[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 2/2] arch/x86/xen: Silence compiler warnings
On July 12, 2014 5:09:48 PM EDT, Daniel Kiper <daniel.kiper@xxxxxxxxxx> 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 âxen_start_kernelâ: >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 <Konrad.wilk@xxxxxxxxxx> >Signed-off-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx> >--- >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 <http://www.gnu.org/licenses/>. >+ */ >+ >+#include <linux/efi.h> >+#include <linux/init.h> >+#include <linux/string.h> >+ >+#include <xen/xen-ops.h> >+ >+#include <asm/setup.h> >+ >+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 <linux/gfp.h> > #include <linux/memblock.h> > #include <linux/edd.h> >-#include <linux/efi.h> > > #include <xen/xen.h> > #include <xen/events.h> >@@ -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, ...) \ _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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