This function although doing simple thing is hard to follow. It's
mainly due to:
- a lot of #ifdef
- bad local names
- redundant tests
So this patch try to address these issues. It also do not use
max_pfn global which is marked as an unused exported symbol.
As a bonus side, it's now really easy to see what part of the
code is for no-numa system.
There's also no point to make this function inline.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@xxxxxxxxx>
---
arch/mips/kernel/setup.c | 135 +++++++++++++++++++---------------------------
1 files changed, 57 insertions(+), 78 deletions(-)
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 8c2b596..e331e63 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -96,6 +96,12 @@ void __init add_memory_region(phys_t sta
int x = boot_mem_map.nr_map;
struct boot_mem_map_entry *prev = boot_mem_map.map + x - 1;
+ /* Sanity check */
+ if (start + size < start) {
+ printk("Trying to add an invalid memory region, skipped\n");
+ return;
+ }
+
/*
* Try to merge with previous entry if any. This is far less than
* perfect but is sufficient for most real world cases.
@@ -257,15 +263,16 @@ #endif
return 0;
}
-#define MAXMEM HIGHMEM_START
-#define MAXMEM_PFN PFN_DOWN(MAXMEM)
-
-static inline void bootmem_init(void)
+/*
+ * Initialize the bootmem allocator. It also setup initrd related data
+ * if needed.
+ */
+static void __init bootmem_init(void)
{
- unsigned long start_pfn;
unsigned long reserved_end = (unsigned long)&_end;
#ifndef CONFIG_SGI_IP27
- unsigned long first_usable_pfn;
+ unsigned long highest = 0;
+ unsigned long mapstart = -1UL;
unsigned long bootmap_size;
int i;
#endif
@@ -281,7 +288,7 @@ #ifdef CONFIG_BLK_DEV_INITRD
unsigned long tmp;
u32 *initrd_header;
- tmp = ((reserved_end + PAGE_SIZE-1) & PAGE_MASK) - sizeof(u32) * 2;
+ tmp = PAGE_ALIGN(reserved_end) - sizeof(u32) * 2;
if (tmp < reserved_end)
tmp += PAGE_SIZE;
initrd_header = (u32 *)tmp;
@@ -294,16 +301,15 @@ #ifdef CONFIG_BLK_DEV_INITRD
}
#endif /* CONFIG_BLK_DEV_INITRD */
+#ifndef CONFIG_SGI_IP27
/*
- * Partially used pages are not usable - thus
- * we are rounding upwards.
+ * reserved_end is now a pfn
*/
- start_pfn = PFN_UP(CPHYSADDR(reserved_end));
+ reserved_end = PFN_UP(CPHYSADDR(reserved_end));
-#ifndef CONFIG_SGI_IP27
- /* Find the highest page frame number we have available. */
- max_pfn = 0;
- first_usable_pfn = -1UL;
+ /*
+ * Find the highest page frame number we have available.
+ */
for (i = 0; i < boot_mem_map.nr_map; i++) {
unsigned long start, end;
@@ -312,56 +318,38 @@ #ifndef CONFIG_SGI_IP27
start = PFN_UP(boot_mem_map.map[i].addr);
end = PFN_DOWN(boot_mem_map.map[i].addr
- + boot_mem_map.map[i].size);
+ + boot_mem_map.map[i].size);
- if (start >= end)
+ if (end > highest)
+ highest = end;
+ if (end <= reserved_end)
continue;
- if (end > max_pfn)
- max_pfn = end;
- if (start < first_usable_pfn) {
- if (start > start_pfn) {
- first_usable_pfn = start;
- } else if (end > start_pfn) {
- first_usable_pfn = start_pfn;
- }
- }
+ if (start >= mapstart)
+ continue;
+ mapstart = max(reserved_end, start);
}
/*
* Determine low and high memory ranges
*/
- max_low_pfn = max_pfn;
- if (max_low_pfn > MAXMEM_PFN) {
- max_low_pfn = MAXMEM_PFN;
-#ifndef CONFIG_HIGHMEM
- /* Maximum memory usable is what is directly addressable */
- printk(KERN_WARNING "Warning only %ldMB will be used.\n",
- MAXMEM >> 20);
- printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
+ if (highest > PFN_DOWN(HIGHMEM_START)) {
+#ifdef CONFIG_HIGHMEM
+ highstart_pfn = PFN_DOWN(HIGHMEM_START);
+ highend_pfn = highest;
#endif
+ highest = PFN_DOWN(HIGHMEM_START);
}
-#ifdef CONFIG_HIGHMEM
/*
- * Crude, we really should make a better attempt at detecting
- * highstart_pfn
+ * Initialize the boot-time allocator with low memory only.
