[apple/xnu.git] / osfmk / i386 / iopb.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code 
 * as defined in and that are subject to the Apple Public Source License 
 * Version 2.0 (the 'License'). You may not use this file except in 
 * compliance with the License.  The rights granted to you under the 
 * License may not be used to create, or enable the creation or 
 * redistribution of, unlawful or unlicensed copies of an Apple operating 
 * system, or to circumvent, violate, or enable the circumvention or 
 * violation of, any terms of an Apple operating system software license 
 * agreement.
 *
 * Please obtain a copy of the License at 
 * http://www.opensource.apple.com/apsl/ and read it before using this 
 * file.
 *
 * The Original Code and all software distributed under the License are 
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
 * Please see the License for the specific language governing rights and 
 * limitations under the License.
 *
 * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */

/*
 */

/*
 * Code to manipulate IO permission bitmaps.
 */
 


#include <mach/boolean.h>
#include <mach/kern_return.h>

#include <ipc/ipc_port.h>

#include <kern/kalloc.h>
#include <kern/lock.h>
#include <kern/queue.h>
#include <kern/thread.h>
#include <kern/misc_protos.h>


#include <i386/io_port.h>
#include <i386/iopb.h>
#include <i386/seg.h>
#include <i386/iopb_entries.h>

void
iopb_init(void)
{
}


void
iopb_destroy(__unused iopb_tss_t      io_tss)
{
}

#if 0                           /* Code removed until better solution comes on board */
/*
 * A set of ports for an IO device.
 */
struct io_port {
        device_t        device;         /* Mach device */
        queue_chain_t   dev_list;       /* link in device list */
        queue_chain_t   io_use_list;    /* List of threads that use it */
        io_reg_t        *io_port_list;  /* list of IO ports that use it */
                                        /* list ends with IO_REG_NULL */
};
typedef struct io_port  *io_port_t;

/*
 * Lookup table for device -> io_port mapping
 * (a linked list - I don't expect too many)
 */
queue_head_t    device_to_io_port_list;

/*
 * Cross-reference:
 *      all threads that have IO ports mapped
 *      all IO ports that have threads mapped
 */
struct io_use {
        queue_chain_t   psq;    /* Links from port set */
        queue_chain_t   tsq;    /* links from tss */
        io_port_t       ps;     /* Port set */
        iopb_tss_t      ts;     /* Task segment */
};
typedef struct io_use   *io_use_t;

/*
 * Big lock for the whole mess.
 */
decl_simple_lock_data(,iopb_lock)

/* Forward */

extern void             io_bitmap_init(
                                isa_iopb                bp);
extern void             io_bitmap_set(
                                isa_iopb                bp,
                                io_reg_t                *bit_list);
extern void             io_bitmap_clear(
                                isa_iopb                bp,
                                io_reg_t                *bit_list);
extern io_port_t        device_to_io_port_lookup(
                                device_t                device);
extern void             io_tss_init(
                                iopb_tss_t              io_tss);


/*
 * Initialize the package.
 */
void
iopb_init(void)
{
        queue_init(&device_to_io_port_list);
        simple_lock_init(&iopb_lock, 0);
}

/*
 * Initialize bitmap (set all bits to OFF == 1)
 */
void
io_bitmap_init(
        isa_iopb        bp)
{
        register unsigned char *b;
        register int    s;

        s = sizeof(isa_iopb);
        b = bp;

        do {
            *b++ = ~0;
        } while (--s >= 0);
}

/*
 * Set selected bits in bitmap to ON == 0
 */
void
io_bitmap_set(
        isa_iopb        bp,
        io_reg_t        *bit_list)
{
        io_reg_t        io_bit;

        while ((io_bit = *bit_list++) != IO_REG_NULL) {
            bp[io_bit>>3] &= ~(1 << (io_bit & 0x7));
        }
}

/*
 * Set selected bits in bitmap to OFF == 1
 */
void
io_bitmap_clear(
        isa_iopb        bp,
        io_reg_t        *bit_list)
{
        io_reg_t        io_bit;

        while ((io_bit = *bit_list++) != IO_REG_NULL) {
            bp[io_bit>>3] |= (1 << (io_bit & 0x7));
        }
}

