xnu-201.5.tar.gz

[apple/xnu.git] / osfmk / ppc / PseudoKernel.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This 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 OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
        File:           PseudoKernel.c

        Contains:       BlueBox PseudoKernel calls
        Written by:     Mark Gorlinsky
                                Bill Angell

        Copyright:      1997 by Apple Computer, Inc., all rights reserved

*/

#include <mach/mach_types.h>
#include <mach/kern_return.h>
#include <kern/host.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <ppc/PseudoKernel.h>
#include <ppc/exception.h>
#include <ppc/misc_protos.h>
#include <ppc/proc_reg.h>
#include <vm/vm_kern.h>

void bbSetRupt(ReturnHandler *rh, thread_act_t ct);

/*
** Function:    NotifyInterruption
**
** Inputs:
**              ppcInterrupHandler      - interrupt handler to execute
**              interruptStatePtr       - current interrupt state
**
** Outputs:
**
** Notes:
**
*/
kern_return_t syscall_notify_interrupt ( void ) {
  
    UInt32                      interruptState; 
    task_t                      task;
    spl_t                       s;
        thread_act_t    act, fact;
        thread_t                thread;
        bbRupt                  *bbr;
        BTTD_t                  *bttd;
        int                             i;

        task = current_task();                                                  /* Figure out who our task is */

        task_lock(task);                                                /* Lock our task */
        
        fact = (thread_act_t)task->thr_acts.next;               /* Get the first activation on task */
        act = 0;                                                                                /* Pretend we didn't find it yet */
        
        for(i = 0; i < task->thr_act_count; i++) {              /* Scan the whole list */
                if(fact->mact.bbDescAddr) {                                     /* Is this a Blue thread? */
                        bttd = (BTTD_t *)(fact->mact.bbDescAddr & -PAGE_SIZE);
                        if(bttd->InterruptVector) {                             /* Is this the Blue interrupt thread? */
                                act = fact;                                                     /* Yeah... */
                                break;                                                          /* Found it, Bail the loop... */
                        }
                }
                fact = (thread_act_t)fact->thr_acts.next;       /* Go to the next one */
        }

        if(!act) {                                                              /* Couldn't find a bluebox */
                task_unlock(task);                                      /* Release task lock */
                return KERN_FAILURE;                            /* No tickie, no shirtee... */
        }
        
        act_lock_thread(act);                                                   /* Make sure this stays 'round */
        task_unlock(task);                                                              /* Safe to release now */

        /* if the calling thread is the BlueBox thread that handles interrupts
         * we know that we are in the PsuedoKernel and we can short circuit 
         * setting up the asynchronous task by setting a pending interrupt.
         */
        
        if ( (unsigned int)act == (unsigned int)current_act() ) {               
                bttd->InterruptControlWord = bttd->InterruptControlWord | 
                        ((bttd->postIntMask >> kCR2ToBackupShift) & kBackupCR2Mask);
                                
                act_unlock_thread(act);                                         /* Unlock the activation */
                return KERN_SUCCESS;
        }

        if(act->mact.emPendRupts >= 16) {                               /* Have we hit the arbitrary maximum? */
                act_unlock_thread(act);                                         /* Unlock the activation */
                return KERN_RESOURCE_SHORTAGE;                          /* Too many pending right now */
        }
        
        if(!(bbr = (bbRupt *)kalloc(sizeof(bbRupt)))) { /* Get a return handler control block */
                act_unlock_thread(act);                                         /* Unlock the activation */
                return KERN_RESOURCE_SHORTAGE;                          /* No storage... */
        }
        
        (void)hw_atomic_add(&act->mact.emPendRupts, 1); /* Count this 'rupt */
        bbr->rh.handler = bbSetRupt;                                    /* Set interruption routine */

        bbr->rh.next = act->handlers;                                   /* Put our interrupt at the start of the list */
        act->handlers = &bbr->rh;

        s = splsched();                                                                 /* No talking in class */
        act_set_apc(act);                                                               /* Set an APC AST */
        splx(s);                                                                                /* Ok, you can talk now */

        act_unlock_thread(act);                                                 /* Unlock the activation */
        return KERN_SUCCESS;                                                    /* We're done... */
}

