// SPDX-License-Identifier: GPL-2.0
/*
 * rsparser.c - parses and encodes pnpbios resource data streams
 */

#include <linux/ctype.h>
#include <linux/pnp.h>
#include <linux/string.h>

#ifdef CONFIG_PCI
#include <linux/pci.h>
#else
inline void pcibios_penalize_isa_irq(int irq, int active)
{
}
#endif                          /* CONFIG_PCI */

#include "../base.h"
#include "pnpbios.h"

/* standard resource tags */
#define SMALL_TAG_PNPVERNO              0x01
#define SMALL_TAG_LOGDEVID              0x02
#define SMALL_TAG_COMPATDEVID           0x03
#define SMALL_TAG_IRQ                   0x04
#define SMALL_TAG_DMA                   0x05
#define SMALL_TAG_STARTDEP              0x06
#define SMALL_TAG_ENDDEP                0x07
#define SMALL_TAG_PORT                  0x08
#define SMALL_TAG_FIXEDPORT             0x09
#define SMALL_TAG_VENDOR                0x0e
#define SMALL_TAG_END                   0x0f
#define LARGE_TAG                       0x80
#define LARGE_TAG_MEM                   0x81
#define LARGE_TAG_ANSISTR               0x82
#define LARGE_TAG_UNICODESTR            0x83
#define LARGE_TAG_VENDOR                0x84
#define LARGE_TAG_MEM32                 0x85
#define LARGE_TAG_FIXEDMEM32            0x86

/*
 * Resource Data Stream Format:
 *
 * Allocated Resources (required)
 * end tag ->
 * Resource Configuration Options (optional)
 * end tag ->
 * Compitable Device IDs (optional)
 * final end tag ->
 */

/*
 * Allocated Resources
 */

static void pnpbios_parse_allocated_ioresource(struct pnp_dev *dev,
                                               int start, int len)
{
        int flags = 0;
        int end = start + len - 1;

        if (len <= 0 || end >= 0x10003)
                flags |= IORESOURCE_DISABLED;

        pnp_add_io_resource(dev, start, end, flags);
}

static void pnpbios_parse_allocated_memresource(struct pnp_dev *dev,
                                                int start, int len)
{
        int flags = 0;
        int end = start + len - 1;

        if (len <= 0)
                flags |= IORESOURCE_DISABLED;

        pnp_add_mem_resource(dev, start, end, flags);
}

static unsigned char *pnpbios_parse_allocated_resource_data(struct pnp_dev *dev,
                                                            unsigned char *p,
                                                            unsigned char *end)
{
        unsigned int len, tag;
        int io, size, mask, i, flags;

        if (!p)
                return NULL;

        pnp_dbg(&dev->dev, "parse allocated resources\n");

        pnp_init_resources(dev);

        while ((char *)p < (char *)end) {

                /* determine the type of tag */
                if (p[0] & LARGE_TAG) { /* large tag */
                        len = (p[2] << 8) | p[1];
                        tag = p[0];
                } else {        /* small tag */
                        len = p[0] & 0x07;
                        tag = ((p[0] >> 3) & 0x0f);
                }

                switch (tag) {

                case LARGE_TAG_MEM:
                        if (len != 9)
                                goto len_err;
                        io = *(short *)&p[4];
                        size = *(short *)&p[10];
                        pnpbios_parse_allocated_memresource(dev, io, size);
                        break;

                case LARGE_TAG_ANSISTR:
                        /* ignore this for now */
                        break;

                case LARGE_TAG_VENDOR:
                        /* do nothing */
                        break;

                case LARGE_TAG_MEM32:
                        if (len != 17)
                                goto len_err;
                        io = *(int *)&p[4];
                        size = *(int *)&p[16];
                        pnpbios_parse_allocated_memresource(dev, io, size);
                        break;

                case LARGE_TAG_FIXEDMEM32:
                        if (len != 9)
                                goto len_err;
                        io = *(int *)&p[4];
                        size = *(int *)&p[8];
                        pnpbios_parse_allocated_memresource(dev, io, size);
                        break;

