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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v3 5/6] xen/arm: Dissociate logical and hardware CPU ID
Introduce cpu_logical_map to associate a logical CPU ID to an hardware CPU ID.
This map will be filled during Xen boot via the device tree. Each CPU node
contains a "reg" property which contains the hardware ID (ie MPIDR[0:23]).
Also move /cpus parsing later so we can use the dt_* API.
Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
---
Changes in v3:
- re-add the mask (lost v2) for the mpidr.
Changes in v2:
- for_each_child was renamed to dt_for_each_child
- move init_cpus_maps later to take advantage of boot_cpu_data
- move to initdata tmp_map
---
xen/arch/arm/setup.c | 112 ++++++++++++++++++++++++++++++++++++++-
xen/arch/arm/smpboot.c | 4 ++
xen/common/device_tree.c | 48 -----------------
xen/include/asm-arm/processor.h | 4 ++
4 files changed, 119 insertions(+), 49 deletions(-)
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index aa87fb1..7dd6c9f 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -498,6 +498,114 @@ void __init setup_cache(void)
cacheline_bytes = 1U << (4 + (ccsid & 0x7));
}
+/* Parse the device tree and build the logical map array containing
+ * MPIDR values related to logical cpus
+ * Code base on Linux arch/arm/kernel/devtree.c
+ */
+static void __init init_cpus_maps(void)
+{
+ register_t mpidr;
+ struct dt_device_node *cpus = dt_find_node_by_path("/cpus");
+ struct dt_device_node *cpu;
+ unsigned int i, j;
+ unsigned int cpuidx = 1;
+ static u32 tmp_map[NR_CPUS] __initdata =
+ {
+ [0 ... NR_CPUS - 1] = MPIDR_INVALID
+ };
+ bool_t bootcpu_valid = 0;
+
+ mpidr = boot_cpu_data.mpidr.bits & MPIDR_HWID_MASK;
+
+ if ( !cpus )
+ {
+ printk(XENLOG_WARNING "WARNING: Can't find /cpus in the device tree.\n"
+ "Using only 1 CPU\n");
+ return;
+ }
+
+ dt_for_each_child_node( cpus, cpu )
+ {
+ u32 hwid;
+
+ if ( !dt_device_type_is_equal(cpu, "cpu") )
+ continue;
+
+ if ( !dt_property_read_u32(cpu, "reg", &hwid) )
+ {
+ printk(XENLOG_WARNING "cpu node `%s`: missing reg property\n",
+ dt_node_full_name(cpu));
+ continue;
+ }
+
+ /*
+ * 8 MSBs must be set to 0 in the DT since the reg property
+ * defines the MPIDR[23:0]
+ */
+ if ( hwid & ~MPIDR_HWID_MASK )
+ {
+ printk(XENLOG_WARNING "cpu node `%s`: invalid hwid value (0x%x)\n",
+ dt_node_full_name(cpu), hwid);
+ continue;
+ }
+
+ /*
+ * Duplicate MPIDRs are a recipe for disaster. Scan all initialized
+ * entries and check for duplicates. If any found just skip the node.
+ * temp values values are initialized to MPIDR_INVALID to avoid
+ * matching valid MPIDR[23:0] values.
+ */
+ for ( j = 0; j < cpuidx; j++ )
+ {
+ if ( tmp_map[j] == hwid )
+ {
+ printk(XENLOG_WARNING "cpu node `%s`: duplicate /cpu reg
properties in the DT\n",
+ dt_node_full_name(cpu));
+ continue;
+ }
+ }
+
+ /*
+ * 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 and so that the logical map build from DT is
+ * validated and can be used to set the map.
