
}
expected_len = struct_size(cfmws, interleave_targets, ways);
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;
}
/*
* 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;
struct resource *cxl_res;
int id;
};
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 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;
int rc;
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;
}
rc = eiw_to_ways(cfmws->interleave_ways, &ways);
if (rc)
return rc;
rc = eig_to_granularity(cfmws->granularity, &ig);
if (rc)
return rc;
for (i = 0; i < ways; i++)
target_map[i] = cfmws->interleave_targets[i];
res = kzalloc(sizeof(*res), GFP_KERNEL);
if (!res)
return -ENOMEM;
res->name = kasprintf(GFP_KERNEL, "CXL Window %d", ctx->id++);
if (!res->name)
goto err_name;
res->start = cfmws->base_hpa;
res->end = cfmws->base_hpa + cfmws->window_size - 1;
res->flags = IORESOURCE_MEM;
/* add to the local resource tracking to establish a sort order */
rc = insert_resource(cxl_res, res);
if (rc)
goto err_insert;
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;
cxld = &cxlrd->cxlsd.cxld;
cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions);
cxld->target_type = CXL_DECODER_EXPANDER;
cxld->hpa_range = (struct range) {
.start = res->start,
.end = res->end,
};
cxld->interleave_ways = ways;
/*
* Minimize the x1 granularity to advertise support for any
* valid region granularity
*/
if (ways == 1)
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
rc = cxl_decoder_autoremove(dev, cxld);
if (rc) {
dev_err(dev, "Failed to add decode range [%#llx - %#llx]\n",
cxld->hpa_range.start, cxld->hpa_range.end);
return 0;
}
dev_dbg(dev, "add: %s node: %d range [%#llx - %#llx]\n",
dev_name(&cxld->dev),
phys_to_target_node(cxld->hpa_range.start),
cxld->hpa_range.start, cxld->hpa_range.end);
return 0;
err_insert:
kfree(res->name);
err_name:
kfree(res);
return -ENOMEM;
}
__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 *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 (!hb)
return 0;
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;
}
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, bridge, dport->component_reg_phys,
dport);
if (IS_ERR(port))
return PTR_ERR(port);
dev_info(bridge, "host supports CXL\n");
return 0;
}
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,
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->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 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 *hb = to_cxl_host_bridge(host, match);
if (!hb)
return 0;
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 = match,
.uid = uid,
};
acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, cxl_get_chbcr, &ctx);
if (!ctx.chbcr) {
dev_warn(match, "No CHBS found for Host Bridge (UID %lld)\n",
uid);
return 0;
}
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(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;
}
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 struct lock_class_key cxl_root_key;
static void cxl_acpi_lock_reset_class(void *dev)
{
device_lock_reset_class(dev);
}
static void del_cxl_resource(struct resource *res)
{
kfree(res->name);
kfree(res);
}
static void cxl_set_public_resource(struct resource *priv, struct resource *pub)
{
priv->desc = (unsigned long) pub;
}
static struct resource *cxl_get_public_resource(struct resource *priv)
{
return (struct resource *) priv->desc;
}
static void remove_cxl_resources(void *data)
{
struct resource *res, *next, *cxl = data;
for (res = cxl->child; res; res = next) {
struct resource *victim = cxl_get_public_resource(res);
next = res->sibling;
remove_resource(res);
if (victim) {
remove_resource(victim);
kfree(victim);
}
del_cxl_resource(res);
}
}
/**
* add_cxl_resources() - reflect CXL fixed memory windows in iomem_resource
* @cxl_res: A standalone resource tree where each CXL window is a sibling
*
* Walk each CXL window in @cxl_res and add it to iomem_resource potentially
* expanding its boundaries to ensure that any conflicting resources become
* children. If a window is expanded it may then conflict with a another window
* entry and require the window to be truncated or trimmed. Consider this
* situation:
*
* |-- "CXL Window 0" --||----- "CXL Window 1" -----|
* |--------------- "System RAM" -------------|
*
* ...where platform firmware has established as System RAM resource across 2
* windows, but has left some portion of window 1 for dynamic CXL region
* provisioning. In this case "Window 0" will span the entirety of the "System
* RAM" span, and "CXL Window 1" is truncated to the remaining tail past the end
* of that "System RAM" resource.
