kernel/linux.git/arch/arc, branch v6.1.85

work around gcc bugs with 'asm goto' with outputs

2024-02-23T08:12:28+00:00

commit 68fb3ca0e408e00db1c3f8fccdfa19e274c033be upstream. We've had issues with gcc and 'asm goto' before, and we created a 'asm_volatile_goto()' macro for that in the past: see commits 3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation bug") and a9f180345f53 ("compiler/gcc4: Make quirk for asm_volatile_goto() unconditional"). Then, much later, we ended up removing the workaround in commit 43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR 58670") because we no longer supported building the kernel with the affected gcc versions, but we left the macro uses around. Now, Sean Christopherson reports a new version of a very similar problem, which is fixed by re-applying that ancient workaround. But the problem in question is limited to only the 'asm goto with outputs' cases, so instead of re-introducing the old workaround as-is, let's rename and limit the workaround to just that much less common case. It looks like there are at least two separate issues that all hit in this area: (a) some versions of gcc don't mark the asm goto as 'volatile' when it has outputs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420 which is easy to work around by just adding the 'volatile' by hand. (b) Internal compiler errors: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422 which are worked around by adding the extra empty 'asm' as a barrier, as in the original workaround. but the problem Sean sees may be a third thing since it involves bad code generation (not an ICE) even with the manually added 'volatile'. The same old workaround works for this case, even if this feels a bit like voodoo programming and may only be hiding the issue. Reported-and-tested-by: Sean Christopherson Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/ Cc: Nick Desaulniers Cc: Uros Bizjak Cc: Jakub Jelinek Cc: Andrew Pinski Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ARC: fix spare error

2024-01-20T10:50:08+00:00

[ Upstream commit aca02d933f63ba8bc84258bf35f9ffaf6b664336 ] Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202312082320.VDN5A9hb-lkp@intel.com/ Signed-off-by: Vineet Gupta Signed-off-by: Sasha Levin

ARC: atomics: Add compiler barrier to atomic operations...

2023-09-19T10:28:04+00:00

commit 42f51fb24fd39cc547c086ab3d8a314cc603a91c upstream. ... to avoid unwanted gcc optimizations SMP kernels fail to boot with commit 596ff4a09b89 ("cpumask: re-introduce constant-sized cpumask optimizations"). | | percpu: BUG: failure at mm/percpu.c:2981/pcpu_build_alloc_info()! | The write operation performed by the SCOND instruction in the atomic inline asm code is not properly passed to the compiler. The compiler cannot correctly optimize a nested loop that runs through the cpumask in the pcpu_build_alloc_info() function. Fix this by add a compiler barrier (memory clobber in inline asm). Apparently atomic ops used to have memory clobber implicitly via surrounding smp_mb(). However commit b64be6836993c431e ("ARC: atomics: implement relaxed variants") removed the smp_mb() for the relaxed variants, but failed to add the explicit compiler barrier. Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/135 Cc: # v6.3+ Fixes: b64be6836993c43 ("ARC: atomics: implement relaxed variants") Signed-off-by: Pavel Kozlov Signed-off-by: Vineet Gupta [vgupta: tweaked the changelog and added Fixes tag] Signed-off-by: Greg Kroah-Hartman

ARC: define ASM_NL and __ALIGN(_STR) outside #ifdef ASSEMBLY guard

2023-07-19T14:21:42+00:00

[ Upstream commit 92e2921eeafdfca9acd9b83f07d2b7ca099bac24 ] ASM_NL is useful not only in *.S files but also in .c files for using inline assembler in C code. On ARC, however, ASM_NL is evaluated inconsistently. It is expanded to a backquote (`) in *.S files, but a semicolon (;) in *.c files because arch/arc/include/asm/linkage.h defines it inside #ifdef __ASSEMBLY__, so the definition for C code falls back to the default value defined in include/linux/linkage.h. If ASM_NL is used in inline assembler in .c files, it will result in wrong assembly code because a semicolon is not an instruction separator, but the start of a comment for ARC. Move ASM_NL (also __ALIGN and __ALIGN_STR) out of the #ifdef. Fixes: 9df62f054406 ("arch: use ASM_NL instead of ';' for assembler new line character in the macro") Fixes: 8d92e992a785 ("ARC: define __ALIGN_STR and __ALIGN symbols for ARC") Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

mm/fault: convert remaining simple cases to lock_mm_and_find_vma()