+ */
+ if ( hwid == mpidr )
+ {
+ i = 0;
+ bootcpu_valid = 1;
+ }
+ else
+ i = cpuidx++;
+
+ if ( cpuidx > NR_CPUS )
+ {
+ printk(XENLOG_WARNING "DT /cpu %u node greater than max cores %u,
capping them\n",
+ cpuidx, NR_CPUS);
+ cpuidx = NR_CPUS;
+ break;
+ }
+
+ tmp_map[i] = hwid;
+ }
+
+ if ( !bootcpu_valid )
+ {
+ printk(XENLOG_WARNING "DT missing boot CPU MPIDR[23:0]\n"
+ "Using only 1 CPU\n");
+ return;
+ }
+
+ for ( i = 0; i < cpuidx; i++ )
+ {
+ cpumask_set_cpu(i, &cpu_possible_map);
+ cpu_logical_map(i) = tmp_map[i];
+ }
+}
+
/* C entry point for boot CPU */
void __init start_xen(unsigned long boot_phys_offset,
unsigned long fdt_paddr,
@@ -517,7 +625,6 @@ void __init start_xen(unsigned long boot_phys_offset,
+ (fdt_paddr & ((1 << SECOND_SHIFT) - 1));
fdt_size = device_tree_early_init(device_tree_flattened);
- cpus = smp_get_max_cpus();
cmdline_parse(device_tree_bootargs(device_tree_flattened));
setup_pagetables(boot_phys_offset, get_xen_paddr());
@@ -534,6 +641,9 @@ void __init start_xen(unsigned long boot_phys_offset,
processor_id();
+ init_cpus_maps();
+ cpus = smp_get_max_cpus();
+
platform_init();
init_xen_time();
diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
index b6aea63..c0d25de 100644
--- a/xen/arch/arm/smpboot.c
+++ b/xen/arch/arm/smpboot.c
@@ -39,6 +39,9 @@ EXPORT_SYMBOL(cpu_possible_map);
struct cpuinfo_arm cpu_data[NR_CPUS];
+/* CPU logical map: map xen cpuid to an MPIDR */
+u32 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
+
/* Fake one node for now. See also include/asm-arm/numa.h */
nodemask_t __read_mostly node_online_map = { { [0] = 1UL } };
@@ -82,6 +85,7 @@ smp_clear_cpu_maps (void)
cpumask_clear(&cpu_online_map);
cpumask_set_cpu(0, &cpu_online_map);
cpumask_set_cpu(0, &cpu_possible_map);
+ cpu_logical_map(0) = READ_SYSREG(MPIDR_EL1) & MPIDR_HWID_MASK;
}
int __init
diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
index 0ece249..9a16650 100644
--- a/xen/common/device_tree.c
+++ b/xen/common/device_tree.c
@@ -118,18 +118,6 @@ static bool_t __init device_tree_node_matches(const void
*fdt, int node,
&& (name[match_len] == '@' || name[match_len] == '\0');
}
-static bool_t __init device_tree_type_matches(const void *fdt, int node,
- const char *match)
-{
- const void *prop;
-
- prop = fdt_getprop(fdt, node, "device_type", NULL);
- if ( prop == NULL )
- return 0;
-
- return !dt_node_cmp(prop, match);
-}
-
static bool_t __init device_tree_node_compatible(const void *fdt, int node,
const char *match)
{
@@ -348,40 +336,6 @@ static void __init process_memory_node(const void *fdt,
int node,
}
}
-static void __init process_cpu_node(const void *fdt, int node,
- const char *name,
- u32 address_cells, u32 size_cells)
-{
- const struct fdt_property *prop;
- u32 cpuid;
- int len;
-
- prop = fdt_get_property(fdt, node, "reg", &len);
- if ( !prop )
- {
- early_printk("fdt: node `%s': missing `reg' property\n", name);
- return;
- }
-
- if ( len < sizeof (cpuid) )
- {
- dt_printk("fdt: node `%s': `reg` property length is too short\n",
- name);
- return;
- }
-
- cpuid = dt_read_number((const __be32 *)prop->data, 1);
-
- /* TODO: handle non-contiguous CPU ID */
- if ( cpuid >= NR_CPUS )
- {
- dt_printk("fdt: node `%s': reg(0x%x) >= NR_CPUS(%d)\n",
- name, cpuid, NR_CPUS);
- return;
- }
- cpumask_set_cpu(cpuid, &cpu_possible_map);
-}
-
static void __init process_multiboot_node(const void *fdt, int node,
const char *name,
u32 address_cells, u32 size_cells)
@@ -435,8 +389,6 @@ static int __init early_scan_node(const void *fdt,
{
if ( device_tree_node_matches(fdt, node, "memory") )
process_memory_node(fdt, node, name, address_cells, size_cells);
- else if ( device_tree_type_matches(fdt, node, "cpu") )
- process_cpu_node(fdt, node, name, address_cells, size_cells);
else if ( device_tree_node_compatible(fdt, node, "xen,multiboot-module" ) )
process_multiboot_node(fdt, node, name, address_cells, size_cells);
diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
index 808567e..0646422 100644
--- a/xen/include/asm-arm/processor.h
+++ b/xen/include/asm-arm/processor.h
@@ -13,6 +13,7 @@
#define MPIDR_AFF0_SHIFT (0)
#define MPIDR_AFF0_MASK (0xff << MPIDR_AFF0_SHIFT)
#define MPIDR_HWID_MASK 0xffffff
+#define MPIDR_INVALID (~MPIDR_HWID_MASK)
/* TTBCR Translation Table Base Control Register */
#define TTBCR_EAE 0x80000000
@@ -230,6 +231,9 @@ extern void identify_cpu(struct cpuinfo_arm *);
extern struct cpuinfo_arm cpu_data[];
#define current_cpu_data cpu_data[smp_processor_id()]
+extern u32 __cpu_logical_map[];
+#define cpu_logical_map(cpu) __cpu_logical_map[cpu]
+
union hsr {
uint32_t bits;
struct {
--
1.7.10.4
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