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  1. /*
  2.  * Copyright (C) 2006 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup sparc64proc
  30.  * @{
  31.  */
  32. /** @file
  33.  */
  34.  
  35. #include <proc/scheduler.h>
  36. #include <proc/thread.h>
  37. #include <arch.h>
  38. #include <arch/asm.h>
  39. #include <arch/regdef.h>
  40. #include <arch/stack.h>
  41. #include <arch/mm/tlb.h>
  42. #include <arch/mm/page.h>
  43. #include <config.h>
  44. #include <align.h>
  45. #include <macros.h>
  46.  
  47. /** Perform sparc64 specific tasks needed before the new task is run. */
  48. void before_task_runs_arch(void)
  49. {
  50. }
  51.  
  52. /** Perform sparc64 specific steps before scheduling a thread.
  53.  *
  54.  * Ensure that thread's kernel stack, as well as userspace window buffer for
  55.  * userspace threads, are locked in DTLB. For userspace threads, initialize
  56.  * reserved global registers in the alternate and interrupt sets.
  57.  */
  58. void before_thread_runs_arch(void)
  59. {
  60.     uintptr_t base;
  61.    
  62.     base = ALIGN_DOWN(config.base, 1<<KERNEL_PAGE_WIDTH);
  63.  
  64.     if (!overlaps((uintptr_t) THREAD->kstack, PAGE_SIZE, base, (1 <<
  65.         KERNEL_PAGE_WIDTH))) {
  66.         /*
  67.          * Kernel stack of this thread is not locked in DTLB.
  68.          * First, make sure it is not mapped already.
  69.          * If not, create a locked mapping for it.
  70.          */
  71.         dtlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_NUCLEUS, (uintptr_t)
  72.             THREAD->kstack);
  73.         dtlb_insert_mapping((uintptr_t) THREAD->kstack,
  74.             KA2PA(THREAD->kstack), PAGESIZE_8K, true, true);
  75.     }
  76.    
  77.     if ((THREAD->flags & THREAD_FLAG_USPACE)) {
  78.         /*
  79.          * If this thread executes also in userspace, we have to lock
  80.          * its userspace window buffer into DTLB.
  81.          */
  82.         ASSERT(THREAD->arch.uspace_window_buffer);
  83.         uintptr_t uw_buf = ALIGN_DOWN((uintptr_t)
  84.             THREAD->arch.uspace_window_buffer, PAGE_SIZE);
  85.         if (!overlaps(uw_buf, PAGE_SIZE, base, 1 << KERNEL_PAGE_WIDTH))
  86.             {
  87.             /*
  88.              * The buffer is not covered by the 4M locked kernel
  89.              * DTLB entry.
  90.              */
  91.             dtlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_NUCLEUS, uw_buf);
  92.             dtlb_insert_mapping(uw_buf, KA2PA(uw_buf), PAGESIZE_8K,
  93.                 true, true);
  94.         }
  95.        
  96.         /*
  97.          * Write kernel stack address to %g6 and a pointer to the last
  98.          * item in the userspace window buffer to %g7 in the alternate
  99.          * and interrupt sets.
  100.          */
  101.         uint64_t sp = (uintptr_t) THREAD->kstack + STACK_SIZE
  102.             - (STACK_BIAS + ALIGN_UP(STACK_ITEM_SIZE,
  103.             STACK_ALIGNMENT));
  104.         write_to_ig_g6(sp);
  105.         write_to_ag_g6(sp);
  106.         write_to_ag_g7((uintptr_t) THREAD->arch.uspace_window_buffer);
  107.     }
  108. }
  109.  
  110. /** Perform sparc64 specific steps before a thread stops running.
  111.  *
  112.  * Demap any locked DTLB entries isntalled by the thread (i.e. kernel stack
  113.  * and userspace window buffer).
  114.  */
  115. void after_thread_ran_arch(void)
  116. {
  117.     uintptr_t base;
  118.  
  119.     base = ALIGN_DOWN(config.base, 1 << KERNEL_PAGE_WIDTH);
  120.  
  121.     if (!overlaps((uintptr_t) THREAD->kstack, PAGE_SIZE, base, (1 <<
  122.         KERNEL_PAGE_WIDTH))) {
  123.         /*
  124.          * Kernel stack of this thread is locked in DTLB.
  125.          * Destroy the mapping.
  126.          */
  127.         dtlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_NUCLEUS, (uintptr_t)
  128.             THREAD->kstack);
  129.     }
  130.    
  131.     if ((THREAD->flags & THREAD_FLAG_USPACE)) {
  132.         /*
  133.          * If this thread executes also in userspace, we have to
  134.          * demap the userspace window buffer from DTLB.
  135.          */
  136.         ASSERT(THREAD->arch.uspace_window_buffer);
  137.        
  138.         uintptr_t uw_buf = ALIGN_DOWN((uintptr_t)
  139.             THREAD->arch.uspace_window_buffer, PAGE_SIZE);
  140.         if (!overlaps(uw_buf, PAGE_SIZE, base, 1 << KERNEL_PAGE_WIDTH)) {
  141.             /*
  142.              * The buffer is not covered by the 4M locked kernel DTLB entry
  143.              * and therefore it was given a dedicated locked DTLB entry.
  144.              * Demap it.
  145.              */
  146.             dtlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_NUCLEUS, uw_buf);
  147.         }
  148.    
  149.         /* sample the state of the userspace window buffer */  
  150.         THREAD->arch.uspace_window_buffer = (uint8_t *) read_from_ag_g7();
  151.     }
  152. }
  153.  
  154. /** @}
  155.  */
  156.