Initial import

1 files changed, 287 insertions, 0 deletions

diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
new file mode 100644
index 000000000..e4fcb87ba
--- /dev/null
+++ b/arch/x86/kernel/setup_percpu.c
@@ -0,0 +1,287 @@
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/percpu.h>
+#include <linux/kexec.h>
+#include <linux/crash_dump.h>
+#include <linux/smp.h>
+#include <linux/topology.h>
+#include <linux/pfn.h>
+#include <asm/sections.h>
+#include <asm/processor.h>
+#include <asm/setup.h>
+#include <asm/mpspec.h>
+#include <asm/apicdef.h>
+#include <asm/highmem.h>
+#include <asm/proto.h>
+#include <asm/cpumask.h>
+#include <asm/cpu.h>
+#include <asm/stackprotector.h>
+
+DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number);
+EXPORT_PER_CPU_SYMBOL(cpu_number);
+
+#ifdef CONFIG_X86_64
+#define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
+#else
+#define BOOT_PERCPU_OFFSET 0
+#endif
+
+DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
+EXPORT_PER_CPU_SYMBOL(this_cpu_off);
+
+unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
+	[0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
+};
+EXPORT_SYMBOL(__per_cpu_offset);
+
+/*
+ * On x86_64 symbols referenced from code should be reachable using
+ * 32bit relocations.  Reserve space for static percpu variables in
+ * modules so that they are always served from the first chunk which
+ * is located at the percpu segment base.  On x86_32, anything can
+ * address anywhere.  No need to reserve space in the first chunk.
+ */
+#ifdef CONFIG_X86_64
+#define PERCPU_FIRST_CHUNK_RESERVE	PERCPU_MODULE_RESERVE
+#else
+#define PERCPU_FIRST_CHUNK_RESERVE	0
+#endif
+
+#ifdef CONFIG_X86_32
+/**
+ * pcpu_need_numa - determine percpu allocation needs to consider NUMA
+ *
+ * If NUMA is not configured or there is only one NUMA node available,
+ * there is no reason to consider NUMA.  This function determines
+ * whether percpu allocation should consider NUMA or not.
+ *
+ * RETURNS:
+ * true if NUMA should be considered; otherwise, false.
+ */
+static bool __init pcpu_need_numa(void)
+{
+#ifdef CONFIG_NEED_MULTIPLE_NODES
+	pg_data_t *last = NULL;
+	unsigned int cpu;
+
+	for_each_possible_cpu(cpu) {
+		int node = early_cpu_to_node(cpu);
+
+		if (node_online(node) && NODE_DATA(node) &&
+		    last && last != NODE_DATA(node))
+			return true;
+
+		last = NODE_DATA(node);
+	}
+#endif
+	return false;
+}
+#endif
+
+/**
+ * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu
+ * @cpu: cpu to allocate for
+ * @size: size allocation in bytes
+ * @align: alignment
+ *
+ * Allocate @size bytes aligned at @align for cpu @cpu.  This wrapper
+ * does the right thing for NUMA regardless of the current
+ * configuration.
+ *
+ * RETURNS:
+ * Pointer to the allocated area on success, NULL on failure.
+ */
+static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size,
+					unsigned long align)
+{
+	const unsigned long goal = __pa(MAX_DMA_ADDRESS);
+#ifdef CONFIG_NEED_MULTIPLE_NODES
+	int node = early_cpu_to_node(cpu);
+	void *ptr;
+
+	if (!node_online(node) || !NODE_DATA(node)) {
+		ptr = __alloc_bootmem_nopanic(size, align, goal);
+		pr_info("cpu %d has no node %d or node-local memory\n",
+			cpu, node);
+		pr_debug("per cpu data for cpu%d %lu bytes at %016lx\n",
+			 cpu, size, __pa(ptr));
+	} else {
+		ptr = __alloc_bootmem_node_nopanic(NODE_DATA(node),
+						   size, align, goal);
+		pr_debug("per cpu data for cpu%d %lu bytes on node%d at %016lx\n",
+			 cpu, size, node, __pa(ptr));
+	}
+	return ptr;
+#else
+	return __alloc_bootmem_nopanic(size, align, goal);
+#endif
+}
+
+/*
+ * Helpers for first chunk memory allocation
+ */
+static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
+{
+	return pcpu_alloc_bootmem(cpu, size, align);
+}
+
+static void __init pcpu_fc_free(void *ptr, size_t size)
+{
+	free_bootmem(__pa(ptr), size);
+}
+
+static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
+{
+#ifdef CONFIG_NEED_MULTIPLE_NODES
+	if (early_cpu_to_node(from) == early_cpu_to_node(to))
+		return LOCAL_DISTANCE;
+	else
+		return REMOTE_DISTANCE;
+#else
+	return LOCAL_DISTANCE;
+#endif
+}
+
+static void __init pcpup_populate_pte(unsigned long addr)
+{
+	populate_extra_pte(addr);
+}
+
+static inline void setup_percpu_segment(int cpu)
+{
+#ifdef CONFIG_X86_32
+	struct desc_struct gdt;
+
+	pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF,
+			0x2 | DESCTYPE_S, 0x8);
+	gdt.s = 1;
+	write_gdt_entry(get_cpu_gdt_table(cpu),
+			GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
+#endif
+}
+
+void __init setup_per_cpu_areas(void)
+{
+	unsigned int cpu;
+	unsigned long delta;
+	int rc;
+
+	pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
+		NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
+
+	/*
+	 * Allocate percpu area.  Embedding allocator is our favorite;
+	 * however, on NUMA configurations, it can result in very
+	 * sparse unit mapping and vmalloc area isn't spacious enough
+	 * on 32bit.  Use page in that case.
