diff options
Diffstat (limited to 'drivers/pnp/system.c')
| -rw-r--r-- | drivers/pnp/system.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/pnp/system.c b/drivers/pnp/system.c new file mode 100644 index 0000000000..835113b2cb --- /dev/null +++ b/drivers/pnp/system.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * system.c - a driver for reserving pnp system resources + * + * Some code is based on pnpbios_core.c + * Copyright 2002 Adam Belay <ambx1@neo.rr.com> + * (c) Copyright 2007 Hewlett-Packard Development Company, L.P. + * Bjorn Helgaas <bjorn.helgaas@hp.com> + */ + +#include <linux/pnp.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/ioport.h> + +static const struct pnp_device_id pnp_dev_table[] = { + /* General ID for reserving resources */ + {"PNP0c02", 0}, + /* memory controller */ + {"PNP0c01", 0}, + {"", 0} +}; + +static void reserve_range(struct pnp_dev *dev, struct resource *r, int port) +{ + char *regionid; + const char *pnpid = dev_name(&dev->dev); + resource_size_t start = r->start, end = r->end; + struct resource *res; + + regionid = kmalloc(16, GFP_KERNEL); + if (!regionid) + return; + + snprintf(regionid, 16, "pnp %s", pnpid); + if (port) + res = request_region(start, end - start + 1, regionid); + else + res = request_mem_region(start, end - start + 1, regionid); + if (res) + res->flags &= ~IORESOURCE_BUSY; + else + kfree(regionid); + + /* + * Failures at this point are usually harmless. pci quirks for + * example do reserve stuff they know about too, so we may well + * have double reservations. + */ + dev_info(&dev->dev, "%pR %s reserved\n", r, + res ? "has been" : "could not be"); +} + +static void reserve_resources_of_dev(struct pnp_dev *dev) +{ + struct resource *res; + int i; + + for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_IO, i)); i++) { + if (res->flags & IORESOURCE_DISABLED) + continue; + if (res->start == 0) + continue; /* disabled */ + if (res->start < 0x100) + /* + * Below 0x100 is only standard PC hardware + * (pics, kbd, timer, dma, ...) + * We should not get resource conflicts there, + * and the kernel reserves these anyway + * (see arch/i386/kernel/setup.c). + * So, do nothing + */ + continue; + if (res->end < res->start) + continue; /* invalid */ + + reserve_range(dev, res, 1); + } + + for (i = 0; (res = pnp_get_resource(dev, IORESOURCE_MEM, i)); i++) { + if (res->flags & IORESOURCE_DISABLED) + continue; + + reserve_range(dev, res, 0); + } +} + +static int system_pnp_probe(struct pnp_dev *dev, + const struct pnp_device_id *dev_id) +{ + reserve_resources_of_dev(dev); + return 0; +} + +static struct pnp_driver system_pnp_driver = { + .name = "system", + .id_table = pnp_dev_table, + .flags = PNP_DRIVER_RES_DO_NOT_CHANGE, + .probe = system_pnp_probe, +}; + +static int __init pnp_system_init(void) +{ + return pnp_register_driver(&system_pnp_driver); +} + +/* + * Reserve motherboard resources after PCI claim BARs, + * but before PCI assign resources for uninitialized PCI devices + */ +fs_initcall(pnp_system_init); |