From mboxrd@z Thu Jan 1 00:00:00 1970 From: suijingfeng Subject: Re: [06/12] arch: Declare screen_info in Date: Fri, 18 Aug 2023 22:04:38 +0800 Message-ID: <924934b8-d2ca-c1ea-b357-202c2f995adc@loongson.cn> References: <20230629121952.10559-7-tzimmermann@suse.de> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=A74IsXX7jE+1UmNfHNOi7QLEpvfRi1Wckm/UXY0kLwc=; b=rXToX9bs3ozfec U1M3OIXmAGiCTciW7HqW5Mq5j19iRIGkZjsz4WiGPa9aL9IqN2kES8+O/di5ygp4rsTXgp80z04EA u3s+yyAZuwbPs9TgEgJaCKBwUXy8IwLy/7husYxhhBjXOq+xzNg6E4l834v7OOYk8bFf1Whn7IOl0 4MeLt7bc3axodXfK6Jt90tPVWsZLltJ+vPInErIHlVnzjtgYgA3jOyw2FJkqwcGNKJgPlrSd/dj8X shA8EW0V8VRGned9B9C2oAL3JSyjP8s4HNT+AEfhZWtz2RNzZi2lhtYOvDjPewrrA182dgXLnJB3r TPAb3M8TQczz8ECVRWAA==; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender :Reply-To:Content-ID:Content-Description; bh=LpYJBrw/KZpqz4CxRW8Voi0gBXzIMHPgm2pnQSIqVuo=; b=gYF6lDCXPfHbhW4iZsj9YJYDN4 Fvb/F2Bje06vGS3QPYH9Mvv846R3veehqbOyp3RlB/3tyBAea3V8TY++8ErQ1bei6ll0q0CijPTrm 7lEsYJ83Ykw+GNee8Kpj6PlI6W/Z1EBYmknwSZ/dp9wA7i4YSj1fd5y5vRA+Id14dAMpQl+i0hJWL YsSmHkKRcDY7GKapATvhcy8IE6j28ZGSh/TsCCS57McQBXGHMKrFnIMtbZ33AHmP1atVe1q73POWj ZlhCsN5CPYP5QtzKySx12g70upPz8PvFmesVZ1lTcdyrvo9GgNO2cy0R99pd480RaR9eGwfkDMfXO 0yRQ+iPw==; Content-Language: en-US In-Reply-To: <20230629121952.10559-7-tzimmermann@suse.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+glpr-linux-riscv=m.gmane-mx.org@lists.infradead.org Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Thomas Zimmermann , arnd@arndb.de, deller@gmx.de, daniel@ffwll.ch, airlied@gmail.com Cc: linux-hyperv@vger.kernel.org, linux-efi@vger.kernel.org, linux-ia64@vger.kernel.org, Anshuman Khandual , linux-sh@vger.kernel.org, Peter Zijlstra , Catalin Marinas , John Paul Adrian Glaubitz , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mips@vger.kernel.org, Max Filippov , Rich Felker , Guo Ren , Michael Ellerman , "H. Peter Anvin" , sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, Will Deacon , WANG Xuerui , linux-arch@vger.kernel.org, "Kirill A. Shutemov" , Yoshinori Sato , linux-hexagon@vger.kernel.org, linux-staging@lists.linux.dev, Russell Hi, Why this patch get dropped in the end? Since the global screen_info is an arch-specific thing, Whenever an arch-neutral module or subsystem references the global screen_info, There are some complaints from either compile testing robot. Well, a programmer may handle it by using the CONFIG_SYSFB guard, but it is not as precise as what this patch provided. Personally, I think this patch is still valuable. I suggest either forcing all other architectures to export screen_info, like the X86 and IA64 arch does, after all the screen_info is a good thing. or provide the fine-control version like this patch does. On 2023/6/29 19:45, Thomas Zimmermann wrote: > The variable screen_info does not exist on all architectures. Declare > it in . All architectures that do declare it > will provide it via . > > Add the Kconfig token ARCH_HAS_SCREEN_INFO to guard against access on > architectures that don't provide screen_info. > > Signed-off-by: Thomas Zimmermann > Cc: Richard Henderson > Cc: Ivan Kokshaysky > Cc: Matt Turner > Cc: Russell King > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Guo Ren > Cc: Brian Cain > Cc: Huacai Chen > Cc: WANG Xuerui > Cc: Thomas Bogendoerfer > Cc: Dinh Nguyen > Cc: Michael Ellerman > Cc: Nicholas Piggin > Cc: Christophe