From: nicolas.pitre@linaro.org (Nicolas Pitre)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 13/13] ARM: bL_switcher: Add query interface to discover CPU affinities
Date: Mon, 23 Sep 2013 19:17:56 -0400 [thread overview]
Message-ID: <1379978276-31241-14-git-send-email-nicolas.pitre@linaro.org> (raw)
In-Reply-To: <1379978276-31241-1-git-send-email-nicolas.pitre@linaro.org>
From: Dave Martin <dave.martin@linaro.org>
When the switcher is active, there is no straightforward way to
figure out which logical CPU a given physical CPU maps to.
This patch provides a function
bL_switcher_get_logical_index(mpidr), which is analogous to
get_logical_index().
This function returns the logical CPU on which the specified
physical CPU is grouped (or -EINVAL if unknown).
If the switcher is inactive or not present, -EUNATCH is returned instead.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
arch/arm/common/bL_switcher.c | 20 ++++++++++++++++++++
arch/arm/include/asm/bL_switcher.h | 2 ++
2 files changed, 22 insertions(+)
diff --git a/arch/arm/common/bL_switcher.c b/arch/arm/common/bL_switcher.c
index f4878a3604..63bbc4f705 100644
--- a/arch/arm/common/bL_switcher.c
+++ b/arch/arm/common/bL_switcher.c
@@ -532,6 +532,26 @@ static int bL_switcher_halve_cpus(void)
return 0;
}
+/* Determine the logical CPU a given physical CPU is grouped on. */
+int bL_switcher_get_logical_index(u32 mpidr)
+{
+ int cpu;
+
+ if (!bL_switcher_active)
+ return -EUNATCH;
+
+ mpidr &= MPIDR_HWID_BITMASK;
+ for_each_online_cpu(cpu) {
+ int pairing = bL_switcher_cpu_pairing[cpu];
+ if (pairing == -1)
+ continue;
+ if ((mpidr == cpu_logical_map(cpu)) ||
+ (mpidr == cpu_logical_map(pairing)))
+ return cpu;
+ }
+ return -EINVAL;
+}
+
static void bL_switcher_trace_trigger_cpu(void *__always_unused info)
{
trace_cpu_migrate_current(get_ns(), read_mpidr());
diff --git a/arch/arm/include/asm/bL_switcher.h b/arch/arm/include/asm/bL_switcher.h
index 8ada5a885c..1714800fa1 100644
--- a/arch/arm/include/asm/bL_switcher.h
+++ b/arch/arm/include/asm/bL_switcher.h
@@ -55,6 +55,7 @@ bool bL_switcher_get_enabled(void);
void bL_switcher_put_enabled(void);
int bL_switcher_trace_trigger(void);
+int bL_switcher_get_logical_index(u32 mpidr);
#else
static inline int bL_switcher_register_notifier(struct notifier_block *nb)
@@ -70,6 +71,7 @@ static inline int bL_switcher_unregister_notifier(struct notifier_block *nb)
static inline bool bL_switcher_get_enabled(void) { return false; }
static inline void bL_switcher_put_enabled(void) { }
static inline int bL_switcher_trace_trigger(void) { return 0; }
+static inline int bL_switcher_get_logical_index(u32 mpidr) { return -EUNATCH; }
#endif /* CONFIG_BL_SWITCHER */
#endif
--
1.8.4.98.gb022869
prev parent reply other threads:[~2013-09-23 23:17 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-23 23:17 [PATCH 00/13] second batch of b.L switcher patches Nicolas Pitre
2013-09-23 23:17 ` [PATCH 01/13] ARM: bL_switcher: Add synchronous enable/disable interface Nicolas Pitre
2013-09-23 23:17 ` [PATCH 02/13] ARM: bL_switcher: Add runtime control notifier Nicolas Pitre
2013-09-23 23:17 ` [PATCH 03/13] ARM: bL_switcher: Add switch completion callback for bL_switch_request() Nicolas Pitre
2013-09-23 23:17 ` [PATCH 04/13] ARM: bL_switcher: synchronize the outbound with the inbound Nicolas Pitre
2013-09-23 23:17 ` [PATCH 05/13] ARM: SMP: basic IPI triggered completion support Nicolas Pitre
2013-09-23 23:17 ` [PATCH 06/13] ARM: mcpm: add a simple poke mechanism to the early entry code Nicolas Pitre
2013-09-23 23:17 ` [PATCH 07/13] ARM: GIC: function to retrieve the physical address of the SGIR Nicolas Pitre
2013-09-23 23:17 ` [PATCH 08/13] ARM: GIC: interface to send a SGI directly Nicolas Pitre
2013-09-23 23:17 ` [PATCH 09/13] ARM: bL_switcher: wait until inbound is alive before performing a switch Nicolas Pitre
2013-09-23 23:17 ` [PATCH 10/13] ARM: bL_switcher: Basic trace events support Nicolas Pitre
2013-09-23 23:17 ` [PATCH 11/13] ARM: bL_switcher/trace: Add trace trigger for trace bootstrapping Nicolas Pitre
2013-09-23 23:17 ` [PATCH 12/13] ARM: bL_switcher/trace: Add kernel trace trigger interface Nicolas Pitre
2013-09-23 23:17 ` Nicolas Pitre [this message]
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