/*
 * Lookup an io-port set by device
 */
io_port_t
device_to_io_port_lookup(
        device_t        device)
{
        register io_port_t io_port;

        queue_iterate(&device_to_io_port_list, io_port, io_port_t, dev_list) {
            if (io_port->device == device) {
                return io_port;
            }
        }
        return 0;
}

/*
 * [exported]
 * Create an io_port set
 */
void
io_port_create(
        device_t        device,
        io_reg_t        *io_port_list)
{
        register io_port_t io_port, old_io_port;

        io_port = (io_port_t) kalloc(sizeof(struct io_port));

        simple_lock(&iopb_lock);
        if (device_to_io_port_lookup(device) != 0) {
            simple_unlock(&iopb_lock);
            kfree((vm_offset_t) io_port, sizeof(struct io_port));
            return;
        }

        io_port->device = device;
        queue_init(&io_port->io_use_list);
        io_port->io_port_list = io_port_list;

        /*
         * Enter in lookup list.
         */
        queue_enter(&device_to_io_port_list, io_port, io_port_t, dev_list);

        simple_unlock(&iopb_lock);
}

/*
 * [exported]
 * Destroy an io port set, removing any IO mappings.
 */
void
io_port_destroy(
        device_t        device)
{
        io_port_t       io_port;
        io_use_t        iu;

        simple_lock(&iopb_lock);
        io_port = device_to_io_port_lookup(device);
        if (io_port == 0) {
            simple_unlock(&iopb_lock);
            return;
        }

        queue_iterate(&io_port->io_use_list, iu, io_use_t, psq) {
            iopb_tss_t  io_tss;
            io_tss = iu->ts;
            io_bitmap_clear(io_tss->bitmap, io_port->io_port_list);
            queue_remove(&io_tss->io_port_list, iu, io_use_t, tsq);
        }
        queue_remove(&device_to_io_port_list, io_port, io_port_t, dev_list);
        simple_unlock(&iopb_lock);

        while (!queue_empty(&io_port->io_use_list)) {
            iu = (io_use_t) queue_first(&io_port->io_use_list);
            queue_remove(&io_port->io_use_list, iu, io_use_t, psq);
            kfree((vm_offset_t)iu, sizeof(struct io_use));
        }

        kfree((vm_offset_t)io_port, sizeof(struct io_port));
}

/*
 * Initialize an IO TSS.
 */
void
io_tss_init(
        iopb_tss_t      io_tss)
{
        vm_offset_t     addr = (vm_offset_t) io_tss;
        vm_size_t       size = (char *)&io_tss->barrier - (char *)io_tss;

        bzero((char *)&io_tss->tss, sizeof(struct i386_tss));
        io_tss->tss.io_bit_map_offset
                        = (char *)&io_tss->bitmap - (char *)io_tss;
        io_tss->tss.ss0 = KERNEL_DS;
        io_bitmap_init(io_tss->bitmap);
        io_tss->barrier = ~0;
        queue_init(&io_tss->io_port_list);
        addr |= LINEAR_KERNEL_ADDRESS;
        io_tss->iopb_desc[0] = ((size-1) & 0xffff)
                | ((addr & 0xffff) << 16);
        io_tss->iopb_desc[1] = ((addr & 0x00ff0000) >> 16)
                | ((ACC_TSS|ACC_PL_K|ACC_P) << 8)
                | ((size-1) & 0x000f0000)
                | (addr & 0xff000000);
}

/*
 * [exported]
 * Create an IOPB_TSS
 */
iopb_tss_t
iopb_create(void)
{
        register iopb_tss_t ts;

        ts = (iopb_tss_t) kalloc(sizeof (struct iopb_tss));
        io_tss_init(ts);
        return (ts);
}

