Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752843AbdFLP2J (ORCPT ); Mon, 12 Jun 2017 11:28:09 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39506 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752413AbdFLP2G (ORCPT ); Mon, 12 Jun 2017 11:28:06 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jane Chu , Bob Picco , Atish Patra , "David S. Miller" Subject: [PATCH 4.11 030/150] arch/sparc: support NR_CPUS = 4096 Date: Mon, 12 Jun 2017 17:23:57 +0200 Message-Id: <20170612152520.762851296@linuxfoundation.org> X-Mailer: git-send-email 2.13.1 In-Reply-To: <20170612152519.404936272@linuxfoundation.org> References: <20170612152519.404936272@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2308 Lines: 79 4.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jane Chu [ Upstream commit c79a13734d104b5b147d7cb0870276ccdd660dae ] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- arch/sparc/Kconfig | 4 ++-- arch/sparc/kernel/irq_64.c | 17 +++++++++++++---- 2 files changed, 15 insertions(+), 6 deletions(-) --- 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 --- a/arch/sparc/kernel/irq_64.c +++ b/arch/sparc/kernel/irq_64.c @@ -1034,17 +1034,26 @@ static void __init init_cpu_send_mondo_i { #ifdef CONFIG_SMP unsigned long page; + void *mondo, *p; - BUILD_BUG_ON((NR_CPUS * sizeof(u16)) > (PAGE_SIZE - 64)); + BUILD_BUG_ON((NR_CPUS * sizeof(u16)) > PAGE_SIZE); + + /* Make sure mondo block is 64byte aligned */ + p = kzalloc(127, GFP_KERNEL); + if (!p) { + prom_printf("SUN4V: Error, cannot allocate mondo block.\n"); + prom_halt(); + } + mondo = (void *)(((unsigned long)p + 63) & ~0x3f); + tb->cpu_mondo_block_pa = __pa(mondo); page = get_zeroed_page(GFP_KERNEL); if (!page) { - prom_printf("SUN4V: Error, cannot allocate cpu mondo page.\n"); + prom_printf("SUN4V: Error, cannot allocate cpu list page.\n"); prom_halt(); } - tb->cpu_mondo_block_pa = __pa(page); - tb->cpu_list_pa = __pa(page + 64); + tb->cpu_list_pa = __pa(page); #endif }