x86: move find_max_low_pfn to init_32.c
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 9808078..d101733 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -540,8 +540,95 @@
}
#endif
+/* user-defined highmem size */
+static unsigned int highmem_pages = -1;
+
+/*
+ * highmem=size forces highmem to be exactly 'size' bytes.
+ * This works even on boxes that have no highmem otherwise.
+ * This also works to reduce highmem size on bigger boxes.
+ */
+static int __init parse_highmem(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT;
+ return 0;
+}
+early_param("highmem", parse_highmem);
+
+/*
+ * Determine low and high memory ranges:
+ */
+unsigned long __init find_max_low_pfn(void)
+{
+ unsigned long max_low_pfn;
+
+ max_low_pfn = max_pfn;
+ if (max_low_pfn > MAXMEM_PFN) {
+ if (highmem_pages == -1)
+ highmem_pages = max_pfn - MAXMEM_PFN;
+ if (highmem_pages + MAXMEM_PFN < max_pfn)
+ max_pfn = MAXMEM_PFN + highmem_pages;
+ if (highmem_pages + MAXMEM_PFN > max_pfn) {
+ printk(KERN_WARNING "only %luMB highmem pages "
+ "available, ignoring highmem size of %uMB.\n",
+ pages_to_mb(max_pfn - MAXMEM_PFN),
+ pages_to_mb(highmem_pages));
+ highmem_pages = 0;
+ }
+ 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);
+ if (max_pfn > MAX_NONPAE_PFN)
+ printk(KERN_WARNING
+ "Use a HIGHMEM64G enabled kernel.\n");
+ else
+ printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
+ max_pfn = MAXMEM_PFN;
+#else /* !CONFIG_HIGHMEM */
+#ifndef CONFIG_HIGHMEM64G
+ if (max_pfn > MAX_NONPAE_PFN) {
+ max_pfn = MAX_NONPAE_PFN;
+ printk(KERN_WARNING "Warning only 4GB will be used."
+ "Use a HIGHMEM64G enabled kernel.\n");
+ }
+#endif /* !CONFIG_HIGHMEM64G */
+#endif /* !CONFIG_HIGHMEM */
+ } else {
+ if (highmem_pages == -1)
+ highmem_pages = 0;
+#ifdef CONFIG_HIGHMEM
+ if (highmem_pages >= max_pfn) {
+ printk(KERN_ERR "highmem size specified (%uMB) is "
+ "bigger than pages available (%luMB)!.\n",
+ pages_to_mb(highmem_pages),
+ pages_to_mb(max_pfn));
+ highmem_pages = 0;
+ }
+ if (highmem_pages) {
+ if (max_low_pfn - highmem_pages <
+ 64*1024*1024/PAGE_SIZE){
+ printk(KERN_ERR "highmem size %uMB results in "
+ "smaller than 64MB lowmem, ignoring it.\n"
+ , pages_to_mb(highmem_pages));
+ highmem_pages = 0;
+ }
+ max_low_pfn -= highmem_pages;
+ }
+#else
+ if (highmem_pages)
+ printk(KERN_ERR "ignoring highmem size on non-highmem"
+ " kernel!\n");
+#endif
+ }
+ return max_low_pfn;
+}
+
#ifndef CONFIG_NEED_MULTIPLE_NODES
-extern unsigned long find_max_low_pfn(void);
unsigned long __init initmem_init(unsigned long start_pfn,
unsigned long end_pfn)
{