/* 
 *      This guy is fired off asynchronously to actually do the 'rupt.
 *      We will find the user state savearea and modify it.  If we can't,
 *      we just leave after releasing our work area
 */

void bbSetRupt(ReturnHandler *rh, thread_act_t act) {

        savearea        *sv;
        BTTD_t          *bttd;
        bbRupt          *bbr;
        UInt32          interruptState;
        
        bbr = (bbRupt *)rh;                                                             /* Make our area convenient */

        if(!(act->mact.bbDescAddr)) {                                   /* Is BlueBox still enabled? */
                kfree((vm_offset_t)bbr, sizeof(bbRupt));        /* No, release the control block */
                return;
        }

        (void)hw_atomic_sub(&act->mact.emPendRupts, 1); /* Uncount this 'rupt */

        if(!(sv = (savearea *)find_user_regs(act))) {   /* Find the user state registers */
                kfree((vm_offset_t)bbr, sizeof(bbRupt));        /* Couldn't find 'em, release the control block */
                return;
        }

        bttd = (BTTD_t *)(act->mact.bbDescAddr & -PAGE_SIZE);
                
    interruptState = (bttd->InterruptControlWord & kInterruptStateMask) >> kInterruptStateShift; 

    switch (interruptState) {
                
                case kInSystemContext:
                        sv->save_cr |= bttd->postIntMask;               /* post int in CR2 */
                        break;
                        
                case kInAlternateContext:
                        bttd->InterruptControlWord = (bttd->InterruptControlWord & ~kInterruptStateMask) | 
                                (kInPseudoKernel << kInterruptStateShift);
                                
                        bttd->exceptionInfo.srr0 = sv->save_srr0;               /* Save the current PC */
                        sv->save_srr0 = bttd->InterruptVector;                  /* Set the new PC */
                        bttd->exceptionInfo.sprg1 = sv->save_r1;                /* Save the original R1 */
                        sv->save_r1 = bttd->exceptionInfo.sprg0;                /* Set the new R1 */
                        bttd->exceptionInfo.srr1 = sv->save_srr1;               /* Save the original MSR */
                        sv->save_srr1 &= ~(MASK(MSR_BE)|MASK(MSR_SE));  /* Clear SE|BE bits in MSR */
                        act->mact.specFlags &= ~bbNoMachSC;                             /* reactivate Mach SCs */ 
                        disable_preemption();                                                   /* Don't move us around */
                        per_proc_info[cpu_number()].spcFlags = act->mact.specFlags;     /* Copy the flags */
                        enable_preemption();                                                    /* Ok to move us around */
                        /* drop through to post int in backup CR2 in ICW */

                case kInExceptionHandler:
                case kInPseudoKernel:
                case kOutsideBlue:
                        bttd->InterruptControlWord = bttd->InterruptControlWord | 
                                ((bttd->postIntMask >> kCR2ToBackupShift) & kBackupCR2Mask);
                        break;
                                
                default:
                        break;
        }

        kfree((vm_offset_t)bbr, sizeof(bbRupt));        /* Release the control block */
        return;

}

/*
 * This function is used to enable the firmware assist code for bluebox traps, system calls
 * and interrupts.
 *
 * The assist code can be called from two types of threads.  The blue thread, which handles 
 * traps, system calls and interrupts and preemptive threads that only issue system calls.
 *
 */ 

kern_return_t enable_bluebox(
      host_t host,
          void *taskID,                                                         /* opaque task ID */
          void *TWI_TableStart,                                         /* Start of TWI table */
          char *Desc_TableStart                                         /* Start of descriptor table */
         ) {
        
        thread_t                th;
        vm_offset_t             kerndescaddr, physdescaddr, origdescoffset;
        kern_return_t   ret;
        
        th = current_thread();                                                                  /* Get our thread */                                    

        if ( host == HOST_NULL ) return KERN_INVALID_HOST;
        if ( ! is_suser() ) return KERN_FAILURE;                                                /* We will only do this for the superuser */
        if ( th->top_act->mact.bbDescAddr ) return KERN_FAILURE;                /* Bail if already authorized... */
        if ( ! (unsigned int) Desc_TableStart ) return KERN_FAILURE;    /* There has to be a descriptor page */ 
        if ( ! TWI_TableStart ) return KERN_FAILURE;                                    /* There has to be a TWI table */ 

