From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751370AbdFAVjk (ORCPT ); Thu, 1 Jun 2017 17:39:40 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:20540 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751160AbdFAVjg (ORCPT ); Thu, 1 Jun 2017 17:39:36 -0400 From: Jane Chu To: davem@davemloft.net, tglx@linutronix.de Cc: atish.patra@oracle.com, Liam.Howlett@oracle.com, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, jane.chu@oracle.com Subject: [PATCH] arch/sparc: support NR_CPUS = 4096 Date: Thu, 1 Jun 2017 15:39:13 -0600 Message-Id: <1496353153-587795-1-git-send-email-jane.chu@oracle.com> X-Mailer: git-send-email 1.7.1 X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linux SPARC64 limits NR_CPUS to 4064 because init_cpu_send_mondo_info() only allocates a single page for NR_CPUS mondo entries. Thus we cannot use all 4096 CPUs on some SPARC platforms. To fix, allocate (2^order) pages where order is set according to the size of cpu_list for possible cpus. Since cpu_list_pa and cpu_mondo_block_pa are not used in asm code, there are no imm13 offsets from the base PA that will break because they can only reach one page. Orabug: 25505750 Signed-off-by: Jane Chu Reviewed-by: Bob Picco Reviewed-by: Atish Patra --- arch/sparc/Kconfig | 4 ++-- arch/sparc/kernel/irq_64.c | 8 ++++---- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig index 58243b0..4399be7 100644 --- a/arch/sparc/Kconfig +++ b/arch/sparc/Kconfig @@ -192,9 +192,9 @@ config NR_CPUS int "Maximum number of CPUs" depends on SMP range 2 32 if SPARC32 - range 2 1024 if SPARC64 + range 2 4096 if SPARC64 default 32 if SPARC32 - default 64 if SPARC64 + default 4096 if SPARC64 source kernel/Kconfig.hz diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c index 4d0248a..5b19108 100644 --- a/arch/sparc/kernel/irq_64.c +++ b/arch/sparc/kernel/irq_64.c @@ -1034,12 +1034,12 @@ static void __init init_cpu_send_mondo_info(struct trap_per_cpu *tb) { #ifdef CONFIG_SMP unsigned long page; + unsigned int order; - BUILD_BUG_ON((NR_CPUS * sizeof(u16)) > (PAGE_SIZE - 64)); - - page = get_zeroed_page(GFP_KERNEL); + order = get_order(num_possible_cpus() * sizeof(u16) + 64); + page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order); if (!page) { - prom_printf("SUN4V: Error, cannot allocate cpu mondo page.\n"); + prom_printf("SUN4V: Error, cannot allocate cpu mondo pages.\n"); prom_halt(); } -- 1.7.1