[PATCH 08/10] ARM: vexpress: Simplify SMP operations for DT-powered system
Pawel Moll
pawel.moll at arm.com
Mon Apr 28 10:57:55 PDT 2014
As all cores must be properly described in the Device Tree,
there is no point in getting their numbers from SCU on
A5/A9 platforms. This significantly simplifies the code,
removing the need for flat-tree scanning and early static
mapping.
Signed-off-by: Pawel Moll <pawel.moll at arm.com>
---
arch/arm/mach-vexpress/core.h | 3 +-
arch/arm/mach-vexpress/platsmp.c | 158 ++++++++++-----------------------------
arch/arm/mach-vexpress/v2m.c | 6 +-
3 files changed, 41 insertions(+), 126 deletions(-)
diff --git a/arch/arm/mach-vexpress/core.h b/arch/arm/mach-vexpress/core.h
index bde4374..152fad9 100644
--- a/arch/arm/mach-vexpress/core.h
+++ b/arch/arm/mach-vexpress/core.h
@@ -4,10 +4,9 @@
/* Tile's peripherals static mappings should start here */
#define V2T_PERIPH 0xf8200000
-void vexpress_dt_smp_map_io(void);
-
bool vexpress_smp_init_ops(void);
extern struct smp_operations vexpress_smp_ops;
+extern struct smp_operations vexpress_smp_dt_ops;
extern void vexpress_cpu_die(unsigned int cpu);
diff --git a/arch/arm/mach-vexpress/platsmp.c b/arch/arm/mach-vexpress/platsmp.c
index 12a8751..a1f3804 100644
--- a/arch/arm/mach-vexpress/platsmp.c
+++ b/arch/arm/mach-vexpress/platsmp.c
@@ -12,8 +12,7 @@
#include <linux/errno.h>
#include <linux/smp.h>
#include <linux/io.h>
-#include <linux/of.h>
-#include <linux/of_fdt.h>
+#include <linux/of_address.h>
#include <linux/vexpress.h>
#include <asm/mcpm.h>
@@ -26,125 +25,13 @@
#include "core.h"
-#if defined(CONFIG_OF)
-
-static enum {
- GENERIC_SCU,
- CORTEX_A9_SCU,
-} vexpress_dt_scu __initdata = GENERIC_SCU;
-
-static struct map_desc vexpress_dt_cortex_a9_scu_map __initdata = {
- .virtual = V2T_PERIPH,
- /* .pfn set in vexpress_dt_init_cortex_a9_scu() */
- .length = SZ_128,
- .type = MT_DEVICE,
-};
-
-static void *vexpress_dt_cortex_a9_scu_base __initdata;
-
-const static char *vexpress_dt_cortex_a9_match[] __initconst = {
- "arm,cortex-a5-scu",
- "arm,cortex-a9-scu",
- NULL
-};
-
-static int __init vexpress_dt_find_scu(unsigned long node,
- const char *uname, int depth, void *data)
-{
- if (of_flat_dt_match(node, vexpress_dt_cortex_a9_match)) {
- phys_addr_t phys_addr;
- __be32 *reg = of_get_flat_dt_prop(node, "reg", NULL);
-
- if (WARN_ON(!reg))
- return -EINVAL;
-
- phys_addr = be32_to_cpup(reg);
- vexpress_dt_scu = CORTEX_A9_SCU;
-
- vexpress_dt_cortex_a9_scu_map.pfn = __phys_to_pfn(phys_addr);
- iotable_init(&vexpress_dt_cortex_a9_scu_map, 1);
- vexpress_dt_cortex_a9_scu_base = ioremap(phys_addr, SZ_256);
- if (WARN_ON(!vexpress_dt_cortex_a9_scu_base))
- return -EFAULT;
- }
-
- return 0;
-}
-
-void __init vexpress_dt_smp_map_io(void)
-{
- if (initial_boot_params)
- WARN_ON(of_scan_flat_dt(vexpress_dt_find_scu, NULL));
-}
-
-static void __init vexpress_dt_smp_init_cpus(void)
-{
- int ncores = 0, i;
-
- switch (vexpress_dt_scu) {
- case GENERIC_SCU:
- return;
- case CORTEX_A9_SCU:
- ncores = scu_get_core_count(vexpress_dt_cortex_a9_scu_base);
- break;
- default:
- WARN_ON(1);
- break;
- }
-
- if (ncores < 2)
- return;
-