        /* Get the page offset of the descriptor */
        origdescoffset = (vm_offset_t)Desc_TableStart & (PAGE_SIZE - 1);

        /* Align the descriptor to a page */
        Desc_TableStart = (char *)((vm_offset_t)Desc_TableStart & -PAGE_SIZE);

        ret = vm_map_wire(th->top_act->map,                                     /* Kernel wire the descriptor in the user's map */
                (vm_offset_t)Desc_TableStart,
                (vm_offset_t)Desc_TableStart + PAGE_SIZE,
                VM_PROT_READ | VM_PROT_WRITE,
                FALSE);                                                                                                                 
                
        if(ret != KERN_SUCCESS) {                                                               /* Couldn't wire it, spit on 'em... */
                return KERN_FAILURE;    
        }
                
        physdescaddr =                                                                                  /* Get the physical address of the page */
                pmap_extract(th->top_act->map->pmap, (vm_offset_t) Desc_TableStart);

        ret =  kmem_alloc_pageable(kernel_map, &kerndescaddr, PAGE_SIZE);       /* Find a virtual address to use */
        if(ret != KERN_SUCCESS) {                                                               /* Could we get an address? */
                (void) vm_map_unwire(th->top_act->map,                          /* No, unwire the descriptor */
                        (vm_offset_t)Desc_TableStart,
                        (vm_offset_t)Desc_TableStart + PAGE_SIZE,
                        TRUE);
                return KERN_FAILURE;                                                            /* Split... */
        }
        
        (void) pmap_enter(kernel_pmap,                                                  /* Map this into the kernel */
                kerndescaddr, physdescaddr, VM_PROT_READ|VM_PROT_WRITE, 
                TRUE);
        
        th->top_act->mact.bbDescAddr = (unsigned int)kerndescaddr+origdescoffset;       /* Set kernel address of the table */
        th->top_act->mact.bbUserDA = (unsigned int)Desc_TableStart;     /* Set user address of the table */
        th->top_act->mact.bbTableStart = (unsigned int)TWI_TableStart;  /* Set address of the trap table */
        th->top_act->mact.bbTaskID = (unsigned int)taskID;              /* Assign opaque task ID */
        th->top_act->mact.bbTaskEnv = 0;                                                /* Clean task environment data */
        th->top_act->mact.emPendRupts = 0;                                              /* Clean pending 'rupt count */
        th->top_act->mact.specFlags &= ~(bbNoMachSC | bbPreemptive);    /* Make sure mach SCs are enabled and we are not marked preemptive */
        th->top_act->mact.specFlags |= bbThread;                                /* Set that we are Classic thread */
                
        if(!(((BTTD_t *)kerndescaddr)->InterruptVector)) {              /* See if this is a preemptive (MP) BlueBox thread */
                th->top_act->mact.specFlags |= bbPreemptive;            /* Yes, remember it */
        }
                
        disable_preemption();                                                                   /* Don't move us around */
        per_proc_info[cpu_number()].spcFlags = th->top_act->mact.specFlags;     /* Copy the flags */
        enable_preemption();                                                                    /* Ok to move us around */
                
        {
                /* mark the proc to indicate that this is a TBE proc */
                extern void tbeproc(void *proc);

                tbeproc(th->top_act->task->bsd_info);
        }

        return KERN_SUCCESS;
}

kern_return_t disable_bluebox( host_t host ) {                          /* User call to terminate bluebox */
        
        thread_act_t    act;
        
        act = current_act();                                                                    /* Get our thread */                                    

        if (host == HOST_NULL) return KERN_INVALID_HOST;
        
        if(!is_suser()) return KERN_FAILURE;                                    /* We will only do this for the superuser */
        if(!act->mact.bbDescAddr) return KERN_FAILURE;                  /* Bail if not authorized... */

        disable_bluebox_internal(act);                                                  /* Clean it all up */
        return KERN_SUCCESS;                                                                    /* Leave */
}

void disable_bluebox_internal(thread_act_t act) {                       /* Terminate bluebox */
                
