#include "mm_internal.h"
+/*
+ * Tables translating between page_cache_type_t and pte encoding.
+ * Minimal supported modes are defined statically, modified if more supported
+ * cache modes are available.
+ * Index into __cachemode2pte_tbl is the cachemode.
+ * Index into __pte2cachemode_tbl are the caching attribute bits of the pte
+ * (_PAGE_PWT, _PAGE_PCD, _PAGE_PAT) at index bit positions 0, 1, 2.
+ */
+uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = {
+ [_PAGE_CACHE_MODE_WB] = 0,
+ [_PAGE_CACHE_MODE_WC] = _PAGE_PWT,
+ [_PAGE_CACHE_MODE_UC_MINUS] = _PAGE_PCD,
+ [_PAGE_CACHE_MODE_UC] = _PAGE_PCD | _PAGE_PWT,
+ [_PAGE_CACHE_MODE_WT] = _PAGE_PCD,
+ [_PAGE_CACHE_MODE_WP] = _PAGE_PCD,
+};
+EXPORT_SYMBOL(__cachemode2pte_tbl);
+uint8_t __pte2cachemode_tbl[8] = {
+ [__pte2cm_idx(0)] = _PAGE_CACHE_MODE_WB,
+ [__pte2cm_idx(_PAGE_PWT)] = _PAGE_CACHE_MODE_WC,
+ [__pte2cm_idx(_PAGE_PCD)] = _PAGE_CACHE_MODE_UC_MINUS,
+ [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD)] = _PAGE_CACHE_MODE_UC,
+ [__pte2cm_idx(_PAGE_PAT)] = _PAGE_CACHE_MODE_WB,
+ [__pte2cm_idx(_PAGE_PWT | _PAGE_PAT)] = _PAGE_CACHE_MODE_WC,
+ [__pte2cm_idx(_PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC_MINUS,
+ [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC,
+};
+EXPORT_SYMBOL(__pte2cachemode_tbl);
+
static unsigned long __initdata pgt_buf_start;
static unsigned long __initdata pgt_buf_end;
static unsigned long __initdata pgt_buf_top;
static unsigned long __init get_new_step_size(unsigned long step_size)
{
/*
- * Explain why we shift by 5 and why we don't have to worry about
- * 'step_size << 5' overflowing:
- *
- * initial mapped size is PMD_SIZE (2M).
+ * Initial mapped size is PMD_SIZE (2M).
* We can not set step_size to be PUD_SIZE (1G) yet.
* In worse case, when we cross the 1G boundary, and
* PG_LEVEL_2M is not set, we will need 1+1+512 pages (2M + 8k)
- * to map 1G range with PTE. Use 5 as shift for now.
+ * to map 1G range with PTE. Hence we use one less than the
+ * difference of page table level shifts.
*
- * Don't need to worry about overflow, on 32bit, when step_size
- * is 0, round_down() returns 0 for start, and that turns it
- * into 0x100000000ULL.
+ * Don't need to worry about overflow in the top-down case, on 32bit,
+ * when step_size is 0, round_down() returns 0 for start, and that
+ * turns it into 0x100000000ULL.
+ * In the bottom-up case, round_up(x, 0) returns 0 though too, which
+ * needs to be taken into consideration by the code below.
*/
- return step_size << 5;
+ return step_size << (PMD_SHIFT - PAGE_SHIFT - 1);
}
/**
unsigned long step_size;
unsigned long addr;
unsigned long mapped_ram_size = 0;
- unsigned long new_mapped_ram_size;
/* xen has big range in reserved near end of ram, skip it at first.*/
addr = memblock_find_in_range(map_start, map_end, PMD_SIZE, PMD_SIZE);
start = map_start;
} else
start = map_start;
- new_mapped_ram_size = init_range_memory_mapping(start,
+ mapped_ram_size += init_range_memory_mapping(start,
last_start);
last_start = start;
min_pfn_mapped = last_start >> PAGE_SHIFT;
- /* only increase step_size after big range get mapped */
- if (new_mapped_ram_size > mapped_ram_size)
+ if (mapped_ram_size >= step_size)
step_size = get_new_step_size(step_size);
- mapped_ram_size += new_mapped_ram_size;
}
if (real_end < map_end)
static void __init memory_map_bottom_up(unsigned long map_start,
unsigned long map_end)
{
- unsigned long next, new_mapped_ram_size, start;
+ unsigned long next, start;
unsigned long mapped_ram_size = 0;
/* step_size need to be small so pgt_buf from BRK could cover it */
unsigned long step_size = PMD_SIZE;
* for page table.
*/
while (start < map_end) {
- if (map_end - start > step_size) {
+ if (step_size && map_end - start > step_size) {
next = round_up(start + 1, step_size);
if (next > map_end)
next = map_end;
- } else
+ } else {
next = map_end;
+ }
- new_mapped_ram_size = init_range_memory_mapping(start, next);
+ mapped_ram_size += init_range_memory_mapping(start, next);
start = next;
- if (new_mapped_ram_size > mapped_ram_size)
+ if (mapped_ram_size >= step_size)
step_size = get_new_step_size(step_size);
- mapped_ram_size += new_mapped_ram_size;
}
}
memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
#ifdef CONFIG_ZONE_DMA
- max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
+ max_zone_pfns[ZONE_DMA] = min(MAX_DMA_PFN, max_low_pfn);
#endif
#ifdef CONFIG_ZONE_DMA32
- max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
+ max_zone_pfns[ZONE_DMA32] = min(MAX_DMA32_PFN, max_low_pfn);
#endif
max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
#ifdef CONFIG_HIGHMEM
free_area_init_nodes(max_zone_pfns);
}
+void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache)
+{
+ /* entry 0 MUST be WB (hardwired to speed up translations) */
+ BUG_ON(!entry && cache != _PAGE_CACHE_MODE_WB);
+
+ __cachemode2pte_tbl[cache] = __cm_idx2pte(entry);
+ __pte2cachemode_tbl[entry] = cache;
+}
projects / cascardo / linux.git / blobdiff