LXR linux/drivers/pnp/system.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * system.c - a driver for reserving pnp system resources
   4 *
   5 * Some code is based on pnpbios_core.c
   6 * Copyright 2002 Adam Belay <ambx1@neo.rr.com>
   7 * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
   8 *      Bjorn Helgaas <bjorn.helgaas@hp.com>
   9 */
  10
  11#include <linux/pnp.h>
  12#include <linux/device.h>
  13#include <linux/init.h>
  14#include <linux/slab.h>
  15#include <linux/kernel.h>
  16#include <linux/ioport.h>
  17
  18static const struct pnp_device_id pnp_dev_table[] = {
  19        /* General ID for reserving resources */
  20        {"PNP0c02", 0},
  21        /* memory controller */
  22        {"PNP0c01", 0},
  23        {"", 0}
  24};
  25
  26static void reserve_range(struct pnp_dev *dev, struct resource *r, int port)
  27{
  28        char *regionid;
  29        const char *pnpid = dev_name(&dev->dev);
  30        resource_size_t start = r->start, end = r->end;
  31        struct resource *res;
  32
  33        regionid = kmalloc(16, GFP_KERNEL);
  34        if (!regionid)
  35                return;
  36
  37        snprintf(regionid, 16, "pnp %s", pnpid);
  38        if (port)
  39                res = request_region(start, end - start + 1, regionid);
  40        else
  41                res = request_mem_region(start, end - start + 1, regionid);
  42        if (res)
  43                res->flags &= ~IORESOURCE_BUSY;
  44        else
  45                kfree(regionid);
  46
  47        /*
  48         * Failures at this point are usually harmless. pci quirks for
  49         * example do reserve stuff they know about too, so we may well
  50         * have double reservations.
  51         */
  52        dev_info(&dev->dev, "%pR %s reserved\n", r,
  53                 res ? "has been" : "could not be");
  54}
  55
  56static void reserve_resources_of_dev(struct pnp_dev *dev)
  57{
  58        struct resource *res;
  59        int i;
  60
  61        for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_IO, i)); i++) {
  62                if (res->flags & IORESOURCE_DISABLED)
  63                        continue;
  64                if (res->start == 0)
  65                        continue;       /* disabled */
  66                if (res->start < 0x100)
  67                        /*
  68                         * Below 0x100 is only standard PC hardware
  69                         * (pics, kbd, timer, dma, ...)
  70                         * We should not get resource conflicts there,
  71                         * and the kernel reserves these anyway
  72                         * (see arch/i386/kernel/setup.c).
  73                         * So, do nothing
  74                         */
  75                        continue;
  76                if (res->end < res->start)
  77                        continue;       /* invalid */
  78
  79                reserve_range(dev, res, 1);
  80        }
  81
  82        for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_MEM, i)); i++) {
  83                if (res->flags & IORESOURCE_DISABLED)
  84                        continue;
  85
  86                reserve_range(dev, res, 0);
  87        }
  88}
  89
  90static int system_pnp_probe(struct pnp_dev *dev,
  91                            const struct pnp_device_id *dev_id)
  92{
  93        reserve_resources_of_dev(dev);
  94        return 0;
  95}
  96
  97static struct pnp_driver system_pnp_driver = {
  98        .name     = "system",
  99        .id_table = pnp_dev_table,
 100        .flags    = PNP_DRIVER_RES_DO_NOT_CHANGE,
 101        .probe    = system_pnp_probe,
 102};
 103
 104static int __init pnp_system_init(void)
 105{
 106        return pnp_register_driver(&system_pnp_driver);
 107}
 108
 109/**
 110 * Reserve motherboard resources after PCI claim BARs,
 111 * but before PCI assign resources for uninitialized PCI devices
 112 */
 113fs_initcall(pnp_system_init);
 114