                case SMALL_TAG_IRQ:
                        if (len < 2 || len > 3)
                                goto len_err;
                        flags = 0;
                        io = -1;
                        mask = p[1] + p[2] * 256;
                        for (i = 0; i < 16; i++, mask = mask >> 1)
                                if (mask & 0x01)
                                        io = i;
                        if (io != -1)
                                pcibios_penalize_isa_irq(io, 1);
                        else
                                flags = IORESOURCE_DISABLED;
                        pnp_add_irq_resource(dev, io, flags);
                        break;

                case SMALL_TAG_DMA:
                        if (len != 2)
                                goto len_err;
                        flags = 0;
                        io = -1;
                        mask = p[1];
                        for (i = 0; i < 8; i++, mask = mask >> 1)
                                if (mask & 0x01)
                                        io = i;
                        if (io == -1)
                                flags = IORESOURCE_DISABLED;
                        pnp_add_dma_resource(dev, io, flags);
                        break;

                case SMALL_TAG_PORT:
                        if (len != 7)
                                goto len_err;
                        io = p[2] + p[3] * 256;
                        size = p[7];
                        pnpbios_parse_allocated_ioresource(dev, io, size);
                        break;

                case SMALL_TAG_VENDOR:
                        /* do nothing */
                        break;

                case SMALL_TAG_FIXEDPORT:
                        if (len != 3)
                                goto len_err;
                        io = p[1] + p[2] * 256;
                        size = p[3];
                        pnpbios_parse_allocated_ioresource(dev, io, size);
                        break;

                case SMALL_TAG_END:
                        p = p + 2;
                        return (unsigned char *)p;
                        break;

                default:        /* an unknown tag */
len_err:
                        dev_err(&dev->dev, "unknown tag %#x length %d\n",
                                tag, len);
                        break;
                }

                /* continue to the next tag */
                if (p[0] & LARGE_TAG)
                        p += len + 3;
                else
                        p += len + 1;
        }

        dev_err(&dev->dev, "no end tag in resource structure\n");

        return NULL;
}

/*
 * Resource Configuration Options
 */

static __init void pnpbios_parse_mem_option(struct pnp_dev *dev,
                                            unsigned char *p, int size,
                                            unsigned int option_flags)
{
        resource_size_t min, max, align, len;
        unsigned char flags;

        min = ((p[5] << 8) | p[4]) << 8;
        max = ((p[7] << 8) | p[6]) << 8;
        align = (p[9] << 8) | p[8];
        len = ((p[11] << 8) | p[10]) << 8;
        flags = p[3];
        pnp_register_mem_resource(dev, option_flags, min, max, align, len,
                                  flags);
}

static __init void pnpbios_parse_mem32_option(struct pnp_dev *dev,
                                              unsigned char *p, int size,
                                              unsigned int option_flags)
{
        resource_size_t min, max, align, len;
        unsigned char flags;

        min = (p[7] << 24) | (p[6] << 16) | (p[5] << 8) | p[4];
        max = (p[11] << 24) | (p[10] << 16) | (p[9] << 8) | p[8];
        align = (p[15] << 24) | (p[14] << 16) | (p[13] << 8) | p[12];
        len = (p[19] << 24) | (p[18] << 16) | (p[17] << 8) | p[16];
        flags = p[3];
        pnp_register_mem_resource(dev, option_flags, min, max, align, len,
                                  flags);
}

static __init void pnpbios_parse_fixed_mem32_option(struct pnp_dev *dev,
                                                    unsigned char *p, int size,
                                                    unsigned int option_flags)
{
        resource_size_t base, len;
        unsigned char flags;

        base = (p[7] << 24) | (p[6] << 16) | (p[5] << 8) | p[4];
        len = (p[11] << 24) | (p[10] << 16) | (p[9] << 8) | p[8];
        flags = p[3];
        pnp_register_mem_resource(dev, option_flags, base, base, 0, len, flags);
}

