Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752961AbaGMJ7q (ORCPT ); Sun, 13 Jul 2014 05:59:46 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:43659 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752526AbaGMJ7j convert rfc822-to-8bit (ORCPT ); Sun, 13 Jul 2014 05:59:39 -0400 User-Agent: K-9 Mail for Android In-Reply-To: <1405199388-5692-3-git-send-email-daniel.kiper@oracle.com> References: <1405199388-5692-1-git-send-email-daniel.kiper@oracle.com> <1405199388-5692-3-git-send-email-daniel.kiper@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Subject: Re: [PATCH v2 2/2] arch/x86/xen: Silence compiler warnings From: Konrad Rzeszutek Wilk Date: Sun, 13 Jul 2014 05:58:45 -0400 To: Daniel Kiper , 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, matt.fleming@intel.com, mingo@redhat.com, stefano.stabellini@eu.citrix.com, tglx@linutronix.de Message-ID: 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 On July 12, 2014 5:09:48 PM EDT, Daniel Kiper wrote: >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 it conditionally to avoid above >mentioned >warning on x86 32-bit architecture. > Reviewed-by: Konrad Rzeszutek Wilk >Signed-off-by: Daniel Kiper >--- >v2 - suggestions/fixes: > - move xen_efi_init() to separate module > (suggested by Konrad Rzeszutek Wilk). >--- > arch/x86/xen/Makefile | 1 + >arch/x86/xen/efi.c | 43 >+++++++++++++++++++++++++++++++++++++++++++ > arch/x86/xen/enlighten.c | 15 +-------------- > arch/x86/xen/xen-ops.h | 8 ++++++++ > 4 files changed, 53 insertions(+), 14 deletions(-) > create mode 100644 arch/x86/xen/efi.c > >diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile >index 96ab2c0..7322755 100644 >--- a/arch/x86/xen/Makefile >+++ b/arch/x86/xen/Makefile >@@ -22,3 +22,4 @@ obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o > obj-$(CONFIG_XEN_DEBUG_FS) += debugfs.o > obj-$(CONFIG_XEN_DOM0) += apic.o vga.o > obj-$(CONFIG_SWIOTLB_XEN) += pci-swiotlb-xen.o >+obj-$(CONFIG_XEN_EFI) += efi.o >diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c >new file mode 100644 >index 0000000..a02e09e >--- /dev/null >+++ b/arch/x86/xen/efi.c >@@ -0,0 +1,43 @@ >+/* >+ * Copyright (c) 2014 Oracle Co., Daniel Kiper >+ * >+ * This program is free software; you can redistribute it and/or >modify >+ * it under the terms of the GNU General Public License as published >by >+ * the Free Software Foundation; either version 2 of the License, or >+ * (at your option) any later version. >+ * >+ * This program is distributed in the hope that it will be useful, >+ * but WITHOUT ANY WARRANTY; without even the implied warranty of >+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >+ * GNU General Public License for more details. >+ * >+ * You should have received a copy of the GNU General Public License >along >+ * with this program. If not, see . >+ */ >+ >+#include >+#include >+#include >+ >+#include >+ >+#include >+ >+void __init xen_efi_init(void) >+{ >+ 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); >+} >diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c >index bc89647..2cd0463 100644 >--- a/arch/x86/xen/enlighten.c >+++ b/arch/x86/xen/enlighten.c >@@ -32,7 +32,6 @@ > #include > #include > #include >-#include > > #include > #include >@@ -1521,7 +1520,6 @@ 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 +1715,7 @@ 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 >diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h >index c834d4b..75f98fe 100644 >--- a/arch/x86/xen/xen-ops.h >+++ b/arch/x86/xen/xen-ops.h >@@ -104,6 +104,14 @@ static inline void __init xen_init_apic(void) > } > #endif > >+#ifdef CONFIG_XEN_EFI >+extern void xen_efi_init(void); >+#else >+static inline void __init xen_efi_init(void) >+{ >+} >+#endif >+ > /* Declare an asm function, along with symbols needed to make it > inlineable */ > #define DECL_ASM(ret, name, ...) \ -- 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/