diff options
Diffstat (limited to 'arch/powerpc/mm/hash_utils_64.c')
| -rw-r--r-- | arch/powerpc/mm/hash_utils_64.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 67e19a0821be..12d679df50bd 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -35,7 +35,9 @@ #include <linux/memblock.h> #include <linux/context_tracking.h> #include <linux/libfdt.h> +#include <linux/debugfs.h> +#include <asm/debug.h> #include <asm/processor.h> #include <asm/pgtable.h> #include <asm/mmu.h> @@ -747,6 +749,35 @@ static unsigned long __init htab_get_table_size(void) } #ifdef CONFIG_MEMORY_HOTPLUG +void resize_hpt_for_hotplug(unsigned long new_mem_size) +{ + unsigned target_hpt_shift; + + if (!mmu_hash_ops.resize_hpt) + return; + + target_hpt_shift = htab_shift_for_mem_size(new_mem_size); + + /* + * To avoid lots of HPT resizes if memory size is fluctuating + * across a boundary, we deliberately have some hysterisis + * here: we immediately increase the HPT size if the target + * shift exceeds the current shift, but we won't attempt to + * reduce unless the target shift is at least 2 below the + * current shift + */ + if ((target_hpt_shift > ppc64_pft_size) + || (target_hpt_shift < (ppc64_pft_size - 1))) { + int rc; + + rc = mmu_hash_ops.resize_hpt(target_hpt_shift); + if (rc) + printk(KERN_WARNING + "Unable to resize hash page table to target order %d: %d\n", + target_hpt_shift, rc); + } +} + int hash__create_section_mapping(unsigned long start, unsigned long end) { int rc = htab_bolt_mapping(start, end, __pa(start), @@ -1795,3 +1826,34 @@ void hash__setup_initial_memory_limit(phys_addr_t first_memblock_base, /* Finally limit subsequent allocations */ memblock_set_current_limit(ppc64_rma_size); } + +#ifdef CONFIG_DEBUG_FS + +static int hpt_order_get(void *data, u64 *val) +{ + *val = ppc64_pft_size; + return 0; +} + +static int hpt_order_set(void *data, u64 val) +{ + if (!mmu_hash_ops.resize_hpt) + return -ENODEV; + + return mmu_hash_ops.resize_hpt(val); +} + +DEFINE_SIMPLE_ATTRIBUTE(fops_hpt_order, hpt_order_get, hpt_order_set, "%llu\n"); + +static int __init hash64_debugfs(void) +{ + if (!debugfs_create_file("hpt_order", 0600, powerpc_debugfs_root, + NULL, &fops_hpt_order)) { + pr_err("lpar: unable to create hpt_order debugsfs file\n"); + } + + return 0; +} +machine_device_initcall(pseries, hash64_debugfs); + +#endif /* CONFIG_DEBUG_FS */ |