*/
static int add_cxl_resources(struct resource *cxl_res)
{
struct resource *res, *new, *next;
for (res = cxl_res->child; res; res = next) {
new = kzalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return -ENOMEM;
new->name = res->name;
new->start = res->start;
new->end = res->end;
new->flags = IORESOURCE_MEM;
new->desc = IORES_DESC_CXL;
/*
* Record the public resource in the private cxl_res tree for
* later removal.
*/
cxl_set_public_resource(res, new);
insert_resource_expand_to_fit(&iomem_resource, new);
next = res->sibling;
while (next && resource_overlaps(new, next)) {
if (resource_contains(new, next)) {
struct resource *_next = next->sibling;
remove_resource(next);
del_cxl_resource(next);
next = _next;
} else
next->start = new->end + 1;
}
}
return 0;
}
static int pair_cxl_resource(struct device *dev, void *data)
{
struct resource *cxl_res = data;
struct resource *p;
if (!is_root_decoder(dev))
return 0;
for (p = cxl_res->child; p; p = p->sibling) {
struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
struct resource res = {
.start = cxld->hpa_range.start,
.end = cxld->hpa_range.end,
.flags = IORESOURCE_MEM,
};
if (resource_contains(p, &res)) {
cxlrd->res = cxl_get_public_resource(p);
break;
}
}
return 0;
}
static int cxl_acpi_probe(struct platform_device *pdev)
{
int rc;
struct resource *cxl_res;
struct cxl_port *root_port;
struct device *host = &pdev->dev;
struct acpi_device *adev = ACPI_COMPANION(host);
struct cxl_cfmws_context ctx;
device_lock_set_class(&pdev->dev, &cxl_root_key);
rc = devm_add_action_or_reset(&pdev->dev, cxl_acpi_lock_reset_class,
&pdev->dev);
if (rc)
return rc;
cxl_res = devm_kzalloc(host, sizeof(*cxl_res), GFP_KERNEL);
if (!cxl_res)
return -ENOMEM;
cxl_res->name = "CXL mem";
cxl_res->start = 0;
cxl_res->end = -1;
cxl_res->flags = IORESOURCE_MEM;
root_port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL);
if (IS_ERR(root_port))
return PTR_ERR(root_port);
rc = bus_for_each_dev(adev->dev.bus, NULL, root_port,
add_host_bridge_dport);
if (rc < 0)
return rc;
rc = devm_add_action_or_reset(host, remove_cxl_resources, cxl_res);
if (rc)
return rc;
ctx = (struct cxl_cfmws_context) {
.dev = host,
.root_port = root_port,
.cxl_res = cxl_res,
};
rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, cxl_parse_cfmws, &ctx);
if (rc < 0)
return -ENXIO;
rc = add_cxl_resources(cxl_res);
if (rc)
return rc;
/*
* Populate the root decoders with their related iomem resource,
* if present
*/
device_for_each_child(&root_port->dev, cxl_res, pair_cxl_resource);
/*
* 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;
/* In case PCI is scanned before ACPI re-trigger memdev attach */
cxl_bus_rescan();
return 0;
}
static const struct acpi_device_id cxl_acpi_ids[] = {
{ "ACPI0017" },
{ },
};
MODULE_DEVICE_TABLE(acpi, cxl_acpi_ids);
static const struct platform_device_id cxl_test_ids[] = {
{ "cxl_acpi" },
{ },
};
MODULE_DEVICE_TABLE(platform, cxl_test_ids);
static struct platform_driver cxl_acpi_driver = {
.probe = cxl_acpi_probe,
.driver = {
.name = KBUILD_MODNAME,
.acpi_match_table = cxl_acpi_ids,
},
.id_table = cxl_test_ids,
};
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);