alistair23-linux/arch/alpha/kernel/pci-noop.c

// SPDX-License-Identifier: GPL-2.0
/*
 *	linux/arch/alpha/kernel/pci-noop.c
 *
 * Stub PCI interfaces for Jensen-specific kernels.
 */

#include <linux/pci.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/gfp.h>
#include <linux/capability.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/syscalls.h>

#include "proto.h"


/*
 * The PCI controller list.
 */

struct pci_controller *hose_head, **hose_tail = &hose_head;
struct pci_controller *pci_isa_hose;


struct pci_controller * __init
alloc_pci_controller(void)
{
	struct pci_controller *hose;

	hose = memblock_alloc(sizeof(*hose), SMP_CACHE_BYTES);
	if (!hose)
		panic("%s: Failed to allocate %zu bytes\n", __func__,
		      sizeof(*hose));

	*hose_tail = hose;
	hose_tail = &hose->next;

	return hose;
}

struct resource * __init
alloc_resource(void)
{
	void *ptr = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);

	if (!ptr)
		panic("%s: Failed to allocate %zu bytes\n", __func__,
		      sizeof(struct resource));

	return ptr;
}

SYSCALL_DEFINE3(pciconfig_iobase, long, which, unsigned long, bus,
		unsigned long, dfn)
{
	struct pci_controller *hose;

	/* from hose or from bus.devfn */
	if (which & IOBASE_FROM_HOSE) {
		for (hose = hose_head; hose; hose = hose->next)
			if (hose->index == bus)
				break;
		if (!hose)
			return -ENODEV;
	} else {
		/* Special hook for ISA access.  */
		if (bus == 0 && dfn == 0)
			hose = pci_isa_hose;
		else
			return -ENODEV;
	}

	switch (which & ~IOBASE_FROM_HOSE) {
	case IOBASE_HOSE:
		return hose->index;
	case IOBASE_SPARSE_MEM:
		return hose->sparse_mem_base;
	case IOBASE_DENSE_MEM:
		return hose->dense_mem_base;
	case IOBASE_SPARSE_IO:
		return hose->sparse_io_base;
	case IOBASE_DENSE_IO:
		return hose->dense_io_base;
	case IOBASE_ROOT_BUS:
		return hose->bus->number;
	}

	return -EOPNOTSUPP;
}

SYSCALL_DEFINE5(pciconfig_read, unsigned long, bus, unsigned long, dfn,
		unsigned long, off, unsigned long, len, void __user *, buf)
{
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;
	else
		return -ENODEV;
}

SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
		unsigned long, off, unsigned long, len, void __user *, buf)
{
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;
	else
		return -ENODEV;
}