static __init void pnpbios_parse_irq_option(struct pnp_dev *dev,
                                            unsigned char *p, int size,
                                            unsigned int option_flags)
{
        unsigned long bits;
        pnp_irq_mask_t map;
        unsigned char flags = IORESOURCE_IRQ_HIGHEDGE;

        bits = (p[2] << 8) | p[1];

        bitmap_zero(map.bits, PNP_IRQ_NR);
        bitmap_copy(map.bits, &bits, 16);

        if (size > 2)
                flags = p[3];

        pnp_register_irq_resource(dev, option_flags, &map, flags);
}

static __init void pnpbios_parse_dma_option(struct pnp_dev *dev,
                                            unsigned char *p, int size,
                                            unsigned int option_flags)
{
        pnp_register_dma_resource(dev, option_flags, p[1], p[2]);
}

static __init void pnpbios_parse_port_option(struct pnp_dev *dev,
                                             unsigned char *p, int size,
                                             unsigned int option_flags)
{
        resource_size_t min, max, align, len;
        unsigned char flags;

        min = (p[3] << 8) | p[2];
        max = (p[5] << 8) | p[4];
        align = p[6];
        len = p[7];
        flags = p[1] ? IORESOURCE_IO_16BIT_ADDR : 0;
        pnp_register_port_resource(dev, option_flags, min, max, align, len,
                                   flags);
}

static __init void pnpbios_parse_fixed_port_option(struct pnp_dev *dev,
                                                   unsigned char *p, int size,
                                                   unsigned int option_flags)
{
        resource_size_t base, len;

        base = (p[2] << 8) | p[1];
        len = p[3];
        pnp_register_port_resource(dev, option_flags, base, base, 0, len,
                                   IORESOURCE_IO_FIXED);
}

static __init unsigned char *
pnpbios_parse_resource_option_data(unsigned char *p, unsigned char *end,
                                   struct pnp_dev *dev)
{
        unsigned int len, tag;
        int priority;
        unsigned int option_flags;

        if (!p)
                return NULL;

        pnp_dbg(&dev->dev, "parse resource options\n");
        option_flags = 0;
        while ((char *)p < (char *)end) {

                /* determine the type of tag */
                if (p[0] & LARGE_TAG) { /* large tag */
                        len = (p[2] << 8) | p[1];
                        tag = p[0];
                } else {        /* small tag */
                        len = p[0] & 0x07;
                        tag = ((p[0] >> 3) & 0x0f);
                }

                switch (tag) {

                case LARGE_TAG_MEM:
                        if (len != 9)
                                goto len_err;
                        pnpbios_parse_mem_option(dev, p, len, option_flags);
                        break;

                case LARGE_TAG_MEM32:
                        if (len != 17)
                                goto len_err;
                        pnpbios_parse_mem32_option(dev, p, len, option_flags);
                        break;

                case LARGE_TAG_FIXEDMEM32:
                        if (len != 9)
                                goto len_err;
                        pnpbios_parse_fixed_mem32_option(dev, p, len,
                                                         option_flags);
                        break;

                case SMALL_TAG_IRQ:
                        if (len < 2 || len > 3)
                                goto len_err;
                        pnpbios_parse_irq_option(dev, p, len, option_flags);
                        break;

                case SMALL_TAG_DMA:
                        if (len != 2)
                                goto len_err;
                        pnpbios_parse_dma_option(dev, p, len, option_flags);
                        break;

                case SMALL_TAG_PORT:
                        if (len != 7)
                                goto len_err;
                        pnpbios_parse_port_option(dev, p, len, option_flags);
                        break;

                case SMALL_TAG_VENDOR:
                        /* do nothing */
                        break;

                case SMALL_TAG_FIXEDPORT:
                        if (len != 3)
                                goto len_err;
                        pnpbios_parse_fixed_port_option(dev, p, len,
                                                        option_flags);
                        break;

