| /* |
| * NUMA emulation |
| */ |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/topology.h> |
| #include <linux/memblock.h> |
| #include <linux/bootmem.h> |
| #include <asm/dma.h> |
| |
| #include "numa_internal.h" |
| |
| static int emu_nid_to_phys[MAX_NUMNODES] __cpuinitdata; |
| static char *emu_cmdline __initdata; |
| |
| void __init numa_emu_cmdline(char *str) |
| { |
| emu_cmdline = str; |
| } |
| |
| static int __init emu_find_memblk_by_nid(int nid, const struct numa_meminfo *mi) |
| { |
| int i; |
| |
| for (i = 0; i < mi->nr_blks; i++) |
| if (mi->blk[i].nid == nid) |
| return i; |
| return -ENOENT; |
| } |
| |
| static u64 __init mem_hole_size(u64 start, u64 end) |
| { |
| unsigned long start_pfn = PFN_UP(start); |
| unsigned long end_pfn = PFN_DOWN(end); |
| |
| if (start_pfn < end_pfn) |
| return PFN_PHYS(absent_pages_in_range(start_pfn, end_pfn)); |
| return 0; |
| } |
| |
| /* |
| * Sets up nid to range from @start to @end. The return value is -errno if |
| * something went wrong, 0 otherwise. |
| */ |
| static int __init emu_setup_memblk(struct numa_meminfo *ei, |
| struct numa_meminfo *pi, |
| int nid, int phys_blk, u64 size) |
| { |
| struct numa_memblk *eb = &ei->blk[ei->nr_blks]; |
| struct numa_memblk *pb = &pi->blk[phys_blk]; |
| |
| if (ei->nr_blks >= NR_NODE_MEMBLKS) { |
| pr_err("NUMA: Too many emulated memblks, failing emulation\n"); |
| return -EINVAL; |
| } |
| |
| ei->nr_blks++; |
| eb->start = pb->start; |
| eb->end = pb->start + size; |
| eb->nid = nid; |
| |
| if (emu_nid_to_phys[nid] == NUMA_NO_NODE) |
| emu_nid_to_phys[nid] = nid; |
| |
| pb->start += size; |
| if (pb->start >= pb->end) { |
| WARN_ON_ONCE(pb->start > pb->end); |
| numa_remove_memblk_from(phys_blk, pi); |
| } |
| |
| printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid, |
| eb->start, eb->end, (eb->end - eb->start) >> 20); |
| return 0; |
| } |
| |
| /* |
| * Sets up nr_nodes fake nodes interleaved over physical nodes ranging from addr |
| * to max_addr. The return value is the number of nodes allocated. |
| */ |
| static int __init split_nodes_interleave(struct numa_meminfo *ei, |
| struct numa_meminfo *pi, |
| u64 addr, u64 max_addr, int nr_nodes) |
| { |
| nodemask_t physnode_mask = NODE_MASK_NONE; |
| u64 size; |
| int big; |
| int nid = 0; |
| int i, ret; |
| |
| if (nr_nodes <= 0) |
| return -1; |
| if (nr_nodes > MAX_NUMNODES) { |
| pr_info("numa=fake=%d too large, reducing to %d\n", |
| nr_nodes, MAX_NUMNODES); |
| nr_nodes = MAX_NUMNODES; |
| } |
| |
| /* |
| * Calculate target node size. x86_32 freaks on __udivdi3() so do |
| * the division in ulong number of pages and convert back. |
| */ |
| size = max_addr - addr - mem_hole_size(addr, max_addr); |
| size = PFN_PHYS((unsigned long)(size >> PAGE_SHIFT) / nr_nodes); |
| |
| /* |
| * Calculate the number of big nodes that can be allocated as a result |
| * of consolidating the remainder. |
| */ |
| big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * nr_nodes) / |
| FAKE_NODE_MIN_SIZE; |
| |
| size &= FAKE_NODE_MIN_HASH_MASK; |
| if (!size) { |
| pr_err("Not enough memory for each node. " |
| "NUMA emulation disabled.\n"); |
| return -1; |
| } |
| |
| for (i = 0; i < pi->nr_blks; i++) |
| node_set(pi->blk[i].nid, physnode_mask); |
| |
| /* |
| * Continue to fill physical nodes with fake nodes until there is no |
| * memory left on any of them. |
| */ |
| while (nodes_weight(physnode_mask)) { |
| for_each_node_mask(i, physnode_mask) { |
| u64 dma32_end = PFN_PHYS(MAX_DMA32_PFN); |
| u64 start, limit, end; |
| int phys_blk; |
| |