/*
 * [exported]
 * Destroy an IOPB_TSS
 */
void
iopb_destroy(
        iopb_tss_t      io_tss)
{
        io_use_t        iu;
        io_port_t       io_port;

        simple_lock(&iopb_lock);

        queue_iterate(&io_tss->io_port_list, iu, io_use_t, tsq) {
            io_port = iu->ps;
            /* skip bitmap clear - entire bitmap will vanish */
            queue_remove(&io_port->io_use_list, iu, io_use_t, psq);
        }

        simple_unlock(&iopb_lock);

        while (!queue_empty(&io_tss->io_port_list)) {
            iu = (io_use_t) queue_first(&io_tss->io_port_list);
            queue_remove(&io_tss->io_port_list, iu, io_use_t, tsq);
            kfree((vm_offset_t)iu, sizeof(struct io_use));
        }

        kfree((vm_offset_t)io_tss, sizeof(struct iopb_tss));
}

/*
 * Add an IO mapping to a thread.
 */
kern_return_t
i386_io_port_add(
        thread_t        thread,
        device_t        device)
{
        pcb_t           pcb;
        iopb_tss_t      io_tss, new_io_tss;
        io_port_t       io_port;
        io_use_t        iu, old_iu;

        if (thread == THREAD_NULL
         || device == DEVICE_NULL)
            return KERN_INVALID_ARGUMENT;

        pcb = thread->machine.pcb;

        new_io_tss = 0;
        iu = (io_use_t) kalloc(sizeof(struct io_use));

    Retry:
        simple_lock(&iopb_lock);

        /* find the io_port_t for the device */
        io_port = device_to_io_port_lookup(device);
        if (io_port == 0) {
            /*
             * Device does not have IO ports available.
             */
            simple_unlock(&iopb_lock);
            if (new_io_tss)
                kfree((vm_offset_t)new_io_tss, sizeof(struct iopb_tss));
            kfree((vm_offset_t) iu, sizeof(struct io_use));
            return KERN_INVALID_ARGUMENT;
        }

        /* Have the IO port. */

        /* Make sure the thread has a TSS. */

        simple_lock(&pcb->lock);
        io_tss = pcb->ims.io_tss;
        if (io_tss == 0) {
            if (new_io_tss == 0) {
                /*
                 * Allocate an IO-tss.
                 */
                simple_unlock(&pcb->lock);
                simple_unlock(&iopb_lock);

                new_io_tss = (iopb_tss_t) kalloc(sizeof(struct iopb_tss));
                io_tss_init(new_io_tss);

                goto Retry;
            }
            io_tss = new_io_tss;
            pcb->ims.io_tss = io_tss;
            new_io_tss = 0;
        }

        /*
         * Have io_port and io_tss.
         * See whether device is already mapped.
         */
        queue_iterate(&io_tss->io_port_list, old_iu, io_use_t, tsq) {
            if (old_iu->ps == io_port) {
                /*
                 * Already mapped.
                 */
                simple_unlock(&pcb->lock);
                simple_unlock(&iopb_lock);

                kfree((vm_offset_t)iu, sizeof(struct io_use));
                if (new_io_tss)
                    kfree((vm_offset_t)new_io_tss, sizeof(struct iopb_tss));
                return KERN_SUCCESS;
            }
        }

        /*
         * Add mapping.
         */
        iu->ps = io_port;
        iu->ts = io_tss;
        queue_enter(&io_port->io_use_list, iu, io_use_t, psq);
        queue_enter(&io_tss->io_port_list, iu, io_use_t, tsq);
        io_bitmap_set(io_tss->bitmap, io_port->io_port_list);

        simple_unlock(&pcb->lock);
        simple_unlock(&iopb_lock);

        if (new_io_tss)
            kfree((vm_offset_t)new_io_tss, sizeof(struct iopb_tss));
        return KERN_SUCCESS;

}

/*
 * Remove an IO mapping from a thread.
 */
kern_return_t
i386_io_port_remove(
        thread_t        thread,
        device_t        device)
{
        pcb_t           pcb;
        iopb_tss_t      io_tss;
        io_port_t       io_port;
        io_use_t        iu;

        if (thread == THREAD_NULL
         || device == DEVICE_NULL)
            return KERN_INVALID_ARGUMENT;

        pcb = thread->machine.pcb;

        simple_lock(&iopb_lock);

        /* find the io_port_t for the device */

        io_port = device_to_io_port_lookup(device);
        if (io_port == 0) {
            /*
             * Device does not have IO ports available.
             */
            simple_unlock(&iopb_lock);
            return KERN_INVALID_ARGUMENT;
        }

        simple_lock(&pcb->lock);
        io_tss = pcb->ims.io_tss;
        if (io_tss == 0) {
            simple_unlock(&pcb->lock);
            simple_unlock(&iopb_lock);
            return KERN_INVALID_ARGUMENT;       /* not mapped */
        }

