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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/firmware/efi/dev-path-parser.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'drivers/firmware/efi/dev-path-parser.c')
| -rw-r--r-- | drivers/firmware/efi/dev-path-parser.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/firmware/efi/dev-path-parser.c b/drivers/firmware/efi/dev-path-parser.c new file mode 100644 index 000000000..13ea141c0 --- /dev/null +++ b/drivers/firmware/efi/dev-path-parser.c @@ -0,0 +1,181 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * dev-path-parser.c - EFI Device Path parser + * Copyright (C) 2016 Lukas Wunner <lukas@wunner.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License (version 2) as + * published by the Free Software Foundation. + */ + +#include <linux/acpi.h> +#include <linux/efi.h> +#include <linux/pci.h> + +static long __init parse_acpi_path(const struct efi_dev_path *node, + struct device *parent, struct device **child) +{ + struct acpi_device *adev; + struct device *phys_dev; + char hid[ACPI_ID_LEN]; + + if (node->header.length != 12) + return -EINVAL; + + sprintf(hid, "%c%c%c%04X", + 'A' + ((node->acpi.hid >> 10) & 0x1f) - 1, + 'A' + ((node->acpi.hid >> 5) & 0x1f) - 1, + 'A' + ((node->acpi.hid >> 0) & 0x1f) - 1, + node->acpi.hid >> 16); + + for_each_acpi_dev_match(adev, hid, NULL, -1) { + if (acpi_dev_uid_match(adev, node->acpi.uid)) + break; + if (!acpi_device_uid(adev) && node->acpi.uid == 0) + break; + } + if (!adev) + return -ENODEV; + + phys_dev = acpi_get_first_physical_node(adev); + if (phys_dev) { + *child = get_device(phys_dev); + acpi_dev_put(adev); + } else + *child = &adev->dev; + + return 0; +} + +static int __init match_pci_dev(struct device *dev, const void *data) +{ + unsigned int devfn = *(const unsigned int *)data; + + return dev_is_pci(dev) && to_pci_dev(dev)->devfn == devfn; +} + +static long __init parse_pci_path(const struct efi_dev_path *node, + struct device *parent, struct device **child) +{ + unsigned int devfn; + + if (node->header.length != 6) + return -EINVAL; + if (!parent) + return -EINVAL; + + devfn = PCI_DEVFN(node->pci.dev, node->pci.fn); + + *child = device_find_child(parent, &devfn, match_pci_dev); + if (!*child) + return -ENODEV; + + return 0; +} + +/* + * Insert parsers for further node types here. + * + * Each parser takes a pointer to the @node and to the @parent (will be NULL + * for the first device path node). If a device corresponding to @node was + * found below @parent, its reference count should be incremented and the + * device returned in @child. + * + * The return value should be 0 on success or a negative int on failure. + * The special return values 0x01 (EFI_DEV_END_INSTANCE) and 0xFF + * (EFI_DEV_END_ENTIRE) signal the end of the device path, only + * parse_end_path() is supposed to return this. + * + * Be sure to validate the node length and contents before commencing the + * search for a device. + */ + +static long __init parse_end_path(const struct efi_dev_path *node, + struct device *parent, struct device **child) +{ + if (node->header.length != 4) + return -EINVAL; + if (node->header.sub_type != EFI_DEV_END_INSTANCE && + node->header.sub_type != EFI_DEV_END_ENTIRE) + return -EINVAL; + if (!parent) + return -ENODEV; + + *child = get_device(parent); + return node->header.sub_type; +} + +/** + * efi_get_device_by_path - find device by EFI Device Path + * @node: EFI Device Path + * @len: maximum length of EFI Device Path in bytes + * + * Parse a series of EFI Device Path nodes at @node and find the corresponding + * device. If the device was found, its reference count is incremented and a + * pointer to it is returned. The caller needs to drop the reference with + * put_device() after use. The @node pointer is updated to point to the + * location immediately after the "End of Hardware Device Path" node. + * + * If another Device Path instance follows, @len is decremented by the number + * of bytes consumed. Otherwise @len is set to %0. + * + * If a Device Path node is malformed or its corresponding device is not found, + * @node is updated to point to this offending node and an ERR_PTR is returned. + * + * If @len is initially %0, the function returns %NULL. Thus, to iterate over + * all instances in a path, the following idiom may be used: + * + * while (!IS_ERR_OR_NULL(dev = efi_get_device_by_path(&node, &len))) { + * // do something with dev + * put_device(dev); + * } + * if (IS_ERR(dev)) + * // report error + * + * Devices can only be found if they're already instantiated. Most buses + * instantiate devices in the "subsys" initcall level, hence the earliest + * initcall level in which this function should be called is "fs". + * + * Returns the device on success or + * %ERR_PTR(-ENODEV) if no device was found, + * %ERR_PTR(-EINVAL) if a node is malformed or exceeds @len, + * %ERR_PTR(-ENOTSUPP) if support for a node type is not yet implemented. + */ +struct device * __init efi_get_device_by_path(const struct efi_dev_path **node, + size_t *len) +{ + struct device *parent = NULL, *child; + long ret = 0; + + if (!*len) + return NULL; + + while (!ret) { + if (*len < 4 || *len < (*node)->header.length) + ret = -EINVAL; + else if ((*node)->header.type == EFI_DEV_ACPI && + (*node)->header.sub_type == EFI_DEV_BASIC_ACPI) + ret = parse_acpi_path(*node, parent, &child); + else if ((*node)->header.type == EFI_DEV_HW && + (*node)->header.sub_type == EFI_DEV_PCI) + ret = parse_pci_path(*node, parent, &child); + else if (((*node)->header.type == EFI_DEV_END_PATH || + (*node)->header.type == EFI_DEV_END_PATH2)) + ret = parse_end_path(*node, parent, &child); + else + ret = -ENOTSUPP; + + put_device(parent); + if (ret < 0) + return ERR_PTR(ret); + + parent = child; + *node = (void *)*node + (*node)->header.length; + *len -= (*node)->header.length; + } + + if (ret == EFI_DEV_END_ENTIRE) + *len = 0; + + return child; +} |
