// SPDX-License-Identifier: GPL-2.0
/*
 * arch/alpha/kernel/pci-sysfs.c
 *
 * Copyright (C) 2009 Ivan Kokshaysky
 *
 * Alpha PCI resource files.
 *
 * Loosely based on generic HAVE_PCI_MMAP implementation in
 * drivers/pci/pci-sysfs.c
 */

#include <linux/sched.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/pci.h>

static int hose_mmap_page_range(struct pci_controller *hose,
                                struct vm_area_struct *vma,
                                enum pci_mmap_state mmap_type, int sparse)
{
        unsigned long base;

        if (mmap_type == pci_mmap_mem)
                base = sparse ? hose->sparse_mem_base : hose->dense_mem_base;
        else
                base = sparse ? hose->sparse_io_base : hose->dense_io_base;

        vma->vm_pgoff += base >> PAGE_SHIFT;

        return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
                                  vma->vm_end - vma->vm_start,
                                  vma->vm_page_prot);
}

static int __pci_mmap_fits(struct pci_dev *pdev, int num,
                           struct vm_area_struct *vma, int sparse)
{
        unsigned long nr, start, size;
        int shift = sparse ? 5 : 0;

        nr = vma_pages(vma);
        start = vma->vm_pgoff;
        size = ((pci_resource_len(pdev, num) - 1) >> (PAGE_SHIFT - shift)) + 1;

        if (start < size && size - start >= nr)
                return 1;
        WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on %s BAR %d "
                "(size 0x%08lx)\n",
                current->comm, sparse ? " sparse" : "", start, start + nr,
                pci_name(pdev), num, size);
        return 0;
}

/**
 * pci_mmap_resource - map a PCI resource into user memory space
 * @kobj: kobject for mapping
 * @attr: struct bin_attribute for the file being mapped
 * @vma: struct vm_area_struct passed into the mmap
 * @sparse: address space type
 *
 * Use the bus mapping routines to map a PCI resource into userspace.
 *
 * Return: %0 on success, negative error code otherwise
 */
static int pci_mmap_resource(struct kobject *kobj,
                             const struct bin_attribute *attr,
                             struct vm_area_struct *vma, int sparse)
{
        struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
        struct resource *res = attr->private;
        enum pci_mmap_state mmap_type;
        struct pci_bus_region bar;
        int i;

        for (i = 0; i < PCI_STD_NUM_BARS; i++)
                if (res == &pdev->resource[i])
                        break;
        if (i >= PCI_STD_NUM_BARS)
                return -ENODEV;

        if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start))
                return -EINVAL;

        if (!__pci_mmap_fits(pdev, i, vma, sparse))
                return -EINVAL;

        pcibios_resource_to_bus(pdev->bus, &bar, res);
        vma->vm_pgoff += bar.start >> (PAGE_SHIFT - (sparse ? 5 : 0));
        mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;

        return hose_mmap_page_range(pdev->sysdata, vma, mmap_type, sparse);
}

static int pci_mmap_resource_sparse(struct file *filp, struct kobject *kobj,
                                    const struct bin_attribute *attr,
                                    struct vm_area_struct *vma)
{
        return pci_mmap_resource(kobj, attr, vma, 1);
}

static int pci_mmap_resource_dense(struct file *filp, struct kobject *kobj,
                                   const struct bin_attribute *attr,
                                   struct vm_area_struct *vma)
{
        return pci_mmap_resource(kobj, attr, vma, 0);
}

/**
 * pci_remove_resource_files - cleanup resource files
 * @pdev: pci_dev to cleanup
 *
 * If we created resource files for @dev, remove them from sysfs and
 * free their resources.
 */
void pci_remove_resource_files(struct pci_dev *pdev)
{
        int i;

        for (i = 0; i < PCI_STD_NUM_BARS; i++) {
                struct bin_attribute *res_attr;

                res_attr = pdev->res_attr[i];
                if (res_attr) {
                        sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
                        kfree(res_attr);
                }

                res_attr = pdev->res_attr_wc[i];
                if (res_attr) {
                        sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
                        kfree(res_attr);
                }
        }
}

static int sparse_mem_mmap_fits(struct pci_dev *pdev, int num)
{
        struct pci_bus_region bar;
        struct pci_controller *hose = pdev->sysdata;
        long dense_offset;
        unsigned long sparse_size;

        pcibios_resource_to_bus(pdev->bus, &bar, &pdev->resource[num]);

        /* All core logic chips have 4G sparse address space, except
           CIA which has 16G (see xxx_SPARSE_MEM and xxx_DENSE_MEM
           definitions in asm/core_xxx.h files). This corresponds
           to 128M or 512M of the bus space. */
        dense_offset = (long)(hose->dense_mem_base - hose->sparse_mem_base);
        sparse_size = dense_offset >= 0x400000000UL ? 0x20000000 : 0x8000000;

        return bar.end < sparse_size;
}

static int pci_create_one_attr(struct pci_dev *pdev, int num, char *name,
                               char *suffix, struct bin_attribute *res_attr,
                               unsigned long sparse)
{
        size_t size = pci_resource_len(pdev, num);

        sprintf(name, "resource%d%s", num, suffix);
        res_attr->mmap = sparse ? pci_mmap_resource_sparse :
                                  pci_mmap_resource_dense;
        res_attr->attr.name = name;
        res_attr->attr.mode = S_IRUSR | S_IWUSR;
        res_attr->size = sparse ? size << 5 : size;
        res_attr->private = &pdev->resource[num];
        return sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
}