*/
- highstart_pfn = highend_pfn = max_pfn;
- if (max_pfn > MAXMEM_PFN) {
- highstart_pfn = MAXMEM_PFN;
- printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
- (highend_pfn - highstart_pfn) >> (20 - PAGE_SHIFT));
- }
-#endif
-
- /* Initialize the boot-time allocator with low memory only. */
- bootmap_size = init_bootmem(first_usable_pfn, max_low_pfn);
+ bootmap_size = init_bootmem(mapstart, highest);
/*
* Register fully available low RAM pages with the bootmem allocator.
*/
for (i = 0; i < boot_mem_map.nr_map; i++) {
- unsigned long curr_pfn, last_pfn, size;
+ unsigned long start, end, size;
/*
* Reserve usable memory.
@@ -369,49 +357,37 @@ #endif
if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
continue;
- /*
- * We are rounding up the start address of usable memory:
- */
- curr_pfn = PFN_UP(boot_mem_map.map[i].addr);
- if (curr_pfn >= max_low_pfn)
- continue;
- if (curr_pfn < start_pfn)
- curr_pfn = start_pfn;
-
- /*
- * ... and at the end of the usable range downwards:
- */
- last_pfn = PFN_DOWN(boot_mem_map.map[i].addr
+ start = PFN_UP(boot_mem_map.map[i].addr);
+ end = PFN_DOWN(boot_mem_map.map[i].addr
+ boot_mem_map.map[i].size);
-
- if (last_pfn > max_low_pfn)
- last_pfn = max_low_pfn;
-
/*
- * Only register lowmem part of lowmem segment with bootmem.
+ * We are rounding up the start address of usable memory
+ * and at the end of the usable range downwards.
*/
- size = last_pfn - curr_pfn;
- if (curr_pfn > PFN_DOWN(HIGHMEM_START))
- continue;
- if (curr_pfn + size - 1 > PFN_DOWN(HIGHMEM_START))
- size = PFN_DOWN(HIGHMEM_START) - curr_pfn;
- if (!size)
+ if (start >= max_low_pfn)
continue;
+ if (start < reserved_end)
+ start = reserved_end;
+ if (end > max_low_pfn)
+ end = max_low_pfn;
/*
- * ... finally, did all the rounding and playing
- * around just make the area go away?
+ * ... finally, is the area going away?
*/
- if (last_pfn <= curr_pfn)
+ if (end <= start)
continue;
+ size = end - start;
/* Register lowmem ranges */
- free_bootmem(PFN_PHYS(curr_pfn), PFN_PHYS(size));
- memory_present(0, curr_pfn, curr_pfn + size - 1);
+ free_bootmem(PFN_PHYS(start), size << PAGE_SHIFT);
+ memory_present(0, start, end);
}
- /* Reserve the bootmap memory. */
- reserve_bootmem(PFN_PHYS(first_usable_pfn), bootmap_size);
+ /*
+ * Reserve the bootmap memory.
+ */
+ reserve_bootmem(PFN_PHYS(mapstart), bootmap_size);
+
#endif /* CONFIG_SGI_IP27 */
#ifdef CONFIG_BLK_DEV_INITRD
@@ -483,6 +459,9 @@ static void __init arch_mem_init(char **
paging_init();
}
+#define MAXMEM HIGHMEM_START
+#define MAXMEM_PFN PFN_DOWN(MAXMEM)
+
static inline void resource_init(void)
{
int i;
--
1.4.2.rc2
