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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-12 11:30:02 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-12 11:30:02 -0800
commitb1286f4e9ac14c8973140b338b4d3c5691264d3b (patch)
tree5a67788bb2276cd67230d24b5a6994ddafb10707 /arch/arm/kernel/devtree.c
parent6facac1ab68fbf9cbad31a9d521f3a0d6aa9470e (diff)
parent0fa5d3996dbda1ee9653c43d39b7ef159fb57ee7 (diff)
downloadtalos-op-linux-b1286f4e9ac14c8973140b338b4d3c5691264d3b.tar.gz
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Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM updates from Russell King: "Here's the updates for ARM for this merge window, which cover quite a variety of areas. There's a bunch of patch series from Will tackling various bugs like the PROT_NONE handling, ASID allocation, cluster boot protocol and ASID TLB tagging updates. We move to a build-time sorted exception table rather than doing the sorting at run-time, add support for the secure computing filter, and some updates to the perf code. We also have sorted out the placement of some headers, fixed some build warnings, fixed some hotplug problems with the per-cpu TWD code." * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (73 commits) ARM: 7594/1: Add .smp entry for REALVIEW_EB ARM: 7599/1: head: Remove boot-time HYP mode check for v5 and below ARM: 7598/1: net: bpf_jit_32: fix sp-relative load/stores offsets. ARM: 7595/1: syscall: rework ordering in syscall_trace_exit ARM: 7596/1: mmci: replace readsl/writesl with ioread32_rep/iowrite32_rep ARM: 7597/1: net: bpf_jit_32: fix kzalloc gfp/size mismatch. ARM: 7593/1: nommu: do not enable DCACHE_WORD_ACCESS when !CONFIG_MMU ARM: 7592/1: nommu: prevent generation of kernel unaligned memory accesses ARM: 7591/1: nommu: Enable the strict alignment (CR_A) bit only if ARCH < v6 ARM: 7590/1: /proc/interrupts: limit the display of IPIs to online CPUs only ARM: 7587/1: implement optimized percpu variable access ARM: 7589/1: integrator: pass the lm resource to amba ARM: 7588/1: amba: create a resource parent registrator ARM: 7582/2: rename kvm_seq to vmalloc_seq so to avoid confusion with KVM ARM: 7585/1: kernel: fix nr_cpu_ids check in DT logical map init ARM: 7584/1: perf: fix link error when CONFIG_HW_PERF_EVENTS is not selected ARM: gic: use a private mapping for CPU target interfaces ARM: kernel: add logical mappings look-up ARM: kernel: add cpu logical map DT init in setup_arch ARM: kernel: add device tree init map function ...
Diffstat (limited to 'arch/arm/kernel/devtree.c')
-rw-r--r--arch/arm/kernel/devtree.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index bee7f9d47f02..70f1bdeb241b 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -19,8 +19,10 @@
#include <linux/of_irq.h>
#include <linux/of_platform.h>
+#include <asm/cputype.h>
#include <asm/setup.h>
#include <asm/page.h>
+#include <asm/smp_plat.h>
#include <asm/mach/arch.h>
#include <asm/mach-types.h>
@@ -61,6 +63,108 @@ void __init arm_dt_memblock_reserve(void)
}
}
+/*
+ * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree
+ * and builds the cpu logical map array containing MPIDR values related to
+ * logical cpus
+ *
+ * Updates the cpu possible mask with the number of parsed cpu nodes
+ */
+void __init arm_dt_init_cpu_maps(void)
+{
+ /*
+ * Temp logical map is initialized with UINT_MAX values that are
+ * considered invalid logical map entries since the logical map must
+ * contain a list of MPIDR[23:0] values where MPIDR[31:24] must
+ * read as 0.
+ */
+ struct device_node *cpu, *cpus;
+ u32 i, j, cpuidx = 1;
+ u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
+
+ u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = UINT_MAX };
+ bool bootcpu_valid = false;
+ cpus = of_find_node_by_path("/cpus");
+
+ if (!cpus)
+ return;
+
+ for_each_child_of_node(cpus, cpu) {
+ u32 hwid;
+
+ pr_debug(" * %s...\n", cpu->full_name);
+ /*
+ * A device tree containing CPU nodes with missing "reg"
+ * properties is considered invalid to build the
+ * cpu_logical_map.
+ */
+ if (of_property_read_u32(cpu, "reg", &hwid)) {
+ pr_debug(" * %s missing reg property\n",
+ cpu->full_name);
+ return;
+ }
+
+ /*
+ * 8 MSBs must be set to 0 in the DT since the reg property
+ * defines the MPIDR[23:0].
+ */
+ if (hwid & ~MPIDR_HWID_BITMASK)
+ return;
+
+ /*
+ * Duplicate MPIDRs are a recipe for disaster.
+ * Scan all initialized entries and check for
+ * duplicates. If any is found just bail out.
+ * temp values were initialized to UINT_MAX
+ * to avoid matching valid MPIDR[23:0] values.
+ */
+ for (j = 0; j < cpuidx; j++)
+ if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg "
+ "properties in the DT\n"))
+ return;
+
+ /*
+ * Build a stashed array of MPIDR values. Numbering scheme
+ * requires that if detected the boot CPU must be assigned
+ * logical id 0. Other CPUs get sequential indexes starting
+ * from 1. If a CPU node with a reg property matching the
+ * boot CPU MPIDR is detected, this is recorded so that the
+ * logical map built from DT is validated and can be used
+ * to override the map created in smp_setup_processor_id().
+ */
+ if (hwid == mpidr) {
+ i = 0;
+ bootcpu_valid = true;
+ } else {
+ i = cpuidx++;
+ }
+
+ if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
+ "max cores %u, capping them\n",
+ cpuidx, nr_cpu_ids)) {
+ cpuidx = nr_cpu_ids;
+ break;
+ }
+
+ tmp_map[i] = hwid;
+ }
+
+ if (WARN(!bootcpu_valid, "DT missing boot CPU MPIDR[23:0], "
+ "fall back to default cpu_logical_map\n"))
+ return;
+
+ /*
+ * Since the boot CPU node contains proper data, and all nodes have
+ * a reg property, the DT CPU list can be considered valid and the
+ * logical map created in smp_setup_processor_id() can be overridden
+ */
+ for (i = 0; i < cpuidx; i++) {
+ set_cpu_possible(i, true);
+ cpu_logical_map(i) = tmp_map[i];
+ pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i));
+ }
+}
+
/**
* setup_machine_fdt - Machine setup when an dtb was passed to the kernel
* @dt_phys: physical address of dt blob
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