x86, 32-bit: clean up find_low_pfn_range()
Impact: cleanup
Split find_low_pfn_range() into two functions:
- lowmem_pfn_init()
- highmem_pfn_init()
The former gets called if all of RAM fits into lowmem,
otherwise we call highmem_pfn_init().
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 e77459d..9d36eb9 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -675,6 +675,82 @@
}
early_param("highmem", parse_highmem);
+#define MSG_HIGHMEM_TOO_BIG \
+ "highmem size (%luMB) is bigger than pages available (%luMB)!\n"
+
+#define MSG_LOWMEM_TOO_SMALL \
+ "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n"
+/*
+ * All of RAM fits into lowmem - but if user wants highmem
+ * artificially via the highmem=x boot parameter then create
+ * it:
+ */
+void __init lowmem_pfn_init(void)
+{
+ if (highmem_pages == -1)
+ highmem_pages = 0;
+#ifdef CONFIG_HIGHMEM
+ if (highmem_pages >= max_pfn) {
+ printk(KERN_ERR MSG_HIGHMEM_TOO_BIG,
+ 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 MSG_LOWMEM_TOO_SMALL,
+ 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
+}
+
+#define MSG_HIGHMEM_TOO_SMALL \
+ "only %luMB highmem pages available, ignoring highmem size of %luMB!\n"
+
+#define MSG_HIGHMEM_TRIMMED \
+ "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n"
+/*
+ * We have more RAM than fits into lowmem - we try to put it into
+ * highmem, also taking the highmem=x boot parameter into account:
+ */
+void __init highmem_pfn_init(void)
+{
+ 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 MSG_HIGHMEM_TOO_SMALL,
+ 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 MSG_HIGHMEM_TRIMMED);
+ }
+#endif /* !CONFIG_HIGHMEM64G */
+#endif /* !CONFIG_HIGHMEM */
+}
+
/*
* Determine low and high memory ranges:
*/
@@ -683,67 +759,12 @@
/* it could update max_pfn */
/* max_low_pfn is 0, we already have early_res support */
-
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 %luMB.\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 (%luMB) 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 %luMB 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
- }
+
+ if (max_low_pfn > MAXMEM_PFN)
+ highmem_pfn_init();
+ else
+ lowmem_pfn_init();
}
#ifndef CONFIG_NEED_MULTIPLE_NODES