From mboxrd@z Thu Jan 1 00:00:00 1970 From: chris.packham@alliedtelesis.co.nz (Chris Packham) Date: Mon, 17 Nov 2014 11:40:07 +1300 Subject: [RFC PATCHv3] ARM: mvebu: Let the device-tree determine smp_ops In-Reply-To: <1415327626-16079-1-git-send-email-chris.packham@alliedtelesis.co.nz> References: <1415327626-16079-1-git-send-email-chris.packham@alliedtelesis.co.nz> Message-ID: <1416177607-11305-1-git-send-email-chris.packham@alliedtelesis.co.nz> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The machine specific SMP operations can be configured either via setup_arch or via arm_dt_init_cpu_maps. For the ARMADA_370_XP_DT devices both of these are called and setup_arch wins because it is called last. This means that it is not possible to substitute a different set of SMP operations via the device-tree. Add a new smp_ops_is_set API that tells us if something else has already set smp_ops. Use this new API in a smp_init function for the ARMADA_370_XP_DT compatible devices to prevent setup_arch from overriding the operations configured earlier. Signed-off-by: Chris Packham --- Hi, I didn't see any comment's on v2[1]. I'm not sure if I should take this as disapproval with that approach or just a sign that people are busy. This is an alternative solution that addresses one issue I had with the v2 implementation namely we now know whether smp_ops have been set or not and can use this information to avoid setting them again. The downside is I'm now modifying core code. Thanks, Chris -- [1] - http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/300480.html arch/arm/include/asm/smp.h | 1 + arch/arm/kernel/smp.c | 10 +++++++++- arch/arm/mach-mvebu/board-v7.c | 6 ++++++ 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index 18f5a55..aa55889 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -122,5 +122,6 @@ struct of_cpu_method { * set platform specific SMP operations */ extern void smp_set_ops(struct smp_operations *); +extern bool smp_ops_is_set(void); #endif /* ifndef __ASM_ARM_SMP_H */ diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 13396d3..f303655 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -77,13 +77,21 @@ enum ipi_msg_type { static DECLARE_COMPLETION(cpu_running); static struct smp_operations smp_ops; +static bool smp_ops_set = false; void __init smp_set_ops(struct smp_operations *ops) { - if (ops) + if (ops) { smp_ops = *ops; + smp_ops_set = true; + } }; +bool smp_ops_is_set(void) +{ + return smp_ops_set; +} + static unsigned long get_arch_pgd(pgd_t *pgd) { phys_addr_t pgdir = virt_to_idmap(pgd); diff --git a/arch/arm/mach-mvebu/board-v7.c b/arch/arm/mach-mvebu/board-v7.c index 6478626..86b4b5d 100644 --- a/arch/arm/mach-mvebu/board-v7.c +++ b/arch/arm/mach-mvebu/board-v7.c @@ -198,6 +198,11 @@ static void __init mvebu_dt_init(void) of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL); } +static bool __init armada_smp_init(void) +{ + return smp_ops_is_set(); +} + static const char * const armada_370_xp_dt_compat[] = { "marvell,armada-370-xp", NULL, @@ -206,6 +211,7 @@ static const char * const armada_370_xp_dt_compat[] = { DT_MACHINE_START(ARMADA_370_XP_DT, "Marvell Armada 370/XP (Device Tree)") .l2c_aux_val = 0, .l2c_aux_mask = ~0, + .smp_init = armada_smp_init, .smp = smp_ops(armada_xp_smp_ops), .init_machine = mvebu_dt_init, .init_irq = mvebu_init_irq, -- 2.2.0.rc0