From 6fc5bae797a6632bbccdd49a1b6a96121368a4b9 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 28 Dec 2006 21:00:23 -0800 Subject: [SPARC64]: Fix "mem=xxx" handling. We were not being careful enough. When we trim the physical memory areas, we have to make sure we don't remove the kernel image or initial ramdisk image ranges. Signed-off-by: David S. Miller --- arch/sparc64/mm/init.c | 147 +++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 124 insertions(+), 23 deletions(-) diff --git a/arch/sparc64/mm/init.c b/arch/sparc64/mm/init.c index a8e8802eed4..054822a3e05 100644 --- a/arch/sparc64/mm/init.c +++ b/arch/sparc64/mm/init.c @@ -872,6 +872,115 @@ static unsigned long __init choose_bootmap_pfn(unsigned long start_pfn, prom_halt(); } +static void __init trim_pavail(unsigned long *cur_size_p, + unsigned long *end_of_phys_p) +{ + unsigned long to_trim = *cur_size_p - cmdline_memory_size; + unsigned long avoid_start, avoid_end; + int i; + + to_trim = PAGE_ALIGN(to_trim); + + avoid_start = avoid_end = 0; +#ifdef CONFIG_BLK_DEV_INITRD + avoid_start = initrd_start; + avoid_end = PAGE_ALIGN(initrd_end); +#endif + + /* Trim some pavail[] entries in order to satisfy the + * requested "mem=xxx" kernel command line specification. + * + * We must not trim off the kernel image area nor the + * initial ramdisk range (if any). Also, we must not trim + * any pavail[] entry down to zero in order to preserve + * the invariant that all pavail[] entries have a non-zero + * size which is assumed by all of the code in here. + */ + for (i = 0; i < pavail_ents; i++) { + unsigned long start, end, kern_end; + unsigned long trim_low, trim_high, n; + + kern_end = PAGE_ALIGN(kern_base + kern_size); + + trim_low = start = pavail[i].phys_addr; + trim_high = end = start + pavail[i].reg_size; + + if (kern_base >= start && + kern_base < end) { + trim_low = kern_base; + if (kern_end >= end) + continue; + } + if (kern_end >= start && + kern_end < end) { + trim_high = kern_end; + } + if (avoid_start && + avoid_start >= start && + avoid_start < end) { + if (trim_low > avoid_start) + trim_low = avoid_start; + if (avoid_end >= end) + continue; + } + if (avoid_end && + avoid_end >= start && + avoid_end < end) { + if (trim_high < avoid_end) + trim_high = avoid_end; + } + + if (trim_high <= trim_low) + continue; + + if (trim_low == start && trim_high == end) { + /* Whole chunk is available for trimming. + * Trim all except one page, in order to keep + * entry non-empty. + */ + n = (end - start) - PAGE_SIZE; + if (n > to_trim) + n = to_trim; + + if (n) { + pavail[i].phys_addr += n; + pavail[i].reg_size -= n; + to_trim -= n; + } + } else { + n = (trim_low - start); + if (n > to_trim) + n = to_trim; + + if (n) { + pavail[i].phys_addr += n; + pavail[i].reg_size -= n; + to_trim -= n; + } + if (to_trim) { + n = end - trim_high; + if (n > to_trim) + n = to_trim; + if (n) { + pavail[i].reg_size -= n; + to_trim -= n; + } + } + } + + if (!to_trim) + break; + } + + /* Recalculate. */ + *cur_size_p = 0UL; + for (i = 0; i < pavail_ents; i++) { + *end_of_phys_p = pavail[i].phys_addr + + pavail[i].reg_size; + *cur_size_p += pavail[i].reg_size; + } +} + static unsigned long __init bootmem_init(unsigned long *pages_avail, unsigned long phys_base) { @@ -889,31 +998,13 @@ static unsigned long __init bootmem_init(unsigned long *pages_avail, end_of_phys_memory = pavail[i].phys_addr + pavail[i].reg_size; bytes_avail += pavail[i].reg_size; - if (cmdline_memory_size) { - if (bytes_avail > cmdline_memory_size) { - unsigned long slack = bytes_avail - cmdline_memory_size; - - bytes_avail -= slack; - end_of_phys_memory -= slack; - - pavail[i].reg_size -= slack; - if ((long)pavail[i].reg_size <= 0L) { - pavail[i].phys_addr = 0xdeadbeefUL; - pavail[i].reg_size = 0UL; - pavail_ents = i; - } else { - pavail[i+1].reg_size = 0Ul; - pavail[i+1].phys_addr = 0xdeadbeefUL; - pavail_ents = i + 1; - } - break; - } - } } - *pages_avail = bytes_avail >> PAGE_SHIFT; - - end_pfn = end_of_phys_memory >> PAGE_SHIFT; + /* Determine the location of the initial ramdisk before trying + * to honor the "mem=xxx" command line argument. We must know + * where the kernel image and the ramdisk image are so that we + * do not trim those two areas from the physical memory map. + */ #ifdef CONFIG_BLK_DEV_INITRD /* Now have to check initial ramdisk, so that bootmap does not overwrite it */ @@ -932,6 +1023,16 @@ static unsigned long __init bootmem_init(unsigned long *pages_avail, } } #endif + + if (cmdline_memory_size && + bytes_avail > cmdline_memory_size) + trim_pavail(&bytes_avail, + &end_of_phys_memory); + + *pages_avail = bytes_avail >> PAGE_SHIFT; + + end_pfn = end_of_phys_memory >> PAGE_SHIFT; + /* Initialize the boot-time allocator. */ max_pfn = max_low_pfn = end_pfn; min_low_pfn = (phys_base >> PAGE_SHIFT); -- cgit v1.2.3