Leroy > Cc: Paul Walmsley > Cc: Palmer Dabbelt > Cc: Albert Ou > Cc: Yoshinori Sato > Cc: Rich Felker > Cc: John Paul Adrian Glaubitz > Cc: "David S. Miller" > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: Dave Hansen > Cc: x86@kernel.org > Cc: "H. Peter Anvin" > Cc: Chris Zankel > Cc: Max Filippov > Cc: Helge Deller > Cc: Arnd Bergmann > Cc: Kees Cook > Cc: "Paul E. McKenney" > Cc: Peter Zijlstra > Cc: Frederic Weisbecker > Cc: Andrew Morton > Cc: Ard Biesheuvel > Cc: Sami Tolvanen > Cc: Juerg Haefliger > Cc: Geert Uytterhoeven > Cc: Anshuman Khandual > Cc: Niklas Schnelle > Cc: "Russell King (Oracle)" > Cc: Linus Walleij > Cc: Sebastian Reichel > Cc: "Mike Rapoport (IBM)" > Cc: "Kirill A. Shutemov" > Cc: Zi Yan > Acked-by: WANG Xuerui # loongarch > --- > arch/Kconfig | 6 ++++++ > arch/alpha/Kconfig | 1 + > arch/arm/Kconfig | 1 + > arch/arm64/Kconfig | 1 + > arch/csky/Kconfig | 1 + > arch/hexagon/Kconfig | 1 + > arch/ia64/Kconfig | 1 + > arch/loongarch/Kconfig | 1 + > arch/mips/Kconfig | 1 + > arch/nios2/Kconfig | 1 + > arch/powerpc/Kconfig | 1 + > arch/riscv/Kconfig | 1 + > arch/sh/Kconfig | 1 + > arch/sparc/Kconfig | 1 + > arch/x86/Kconfig | 1 + > arch/xtensa/Kconfig | 1 + > drivers/video/Kconfig | 3 +++ > include/asm-generic/Kbuild | 1 + > include/asm-generic/screen_info.h | 12 ++++++++++++ > include/linux/screen_info.h | 2 +- > 20 files changed, 38 insertions(+), 1 deletion(-) > create mode 100644 include/asm-generic/screen_info.h > > diff --git a/arch/Kconfig b/arch/Kconfig > index 205fd23e0cada..2f58293fd7bcb 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -1466,6 +1466,12 @@ config ARCH_HAS_NONLEAF_PMD_YOUNG > address translations. Page table walkers that clear the accessed bit > may use this capability to reduce their search space. > > +config ARCH_HAS_SCREEN_INFO > + bool > + help > + Selected by architectures that provide a global instance of > + screen_info. > + > source "kernel/gcov/Kconfig" > > source "scripts/gcc-plugins/Kconfig" > diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig > index a5c2b1aa46b02..d749011d88b14 100644 > --- a/arch/alpha/Kconfig > +++ b/arch/alpha/Kconfig > @@ -4,6 +4,7 @@ config ALPHA > default y > select ARCH_32BIT_USTAT_F_TINODE > select ARCH_HAS_CURRENT_STACK_POINTER > + select ARCH_HAS_SCREEN_INFO > select ARCH_MIGHT_HAVE_PC_PARPORT > select ARCH_MIGHT_HAVE_PC_SERIO > select ARCH_NO_PREEMPT > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 0fb4b218f6658..a9d01ee67a90e 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -15,6 +15,7 @@ config ARM > select ARCH_HAS_MEMBARRIER_SYNC_CORE > select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE > select ARCH_HAS_PTE_SPECIAL if ARM_LPAE > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_SETUP_DMA_OPS > select ARCH_HAS_SET_MEMORY > select ARCH_STACKWALK > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 343e1e1cae10a..21addc4715bb3 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -36,6 +36,7 @@ config ARM64 > select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE > select ARCH_HAS_PTE_DEVMAP > select ARCH_HAS_PTE_SPECIAL > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_SETUP_DMA_OPS > select ARCH_HAS_SET_DIRECT_MAP > select ARCH_HAS_SET_MEMORY > diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig > index 4df1f8c9d170b..28444e581fc1f 100644 > --- a/arch/csky/Kconfig > +++ b/arch/csky/Kconfig > @@ -10,6 +10,7 @@ config CSKY > select ARCH_USE_QUEUED_RWLOCKS > select ARCH_USE_QUEUED_SPINLOCKS > select ARCH_HAS_CURRENT_STACK_POINTER > + select ARCH_HAS_SCREEN_INFO > select ARCH_INLINE_READ_LOCK if !PREEMPTION > select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION > select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION > diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig > index 54eadf2651786..cc683c0a43d34 100644 > --- a/arch/hexagon/Kconfig > +++ b/arch/hexagon/Kconfig > @@ -5,6 +5,7 @@ comment "Linux Kernel Configuration for Hexagon" > config HEXAGON > def_bool y > select ARCH_32BIT_OFF_T > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_SYNC_DMA_FOR_DEVICE > select ARCH_NO_PREEMPT > select DMA_GLOBAL_POOL > diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig > index e79f15e32a451..8b1e785e6d53d 100644 > --- a/arch/ia64/Kconfig > +++ b/arch/ia64/Kconfig > @@ -10,6 +10,7 @@ config IA64 > bool > select ARCH_BINFMT_ELF_EXTRA_PHDRS > select ARCH_HAS_DMA_MARK_CLEAN > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_STRNCPY_FROM_USER > select ARCH_HAS_STRNLEN_USER > select ARCH_MIGHT_HAVE_PC_PARPORT > diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig > index d38b066fc931b..6aab2fb7753da 100644 > --- a/arch/loongarch/Kconfig > +++ b/arch/loongarch/Kconfig > @@ -13,6 +13,7 @@ config LOONGARCH > select ARCH_HAS_FORTIFY_SOURCE > select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS > select ARCH_HAS_PTE_SPECIAL > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > select ARCH_INLINE_READ_LOCK if !PREEMPTION > select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig > index 675a8660cb85a..c0ae09789cb6d 100644 > --- a/arch/mips/Kconfig > +++ b/arch/mips/Kconfig > @@ -10,6 +10,7 @@ config MIPS > select ARCH_HAS_KCOV > select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE if !EVA > select ARCH_HAS_PTE_SPECIAL if !(32BIT && CPU_HAS_RIXI) > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_STRNCPY_FROM_USER > select ARCH_HAS_STRNLEN_USER > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig > index e5936417d3cd3..7183eea282212 100644 > --- a/arch/nios2/Kconfig > +++ b/arch/nios2/Kconfig > @@ -3,6 +3,7 @@ config NIOS2 > def_bool y > select ARCH_32BIT_OFF_T > select ARCH_HAS_DMA_PREP_COHERENT > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_SYNC_DMA_FOR_CPU > select ARCH_HAS_SYNC_DMA_FOR_DEVICE > select ARCH_HAS_DMA_SET_UNCACHED > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index bff5820b7cda1..b1acad3076180 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -148,6 +148,7 @@ config PPC > select ARCH_HAS_PTE_DEVMAP if PPC_BOOK3S_64 > select ARCH_HAS_PTE_SPECIAL > select ARCH_HAS_SCALED_CPUTIME if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64 > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_SET_MEMORY > select ARCH_HAS_STRICT_KERNEL_RWX if (PPC_BOOK3S || PPC_8xx || 40x) && !HIBERNATION > select ARCH_HAS_STRICT_KERNEL_RWX if PPC_85xx && !HIBERNATION && !RANDOMIZE_BASE > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 5966ad97c30c3..b5a48f8424af9 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -29,6 +29,7 @@ config RISCV > select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE > select ARCH_HAS_PMEM_API > select ARCH_HAS_PTE_SPECIAL > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_SET_DIRECT_MAP