- if (ncores > nr_cpu_ids) {
- pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
- ncores, nr_cpu_ids);
- ncores = nr_cpu_ids;
- }
-
- for (i = 0; i < ncores; ++i)
- set_cpu_possible(i, true);
-}
-
-static void __init vexpress_dt_smp_prepare_cpus(unsigned int max_cpus)
-{
-
- switch (vexpress_dt_scu) {
- case GENERIC_SCU:
- break;
- case CORTEX_A9_SCU:
- scu_enable(vexpress_dt_cortex_a9_scu_base);
- break;
- default:
- WARN_ON(1);
- break;
- }
-}
-
-#else
-
-static void __init vexpress_dt_smp_init_cpus(void)
-{
- WARN_ON(1);
-}
-
-void __init vexpress_dt_smp_prepare_cpus(unsigned int max_cpus)
-{
- WARN_ON(1);
-}
-
-#endif
-
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init vexpress_smp_init_cpus(void)
{
- if (ct_desc)
- ct_desc->init_cpu_map();
- else
- vexpress_dt_smp_init_cpus();
-
+ ct_desc->init_cpu_map();
}
static void __init vexpress_smp_prepare_cpus(unsigned int max_cpus)
@@ -153,10 +40,7 @@ static void __init vexpress_smp_prepare_cpus(unsigned int max_cpus)
* Initialise the present map, which describes the set of CPUs
* actually populated at the present time.
*/
- if (ct_desc)
- ct_desc->smp_enable(max_cpus);
- else
- vexpress_dt_smp_prepare_cpus(max_cpus);
+ ct_desc->smp_enable(max_cpus);
/*
* Write the address of secondary startup into the
@@ -194,3 +78,39 @@ bool __init vexpress_smp_init_ops(void)
#endif
return false;
}
+
+#if defined(CONFIG_OF)
+
+static const struct of_device_id vexpress_smp_dt_scu_match[] __initconst = {
+ { .compatible = "arm,cortex-a5-scu", },
+ { .compatible = "arm,cortex-a9-scu", },
+ {}
+};
+
+static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus)
+{
+ struct device_node *scu = of_find_matching_node(NULL,
+ vexpress_smp_dt_scu_match);
+
+ if (scu)
+ scu_enable(of_iomap(scu, 0));
+
+ /*
+ * Write the address of secondary startup into the
+ * system-wide flags register. The boot monitor waits
+ * until it receives a soft interrupt, and then the
+ * secondary CPU branches to this address.
+ */
+ vexpress_flags_set(virt_to_phys(versatile_secondary_startup));
+}
+
+struct smp_operations __initdata vexpress_smp_dt_ops = {
+ .smp_prepare_cpus = vexpress_smp_dt_prepare_cpus,
+ .smp_secondary_init = versatile_secondary_init,
+ .smp_boot_secondary = versatile_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_die = vexpress_cpu_die,
+#endif
+};
+
+#endif
diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
index d8a9fd7..d8b419b 100644
--- a/arch/arm/mach-vexpress/v2m.c
+++ b/arch/arm/mach-vexpress/v2m.c
@@ -400,10 +400,6 @@ void __init v2m_dt_map_io(void)
iotable_init(&v2m_rs1_io_desc, 1);
else
iotable_init(v2m_io_desc, ARRAY_SIZE(v2m_io_desc));
-
-#if defined(CONFIG_SMP)
- vexpress_dt_smp_map_io();
-#endif
}
void __init v2m_dt_init_early(void)
@@ -434,7 +430,7 @@ static const char * const v2m_dt_match[] __initconst = {
DT_MACHINE_START(VEXPRESS_DT, "ARM-Versatile Express")
.dt_compat = v2m_dt_match,
- .smp = smp_ops(vexpress_smp_ops),
+ .smp = smp_ops(vexpress_smp_dt_ops),
.smp_init = smp_init_ops(vexpress_smp_init_ops),
.map_io = v2m_dt_map_io,
.init_early = v2m_dt_init_early,
--
1.9.1
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