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-rw-r--r--arch/x86/include/asm/page_types.h8
-rw-r--r--arch/x86/kernel/setup.c8
-rw-r--r--arch/x86/mm/init.c120
-rw-r--r--arch/x86/mm/init_64.c6
4 files changed, 117 insertions, 25 deletions
diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
index 45aae6e..54c9787 100644
--- a/arch/x86/include/asm/page_types.h
+++ b/arch/x86/include/asm/page_types.h
@@ -51,13 +51,7 @@ static inline phys_addr_t get_max_mapped(void)
return (phys_addr_t)max_pfn_mapped << PAGE_SHIFT;
}
-static inline bool pfn_range_is_mapped(unsigned long start_pfn,
- unsigned long end_pfn)
-{
- return end_pfn <= max_low_pfn_mapped ||
- (end_pfn > (1UL << (32 - PAGE_SHIFT)) &&
- end_pfn <= max_pfn_mapped);
-}
+bool pfn_range_is_mapped(unsigned long start_pfn, unsigned long end_pfn);
extern unsigned long init_memory_mapping(unsigned long start,
unsigned long end);
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index bd52f9d..68dffec 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -116,9 +116,11 @@
#include <asm/prom.h>
/*
- * end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
- * The direct mapping extends to max_pfn_mapped, so that we can directly access
- * apertures, ACPI and other tables without having to play with fixmaps.
+ * max_low_pfn_mapped: highest direct mapped pfn under 4GB
+ * max_pfn_mapped: highest direct mapped pfn over 4GB
+ *
+ * The direct mapping only covers E820_RAM regions, so the ranges and gaps are
+ * represented by pfn_mapped
*/
unsigned long max_low_pfn_mapped;
unsigned long max_pfn_mapped;
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 7b961d0..bb44e9f 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -243,6 +243,38 @@ static unsigned long __init calculate_table_space_size(unsigned long start, unsi
return tables;
}
+static unsigned long __init calculate_all_table_space_size(void)
+{
+ unsigned long start_pfn, end_pfn;
+ unsigned long tables;
+ int i;
+
+ /* the ISA range is always mapped regardless of memory holes */
+ tables = calculate_table_space_size(0, ISA_END_ADDRESS);
+
+ for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
+ u64 start = start_pfn << PAGE_SHIFT;
+ u64 end = end_pfn << PAGE_SHIFT;
+
+ if (end <= ISA_END_ADDRESS)
+ continue;
+
+ if (start < ISA_END_ADDRESS)
+ start = ISA_END_ADDRESS;
+#ifdef CONFIG_X86_32
+ /* on 32 bit, we only map up to max_low_pfn */
+ if ((start >> PAGE_SHIFT) >= max_low_pfn)
+ continue;
+
+ if ((end >> PAGE_SHIFT) > max_low_pfn)
+ end = max_low_pfn << PAGE_SHIFT;
+#endif
+ tables += calculate_table_space_size(start, end);
+ }
+
+ return tables;
+}
+
static void __init find_early_table_space(unsigned long start,
unsigned long good_end,
unsigned long tables)
@@ -258,6 +290,34 @@ static void __init find_early_table_space(unsigned long start,
pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
}
+static struct range pfn_mapped[E820_X_MAX];
+static int nr_pfn_mapped;
+
+static void add_pfn_range_mapped(unsigned long start_pfn, unsigned long end_pfn)
+{
+ nr_pfn_mapped = add_range_with_merge(pfn_mapped, E820_X_MAX,
+ nr_pfn_mapped, start_pfn, end_pfn);
+ nr_pfn_mapped = clean_sort_range(pfn_mapped, E820_X_MAX);
+
+ max_pfn_mapped = max(max_pfn_mapped, end_pfn);
+
+ if (start_pfn < (1UL<<(32-PAGE_SHIFT)))
+ max_low_pfn_mapped = max(max_low_pfn_mapped,
+ min(end_pfn, 1UL<<(32-PAGE_SHIFT)));
+}
+
+bool pfn_range_is_mapped(unsigned long start_pfn, unsigned long end_pfn)
+{
+ int i;
+
+ for (i = 0; i < nr_pfn_mapped; i++)
+ if ((start_pfn >= pfn_mapped[i].start) &&
+ (end_pfn <= pfn_mapped[i].end))
+ return true;
+
+ return false;
+}
+
/*
* Setup the direct mapping of the physical memory at PAGE_OFFSET.
