grub/grub-core/mmap/mmap.c
2013-10-14 16:33:44 +02:00

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/* Mmap management. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/memory.h>
#include <grub/machine/memory.h>
#include <grub/err.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/command.h>
#include <grub/dl.h>
#include <grub/i18n.h>
GRUB_MOD_LICENSE ("GPLv3+");
#ifndef GRUB_MMAP_REGISTER_BY_FIRMWARE
struct grub_mmap_region *grub_mmap_overlays = 0;
static int curhandle = 1;
#endif
static int current_priority = 1;
/* Scanline events. */
struct grub_mmap_scan
{
/* At which memory address. */
grub_uint64_t pos;
/* 0 = region starts, 1 = region ends. */
int type;
/* Which type of memory region? */
grub_memory_type_t memtype;
/* Priority. 0 means coming from firmware. */
int priority;
};
/* Context for grub_mmap_iterate. */
struct grub_mmap_iterate_ctx
{
struct grub_mmap_scan *scanline_events;
int i;
};
/* Helper for grub_mmap_iterate. */
static int
count_hook (grub_uint64_t addr __attribute__ ((unused)),
grub_uint64_t size __attribute__ ((unused)),
grub_memory_type_t type __attribute__ ((unused)), void *data)
{
int *mmap_num = data;
(*mmap_num)++;
return 0;
}
/* Helper for grub_mmap_iterate. */
static int
fill_hook (grub_uint64_t addr, grub_uint64_t size, grub_memory_type_t type,
void *data)
{
struct grub_mmap_iterate_ctx *ctx = data;
if (type == GRUB_MEMORY_HOLE)
{
grub_dprintf ("mmap", "Unknown memory type %d. Assuming unusable\n",
type);
type = GRUB_MEMORY_RESERVED;
}
ctx->scanline_events[ctx->i].pos = addr;
ctx->scanline_events[ctx->i].type = 0;
ctx->scanline_events[ctx->i].memtype = type;
ctx->scanline_events[ctx->i].priority = 0;
ctx->i++;
ctx->scanline_events[ctx->i].pos = addr + size;
ctx->scanline_events[ctx->i].type = 1;
ctx->scanline_events[ctx->i].memtype = type;
ctx->scanline_events[ctx->i].priority = 0;
ctx->i++;
return 0;
}
struct mm_list
{
struct mm_list *next;
grub_memory_type_t val;
int present;
};
grub_err_t
grub_mmap_iterate (grub_memory_hook_t hook, void *hook_data)
{
/* This function resolves overlapping regions and sorts the memory map.
It uses scanline (sweeping) algorithm.
*/
struct grub_mmap_iterate_ctx ctx;
int i, done;
struct grub_mmap_scan t;
/* Previous scanline event. */
grub_uint64_t lastaddr;
int lasttype;
/* Current scanline event. */
int curtype;
/* How many regions of given type/priority overlap at current location? */
/* Normally there shouldn't be more than one region per priority but be robust. */
struct mm_list *present;
/* Number of mmap chunks. */
int mmap_num;
#ifndef GRUB_MMAP_REGISTER_BY_FIRMWARE
struct grub_mmap_region *cur;
#endif
mmap_num = 0;
#ifndef GRUB_MMAP_REGISTER_BY_FIRMWARE
for (cur = grub_mmap_overlays; cur; cur = cur->next)
mmap_num++;
#endif
grub_machine_mmap_iterate (count_hook, &mmap_num);
/* Initialize variables. */
ctx.scanline_events = (struct grub_mmap_scan *)
grub_malloc (sizeof (struct grub_mmap_scan) * 2 * mmap_num);
present = grub_zalloc (sizeof (present[0]) * current_priority);
if (! ctx.scanline_events || !present)
{
grub_free (ctx.scanline_events);
grub_free (present);
return grub_errno;
}
ctx.i = 0;
#ifndef GRUB_MMAP_REGISTER_BY_FIRMWARE
/* Register scanline events. */
for (cur = grub_mmap_overlays; cur; cur = cur->next)
{
ctx.scanline_events[ctx.i].pos = cur->start;
ctx.scanline_events[ctx.i].type = 0;
ctx.scanline_events[ctx.i].memtype = cur->type;
ctx.scanline_events[ctx.i].priority = cur->priority;
ctx.i++;
ctx.scanline_events[ctx.i].pos = cur->end;
ctx.scanline_events[ctx.i].type = 1;
ctx.scanline_events[ctx.i].memtype = cur->type;
ctx.scanline_events[ctx.i].priority = cur->priority;
ctx.i++;
}
#endif /* ! GRUB_MMAP_REGISTER_BY_FIRMWARE */
grub_machine_mmap_iterate (fill_hook, &ctx);
/* Primitive bubble sort. It has complexity O(n^2) but since we're