+	 */
+#ifdef CONFIG_X86_32
+	if (pcpu_chosen_fc == PCPU_FC_AUTO && pcpu_need_numa())
+		pcpu_chosen_fc = PCPU_FC_PAGE;
+#endif
+	rc = -EINVAL;
+	if (pcpu_chosen_fc != PCPU_FC_PAGE) {
+		const size_t dyn_size = PERCPU_MODULE_RESERVE +
+			PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE;
+		size_t atom_size;
+
+		/*
+		 * On 64bit, use PMD_SIZE for atom_size so that embedded
+		 * percpu areas are aligned to PMD.  This, in the future,
+		 * can also allow using PMD mappings in vmalloc area.  Use
+		 * PAGE_SIZE on 32bit as vmalloc space is highly contended
+		 * and large vmalloc area allocs can easily fail.
+		 */
+#ifdef CONFIG_X86_64
+		atom_size = PMD_SIZE;
+#else
+		atom_size = PAGE_SIZE;
+#endif
+		rc = pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
+					    dyn_size, atom_size,
+					    pcpu_cpu_distance,
+					    pcpu_fc_alloc, pcpu_fc_free);
+		if (rc < 0)
+			pr_warning("%s allocator failed (%d), falling back to page size\n",
+				   pcpu_fc_names[pcpu_chosen_fc], rc);
+	}
+	if (rc < 0)
+		rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
+					   pcpu_fc_alloc, pcpu_fc_free,
+					   pcpup_populate_pte);
+	if (rc < 0)
+		panic("cannot initialize percpu area (err=%d)", rc);
+
+	/* alrighty, percpu areas up and running */
+	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
+	for_each_possible_cpu(cpu) {
+		per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu];
+		per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
+		per_cpu(cpu_number, cpu) = cpu;
+		setup_percpu_segment(cpu);
+		setup_stack_canary_segment(cpu);
+		/*
+		 * Copy data used in early init routines from the
+		 * initial arrays to the per cpu data areas.  These
+		 * arrays then become expendable and the *_early_ptr's
+		 * are zeroed indicating that the static arrays are
+		 * gone.
+		 */
+#ifdef CONFIG_X86_LOCAL_APIC
+		per_cpu(x86_cpu_to_apicid, cpu) =
+			early_per_cpu_map(x86_cpu_to_apicid, cpu);
+		per_cpu(x86_bios_cpu_apicid, cpu) =
+			early_per_cpu_map(x86_bios_cpu_apicid, cpu);
+#endif
+#ifdef CONFIG_X86_32
+		per_cpu(x86_cpu_to_logical_apicid, cpu) =
+			early_per_cpu_map(x86_cpu_to_logical_apicid, cpu);
+#endif
+#ifdef CONFIG_X86_64
+		per_cpu(irq_stack_ptr, cpu) =
+			per_cpu(irq_stack_union.irq_stack, cpu) +
+			IRQ_STACK_SIZE - 64;
+#endif
+#ifdef CONFIG_NUMA
+		per_cpu(x86_cpu_to_node_map, cpu) =
+			early_per_cpu_map(x86_cpu_to_node_map, cpu);
+		/*
+		 * Ensure that the boot cpu numa_node is correct when the boot
+		 * cpu is on a node that doesn't have memory installed.
+		 * Also cpu_up() will call cpu_to_node() for APs when
+		 * MEMORY_HOTPLUG is defined, before per_cpu(numa_node) is set
+		 * up later with c_init aka intel_init/amd_init.
+		 * So set them all (boot cpu and all APs).
+		 */
+		set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
+#endif
+		/*
+		 * Up to this point, the boot CPU has been using .init.data
+		 * area.  Reload any changed state for the boot CPU.
+		 */
+		if (!cpu)
+			switch_to_new_gdt(cpu);
+	}
+
+	/* indicate the early static arrays will soon be gone */
+#ifdef CONFIG_X86_LOCAL_APIC
+	early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
+	early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
+#endif
+#ifdef CONFIG_X86_32
+	early_per_cpu_ptr(x86_cpu_to_logical_apicid) = NULL;
+#endif
+#ifdef CONFIG_NUMA
+	early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
+#endif
+
+	/* Setup node to cpumask map */
+	setup_node_to_cpumask_map();
+
+	/* Setup cpu initialized, callin, callout masks */
+	setup_cpu_local_masks();
+}