efi/arm: Defer probe of PCIe backed efifb on DT systems (64c8a0cd) · Commits · 戴 / test

drivers/firmware/efi/arm-init.c

+103 −4

Original line number	Diff line number	Diff line
		@@ -10,10 +10,12 @@
		#define pr_fmt(fmt) "efi: " fmt

		#include <linux/efi.h>
		#include <linux/fwnode.h>
		#include <linux/init.h>
		#include <linux/memblock.h>
		#include <linux/mm_types.h>
		#include <linux/of.h>
		#include <linux/of_address.h>
		#include <linux/of_fdt.h>
		#include <linux/platform_device.h>
		#include <linux/screen_info.h>
		@@ -276,15 +278,112 @@ void __init efi_init(void)
		efi_memmap_unmap();
		}

		static bool efifb_overlaps_pci_range(const struct of_pci_range *range)
		{
		u64 fb_base = screen_info.lfb_base;

		if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
		fb_base \|= (u64)(unsigned long)screen_info.ext_lfb_base << 32;

		return fb_base >= range->cpu_addr &&
		fb_base < (range->cpu_addr + range->size);
		}

		static struct device_node *find_pci_overlap_node(void)
		{
		struct device_node *np;

		for_each_node_by_type(np, "pci") {
		struct of_pci_range_parser parser;
		struct of_pci_range range;
		int err;

		err = of_pci_range_parser_init(&parser, np);
		if (err) {
		pr_warn("of_pci_range_parser_init() failed: %d\n", err);
		continue;
		}

		for_each_of_pci_range(&parser, &range)
		if (efifb_overlaps_pci_range(&range))
		return np;
		}
		return NULL;
		}

		/*
		* If the efifb framebuffer is backed by a PCI graphics controller, we have
		* to ensure that this relation is expressed using a device link when
		* running in DT mode, or the probe order may be reversed, resulting in a
		* resource reservation conflict on the memory window that the efifb
		* framebuffer steals from the PCIe host bridge.
		*/
		static int efifb_add_links(const struct fwnode_handle *fwnode,
		struct device *dev)
		{
		struct device_node *sup_np;
		struct device *sup_dev;

		sup_np = find_pci_overlap_node();

		/*
		* If there's no PCI graphics controller backing the efifb, we are
		* done here.
		*/
		if (!sup_np)
		return 0;

		sup_dev = get_dev_from_fwnode(&sup_np->fwnode);
		of_node_put(sup_np);

		/*
		* Return -ENODEV if the PCI graphics controller device hasn't been
		* registered yet. This ensures that efifb isn't allowed to probe
		* and this function is retried again when new devices are
		* registered.
		*/
		if (!sup_dev)
		return -ENODEV;

		/*
		* If this fails, retrying this function at a later point won't
		* change anything. So, don't return an error after this.
		*/
		if (!device_link_add(dev, sup_dev, 0))
		dev_warn(dev, "device_link_add() failed\n");

		put_device(sup_dev);

		return 0;
		}

		static const struct fwnode_operations efifb_fwnode_ops = {
		.add_links = efifb_add_links,
		};

		static struct fwnode_handle efifb_fwnode = {
		.ops = &efifb_fwnode_ops,
		};

		static int __init register_gop_device(void)
		{
		void *pd;
		struct platform_device *pd;
		int err;

		if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
		return 0;

		pd = platform_device_register_data(NULL, "efi-framebuffer", 0,
		&screen_info, sizeof(screen_info));
		return PTR_ERR_OR_ZERO(pd);
		pd = platform_device_alloc("efi-framebuffer", 0);
		if (!pd)
		return -ENOMEM;

		if (IS_ENABLED(CONFIG_PCI))
		pd->dev.fwnode = &efifb_fwnode;

		err = platform_device_add_data(pd, &screen_info, sizeof(screen_info));
		if (err)
		return err;

		return platform_device_add(pd);
		}
		subsys_initcall(register_gop_device);

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