From fe8e0c25cad28e8858ecfa5863333c70685a6811 Mon Sep 17 00:00:00 2001 From: Alexander van Heukelum Date: Mon, 6 Sep 2010 20:53:42 +0200 Subject: [PATCH] x86, 32-bit: Align percpu area and irq stacks to THREAD_SIZE The irq stacks, located in the percpu-area, need to be THREAD_SIZE aligned. Add the infrastucture to align percpu variables to larger-than-pagesize amounts within the percpu area, and use it to specify the alignment for the irq stacks. Also align the percpu area itself to THREAD_SIZE. This should make irq stacks work with 8K THREAD_SIZE. Signed-off-by: Alexander van Heukelum Cc: Tejun Heo Cc: hch@lst.de LKML-Reference: <1283799222.15941.1393621887@webmail.messagingengine.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/irq_32.c | 4 ++-- arch/x86/kernel/vmlinux.lds.S | 2 +- include/linux/percpu-defs.h | 12 ++++++++++++ 3 files changed, 15 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 3b5609f54c4..50fbbe60e50 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -60,8 +60,8 @@ union irq_ctx { static DEFINE_PER_CPU(union irq_ctx *, hardirq_ctx); static DEFINE_PER_CPU(union irq_ctx *, softirq_ctx); -static DEFINE_PER_CPU_PAGE_ALIGNED(union irq_ctx, hardirq_stack); -static DEFINE_PER_CPU_PAGE_ALIGNED(union irq_ctx, softirq_stack); +static DEFINE_PER_CPU_MULTIPAGE_ALIGNED(union irq_ctx, hardirq_stack, THREAD_SIZE); +static DEFINE_PER_CPU_MULTIPAGE_ALIGNED(union irq_ctx, softirq_stack, THREAD_SIZE); static void call_on_stack(void *func, void *stack) { diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index d0bb52296fa..bb899475355 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -273,7 +273,7 @@ SECTIONS } #if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP) - PERCPU(PAGE_SIZE) + PERCPU(THREAD_SIZE) #endif . = ALIGN(PAGE_SIZE); diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index ce2dc655cd1..ab20d119a85 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -138,6 +138,18 @@ DEFINE_PER_CPU_SECTION(type, name, "..page_aligned") \ __aligned(PAGE_SIZE) +/* + * Declaration/definition used for large per-CPU variables that must be + * aligned to something larger than the pagesize. + */ +#define DECLARE_PER_CPU_MULTIPAGE_ALIGNED(type, name, size) \ + DECLARE_PER_CPU_SECTION(type, name, "..page_aligned") \ + __aligned(size) + +#define DEFINE_PER_CPU_MULTIPAGE_ALIGNED(type, name, size) \ + DEFINE_PER_CPU_SECTION(type, name, "..page_aligned") \ + __aligned(size) + /* * Intermodule exports for per-CPU variables. sparse forgets about * address space across EXPORT_SYMBOL(), change EXPORT_SYMBOL() to