static int pci_create_attr(struct pci_dev *pdev, int num)
{
        /* allocate attribute structure, piggyback attribute name */
        int retval, nlen1, nlen2 = 0, res_count = 1;
        unsigned long sparse_base, dense_base;
        struct bin_attribute *attr;
        struct pci_controller *hose = pdev->sysdata;
        char *suffix, *attr_name;

        suffix = "";    /* Assume bwx machine, normal resourceN files. */
        nlen1 = 10;

        if (pdev->resource[num].flags & IORESOURCE_MEM) {
                sparse_base = hose->sparse_mem_base;
                dense_base = hose->dense_mem_base;
                if (sparse_base && !sparse_mem_mmap_fits(pdev, num)) {
                        sparse_base = 0;
                        suffix = "_dense";
                        nlen1 = 16;     /* resourceN_dense */
                }
        } else {
                sparse_base = hose->sparse_io_base;
                dense_base = hose->dense_io_base;
        }

        if (sparse_base) {
                suffix = "_sparse";
                nlen1 = 17;
                if (dense_base) {
                        nlen2 = 16;     /* resourceN_dense */
                        res_count = 2;
                }
        }

        attr = kzalloc(sizeof(*attr) * res_count + nlen1 + nlen2, GFP_ATOMIC);
        if (!attr)
                return -ENOMEM;

        /* Create bwx, sparse or single dense file */
        attr_name = (char *)(attr + res_count);
        pdev->res_attr[num] = attr;
        retval = pci_create_one_attr(pdev, num, attr_name, suffix, attr,
                                     sparse_base);
        if (retval || res_count == 1)
                return retval;

        /* Create dense file */
        attr_name += nlen1;
        attr++;
        pdev->res_attr_wc[num] = attr;
        return pci_create_one_attr(pdev, num, attr_name, "_dense", attr, 0);
}

/**
 * pci_create_resource_files - create resource files in sysfs for @pdev
 * @pdev: pci_dev in question
 *
 * Walk the resources in @dev creating files for each resource available.
 *
 * Return: %0 on success, or negative error code
 */
int pci_create_resource_files(struct pci_dev *pdev)
{
        int i;
        int retval;

        /* Expose the PCI resources from this device as files */
        for (i = 0; i < PCI_STD_NUM_BARS; i++) {

                /* skip empty resources */
                if (!pci_resource_len(pdev, i))
                        continue;

                retval = pci_create_attr(pdev, i);
                if (retval) {
                        pci_remove_resource_files(pdev);
                        return retval;
                }
        }
        return 0;
}

/* Legacy I/O bus mapping stuff. */

static int __legacy_mmap_fits(struct pci_controller *hose,
                              struct vm_area_struct *vma,
                              unsigned long res_size, int sparse)
{
        unsigned long nr, start, size;

        nr = vma_pages(vma);
        start = vma->vm_pgoff;
        size = ((res_size - 1) >> PAGE_SHIFT) + 1;

        if (start < size && size - start >= nr)
                return 1;
        WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on hose %d "
                "(size 0x%08lx)\n",
                current->comm, sparse ? " sparse" : "", start, start + nr,
                hose->index, size);
        return 0;
}

static inline int has_sparse(struct pci_controller *hose,
                             enum pci_mmap_state mmap_type)
{
        unsigned long base;

        base = (mmap_type == pci_mmap_mem) ? hose->sparse_mem_base :
                                             hose->sparse_io_base;

        return base != 0;
}

int pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma,
                               enum pci_mmap_state mmap_type)
{
        struct pci_controller *hose = bus->sysdata;
        int sparse = has_sparse(hose, mmap_type);
        unsigned long res_size;

        res_size = (mmap_type == pci_mmap_mem) ? bus->legacy_mem->size :
                                                 bus->legacy_io->size;
        if (!__legacy_mmap_fits(hose, vma, res_size, sparse))
                return -EINVAL;

        return hose_mmap_page_range(hose, vma, mmap_type, sparse);
}

/**
 * pci_adjust_legacy_attr - adjustment of legacy file attributes
 * @bus: bus to create files under
 * @mmap_type: I/O port or memory
 *
 * Adjust file name and size for sparse mappings.
 */
void pci_adjust_legacy_attr(struct pci_bus *bus, enum pci_mmap_state mmap_type)
{
        struct pci_controller *hose = bus->sysdata;

        if (!has_sparse(hose, mmap_type))
                return;

        if (mmap_type == pci_mmap_mem) {
                bus->legacy_mem->attr.name = "legacy_mem_sparse";
                bus->legacy_mem->size <<= 5;
        } else {
                bus->legacy_io->attr.name = "legacy_io_sparse";
                bus->legacy_io->size <<= 5;
        }
        return;
}

/* Legacy I/O bus read/write functions */
int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val, size_t size)
{
        struct pci_controller *hose = bus->sysdata;

        port += hose->io_space->start;

        switch(size) {
        case 1:
                *((u8 *)val) = inb(port);
                return 1;
        case 2:
                if (port & 1)
                        return -EINVAL;
                *((u16 *)val) = inw(port);
                return 2;
        case 4:
                if (port & 3)
                        return -EINVAL;
                *((u32 *)val) = inl(port);
                return 4;
        }
        return -EINVAL;
}

int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val, size_t size)
{
        struct pci_controller *hose = bus->sysdata;

        port += hose->io_space->start;

        switch(size) {
        case 1:
                outb(port, val);
                return 1;
        case 2:
                if (port & 1)
                        return -EINVAL;
                outw(port, val);
                return 2;
        case 4:
                if (port & 3)
                        return -EINVAL;
                outl(port, val);
                return 4;
        }
        return -EINVAL;
}