| phys_blk = emu_find_memblk_by_nid(i, pi); |
| if (phys_blk < 0) { |
| node_clear(i, physnode_mask); |
| continue; |
| } |
| start = pi->blk[phys_blk].start; |
| limit = pi->blk[phys_blk].end; |
| end = start + size; |
| |
| if (nid < big) |
| end += FAKE_NODE_MIN_SIZE; |
| |
| /* |
| * Continue to add memory to this fake node if its |
| * non-reserved memory is less than the per-node size. |
| */ |
| while (end - start - mem_hole_size(start, end) < size) { |
| end += FAKE_NODE_MIN_SIZE; |
| if (end > limit) { |
| end = limit; |
| break; |
| } |
| } |
| |
| /* |
| * If there won't be at least FAKE_NODE_MIN_SIZE of |
| * non-reserved memory in ZONE_DMA32 for the next node, |
| * this one must extend to the boundary. |
| */ |
| if (end < dma32_end && dma32_end - end - |
| mem_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE) |
| end = dma32_end; |
| |
| /* |
| * If there won't be enough non-reserved memory for the |
| * next node, this one must extend to the end of the |
| * physical node. |
| */ |
| if (limit - end - mem_hole_size(end, limit) < size) |
| end = limit; |
| |
| ret = emu_setup_memblk(ei, pi, nid++ % nr_nodes, |
| phys_blk, |
| min(end, limit) - start); |
| if (ret < 0) |
| return ret; |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| * Returns the end address of a node so that there is at least `size' amount of |
| * non-reserved memory or `max_addr' is reached. |
| */ |
| static u64 __init find_end_of_node(u64 start, u64 max_addr, u64 size) |
| { |
| u64 end = start + size; |
| |
| while (end - start - mem_hole_size(start, end) < size) { |
| end += FAKE_NODE_MIN_SIZE; |
| if (end > max_addr) { |
| end = max_addr; |
| break; |
| } |
| } |
| return end; |
| } |
| |
| /* |
| * Sets up fake nodes of `size' interleaved over physical nodes ranging from |
| * `addr' to `max_addr'. The return value is the number of nodes allocated. |
| */ |
| static int __init split_nodes_size_interleave(struct numa_meminfo *ei, |
| struct numa_meminfo *pi, |
| u64 addr, u64 max_addr, u64 size) |
| { |
| nodemask_t physnode_mask = NODE_MASK_NONE; |
| u64 min_size; |
| int nid = 0; |
| int i, ret; |
| |
| if (!size) |
| return -1; |
| /* |
| * The limit on emulated nodes is MAX_NUMNODES, so the size per node is |
| * increased accordingly if the requested size is too small. This |
| * creates a uniform distribution of node sizes across the entire |
| * machine (but not necessarily over physical nodes). |
| */ |
| min_size = (max_addr - addr - mem_hole_size(addr, max_addr)) / MAX_NUMNODES; |
| min_size = max(min_size, FAKE_NODE_MIN_SIZE); |
| if ((min_size & FAKE_NODE_MIN_HASH_MASK) < min_size) |
| min_size = (min_size + FAKE_NODE_MIN_SIZE) & |
| FAKE_NODE_MIN_HASH_MASK; |
| if (size < min_size) { |
| pr_err("Fake node size %LuMB too small, increasing to %LuMB\n", |
| size >> 20, min_size >> 20); |
| size = min_size; |
| } |
| size &= FAKE_NODE_MIN_HASH_MASK; |
| |
| for (i = 0; i < pi->nr_blks; i++) |
| node_set(pi->blk[i].nid, physnode_mask); |
| |
| /* |
| * Fill physical nodes with fake nodes of size until there is no memory |
| * left on any of them. |
| */ |
| while (nodes_weight(physnode_mask)) { |
| for_each_node_mask(i, physnode_mask) { |
| u64 dma32_end = PFN_PHYS(MAX_DMA32_PFN); |
| u64 start, limit, end; |
| int phys_blk; |
| |
| phys_blk = emu_find_memblk_by_nid(i, pi); |
| if (phys_blk < 0) { |
| node_clear(i, physnode_mask); |
| continue; |
| } |
| start = pi->blk[phys_blk].start; |
| limit = pi->blk[phys_blk].end; |
| |
| end = find_end_of_node(start, limit, size); |
| /* |