                case SMALL_TAG_STARTDEP:
                        if (len > 1)
                                goto len_err;
                        priority = PNP_RES_PRIORITY_ACCEPTABLE;
                        if (len > 0)
                                priority = p[1];
                        option_flags = pnp_new_dependent_set(dev, priority);
                        break;

                case SMALL_TAG_ENDDEP:
                        if (len != 0)
                                goto len_err;
                        option_flags = 0;
                        break;

                case SMALL_TAG_END:
                        return p + 2;

                default:        /* an unknown tag */
len_err:
                        dev_err(&dev->dev, "unknown tag %#x length %d\n",
                                tag, len);
                        break;
                }

                /* continue to the next tag */
                if (p[0] & LARGE_TAG)
                        p += len + 3;
                else
                        p += len + 1;
        }

        dev_err(&dev->dev, "no end tag in resource structure\n");

        return NULL;
}

/*
 * Compatible Device IDs
 */

static unsigned char *pnpbios_parse_compatible_ids(unsigned char *p,
                                                   unsigned char *end,
                                                   struct pnp_dev *dev)
{
        int len, tag;
        u32 eisa_id;
        char id[8];
        struct pnp_id *dev_id;

        if (!p)
                return NULL;

        while ((char *)p < (char *)end) {

                /* determine the type of tag */
                if (p[0] & LARGE_TAG) { /* large tag */
                        len = (p[2] << 8) | p[1];
                        tag = p[0];
                } else {        /* small tag */
                        len = p[0] & 0x07;
                        tag = ((p[0] >> 3) & 0x0f);
                }

                switch (tag) {

                case LARGE_TAG_ANSISTR:
                        memcpy(dev->name, p + 3,
                               len >= PNP_NAME_LEN ? PNP_NAME_LEN - 2 : len);
                        dev->name[len >=
                                  PNP_NAME_LEN ? PNP_NAME_LEN - 1 : len] = '\0';
                        break;

                case SMALL_TAG_COMPATDEVID:     /* compatible ID */
                        if (len != 4)
                                goto len_err;
                        eisa_id = p[1] | p[2] << 8 | p[3] << 16 | p[4] << 24;
                        pnp_eisa_id_to_string(eisa_id & PNP_EISA_ID_MASK, id);
                        dev_id = pnp_add_id(dev, id);
                        if (!dev_id)
                                return NULL;
                        break;

                case SMALL_TAG_END:
                        p = p + 2;
                        return (unsigned char *)p;
                        break;

                default:        /* an unknown tag */
len_err:
                        dev_err(&dev->dev, "unknown tag %#x length %d\n",
                                tag, len);
                        break;
                }

                /* continue to the next tag */
                if (p[0] & LARGE_TAG)
                        p += len + 3;
                else
                        p += len + 1;
        }

        dev_err(&dev->dev, "no end tag in resource structure\n");

        return NULL;
}

/*
 * Allocated Resource Encoding
 */

static void pnpbios_encode_mem(struct pnp_dev *dev, unsigned char *p,
                               struct resource *res)
{
        unsigned long base;
        unsigned long len;

        if (pnp_resource_enabled(res)) {
                base = res->start;
                len = resource_size(res);
        } else {
                base = 0;
                len = 0;
        }

        p[4] = (base >> 8) & 0xff;
        p[5] = ((base >> 8) >> 8) & 0xff;
        p[6] = (base >> 8) & 0xff;
        p[7] = ((base >> 8) >> 8) & 0xff;
        p[10] = (len >> 8) & 0xff;
        p[11] = ((len >> 8) >> 8) & 0xff;

        pnp_dbg(&dev->dev, "  encode mem %#lx-%#lx\n", base, base + len - 1);
}

static void pnpbios_encode_mem32(struct pnp_dev *dev, unsigned char *p,
                                 struct resource *res)
{
        unsigned long base;
        unsigned long len;

        if (pnp_resource_enabled(res)) {
                base = res->start;
                len = resource_size(res);
        } else {
                base = 0;
                len = 0;
        }

