[PATCH v3 18/62] arm/acpi: Parse MADT to map logical cpu to MPIDR and get cpu_possible_map

[shannon.zhao at linaro.org]

From: Parth Dixit <parth.dixit at linaro.org>

MADT contains the information for MPIDR which is essential for SMP
initialization, parse the GIC cpu interface structures to get the MPIDR
value and map it to cpu_logical_map(), and add enabled cpu with valid
MPIDR into cpu_possible_map.

Signed-off-by: Hanjun Guo <hanjun.guo at linaro.org>
Signed-off-by: Tomasz Nowicki <tomasz.nowicki at linaro.org>
Signed-off-by: Naresh Bhat <naresh.bhat at linaro.org>
Signed-off-by: Parth Dixit <parth.dixit at linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao at linaro.org>
---
 xen/arch/arm/acpi/boot.c   | 121 +++++++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-arm/acpi.h |   2 +
 xen/include/xen/acpi.h     |   4 ++
 3 files changed, 127 insertions(+)

diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c
index 0fabe7d..913d2a5 100644
--- a/xen/arch/arm/acpi/boot.c
+++ b/xen/arch/arm/acpi/boot.c
@@ -32,6 +32,127 @@
 #include <xen/mm.h>
 
 #include <asm/acpi.h>
+#include <asm/smp.h>
+
+/* Processors with enabled flag and sane MPIDR */
+static int enabled_cpus;
+
+/* Boot CPU is valid or not in MADT */
+static bool_t __initdata bootcpu_valid;
+
+/* total number of cpus in this system */
+static unsigned int __initdata total_cpus = 0;
+
+/*
+ * acpi_map_gic_cpu_interface - generates a logical cpu number
+ * and map to MPIDR represented by GICC structure
+ */
+static void __init
+acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
+{
+    int i;
+    u64 mpidr = processor->arm_mpidr & MPIDR_HWID_MASK;
+    bool enabled = !!(processor->flags & ACPI_MADT_ENABLED);
+
+    if (mpidr == MPIDR_INVALID) {
+        printk("Skip MADT cpu entry with invalid MPIDR\n");
+        return;
+    }
+
+    total_cpus++;
+    if (!enabled)
+        return;
+
+    if (enabled_cpus >=  NR_CPUS) {
+        printk("NR_CPUS limit of %d reached, Processor %d/0x%"PRIx64" ignored.\n",
+               NR_CPUS, total_cpus, mpidr);
+        return;
+    }
+
+    /* Check if GICC structure of boot CPU is available in the MADT */
+    if (cpu_logical_map(0) == mpidr) {
+        if (bootcpu_valid) {
+            printk("Firmware bug, duplicate CPU MPIDR: 0x%"PRIx64" in MADT\n",
+                   mpidr);
+            return;
+        }
+
+        bootcpu_valid = true;
+    }
+
+    /*
+     * Duplicate MPIDRs are a recipe for disaster. Scan
+     * all initialized entries and check for
+     * duplicates. If any is found just ignore the CPU.
+     */
+    for (i = 1; i < enabled_cpus; i++) {
+        if (cpu_logical_map(i) == mpidr) {
+            printk("Firmware bug, duplicate CPU MPIDR: 0x%"PRIx64" in MADT\n",
+                   mpidr);
+            return;
+        }
+    }
+
+    if (!acpi_psci_present())
+        return;
+
+    /* CPU 0 was already initialized */
+    if (enabled_cpus) {
+        if (arch_cpu_init(enabled_cpus, NULL) < 0)
+            return;
+
+        /* map the logical cpu id to cpu MPIDR */
+        cpu_logical_map(enabled_cpus) = mpidr;
+    }
+
+    enabled_cpus++;
+}
+
+static int __init
+acpi_parse_gic_cpu_interface(struct acpi_subtable_header *header,
+                             const unsigned long end)
+{
+    struct acpi_madt_generic_interrupt *processor;
+
+    processor = (struct acpi_madt_generic_interrupt *)header;
+
+    if (BAD_MADT_ENTRY(processor, end))
+        return -EINVAL;
+
+    acpi_table_print_madt_entry(header);
+    acpi_map_gic_cpu_interface(processor);
+    return 0;
+}
+
+/* Parse GIC cpu interface entries in MADT for SMP init */
+void __init acpi_smp_init_cpus(void)
+{
+    int count, i;
+
+    /*
+     * do a partial walk of MADT to determine how many CPUs
+     * we have including disabled CPUs, and get information
+     * we need for SMP init
+     */
+    count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
+                    acpi_parse_gic_cpu_interface, 0);
+
+    if (count <= 0) {
+        printk("Error parsing GIC CPU interface entry\n");
+        return;
+    }
+
+    if (!bootcpu_valid) {
+        printk("MADT missing boot CPU MPIDR, not enabling secondaries\n");
+        return;
+    }
+
+    for (i = 0; i < enabled_cpus; i++)
+        cpumask_set_cpu(i, &cpu_possible_map);
+
+    /* Make boot-up look pretty */
+    printk("%d CPUs enabled, %d CPUs total\n", enabled_cpus, total_cpus);
+}
 
 static int __init acpi_parse_fadt(struct acpi_table_header *table)
 {
diff --git a/xen/include/asm-arm/acpi.h b/xen/include/asm-arm/acpi.h
index 65f80b1..1efa29d 100644
--- a/xen/include/asm-arm/acpi.h
+++ b/xen/include/asm-arm/acpi.h
@@ -33,9 +33,11 @@ extern bool_t acpi_disabled;
 #ifdef CONFIG_ACPI
 bool_t __init acpi_psci_present(void);
 bool_t __init acpi_psci_hvc_present(void);
+void __init acpi_smp_init_cpus(void);
 #else
 static inline bool_t acpi_psci_present(void) { return false; }
 static inline bool_t acpi_psci_hvc_present(void) {return false; }
+static inline void acpi_smp_init_cpus(void) { }
 #endif /* CONFIG_ACPI */
 
 /* Basic configuration for ACPI */
diff --git a/xen/include/xen/acpi.h b/xen/include/xen/acpi.h
index 48d7810..723ece8 100644
--- a/xen/include/xen/acpi.h
+++ b/xen/include/xen/acpi.h
@@ -39,6 +39,10 @@
 #define ACPI_MADT_GET_POLARITY(inti)	ACPI_MADT_GET_(POLARITY, inti)
 #define ACPI_MADT_GET_TRIGGER(inti)	ACPI_MADT_GET_(TRIGGER, inti)
 
+#define BAD_MADT_ENTRY(entry, end) (                                        \
+                (!entry) || (unsigned long)entry + sizeof(*entry) > end ||  \
+                ((struct acpi_subtable_header *)entry)->length < sizeof(*entry))
+
 #ifdef CONFIG_ACPI_BOOT
 
 enum acpi_interrupt_id {
-- 
2.1.0