| * If there won't be at least FAKE_NODE_MIN_SIZE of |
| * non-reserved memory in ZONE_DMA32 for the next node, |
| * this one must extend to the boundary. |
| */ |
| if (end < dma32_end && dma32_end - end - |
| mem_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE) |
| end = dma32_end; |
| |
| /* |
| * If there won't be enough non-reserved memory for the |
| * next node, this one must extend to the end of the |
| * physical node. |
| */ |
| if (limit - end - mem_hole_size(end, limit) < size) |
| end = limit; |
| |
| ret = emu_setup_memblk(ei, pi, nid++ % MAX_NUMNODES, |
| phys_blk, |
| min(end, limit) - start); |
| if (ret < 0) |
| return ret; |
| } |
| } |
| return 0; |
| } |
| |
| /** |
| * numa_emulation - Emulate NUMA nodes |
| * @numa_meminfo: NUMA configuration to massage |
| * @numa_dist_cnt: The size of the physical NUMA distance table |
| * |
| * Emulate NUMA nodes according to the numa=fake kernel parameter. |
| * @numa_meminfo contains the physical memory configuration and is modified |
| * to reflect the emulated configuration on success. @numa_dist_cnt is |
| * used to determine the size of the physical distance table. |
| * |
| * On success, the following modifications are made. |
| * |
| * - @numa_meminfo is updated to reflect the emulated nodes. |
| * |
| * - __apicid_to_node[] is updated such that APIC IDs are mapped to the |
| * emulated nodes. |
| * |
| * - NUMA distance table is rebuilt to represent distances between emulated |
| * nodes. The distances are determined considering how emulated nodes |
| * are mapped to physical nodes and match the actual distances. |
| * |
| * - emu_nid_to_phys[] reflects how emulated nodes are mapped to physical |
| * nodes. This is used by numa_add_cpu() and numa_remove_cpu(). |
| * |
| * If emulation is not enabled or fails, emu_nid_to_phys[] is filled with |
| * identity mapping and no other modification is made. |
| */ |
| void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) |
| { |
| static struct numa_meminfo ei __initdata; |
| static struct numa_meminfo pi __initdata; |
| const u64 max_addr = PFN_PHYS(max_pfn); |
| u8 *phys_dist = NULL; |
| size_t phys_size = numa_dist_cnt * numa_dist_cnt * sizeof(phys_dist[0]); |
| int max_emu_nid, dfl_phys_nid; |
| int i, j, ret; |
| |
| if (!emu_cmdline) |
| goto no_emu; |
| |
| memset(&ei, 0, sizeof(ei)); |
| pi = *numa_meminfo; |
| |
| for (i = 0; i < MAX_NUMNODES; i++) |
| emu_nid_to_phys[i] = NUMA_NO_NODE; |
| |
| /* |
| * If the numa=fake command-line contains a 'M' or 'G', it represents |
| * the fixed node size. Otherwise, if it is just a single number N, |
| * split the system RAM into N fake nodes. |
| */ |
| if (strchr(emu_cmdline, 'M') || strchr(emu_cmdline, 'G')) { |
| u64 size; |
| |
| size = memparse(emu_cmdline, &emu_cmdline); |
| ret = split_nodes_size_interleave(&ei, &pi, 0, max_addr, size); |
| } else { |
| unsigned long n; |
| |
| n = simple_strtoul(emu_cmdline, NULL, 0); |
| ret = split_nodes_interleave(&ei, &pi, 0, max_addr, n); |
| } |
| |
| if (ret < 0) |
| goto no_emu; |
| |
| if (numa_cleanup_meminfo(&ei) < 0) { |
| pr_warning("NUMA: Warning: constructed meminfo invalid, disabling emulation\n"); |
| goto no_emu; |
| } |
| |
| /* copy the physical distance table */ |
| if (numa_dist_cnt) { |
| u64 phys; |
| |
| phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped), |
| phys_size, PAGE_SIZE); |
| if (!phys) { |
| pr_warning("NUMA: Warning: can't allocate copy of distance table, disabling emulation\n"); |
| goto no_emu; |
| } |
| memblock_reserve(phys, phys_size); |
| phys_dist = __va(phys); |
| |