* This runs before bootmem is initialized and gets pages directly from
@@ -288,9 +348,55 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
__flush_tlb_all();
+ add_pfn_range_mapped(start >> PAGE_SHIFT, ret >> PAGE_SHIFT);
+
return ret >> PAGE_SHIFT;
}
+/*
+ * Iterate through E820 memory map and create direct mappings for only E820_RAM
+ * regions. We cannot simply create direct mappings for all pfns from
+ * [0 to max_low_pfn) and [4GB to max_pfn) because of possible memory holes in
+ * high addresses that cannot be marked as UC by fixed/variable range MTRRs.
+ * Depending on the alignment of E820 ranges, this may possibly result in using
+ * smaller size (i.e. 4K instead of 2M or 1G) page tables.
+ */
+static void __init init_all_memory_mapping(void)
+{
+ unsigned long start_pfn, end_pfn;
+ int i;
+
+ /* the ISA range is always mapped regardless of memory holes */
+ init_memory_mapping(0, ISA_END_ADDRESS);
+
+ for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
+ u64 start = (u64)start_pfn << PAGE_SHIFT;
+ u64 end = (u64)end_pfn << PAGE_SHIFT;
+
+ if (end <= ISA_END_ADDRESS)
+ continue;
+
+ if (start < ISA_END_ADDRESS)
+ start = ISA_END_ADDRESS;
+#ifdef CONFIG_X86_32
+ /* on 32 bit, we only map up to max_low_pfn */
+ if ((start >> PAGE_SHIFT) >= max_low_pfn)
+ continue;
+
+ if ((end >> PAGE_SHIFT) > max_low_pfn)
+ end = max_low_pfn << PAGE_SHIFT;
+#endif
+ init_memory_mapping(start, end);
+ }
+
+#ifdef CONFIG_X86_64
+ if (max_pfn > max_low_pfn) {
+ /* can we preseve max_low_pfn ?*/
+ max_low_pfn = max_pfn;
+ }
+#endif
+}
+
void __init init_mem_mapping(void)
{
unsigned long tables, good_end, end;
@@ -311,23 +417,15 @@ void __init init_mem_mapping(void)
end = max_low_pfn << PAGE_SHIFT;
good_end = max_pfn_mapped << PAGE_SHIFT;
#endif
- tables = calculate_table_space_size(0, end);
+ tables = calculate_all_table_space_size();
find_early_table_space(0, good_end, tables);
printk(KERN_DEBUG "kernel direct mapping tables up to %#lx @ [mem %#010lx-%#010lx] prealloc\n",
end - 1, pgt_buf_start << PAGE_SHIFT,
(pgt_buf_top << PAGE_SHIFT) - 1);
- max_low_pfn_mapped = init_memory_mapping(0, max_low_pfn<<PAGE_SHIFT);
- max_pfn_mapped = max_low_pfn_mapped;
+ max_pfn_mapped = 0; /* will get exact value next */
+ init_all_memory_mapping();
-#ifdef CONFIG_X86_64
- if (max_pfn > max_low_pfn) {
- max_pfn_mapped = init_memory_mapping(1UL<<32,
- max_pfn<<PAGE_SHIFT);
- /* can we preseve max_low_pfn ?*/
- max_low_pfn = max_pfn;
- }
-#endif
/*
* Reserve the kernel pagetable pages we used (pgt_buf_start -
* pgt_buf_end) and free the other ones (pgt_buf_end - pgt_buf_top)
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 3baff25..32c7e38 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -662,13 +662,11 @@ int arch_add_memory(int nid, u64 start, u64 size)
{
struct pglist_data *pgdat = NODE_DATA(nid);
struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
- unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
+ unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
int ret;
- last_mapped_pfn = init_memory_mapping(start, start + size);
- if (last_mapped_pfn > max_pfn_mapped)
- max_pfn_mapped = last_mapped_pfn;
+ init_memory_mapping(start, start + size);
ret = __add_pages(nid, zone, start_pfn, nr_pages);
WARN_ON_ONCE(ret);
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