        p[4] = base & 0xff;
        p[5] = (base >> 8) & 0xff;
        p[6] = (base >> 16) & 0xff;
        p[7] = (base >> 24) & 0xff;
        p[8] = base & 0xff;
        p[9] = (base >> 8) & 0xff;
        p[10] = (base >> 16) & 0xff;
        p[11] = (base >> 24) & 0xff;
        p[16] = len & 0xff;
        p[17] = (len >> 8) & 0xff;
        p[18] = (len >> 16) & 0xff;
        p[19] = (len >> 24) & 0xff;

        pnp_dbg(&dev->dev, "  encode mem32 %#lx-%#lx\n", base, base + len - 1);
}

static void pnpbios_encode_fixed_mem32(struct pnp_dev *dev, unsigned char *p,
                                       struct resource *res)
{
        unsigned long base;
        unsigned long len;

        if (pnp_resource_enabled(res)) {
                base = res->start;
                len = resource_size(res);
        } else {
                base = 0;
                len = 0;
        }

        p[4] = base & 0xff;
        p[5] = (base >> 8) & 0xff;
        p[6] = (base >> 16) & 0xff;
        p[7] = (base >> 24) & 0xff;
        p[8] = len & 0xff;
        p[9] = (len >> 8) & 0xff;
        p[10] = (len >> 16) & 0xff;
        p[11] = (len >> 24) & 0xff;

        pnp_dbg(&dev->dev, "  encode fixed_mem32 %#lx-%#lx\n", base,
                base + len - 1);
}

static void pnpbios_encode_irq(struct pnp_dev *dev, unsigned char *p,
                               struct resource *res)
{
        unsigned long map;

        if (pnp_resource_enabled(res))
                map = 1 << res->start;
        else
                map = 0;

        p[1] = map & 0xff;
        p[2] = (map >> 8) & 0xff;

        pnp_dbg(&dev->dev, "  encode irq mask %#lx\n", map);
}

static void pnpbios_encode_dma(struct pnp_dev *dev, unsigned char *p,
                               struct resource *res)
{
        unsigned long map;

        if (pnp_resource_enabled(res))
                map = 1 << res->start;
        else
                map = 0;

        p[1] = map & 0xff;

        pnp_dbg(&dev->dev, "  encode dma mask %#lx\n", map);
}

static void pnpbios_encode_port(struct pnp_dev *dev, unsigned char *p,
                                struct resource *res)
{
        unsigned long base;
        unsigned long len;

        if (pnp_resource_enabled(res)) {
                base = res->start;
                len = resource_size(res);
        } else {
                base = 0;
                len = 0;
        }

        p[2] = base & 0xff;
        p[3] = (base >> 8) & 0xff;
        p[4] = base & 0xff;
        p[5] = (base >> 8) & 0xff;
        p[7] = len & 0xff;

        pnp_dbg(&dev->dev, "  encode io %#lx-%#lx\n", base, base + len - 1);
}

static void pnpbios_encode_fixed_port(struct pnp_dev *dev, unsigned char *p,
                                      struct resource *res)
{
        unsigned long base = res->start;
        unsigned long len = resource_size(res);

        if (pnp_resource_enabled(res)) {
                base = res->start;
                len = resource_size(res);
        } else {
                base = 0;
                len = 0;
        }

        p[1] = base & 0xff;
        p[2] = (base >> 8) & 0xff;
        p[3] = len & 0xff;

        pnp_dbg(&dev->dev, "  encode fixed_io %#lx-%#lx\n", base,
                base + len - 1);
}

static unsigned char *pnpbios_encode_allocated_resource_data(struct pnp_dev
                                                                *dev,
                                                             unsigned char *p,
                                                             unsigned char *end)
{
        unsigned int len, tag;
        int port = 0, irq = 0, dma = 0, mem = 0;

        if (!p)
                return NULL;