| for (i = 0; i < numa_dist_cnt; i++) |
| for (j = 0; j < numa_dist_cnt; j++) |
| phys_dist[i * numa_dist_cnt + j] = |
| node_distance(i, j); |
| } |
| |
| /* |
| * Determine the max emulated nid and the default phys nid to use |
| * for unmapped nodes. |
| */ |
| max_emu_nid = 0; |
| dfl_phys_nid = NUMA_NO_NODE; |
| for (i = 0; i < ARRAY_SIZE(emu_nid_to_phys); i++) { |
| if (emu_nid_to_phys[i] != NUMA_NO_NODE) { |
| max_emu_nid = i; |
| if (dfl_phys_nid == NUMA_NO_NODE) |
| dfl_phys_nid = emu_nid_to_phys[i]; |
| } |
| } |
| if (dfl_phys_nid == NUMA_NO_NODE) { |
| pr_warning("NUMA: Warning: can't determine default physical node, disabling emulation\n"); |
| goto no_emu; |
| } |
| |
| /* commit */ |
| *numa_meminfo = ei; |
| |
| /* |
| * Transform __apicid_to_node table to use emulated nids by |
| * reverse-mapping phys_nid. The maps should always exist but fall |
| * back to zero just in case. |
| */ |
| for (i = 0; i < ARRAY_SIZE(__apicid_to_node); i++) { |
| if (__apicid_to_node[i] == NUMA_NO_NODE) |
| continue; |
| for (j = 0; j < ARRAY_SIZE(emu_nid_to_phys); j++) |
| if (__apicid_to_node[i] == emu_nid_to_phys[j]) |
| break; |
| __apicid_to_node[i] = j < ARRAY_SIZE(emu_nid_to_phys) ? j : 0; |
| } |
| |
| /* make sure all emulated nodes are mapped to a physical node */ |
| for (i = 0; i < ARRAY_SIZE(emu_nid_to_phys); i++) |
| if (emu_nid_to_phys[i] == NUMA_NO_NODE) |
| emu_nid_to_phys[i] = dfl_phys_nid; |
| |
| /* transform distance table */ |
| numa_reset_distance(); |
| for (i = 0; i < max_emu_nid + 1; i++) { |
| for (j = 0; j < max_emu_nid + 1; j++) { |
| int physi = emu_nid_to_phys[i]; |
| int physj = emu_nid_to_phys[j]; |
| int dist; |
| |
| if (physi >= numa_dist_cnt || physj >= numa_dist_cnt) |
| dist = physi == physj ? |
| LOCAL_DISTANCE : REMOTE_DISTANCE; |
| else |
| dist = phys_dist[physi * numa_dist_cnt + physj]; |
| |
| numa_set_distance(i, j, dist); |
| } |
| } |
| |
| /* free the copied physical distance table */ |
| if (phys_dist) |
| memblock_free(__pa(phys_dist), phys_size); |
| return; |
| |
| no_emu: |
| /* No emulation. Build identity emu_nid_to_phys[] for numa_add_cpu() */ |
| for (i = 0; i < ARRAY_SIZE(emu_nid_to_phys); i++) |
| emu_nid_to_phys[i] = i; |
| } |
| |
| #ifndef CONFIG_DEBUG_PER_CPU_MAPS |
| void __cpuinit numa_add_cpu(int cpu) |
| { |
| int physnid, nid; |
| |
| nid = early_cpu_to_node(cpu); |
| BUG_ON(nid == NUMA_NO_NODE || !node_online(nid)); |
| |
| physnid = emu_nid_to_phys[nid]; |
| |
| /* |
| * Map the cpu to each emulated node that is allocated on the physical |
| * node of the cpu's apic id. |
| */ |
| for_each_online_node(nid) |
| if (emu_nid_to_phys[nid] == physnid) |
| cpumask_set_cpu(cpu, node_to_cpumask_map[nid]); |
| } |
| |
| void __cpuinit numa_remove_cpu(int cpu) |
| { |
| int i; |
| |
| for_each_online_node(i) |
| cpumask_clear_cpu(cpu, node_to_cpumask_map[i]); |
| } |
| #else /* !CONFIG_DEBUG_PER_CPU_MAPS */ |
| static void __cpuinit numa_set_cpumask(int cpu, bool enable) |
| { |
| int nid, physnid; |
| |
| nid = early_cpu_to_node(cpu); |
| if (nid == NUMA_NO_NODE) { |
| /* early_cpu_to_node() already emits a warning and trace */ |
| return; |
| } |
| |
| physnid = emu_nid_to_phys[nid]; |
| |
| for_each_online_node(nid) { |
| if (emu_nid_to_phys[nid] != physnid) |
| continue; |
| |
| debug_cpumask_set_cpu(cpu, nid, enable); |
| } |
| } |
| |
| void __cpuinit numa_add_cpu(int cpu) |
| { |
| numa_set_cpumask(cpu, true); |
| } |
| |
| void __cpuinit numa_remove_cpu(int cpu) |
| { |
| numa_set_cpumask(cpu, false); |
| } |
| #endif /* !CONFIG_DEBUG_PER_CPU_MAPS */ |