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 <asm-generic/screen_info.h>. All architectures that do declare it will provide it via <asm/screen_info.h>. 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 <tzimmermann@xxxxxxx> Cc: Richard Henderson <richard.henderson@xxxxxxxxxx> Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx> Cc: Matt Turner <mattst88@xxxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Guo Ren <guoren@xxxxxxxxxx> Cc: Brian Cain <bcain@xxxxxxxxxxx> Cc: Huacai Chen <chenhuacai@xxxxxxxxxx> Cc: WANG Xuerui <kernel@xxxxxxxxxx> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> Cc: Dinh Nguyen <dinguyen@xxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx> Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx> Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx> Cc: Rich Felker <dalias@xxxxxxxx> Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: x86@xxxxxxxxxx Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Chris Zankel <chris@xxxxxxxxxx> Cc: Max Filippov <jcmvbkbc@xxxxxxxxx> Cc: Helge Deller <deller@xxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Frederic Weisbecker <frederic@xxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> Cc: Sami Tolvanen <samitolvanen@xxxxxxxxxx> Cc: Juerg Haefliger <juerg.haefliger@xxxxxxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx> Cc: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> Cc: "Russell King (Oracle)" <rmk+kernel@xxxxxxxxxxxxxxx> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx> Cc: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx> Cc: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Zi Yan <ziy@xxxxxxxxxx> Acked-by: WANG Xuerui <git@xxxxxxxxxx> # 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 <uapi/linux/screen_info.h> + +#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 <uapi/linux/screen_info.h> -extern struct screen_info screen_info;+#include <asm/screen_info.h>#endif /* _SCREEN_INFO_H */
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