        /*
         * Find the mapping.
         */
        queue_iterate(&io_tss->io_port_list, iu, io_use_t, tsq) {
            if (iu->ps == io_port) {
                /*
                 * Found mapping.  Remove it.
                 */
                io_bitmap_clear(io_tss->bitmap, io_port->io_port_list);

                queue_remove(&io_port->io_use_list, iu, io_use_t, psq);
                queue_remove(&io_tss->io_port_list, iu, io_use_t, tsq);

                simple_unlock(&pcb->lock);
                simple_unlock(&iopb_lock);

                kfree((vm_offset_t)iu, sizeof(struct io_use));

                return KERN_SUCCESS;
            }
        }

        /*
         * No mapping.
         */
        return KERN_INVALID_ARGUMENT;
}

/*
 * Return the IO ports mapped into a thread.
 */

kern_return_t
i386_io_port_list(thread, list, list_count)
        thread_t        thread;
        device_t        **list;
        unsigned int    *list_count;
{
        register pcb_t  pcb;
        register iopb_tss_t io_tss;
        unsigned int    count, alloc_count;
        device_t        *devices;
        vm_size_t       size_needed, size;
        vm_offset_t     addr;
        int             i;

        if (thread == THREAD_NULL)
            return KERN_INVALID_ARGUMENT;

        pcb = thread->machine.pcb;

        alloc_count = 16;               /* a guess */

        do {
            size_needed = alloc_count * sizeof(ipc_port_t);
            if (size_needed <= size)
                break;

            if (size != 0)
                kfree(addr, size);

            assert(size_needed > 0);
            size = size_needed;

            addr = kalloc(size);
            if (addr == 0)
                return KERN_RESOURCE_SHORTAGE;

            devices = (device_t *)addr;
            count = 0;

            simple_lock(&iopb_lock);
            simple_lock(&pcb->lock);
            io_tss = pcb->ims.io_tss;
            if (io_tss != 0) {
                register io_use_t iu;

                queue_iterate(&io_tss->io_port_list, iu, io_use_t, tsq) {
                    if (++count < alloc_count) {
                        *devices = iu->ps->device;
                        device_reference(*devices);
                        devices++;
                    }
                }
            }
            simple_unlock(&pcb->lock);
            simple_unlock(&iopb_lock);
        } while (count > alloc_count);

        if (count == 0) {
            /*
             * No IO ports
             */
            *list = 0;
            *list_count = 0;

            if (size != 0)
                kfree(addr, size);
        }
        else {
            /*
             * If we allocated too much, must copy.
             */
            size_needed = count * sizeof(ipc_port_t);
            if (size_needed < size) {
                vm_offset_t     new_addr;

                new_addr = kalloc(size_needed);
                if (new_addr == 0) {
                    for (i = 0; i < count; i++)
                        device_deallocate(devices[i]);
                    kfree(addr, size);
                    return KERN_RESOURCE_SHORTAGE;
                }

                bcopy((char *)addr, (char *)new_addr, size_needed);
                kfree(addr, size);
                devices = (device_t *)new_addr;
            }

            for (i = 0; i < count; i++)
                ((ipc_port_t *)devices)[i] =
                        convert_device_to_port(devices[i]);
        }
        *list = devices;
        *list_count = count;

        return KERN_SUCCESS;
}

/*
 * Check whether an IO device is mapped to a particular thread.
 * Used to support the 'iopl' device automatic mapping.
 */
boolean_t
iopb_check_mapping(
        thread_t        thread,
        device_t        device)
{
        pcb_t           pcb;
        io_port_t       io_port;
        io_use_t        iu;

        pcb = thread->machine.pcb;

        simple_lock(&iopb_lock);

        /* Find the io port for the device */

        io_port = device_to_io_port_lookup(device);
        if (io_port == 0) {
            simple_unlock(&iopb_lock);
            return FALSE;
        }

        /* Look up the mapping in the device`s mapping list. */

        queue_iterate(&io_port->io_use_list, iu, io_use_t, psq) {
            if (iu->ts == pcb->ims.io_tss) {
                /*
                 * Device is mapped.
                 */
                simple_unlock(&iopb_lock);
                return TRUE;
            }
        }
        simple_unlock(&iopb_lock);
        return FALSE;
}
#endif