Thread (25 messages) 25 messages, 2 authors, 2012-07-05
STALE5116d
Revisions (2)
  1. v1 current
  2. v2 [diff vs current]

[PATCH v1 09/14] ARM: OMAP5: Add SMP support.

From: Santosh Shilimkar <hidden>
Date: 2012-07-05 12:08:51
Also in: linux-omap
Subsystem: arm port, omap2+ support, the rest · Maintainers: Russell King, Aaro Koskinen, Andreas Kemnade, Kevin Hilman, Roger Quadros, Tony Lindgren, Linus Torvalds

Add OMAP5 SMP boot support using OMAP4 SMP code. The relevant code paths
are runtime checked using cpu id

Signed-off-by: R Sricharan <redacted>
Signed-off-by: Santosh Shilimkar <redacted>
---
 arch/arm/mach-omap2/common.h       |    1 +
 arch/arm/mach-omap2/omap-headsmp.S |   21 +++++++++++++++++++++
 arch/arm/mach-omap2/omap-smp.c     |   35 +++++++++++++++++++++++------------
 3 files changed, 45 insertions(+), 12 deletions(-)
diff --git a/arch/arm/mach-omap2/common.h b/arch/arm/mach-omap2/common.h
index 53c87ab..367e1fe 100644
--- a/arch/arm/mach-omap2/common.h
+++ b/arch/arm/mach-omap2/common.h
@@ -271,6 +271,7 @@ extern void omap_secondary_startup(void);
 extern u32 omap_modify_auxcoreboot0(u32 set_mask, u32 clear_mask);
 extern void omap_auxcoreboot_addr(u32 cpu_addr);
 extern u32 omap_read_auxcoreboot0(void);
+extern void omap5_secondary_startup(void);
 #endif
 
 #if defined(CONFIG_SMP) && defined(CONFIG_PM)
diff --git a/arch/arm/mach-omap2/omap-headsmp.S b/arch/arm/mach-omap2/omap-headsmp.S
index 503ac77..502e313 100644
--- a/arch/arm/mach-omap2/omap-headsmp.S
+++ b/arch/arm/mach-omap2/omap-headsmp.S
@@ -19,6 +19,27 @@
 #include <linux/init.h>
 
 	__CPUINIT
+
+/* Physical address needed since MMU not enabled yet on secondary core */
+#define AUX_CORE_BOOT0_PA			0x48281800
+
+/*
+ * OMAP5 specific entry point for secondary CPU to jump from ROM
+ * code.  This routine also provides a holding flag into which
+ * secondary core is held until we're ready for it to initialise.
+ * The primary core will update this flag using a hardware
++ * register AuxCoreBoot0.
+ */
+ENTRY(omap5_secondary_startup)
+wait:	ldr	r2, =AUX_CORE_BOOT0_PA	@ read from AuxCoreBoot0
+	ldr	r0, [r2]
+	mov	r0, r0, lsr #5
+	mrc	p15, 0, r4, c0, c0, 5
+	and	r4, r4, #0x0f
+	cmp	r0, r4
+	bne	wait
+	b	secondary_startup
+END(omap5_secondary_startup)
 /*
  * OMAP4 specific entry point for secondary CPU to jump from ROM
  * code.  This routine also provides a holding flag into which
diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
index badfe39..7d118b9 100644
--- a/arch/arm/mach-omap2/omap-smp.c
+++ b/arch/arm/mach-omap2/omap-smp.c
@@ -33,6 +33,12 @@
 #include "common.h"
 #include "clockdomain.h"
 
+#define CPU_MASK		0xff0ffff0
+#define CPU_CORTEX_A9		0x410FC090
+#define CPU_CORTEX_A15		0x410FC0F0
+
+#define OMAP5_CORE_COUNT	0x2
+
 /* SCU base address */
 static void __iomem *scu_base;
 
@@ -133,7 +139,6 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
 static void __init wakeup_secondary(void)
 {
 	void __iomem *base = omap_get_wakeupgen_base();
-
 	/*
 	 * Write the address of secondary startup routine into the
 	 * AuxCoreBoot1 where ROM code will jump and start executing
@@ -162,16 +167,21 @@ static void __init wakeup_secondary(void)
  */
 void __init smp_init_cpus(void)
 {
-	unsigned int i, ncores;
-
-	/*
-	 * Currently we can't call ioremap here because
-	 * SoC detection won't work until after init_early.
-	 */
-	scu_base =  OMAP2_L4_IO_ADDRESS(OMAP44XX_SCU_BASE);
-	BUG_ON(!scu_base);
-
-	ncores = scu_get_core_count(scu_base);
+	unsigned int i = 0, ncores = 1, cpu_id;
+
+	/* Use ARM cpuid check here, as SoC detection will not work so early */
+	cpu_id = read_cpuid(CPUID_ID) & CPU_MASK;
+	if (cpu_id == CPU_CORTEX_A9) {
+		/*
+		 * Currently we can't call ioremap here because
+		 * SoC detection won't work until after init_early.
+		 */
+		scu_base =  OMAP2_L4_IO_ADDRESS(OMAP44XX_SCU_BASE);
+		BUG_ON(!scu_base);
+		ncores = scu_get_core_count(scu_base);
+	} else if (cpu_id == CPU_CORTEX_A15) {
+		ncores = OMAP5_CORE_COUNT;
+	}
 
 	/* sanity check */
 	if (ncores > nr_cpu_ids) {
@@ -193,6 +203,7 @@ void __init platform_smp_prepare_cpus(unsigned int max_cpus)
 	 * Initialise the SCU and wake up the secondary core using
 	 * wakeup_secondary().
 	 */
-	scu_enable(scu_base);
+	if (scu_base)
+		scu_enable(scu_base);
 	wakeup_secondary();
 }
-- 
1.7.9.5
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