        while ((char *)p < (char *)end) {

                /* determine the type of tag */
                if (p[0] & LARGE_TAG) { /* large tag */
                        len = (p[2] << 8) | p[1];
                        tag = p[0];
                } else {        /* small tag */
                        len = p[0] & 0x07;
                        tag = ((p[0] >> 3) & 0x0f);
                }

                switch (tag) {

                case LARGE_TAG_MEM:
                        if (len != 9)
                                goto len_err;
                        pnpbios_encode_mem(dev, p,
                                pnp_get_resource(dev, IORESOURCE_MEM, mem));
                        mem++;
                        break;

                case LARGE_TAG_MEM32:
                        if (len != 17)
                                goto len_err;
                        pnpbios_encode_mem32(dev, p,
                                pnp_get_resource(dev, IORESOURCE_MEM, mem));
                        mem++;
                        break;

                case LARGE_TAG_FIXEDMEM32:
                        if (len != 9)
                                goto len_err;
                        pnpbios_encode_fixed_mem32(dev, p,
                                pnp_get_resource(dev, IORESOURCE_MEM, mem));
                        mem++;
                        break;

                case SMALL_TAG_IRQ:
                        if (len < 2 || len > 3)
                                goto len_err;
                        pnpbios_encode_irq(dev, p,
                                pnp_get_resource(dev, IORESOURCE_IRQ, irq));
                        irq++;
                        break;

                case SMALL_TAG_DMA:
                        if (len != 2)
                                goto len_err;
                        pnpbios_encode_dma(dev, p,
                                pnp_get_resource(dev, IORESOURCE_DMA, dma));
                        dma++;
                        break;

                case SMALL_TAG_PORT:
                        if (len != 7)
                                goto len_err;
                        pnpbios_encode_port(dev, p,
                                pnp_get_resource(dev, IORESOURCE_IO, port));
                        port++;
                        break;

                case SMALL_TAG_VENDOR:
                        /* do nothing */
                        break;

                case SMALL_TAG_FIXEDPORT:
                        if (len != 3)
                                goto len_err;
                        pnpbios_encode_fixed_port(dev, p,
                                pnp_get_resource(dev, IORESOURCE_IO, port));
                        port++;
                        break;

                case SMALL_TAG_END:
                        p = p + 2;
                        return (unsigned char *)p;
                        break;

                default:        /* an unknown tag */
len_err:
                        dev_err(&dev->dev, "unknown tag %#x length %d\n",
                                tag, len);
                        break;
                }

                /* continue to the next tag */
                if (p[0] & LARGE_TAG)
                        p += len + 3;
                else
                        p += len + 1;
        }

        dev_err(&dev->dev, "no end tag in resource structure\n");

        return NULL;
}

/*
 * Core Parsing Functions
 */

int __init pnpbios_parse_data_stream(struct pnp_dev *dev,
                                        struct pnp_bios_node *node)
{
        unsigned char *p = (char *)node->data;
        unsigned char *end = (char *)(node->data + node->size);

        p = pnpbios_parse_allocated_resource_data(dev, p, end);
        if (!p)
                return -EIO;
        p = pnpbios_parse_resource_option_data(p, end, dev);
        if (!p)
                return -EIO;
        p = pnpbios_parse_compatible_ids(p, end, dev);
        if (!p)
                return -EIO;
        return 0;
}

int pnpbios_read_resources_from_node(struct pnp_dev *dev,
                                     struct pnp_bios_node *node)
{
        unsigned char *p = (char *)node->data;
        unsigned char *end = (char *)(node->data + node->size);

        p = pnpbios_parse_allocated_resource_data(dev, p, end);
        if (!p)
                return -EIO;
        return 0;
}

int pnpbios_write_resources_to_node(struct pnp_dev *dev,
                                    struct pnp_bios_node *node)
{
        unsigned char *p = (char *)node->data;
        unsigned char *end = (char *)(node->data + node->size);

        p = pnpbios_encode_allocated_resource_data(dev, p, end);
        if (!p)
                return -EIO;
        return 0;
}