if MMU > select ARCH_HAS_SET_MEMORY if MMU > select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL > diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig > index 04b9550cf0070..001f5149952b4 100644 > --- a/arch/sh/Kconfig > +++ b/arch/sh/Kconfig > @@ -10,6 +10,7 @@ config SUPERH > select ARCH_HAS_GIGANTIC_PAGE > select ARCH_HAS_GCOV_PROFILE_ALL > select ARCH_HAS_PTE_SPECIAL > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > select ARCH_HIBERNATION_POSSIBLE if MMU > select ARCH_MIGHT_HAVE_PC_PARPORT > diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig > index 8535e19062f65..e4bfb80b48cfe 100644 > --- a/arch/sparc/Kconfig > +++ b/arch/sparc/Kconfig > @@ -13,6 +13,7 @@ config 64BIT > config SPARC > bool > default y > + select ARCH_HAS_SCREEN_INFO > select ARCH_MIGHT_HAVE_PC_PARPORT if SPARC64 && PCI > select ARCH_MIGHT_HAVE_PC_SERIO > select DMA_OPS > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 53bab123a8ee4..d7c2bf4ee403d 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -91,6 +91,7 @@ config X86 > select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2 > select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 > select ARCH_HAS_COPY_MC if X86_64 > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_SET_MEMORY > select ARCH_HAS_SET_DIRECT_MAP > select ARCH_HAS_STRICT_KERNEL_RWX > diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig > index 3c6e5471f025b..c6cbd7459939c 100644 > --- a/arch/xtensa/Kconfig > +++ b/arch/xtensa/Kconfig > @@ -8,6 +8,7 @@ config XTENSA > select ARCH_HAS_DMA_PREP_COHERENT if MMU > select ARCH_HAS_GCOV_PROFILE_ALL > select ARCH_HAS_KCOV > + select ARCH_HAS_SCREEN_INFO > select ARCH_HAS_SYNC_DMA_FOR_CPU if MMU > select ARCH_HAS_SYNC_DMA_FOR_DEVICE if MMU > select ARCH_HAS_DMA_SET_UNCACHED if MMU > diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig > index 8b2b9ac37c3df..d4a72bea56be0 100644 > --- a/drivers/video/Kconfig > +++ b/drivers/video/Kconfig > @@ -21,6 +21,9 @@ config STI_CORE > config VIDEO_CMDLINE > bool > > +config ARCH_HAS_SCREEN_INFO > + bool > + > config VIDEO_NOMODESET > bool > default n > diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild > index 941be574bbe00..5e5d4158a4b4b 100644 > --- a/include/asm-generic/Kbuild > +++ b/include/asm-generic/Kbuild > @@ -47,6 +47,7 @@ mandatory-y += percpu.h > mandatory-y += pgalloc.h > mandatory-y += preempt.h > mandatory-y += rwonce.h > +mandatory-y += screen_info.h > mandatory-y += sections.h > mandatory-y += serial.h > mandatory-y += shmparam.h > diff --git a/include/asm-generic/screen_info.h b/include/asm-generic/screen_info.h > new file mode 100644 > index 0000000000000..6fd0e50fabfcd > --- /dev/null > +++ b/include/asm-generic/screen_info.h > @@ -0,0 +1,12 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +#ifndef _ASM_GENERIC_SCREEN_INFO_H > +#define _ASM_GENERIC_SCREEN_INFO_H > + > +#include > + > +#if defined(CONFIG_ARCH_HAS_SCREEN_INFO) > +extern struct screen_info screen_info; > +#endif > + > +#endif /* _ASM_GENERIC_SCREEN_INFO_H */ > diff --git a/include/linux/screen_info.h b/include/linux/screen_info.h > index eab7081392d50..c764b9a51c24b 100644 > --- a/include/linux/screen_info.h > +++ b/include/linux/screen_info.h > @@ -4,6 +4,6 @@ > > #include > > -extern struct screen_info screen_info; > +#include > > #endif /* _SCREEN_INFO_H */