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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
  55.  * buffer for userspace threads, are locked in DTLB.
  56.  * For userspace threads, initialize reserved global registers
  57.  * in the alternate and interrupt sets.
  58.  */
  59. void before_thread_runs_arch(void)
  60. {
  61.     uintptr_t base;
  62.    
  63.     base = ALIGN_DOWN(config.base, 1<<KERNEL_PAGE_WIDTH);
  64.  
  65.     if (!overlaps((uintptr_t) THREAD->kstack, PAGE_SIZE, base, (1<<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) THREAD->kstack);
  72.         dtlb_insert_mapping((uintptr_t) THREAD->kstack, KA2PA(THREAD->kstack), PAGESIZE_8K, true, true);
  73.     }
  74.    
  75.     if ((THREAD->flags & THREAD_FLAG_USPACE)) {
  76.         /*
  77.          * If this thread executes also in userspace, we have to lock
  78.          * its userspace window buffer into DTLB.
  79.          */
  80.         ASSERT(THREAD->arch.uspace_window_buffer);
  81.         uintptr_t uw_buf = ALIGN_DOWN((uintptr_t) THREAD->arch.uspace_window_buffer, PAGE_SIZE);
  82.         if (!overlaps(uw_buf, PAGE_SIZE, base, 1<<KERNEL_PAGE_WIDTH)) {
  83.             /*
  84.              * The buffer is not covered by the 4M locked kernel DTLB entry.
  85.              */
  86.             dtlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_NUCLEUS, uw_buf);
  87.             dtlb_insert_mapping(uw_buf, KA2PA(uw_buf), PAGESIZE_8K, true, true);
  88.         }
  89.        
  90.         /*
  91.          * Write kernel stack address to %g6 and a pointer to the last item
  92.          * in the userspace window buffer to %g7 in the alternate and interrupt sets.
  93.          */
  94.         uint64_t sp = (uintptr_t) THREAD->kstack + STACK_SIZE
  95.             - (STACK_BIAS + ALIGN_UP(STACK_ITEM_SIZE, STACK_ALIGNMENT));
  96.         write_to_ig_g6(sp);
  97.         write_to_ag_g6(sp);
  98.         write_to_ag_g7((uintptr_t) THREAD->arch.uspace_window_buffer);
  99.     }
  100. }
  101.  
  102. /** Perform sparc64 specific steps before a thread stops running.
  103.  *
  104.  * Demap any locked DTLB entries isntalled by the thread (i.e. kernel stack
  105.  * and userspace window buffer).
  106.  */
  107. void after_thread_ran_arch(void)
  108. {
  109.     uintptr_t base;
  110.  
  111.     base = ALIGN_DOWN(config.base, 1<<KERNEL_PAGE_WIDTH);
  112.  
  113.     if (!overlaps((uintptr_t) THREAD->kstack, PAGE_SIZE, base, (1<<KERNEL_PAGE_WIDTH))) {
  114.         /*
  115.          * Kernel stack of this thread is locked in DTLB.
  116.          * Destroy the mapping.
  117.          */
  118.         dtlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_NUCLEUS, (uintptr_t) THREAD->kstack);
  119.     }
  120.    
  121.     if ((THREAD->flags & THREAD_FLAG_USPACE)) {
  122.         /*
  123.          * If this thread executes also in userspace, we have to force all
  124.          * its still-active userspace windows into the userspace window buffer
  125.          * and demap the buffer from DTLB.
  126.          */
  127.         ASSERT(THREAD->arch.uspace_window_buffer);
  128.        
  129.         flushw();   /* force all userspace windows into memory */
  130.        
  131.         uintptr_t uw_buf = ALIGN_DOWN((uintptr_t) THREAD->arch.uspace_window_buffer, PAGE_SIZE);
  132.         if (!overlaps(uw_buf, PAGE_SIZE, base, 1<<KERNEL_PAGE_WIDTH)) {
  133.             /*
  134.              * The buffer is not covered by the 4M locked kernel DTLB entry
  135.              * and therefore it was given a dedicated locked DTLB entry.
  136.              * Demap it.
  137.              */
  138.             dtlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_NUCLEUS, uw_buf);
  139.         }
  140.    
  141.         /* sample the state of the userspace window buffer */  
  142.         THREAD->arch.uspace_window_buffer = (uint8_t *) read_from_ag_g7();
  143.     }
  144. }
  145.  
  146. /** @}
  147.  */
  148.