unlikely to have more than 100 chunks it's probably one of the
fastest for one purpose. */
done = 1;
while (done)
{
done = 0;
for (i = 0; i < 2 * mmap_num - 1; i++)
if (ctx.scanline_events[i + 1].pos < ctx.scanline_events[i].pos
|| (ctx.scanline_events[i + 1].pos == ctx.scanline_events[i].pos
&& ctx.scanline_events[i + 1].type == 0
&& ctx.scanline_events[i].type == 1))
{
t = ctx.scanline_events[i + 1];
ctx.scanline_events[i + 1] = ctx.scanline_events[i];
ctx.scanline_events[i] = t;
done = 1;
}
}
lastaddr = ctx.scanline_events[0].pos;
lasttype = ctx.scanline_events[0].memtype;
for (i = 0; i < 2 * mmap_num; i++)
{
/* Process event. */
if (ctx.scanline_events[i].type)
{
if (present[ctx.scanline_events[i].priority].present)
{
if (present[ctx.scanline_events[i].priority].val == ctx.scanline_events[i].memtype)
{
if (present[ctx.scanline_events[i].priority].next)
{
struct mm_list *p = present[ctx.scanline_events[i].priority].next;
present[ctx.scanline_events[i].priority] = *p;
grub_free (p);
}
else
{
present[ctx.scanline_events[i].priority].present = 0;
}
}
else
{
struct mm_list **q = &(present[ctx.scanline_events[i].priority].next), *p;
for (; *q; q = &((*q)->next))
if ((*q)->val == ctx.scanline_events[i].memtype)
{
p = *q;
*q = p->next;
grub_free (p);
break;
}
}
}
}
else
{
if (!present[ctx.scanline_events[i].priority].present)
{
present[ctx.scanline_events[i].priority].present = 1;
present[ctx.scanline_events[i].priority].val = ctx.scanline_events[i].memtype;
}
else
{
struct mm_list *n = grub_malloc (sizeof (*n));
n->val = ctx.scanline_events[i].memtype;
n->present = 1;
n->next = present[ctx.scanline_events[i].priority].next;
present[ctx.scanline_events[i].priority].next = n;
}
}
/* Determine current region type. */
curtype = -1;
{
int k;
for (k = current_priority - 1; k >= 0; k--)
if (present[k].present)
{
curtype = present[k].val;
break;
}
}
/* Announce region to the hook if necessary. */
if ((curtype == -1 || curtype != lasttype)
&& lastaddr != ctx.scanline_events[i].pos
&& lasttype != -1
&& lasttype != GRUB_MEMORY_HOLE
&& hook (lastaddr, ctx.scanline_events[i].pos - lastaddr, lasttype,
hook_data))
{
grub_free (ctx.scanline_events);
return GRUB_ERR_NONE;
}
/* Update last values if necessary. */
if (curtype == -1 || curtype != lasttype)
{
lasttype = curtype;
lastaddr = ctx.scanline_events[i].pos;
}
}
grub_free (ctx.scanline_events);
return GRUB_ERR_NONE;
}
#ifndef GRUB_MMAP_REGISTER_BY_FIRMWARE
int
grub_mmap_register (grub_uint64_t start, grub_uint64_t size, int type)
{
struct grub_mmap_region *cur;
grub_dprintf ("mmap", "registering\n");
cur = (struct grub_mmap_region *)
grub_malloc (sizeof (struct grub_mmap_region));
if (! cur)
return 0;
cur->next = grub_mmap_overlays;
cur->start = start;
cur->end = start + size;
cur->type = type;
cur->handle = curhandle++;
cur->priority = current_priority++;
grub_mmap_overlays = cur;
if (grub_machine_mmap_register (start, size, type, curhandle))
{
grub_mmap_overlays = cur->next;
grub_free (cur);
return 0;
}
return cur->handle;
}
grub_err_t
grub_mmap_unregister (int handle)
{
struct grub_mmap_region *cur, *prev;
for (cur = grub_mmap_overlays, prev = 0; cur; prev = cur, cur = cur->next)
if (handle == cur->handle)
{
grub_err_t err;
err = grub_machine_mmap_unregister (handle);
if (err)
return err;
if (prev)
prev->next = cur->next;
else
grub_mmap_overlays = cur->next;
grub_free (cur);
return GRUB_ERR_NONE;
}
return grub_error (GRUB_ERR_BUG, "mmap overlay not found");
}
#endif /* ! GRUB_MMAP_REGISTER_BY_FIRMWARE */
#define CHUNK_SIZE 0x400
struct badram_entry {
grub_uint64_t addr, mask;
};
static inline grub_uint64_t
fill_mask (struct badram_entry *entry, grub_uint64_t iterator)
{
int i, j;
grub_uint64_t ret = (entry->addr & entry->mask);
/* Find first fixed bit. */
for (i = 0; i < 64; i++)
