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7dab174e2e
In preparation for the CXL region driver to take over the responsibility of registering device-dax instances for CXL regions, move the registration of "hmem" devices to dax_hmem.ko. Previously the builtin component of this enabling (drivers/dax/hmem/device.o) would register platform devices for each address range and trigger the dax_hmem.ko module to load and attach device-dax instances to those devices. Now, the ranges are collected from the HMAT and EFI memory map walking, but the device creation is deferred. A new "hmem_platform" device is created which triggers dax_hmem.ko to load and register the platform devices. Tested-by: Fan Ni <fan.ni@samsung.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/167602002771.1924368.5653558226424530127.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
95 lines
2 KiB
C
95 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/platform_device.h>
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#include <linux/memregion.h>
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#include <linux/module.h>
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#include <linux/dax.h>
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#include <linux/mm.h>
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static bool nohmem;
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module_param_named(disable, nohmem, bool, 0444);
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static bool platform_initialized;
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static DEFINE_MUTEX(hmem_resource_lock);
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static struct resource hmem_active = {
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.name = "HMEM devices",
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.start = 0,
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.end = -1,
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.flags = IORESOURCE_MEM,
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};
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int walk_hmem_resources(struct device *host, walk_hmem_fn fn)
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{
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struct resource *res;
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int rc = 0;
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mutex_lock(&hmem_resource_lock);
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for (res = hmem_active.child; res; res = res->sibling) {
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rc = fn(host, (int) res->desc, res);
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if (rc)
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break;
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}
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mutex_unlock(&hmem_resource_lock);
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return rc;
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}
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EXPORT_SYMBOL_GPL(walk_hmem_resources);
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static void __hmem_register_resource(int target_nid, struct resource *res)
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{
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struct platform_device *pdev;
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struct resource *new;
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int rc;
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new = __request_region(&hmem_active, res->start, resource_size(res), "",
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0);
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if (!new) {
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pr_debug("hmem range %pr already active\n", res);
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return;
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}
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new->desc = target_nid;
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if (platform_initialized)
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return;
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pdev = platform_device_alloc("hmem_platform", 0);
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if (!pdev) {
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pr_err_once("failed to register device-dax hmem_platform device\n");
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return;
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}
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rc = platform_device_add(pdev);
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if (rc)
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platform_device_put(pdev);
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else
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platform_initialized = true;
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}
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void hmem_register_resource(int target_nid, struct resource *res)
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{
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if (nohmem)
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return;
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mutex_lock(&hmem_resource_lock);
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__hmem_register_resource(target_nid, res);
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mutex_unlock(&hmem_resource_lock);
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}
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static __init int hmem_register_one(struct resource *res, void *data)
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{
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hmem_register_resource(phys_to_target_node(res->start), res);
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return 0;
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}
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static __init int hmem_init(void)
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{
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walk_iomem_res_desc(IORES_DESC_SOFT_RESERVED,
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IORESOURCE_MEM, 0, -1, NULL, hmem_register_one);
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return 0;
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}
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/*
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* As this is a fallback for address ranges unclaimed by the ACPI HMAT
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* parsing it must be at an initcall level greater than hmat_init().
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*/
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device_initcall(hmem_init);
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