Re: [06/12] arch: Declare screen_info in <asm/screen_info.h>

Hi

Am 05.07.23 um 03:21 schrieb Sui Jingfeng:
> Hi, Thomas
> 
> 
> I love your patch, yet after applied your patch, the linux kernel fail 
> to compile on my LoongArch machine.

screen_info is missing. I think this should be solved with your update 
to patch 1.

Best regards
Thomas

> 
> 
> ```
> 
>    CC      arch/loongarch/kernel/efi.o
> arch/loongarch/kernel/efi.c: In function ‘init_screen_info’:
> arch/loongarch/kernel/efi.c:77:54: error: invalid application of 
> ‘sizeof’ to incomplete type ‘struct screen_info’
>     77 |         si = early_memremap(screen_info_table, sizeof(*si));
>        |                                                      ^
> arch/loongarch/kernel/efi.c:82:9: error: ‘screen_info’ undeclared (first 
> use in this function)
>     82 |         screen_info = *si;
>        |         ^~~~~~~~~~~
> arch/loongarch/kernel/efi.c:82:9: note: each undeclared identifier is 
> reported only once for each function it appears in
> arch/loongarch/kernel/efi.c:82:23: error: invalid use of undefined type 
> ‘struct screen_info’
>     82 |         screen_info = *si;
>        |                       ^
> arch/loongarch/kernel/efi.c:83:29: error: invalid application of 
> ‘sizeof’ to incomplete type ‘struct screen_info’
>     83 |         memset(si, 0, sizeof(*si));
>        |                             ^
> arch/loongarch/kernel/efi.c:84:34: error: invalid application of 
> ‘sizeof’ to incomplete type ‘struct screen_info’
>     84 |         early_memunmap(si, sizeof(*si));
>        |                                  ^
> make[3]: *** [scripts/Makefile.build:252: arch/loongarch/kernel/efi.o] 
> Error 1
> make[3]: *** Waiting for unfinished jobs....
> make[2]: *** [scripts/Makefile.build:494: arch/loongarch/kernel] Error 2
> make[1]: *** [scripts/Makefile.build:494: arch/loongarch] Error 2
> make[1]: *** Waiting for unfinished jobs....
> make: *** [Makefile:2026: .] Error 2
> 
> ```
> 
> 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 <[email protected]>
>> Cc: Richard Henderson <[email protected]>
>> Cc: Ivan Kokshaysky <[email protected]>
>> Cc: Matt Turner <[email protected]>
>> Cc: Russell King <[email protected]>
>> Cc: Catalin Marinas <[email protected]>
>> Cc: Will Deacon <[email protected]>
>> Cc: Guo Ren <[email protected]>
>> Cc: Brian Cain <[email protected]>
>> Cc: Huacai Chen <[email protected]>
>> Cc: WANG Xuerui <[email protected]>
>> Cc: Thomas Bogendoerfer <[email protected]>
>> Cc: Dinh Nguyen <[email protected]>
>> Cc: Michael Ellerman <[email protected]>
>> Cc: Nicholas Piggin <[email protected]>
>> Cc: Christophe Leroy <[email protected]>
>> Cc: Paul Walmsley <[email protected]>
>> Cc: Palmer Dabbelt <[email protected]>
>> Cc: Albert Ou <[email protected]>
>> Cc: Yoshinori Sato <[email protected]>
>> Cc: Rich Felker <[email protected]>
>> Cc: John Paul Adrian Glaubitz <[email protected]>
>> Cc: "David S. Miller" <[email protected]>
>> Cc: Thomas Gleixner <[email protected]>
>> Cc: Ingo Molnar <[email protected]>
>> Cc: Borislav Petkov <[email protected]>
>> Cc: Dave Hansen <[email protected]>
>> Cc: [email protected]
>> Cc: "H. Peter Anvin" <[email protected]>
>> Cc: Chris Zankel <[email protected]>
>> Cc: Max Filippov <[email protected]>
>> Cc: Helge Deller <[email protected]>
>> Cc: Arnd Bergmann <[email protected]>
>> Cc: Kees Cook <[email protected]>
>> Cc: "Paul E. McKenney" <[email protected]>
>> Cc: Peter Zijlstra <[email protected]>
>> Cc: Frederic Weisbecker <[email protected]>
>> Cc: Andrew Morton <[email protected]>
>> Cc: Ard Biesheuvel <[email protected]>
>> Cc: Sami Tolvanen <[email protected]>
>> Cc: Juerg Haefliger <[email protected]>
>> Cc: Geert Uytterhoeven <[email protected]>
>> Cc: Anshuman Khandual <[email protected]>
>> Cc: Niklas Schnelle <[email protected]>
>> Cc: "Russell King (Oracle)" <[email protected]>
>> Cc: Linus Walleij <[email protected]>
>> Cc: Sebastian Reichel <[email protected]>
>> Cc: "Mike Rapoport (IBM)" <[email protected]>
>> Cc: "Kirill A. Shutemov" <[email protected]>
>> Cc: Zi Yan <[email protected]>
>> Acked-by: WANG Xuerui <[email protected]> # 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 */
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)