[06/12] arch: Declare screen_info in <asm/screen_info.h>
suijingfeng
suijingfeng at loongson.cn
Fri Aug 18 07:18:55 PDT 2023
On 2023/8/18 22:04, suijingfeng wrote:
> 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.
There are some complaints from either compile testing robot or domain
specific reviewers who doubt why you select the CONFIG_SYSFB not
CONFIG_VT or CONFIG_EFI.
> 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.
>
Because all of the three tokens(CONFIG_SYSFB not CONFIG_VT or CONFIG_EFI.)
have no direct relationship with the global screen_info if an arch is
not mentioned first.
> 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 at suse.de>
>> Cc: Richard Henderson <richard.henderson at linaro.org>
>> Cc: Ivan Kokshaysky <ink at jurassic.park.msu.ru>
>> Cc: Matt Turner <mattst88 at gmail.com>
>> Cc: Russell King <linux at armlinux.org.uk>
>> Cc: Catalin Marinas <catalin.marinas at arm.com>
>> Cc: Will Deacon <will at kernel.org>
>> Cc: Guo Ren <guoren at kernel.org>
>> Cc: Brian Cain <bcain at quicinc.com>
>> Cc: Huacai Chen <chenhuacai at kernel.org>
>> Cc: WANG Xuerui <kernel at xen0n.name>
>> Cc: Thomas Bogendoerfer <tsbogend at alpha.franken.de>
>> Cc: Dinh Nguyen <dinguyen at kernel.org>
>> Cc: Michael Ellerman <mpe at ellerman.id.au>
>> Cc: Nicholas Piggin <npiggin at gmail.com>
>> Cc: Christophe Leroy <christophe.leroy at csgroup.eu>
>> Cc: Paul Walmsley <paul.walmsley at sifive.com>
>> Cc: Palmer Dabbelt <palmer at dabbelt.com>
>> Cc: Albert Ou <aou at eecs.berkeley.edu>
>> Cc: Yoshinori Sato <ysato at users.sourceforge.jp>
>> Cc: Rich Felker <dalias at libc.org>
>> Cc: John Paul Adrian Glaubitz <glaubitz at physik.fu-berlin.de>
>> Cc: "David S. Miller" <davem at davemloft.net>
>> Cc: Thomas Gleixner <tglx at linutronix.de>
>> Cc: Ingo Molnar <mingo at redhat.com>
>> Cc: Borislav Petkov <bp at alien8.de>
>> Cc: Dave Hansen <dave.hansen at linux.intel.com>
>> Cc: x86 at kernel.org
>> Cc: "H. Peter Anvin" <hpa at zytor.com>
>> Cc: Chris Zankel <chris at zankel.net>
>> Cc: Max Filippov <jcmvbkbc at gmail.com>
>> Cc: Helge Deller <deller at gmx.de>
>> Cc: Arnd Bergmann <arnd at arndb.de>
>> Cc: Kees Cook <keescook at chromium.org>
>> Cc: "Paul E. McKenney" <paulmck at kernel.org>
>> Cc: Peter Zijlstra <peterz at infradead.org>
>> Cc: Frederic Weisbecker <frederic at kernel.org>
>> Cc: Andrew Morton <akpm at linux-foundation.org>
>> Cc: Ard Biesheuvel <ardb at kernel.org>
>> Cc: Sami Tolvanen <samitolvanen at google.com>
>> Cc: Juerg Haefliger <juerg.haefliger at canonical.com>
>> Cc: Geert Uytterhoeven <geert at linux-m68k.org>
>> Cc: Anshuman Khandual <anshuman.khandual at arm.com>
>> Cc: Niklas Schnelle <schnelle at linux.ibm.com>
>> Cc: "Russell King (Oracle)" <rmk+kernel at armlinux.org.uk>
>> Cc: Linus Walleij <linus.walleij at linaro.org>
>> Cc: Sebastian Reichel <sebastian.reichel at collabora.com>
>> Cc: "Mike Rapoport (IBM)" <rppt at kernel.org>
>> Cc: "Kirill A. Shutemov" <kirill.shutemov at linux.intel.com>
>> Cc: Zi Yan <ziy at nvidia.com>
>> Acked-by: WANG Xuerui <git at xen0n.name> # 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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