Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755257AbaGKTzL (ORCPT ); Fri, 11 Jul 2014 15:55:11 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:18115 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755108AbaGKTzI (ORCPT ); Fri, 11 Jul 2014 15:55:08 -0400 From: Daniel Kiper To: linux-kernel@vger.kernel.org, x86@kernel.org, xen-devel@lists.xenproject.org Cc: andrew.cooper3@citrix.com, boris.ostrovsky@oracle.com, david.vrabel@citrix.com, hpa@zytor.com, ian.campbell@citrix.com, jbeulich@suse.com, jeremy@goop.org, konrad.wilk@oracle.com, matt.fleming@intel.com, mingo@redhat.com, stefano.stabellini@eu.citrix.com, tglx@linutronix.de Subject: [PATCH 2/2] arch/x86/xen: Silence compiler warnings Date: Fri, 11 Jul 2014 21:54:21 +0200 Message-Id: <1405108461-3223-3-git-send-email-daniel.kiper@oracle.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1405108461-3223-1-git-send-email-daniel.kiper@oracle.com> References: <1405108461-3223-1-git-send-email-daniel.kiper@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Compiler complains in the following way when x86 32-bit kernel with Xen support is build: CC arch/x86/xen/enlighten.o arch/x86/xen/enlighten.c: In function ‘xen_start_kernel’: arch/x86/xen/enlighten.c:1726:3: warning: right shift count >= width of type [enabled by default] Such line contains following EFI initialization code: boot_params.efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32); There is no issue if x86 64-bit kernel is build. However, 32-bit case generate warning (even if that code will not be executed because Xen does not work on 32-bit EFI platforms) due to __pa() returning unsigned long type which has 32-bits width. So move whole EFI initialization stuff to separate function and build its body conditionally to avoid above mentioned warning on x86 32-bit architecture. Signed-off-by: Daniel Kiper --- arch/x86/xen/enlighten.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index bc89647..6abec74 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1516,12 +1516,32 @@ static void __init xen_pvh_early_guest_init(void) #endif } +static void __init xen_efi_init(void) +{ +#ifdef CONFIG_XEN_EFI + efi_system_table_t *efi_systab_xen; + + efi_systab_xen = xen_efi_probe(); + + if (efi_systab_xen == NULL) + return; + + strncpy((char *)&boot_params.efi_info.efi_loader_signature, "Xen", + sizeof(boot_params.efi_info.efi_loader_signature)); + boot_params.efi_info.efi_systab = (__u32)__pa(efi_systab_xen); + boot_params.efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32); + + set_bit(EFI_BOOT, &efi.flags); + set_bit(EFI_PARAVIRT, &efi.flags); + set_bit(EFI_64BIT, &efi.flags); +#endif +} + /* First C function to be called on Xen boot */ asmlinkage __visible void __init xen_start_kernel(void) { struct physdev_set_iopl set_iopl; int rc; - efi_system_table_t *efi_systab_xen; if (!xen_start_info) return; @@ -1717,18 +1737,7 @@ asmlinkage __visible void __init xen_start_kernel(void) xen_setup_runstate_info(0); - efi_systab_xen = xen_efi_probe(); - - if (efi_systab_xen) { - strncpy((char *)&boot_params.efi_info.efi_loader_signature, "Xen", - sizeof(boot_params.efi_info.efi_loader_signature)); - boot_params.efi_info.efi_systab = (__u32)__pa(efi_systab_xen); - boot_params.efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32); - - set_bit(EFI_BOOT, &efi.flags); - set_bit(EFI_PARAVIRT, &efi.flags); - set_bit(EFI_64BIT, &efi.flags); - } + xen_efi_init(); /* Start the world */ #ifdef CONFIG_X86_32 -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/