if ((entry->mask & (1ULL << i)) != 0)
break;
j = 0;
for (; i < 64; i++)
if ((entry->mask & (1ULL << i)) == 0)
{
if ((iterator & (1ULL << j)) != 0)
ret |= 1ULL << i;
j++;
}
return ret;
}
/* Helper for grub_cmd_badram. */
static int
badram_iter (grub_uint64_t addr, grub_uint64_t size,
grub_memory_type_t type __attribute__ ((unused)), void *data)
{
struct badram_entry *entry = data;
grub_uint64_t iterator, low, high, cur;
int tail, var;
int i;
grub_dprintf ("badram", "hook %llx+%llx\n", (unsigned long long) addr,
(unsigned long long) size);
/* How many trailing zeros? */
for (tail = 0; ! (entry->mask & (1ULL << tail)); tail++);
/* How many zeros in mask? */
var = 0;
for (i = 0; i < 64; i++)
if (! (entry->mask & (1ULL << i)))
var++;
if (fill_mask (entry, 0) >= addr)
iterator = 0;
else
{
low = 0;
high = ~0ULL;
/* Find starting value. Keep low and high such that
fill_mask (low) < addr and fill_mask (high) >= addr;
*/
while (high - low > 1)
{
cur = (low + high) / 2;
if (fill_mask (entry, cur) >= addr)
high = cur;
else
low = cur;
}
iterator = high;
}
for (; iterator < (1ULL << (var - tail))
&& (cur = fill_mask (entry, iterator)) < addr + size;
iterator++)
{
grub_dprintf ("badram", "%llx (size %llx) is a badram range\n",
(unsigned long long) cur, (1ULL << tail));
grub_mmap_register (cur, (1ULL << tail), GRUB_MEMORY_HOLE);
}
return 0;
}
static grub_err_t
grub_cmd_badram (grub_command_t cmd __attribute__ ((unused)),
int argc, char **args)
{
char * str;
struct badram_entry entry;
if (argc != 1)
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("one argument expected"));
grub_dprintf ("badram", "executing badram\n");
str = args[0];
while (1)
{
/* Parse address and mask. */
entry.addr = grub_strtoull (str, &str, 16);
if (*str == ',')
str++;
entry.mask = grub_strtoull (str, &str, 16);
if (*str == ',')
str++;
if (grub_errno == GRUB_ERR_BAD_NUMBER)
{
grub_errno = 0;
return GRUB_ERR_NONE;
}
/* When part of a page is tainted, we discard the whole of it. There's
no point in providing sub-page chunks. */
entry.mask &= ~(CHUNK_SIZE - 1);
grub_dprintf ("badram", "badram %llx:%llx\n",
(unsigned long long) entry.addr,
(unsigned long long) entry.mask);
grub_mmap_iterate (badram_iter, &entry);
}
}
static grub_uint64_t
parsemem (const char *str)
{
grub_uint64_t ret;
char *ptr;
ret = grub_strtoul (str, &ptr, 0);
switch (*ptr)
{
case 'K':
return ret << 10;
case 'M':
return ret << 20;
case 'G':
return ret << 30;
case 'T':
return ret << 40;
}
return ret;
}
struct cutmem_range {
grub_uint64_t from, to;
};
/* Helper for grub_cmd_cutmem. */
static int
cutmem_iter (grub_uint64_t addr, grub_uint64_t size,
grub_memory_type_t type __attribute__ ((unused)), void *data)
{
struct cutmem_range *range = data;
grub_uint64_t end = addr + size;
if (addr <= range->from)
addr = range->from;
if (end >= range->to)
end = range->to;
if (end <= addr)
return 0;
grub_mmap_register (addr, end - addr, GRUB_MEMORY_HOLE);
return 0;
}
static grub_err_t
grub_cmd_cutmem (grub_command_t cmd __attribute__ ((unused)),
int argc, char **args)
{
struct cutmem_range range;
if (argc != 2)
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("two arguments expected"));
range.from = parsemem (args[0]);
if (grub_errno)
return grub_errno;
range.to = parsemem (args[1]);
if (grub_errno)
return grub_errno;
grub_mmap_iterate (cutmem_iter, &range);
return GRUB_ERR_NONE;
}
static grub_command_t cmd, cmd_cut;
GRUB_MOD_INIT(mmap)
{
cmd = grub_register_command ("badram", grub_cmd_badram,
N_("ADDR1,MASK1[,ADDR2,MASK2[,...]]"),
N_("Declare memory regions as faulty (badram)."));
cmd_cut = grub_register_command ("cutmem", grub_cmd_cutmem,
N_("FROM[K|M|G] TO[K|M|G]"),
N_("Remove any memory regions in specified range."));
}
GRUB_MOD_FINI(mmap)
{
grub_unregister_command (cmd);
grub_unregister_command (cmd_cut);
}