arch/powerpc/platforms/pseries/phyp_dump.c

   1 /*
   2  * Hypervisor-assisted dump
   3  *
   4  * Linas Vepstas, Manish Ahuja 2008
   5  * Copyright 2008 IBM Corp.
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  *
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/mm.h>
  16 #include <linux/pfn.h>
  17 #include <linux/swap.h>
  18
  19 #include <asm/page.h>
  20 #include <asm/phyp_dump.h>
  21 #include <asm/machdep.h>
  22 #include <asm/prom.h>
  23
  24 /* Variables, used to communicate data between early boot and late boot */
  25 static struct phyp_dump phyp_dump_vars;
  26 struct phyp_dump *phyp_dump_info = &phyp_dump_vars;
  27
  28 /**
  29  * release_memory_range -- release memory previously lmb_reserved
  30  * @start_pfn: starting physical frame number
  31  * @nr_pages: number of pages to free.
  32  *
  33  * This routine will release memory that had been previously
  34  * lmb_reserved in early boot. The released memory becomes
  35  * available for genreal use.
  36  */
  37 static void
  38 release_memory_range(unsigned long start_pfn, unsigned long nr_pages)
  39 {
  40         struct page *rpage;
  41         unsigned long end_pfn;
  42         long i;
  43
  44         end_pfn = start_pfn + nr_pages;
  45
  46         for (i = start_pfn; i <= end_pfn; i++) {
  47                 rpage = pfn_to_page(i);
  48                 if (PageReserved(rpage)) {
  49                         ClearPageReserved(rpage);
  50                         init_page_count(rpage);
  51                         __free_page(rpage);
  52                         totalram_pages++;
  53                 }
  54         }
  55 }
  56
  57 static int __init phyp_dump_setup(void)
  58 {
  59         unsigned long start_pfn, nr_pages;
  60
  61         /* If no memory was reserved in early boot, there is nothing to do */
  62         if (phyp_dump_info->init_reserve_size == 0)
  63                 return 0;
  64
  65         /* Release memory that was reserved in early boot */
  66         start_pfn = PFN_DOWN(phyp_dump_info->init_reserve_start);
  67         nr_pages = PFN_DOWN(phyp_dump_info->init_reserve_size);
  68         release_memory_range(start_pfn, nr_pages);
  69
  70         return 0;
  71 }
  72 machine_subsys_initcall(pseries, phyp_dump_setup);
  73
  74 int __init early_init_dt_scan_phyp_dump(unsigned long node,
  75                 const char *uname, int depth, void *data)
  76 {
  77         const unsigned int *sizes;
  78
  79         phyp_dump_info->phyp_dump_configured = 0;
  80         phyp_dump_info->phyp_dump_is_active = 0;
  81
  82         if (depth != 1 || strcmp(uname, "rtas") != 0)
  83                 return 0;
  84
  85         if (of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL))
  86                 phyp_dump_info->phyp_dump_configured++;
  87
  88         if (of_get_flat_dt_prop(node, "ibm,dump-kernel", NULL))
  89                 phyp_dump_info->phyp_dump_is_active++;
  90
  91         sizes = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
  92                                     NULL);
  93         if (!sizes)
  94                 return 0;
  95
  96         if (sizes[0] == 1)
  97                 phyp_dump_info->cpu_state_size = *((unsigned long *)&sizes[1]);
  98
  99         if (sizes[3] == 2)
 100                 phyp_dump_info->hpte_region_size =
 101                                                 *((unsigned long *)&sizes[4]);
 102         return 1;
 103 }