diff options
| -rw-r--r-- | arch/x86/include/asm/percpu.h | 10 | ||||
| -rw-r--r-- | arch/x86/kernel/setup_percpu.c | 72 | ||||
| -rw-r--r-- | arch/x86/mm/pageattr.c | 21 |
3 files changed, 93 insertions, 10 deletions
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 02ecb30982a3..103f1ddb0d85 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -42,6 +42,7 @@ #else /* ...!ASSEMBLY */ +#include <linux/kernel.h> #include <linux/stringify.h> #ifdef CONFIG_SMP @@ -155,6 +156,15 @@ do { \ /* We can use this directly for local CPU (faster). */ DECLARE_PER_CPU(unsigned long, this_cpu_off); +#ifdef CONFIG_NEED_MULTIPLE_NODES +void *pcpu_lpage_remapped(void *kaddr); +#else +static inline void *pcpu_lpage_remapped(void *kaddr) +{ + return NULL; +} +#endif + #endif /* !__ASSEMBLY__ */ #ifdef CONFIG_SMP diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index 7d38941e2b8c..bad2fd223114 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -142,8 +142,8 @@ struct pcpul_ent { void *ptr; }; -static size_t pcpul_size __initdata; -static struct pcpul_ent *pcpul_map __initdata; +static size_t pcpul_size; +static struct pcpul_ent *pcpul_map; static struct vm_struct pcpul_vm; static struct page * __init pcpul_get_page(unsigned int cpu, int pageno) @@ -160,15 +160,14 @@ static ssize_t __init setup_pcpu_lpage(size_t static_size) { size_t map_size, dyn_size; unsigned int cpu; + int i, j; ssize_t ret; /* * If large page isn't supported, there's no benefit in doing * this. Also, on non-NUMA, embedding is better. - * - * NOTE: disabled for now. */ - if (true || !cpu_has_pse || !pcpu_need_numa()) + if (!cpu_has_pse || !pcpu_need_numa()) return -EINVAL; /* @@ -231,16 +230,71 @@ static ssize_t __init setup_pcpu_lpage(size_t static_size) ret = pcpu_setup_first_chunk(pcpul_get_page, static_size, PERCPU_FIRST_CHUNK_RESERVE, dyn_size, PMD_SIZE, pcpul_vm.addr, NULL); - goto out_free_map; + + /* sort pcpul_map array for pcpu_lpage_remapped() */ + for (i = 0; i < num_possible_cpus() - 1; i++) + for (j = i + 1; j < num_possible_cpus(); j++) + if (pcpul_map[i].ptr > pcpul_map[j].ptr) { + struct pcpul_ent tmp = pcpul_map[i]; + pcpul_map[i] = pcpul_map[j]; + pcpul_map[j] = tmp; + } + + return ret; enomem: for_each_possible_cpu(cpu) if (pcpul_map[cpu].ptr) free_bootmem(__pa(pcpul_map[cpu].ptr), pcpul_size); - ret = -ENOMEM; -out_free_map: free_bootmem(__pa(pcpul_map), map_size); - return ret; + return -ENOMEM; +} + +/** + * pcpu_lpage_remapped - determine whether a kaddr is in pcpul recycled area + * @kaddr: the kernel address in question + * + * Determine whether @kaddr falls in the pcpul recycled area. This is + * used by pageattr to detect VM aliases and break up the pcpu PMD + * mapping such that the same physical page is not mapped under + * different attributes. + * + * The recycled area is always at the tail of a partially used PMD + * page. + * + * RETURNS: + * Address of corresponding remapped pcpu address if match is found; + * otherwise, NULL. + */ +void *pcpu_lpage_remapped(void *kaddr) +{ + void *pmd_addr = (void *)((unsigned long)kaddr & PMD_MASK); + unsigned long offset = (unsigned long)kaddr & ~PMD_MASK; + int left = 0, right = num_possible_cpus() - 1; + int pos; + + /* pcpul in use at all? */ + if (!pcpul_map) + return NULL; + + /* okay, perform binary search */ + while (left <= right) { + pos = (left + right) / 2; + + if (pcpul_map[pos].ptr < pmd_addr) + left = pos + 1; + else if (pcpul_map[pos].ptr > pmd_addr) + right = pos - 1; + else { + /* it shouldn't be in the area for the first chunk */ + WARN_ON(offset < pcpul_size); + + return pcpul_vm.addr + + pcpul_map[pos].cpu * PMD_SIZE + offset; + } + } + + return NULL; } #else static ssize_t __init setup_pcpu_lpage(size_t static_size) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 2ab058b0947d..1b734d7a8966 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -11,6 +11,7 @@ #include <linux/interrupt.h> #include <linux/seq_file.h> #include <linux/debugfs.h> +#include <linux/pfn.h> #include <asm/e820.h> #include <asm/processor.h> @@ -682,7 +683,7 @@ static int cpa_process_alias(struct cpa_data *cpa) { struct cpa_data alias_cpa; unsigned long laddr = (unsigned long)__va(cpa->pfn << PAGE_SHIFT); - unsigned long vaddr; + unsigned long vaddr, remapped; int ret; if (cpa->pfn >= max_pfn_mapped) @@ -737,6 +738,24 @@ static int cpa_process_alias(struct cpa_data *cpa) } #endif + /* + * If the PMD page was partially used for per-cpu remapping, + * the recycled area needs to be split and modified. Because + * the area is always proper subset of a PMD page + * cpa->numpages is guaranteed to be 1 for these areas, so + * there's no need to loop over and check for further remaps. + */ + remapped = (unsigned long)pcpu_lpage_remapped((void *)laddr); + if (remapped) { + WARN_ON(cpa->numpages > 1); + alias_cpa = *cpa; + alias_cpa.vaddr = &remapped; + alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY); + ret = __change_page_attr_set_clr(&alias_cpa, 0); + if (ret) + return ret; + } + return 0; } |