From 4769843bc265a9c24584b98709cf39e1df5c1404 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 12 Feb 2009 13:31:41 +0100 Subject: [PATCH] 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 --- arch/x86/mm/init_32.c | 141 ++++++++++++++++++++++++------------------ 1 file changed, 81 insertions(+), 60 deletions(-) diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index e77459dd38ae..9d36eb9ebd53 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -675,6 +675,82 @@ static int __init parse_highmem(char *arg) } 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 @@ void __init find_low_pfn_range(void) /* 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