-stable review patch. If anyone has any objections, please let us know. ------------------ From: David Miller 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 Signed-off-by: Chris Wright --- arch/sparc64/mm/init.c | 147 +++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 124 insertions(+), 23 deletions(-) --- linux-2.6.19.1.orig/arch/sparc64/mm/init.c +++ linux-2.6.19.1/arch/sparc64/mm/init.c @@ -872,6 +872,115 @@ static unsigned long __init choose_bootm 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 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 } } #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); -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/