        (void) vm_map_unwire(act->map,                                                  /* Unwire the descriptor in user's address space */
                (vm_offset_t)act->mact.bbUserDA,
                (vm_offset_t)act->mact.bbUserDA + PAGE_SIZE,
                FALSE);
                
        kmem_free(kernel_map, (vm_offset_t)act->mact.bbDescAddr & -PAGE_SIZE, PAGE_SIZE);       /* Release the page */
        
        act->mact.bbDescAddr = 0;                                                               /* Clear kernel pointer to it */
        act->mact.bbUserDA = 0;                                                                 /* Clear user pointer to it */
        act->mact.bbTableStart = 0;                                                             /* Clear user pointer to TWI table */
        act->mact.bbTaskID = 0;                                                                 /* Clear opaque task ID */
        act->mact.bbTaskEnv = 0;                                                                /* Clean task environment data */
        act->mact.emPendRupts = 0;                                                              /* Clean pending 'rupt count */
        act->mact.specFlags &= ~(bbNoMachSC | bbPreemptive | bbThread); /* Clean up Blue Box enables */
        disable_preemption();                                                           /* Don't move us around */
        per_proc_info[cpu_number()].spcFlags = act->mact.specFlags;     /* Copy the flags */
        enable_preemption();                                                            /* Ok to move us around */
        return;
}

/*
 * Use the new PPCcall method to enable blue box threads
 *
 *      save->r3 = taskID
 *      save->r4 = TWI_TableStart
 *      save->r5 = Desc_TableStart
 *
 */
int bb_enable_bluebox( struct savearea *save )
{
        kern_return_t rc;

        rc = enable_bluebox( (host_t)0xFFFFFFFF, (void *)save->save_r3, (void *)save->save_r4, (char *)save->save_r5 );
        save->save_r3 = rc;
        return 1;                                                                               /* Return with normal AST checking */
}

/*
 * Use the new PPCcall method to disable blue box threads
 *
 */
int bb_disable_bluebox( struct savearea *save )
{
        kern_return_t rc;

        rc = disable_bluebox( (host_t)0xFFFFFFFF );
        save->save_r3 = rc;
        return 1;                                                                               /* Return with normal AST checking */
}

/*
 * Search through the list of threads to find the matching taskIDs, then
 * set the task environment pointer.  A task in this case is a preemptive thread
 * in MacOS 9.
 *
 *      save->r3 = taskID
 *      save->r4 = taskEnv
 */

int bb_settaskenv( struct savearea *save )
{
        int                             i;
    task_t                      task;
        thread_act_t    act, fact;


        task = current_task();                                                  /* Figure out who our task is */

        task_lock(task);                                                                /* Lock our task */
        fact = (thread_act_t)task->thr_acts.next;               /* Get the first activation on task */
        act = 0;                                                                                /* Pretend we didn't find it yet */
        
        for(i = 0; i < task->thr_act_count; i++) {              /* Scan the whole list */
                if(fact->mact.bbDescAddr) {                                     /* Is this a Blue thread? */
                        if ( fact->mact.bbTaskID == save->save_r3 ) {   /* Is this the task we are looking for? */
                                act = fact;                                                     /* Yeah... */
                                break;                                                          /* Found it, Bail the loop... */
                        }
                }
                fact = (thread_act_t)fact->thr_acts.next;       /* Go to the next one */
        }

        if ( !act || !act->active) {
                task_unlock(task);                                                      /* Release task lock */
                goto failure;
        }

        act_lock_thread(act);                                                   /* Make sure this stays 'round */
        task_unlock(task);                                                              /* Safe to release now */

        act->mact.bbTaskEnv = save->save_r4;
        if(act == current_act()) {                                              /* Are we setting our own? */
                disable_preemption();                                           /* Don't move us around */
                per_proc_info[cpu_number()].spcFlags = act->mact.specFlags;     /* Copy the flags */
                enable_preemption();                                            /* Ok to move us around */
        }

        act_unlock_thread(act);                                                 /* Unlock the activation */
        save->save_r3 = 0;
        return 1;

failure:
        save->save_r3 = -1;                                                             /* we failed to find the taskID */
        return 1;
}