2023-07-01T11:16:25+00:00

commit a050ba1e7422f2cc60ff8bfde3f96d34d00cb585 upstream. This does the simple pattern conversion of alpha, arc, csky, hexagon, loongarch, nios2, sh, sparc32, and xtensa to the lock_mm_and_find_vma() helper. They all have the regular fault handling pattern without odd special cases. The remaining architectures all have something that keeps us from a straightforward conversion: ia64 and parisc have stacks that can grow both up as well as down (and ia64 has special address region checks). And m68k, microblaze, openrisc, sparc64, and um end up having extra rules about only expanding the stack down a limited amount below the user space stack pointer. That is something that x86 used to do too (long long ago), and it probably could just be skipped, but it still makes the conversion less than trivial. Note that this conversion was done manually and with the exception of alpha without any build testing, because I have a fairly limited cross- building environment. The cases are all simple, and I went through the changes several times, but... Signed-off-by: Linus Torvalds Signed-off-by: Samuel Mendoza-Jonas Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman

ARC: mm: fix leakage of memory allocated for PTE

2022-10-17T23:32:12+00:00

Since commit d9820ff ("ARC: mm: switch pgtable_t back to struct page *") a memory leakage problem occurs. Memory allocated for page table entries not released during process termination. This issue can be reproduced by a small program that allocates a large amount of memory. After several runs, you'll see that the amount of free memory has reduced and will continue to reduce after each run. All ARC CPUs are effected by this issue. The issue was introduced since the kernel stable release v5.15-rc1. As described in commit d9820ff after switch pgtable_t back to struct page *, a pointer to "struct page" and appropriate functions are used to allocate and free a memory page for PTEs, but the pmd_pgtable macro hasn't changed and returns the direct virtual address from the PMD (PGD) entry. Than this address used as a parameter in the __pte_free() and as a result this function couldn't release memory page allocated for PTEs. Fix this issue by changing the pmd_pgtable macro and returning pointer to struct page. Fixes: d9820ff76f95 ("ARC: mm: switch pgtable_t back to struct page *") Cc: Mike Rapoport Cc: # 5.15.x Signed-off-by: Pavel Kozlov Signed-off-by: Vineet Gupta

arc: update config files

2022-10-17T23:32:12+00:00

Clean up config files by: - removing configs that were deleted in the past - removing configs not in tree and without recently pending patches - adding new configs that are replacements for old configs in the file For some detailed information, see Link. Link: https://lore.kernel.org/kernel-janitors/20220929090645.1389-1-lukas.bulwahn@gmail.com/ Signed-off-by: Lukas Bulwahn Signed-off-by: Vineet Gupta

arc: iounmap() arg is volatile

2022-10-17T23:32:12+00:00

Add 'volatile' to iounmap()'s argument to prevent build warnings. This make it the same as other major architectures. Placates these warnings: (12 such warnings) ../drivers/video/fbdev/riva/fbdev.c: In function 'rivafb_probe': ../drivers/video/fbdev/riva/fbdev.c:2067:42: error: passing argument 1 of 'iounmap' discards 'volatile' qualifier from pointer target type [-Werror=discarded-qualifiers] 2067 | iounmap(default_par->riva.PRAMIN); Fixes: 1162b0701b14b ("ARC: I/O and DMA Mappings") Signed-off-by: Randy Dunlap Cc: Vineet Gupta Cc: linux-snps-arc@lists.infradead.org Cc: Arnd Bergmann Signed-off-by: Vineet Gupta

arc: dts: Harmonize EHCI/OHCI DT nodes name

2022-10-17T23:32:12+00:00

In accordance with the Generic EHCI/OHCI bindings the corresponding node name is suppose to comply with the Generic USB HCD DT schema, which requires the USB nodes to have the name acceptable by the regexp: "^usb(@.*)?" . Make sure the "generic-ehci" and "generic-ohci"-compatible nodes are correctly named. Signed-off-by: Serge Semin Acked-by: Alexey Brodkin Acked-by: Krzysztof Kozlowski Signed-off-by: Vineet Gupta

ARC: bitops: Change __fls to return unsigned long

2022-10-17T23:32:12+00:00

As per asm-generic definition and other architectures __fls should return unsigned long. No functional change is expected as return value should fit in unsigned long. Reviewed-by: Cezary Rojewski Signed-off-by: Amadeusz Sławiński Signed-off-by: Vineet Gupta

kernel/linux.git/arch/arc, branch v6.1.85

work around gcc bugs with 'asm goto' with outputs

ARC: fix spare error

ARC: atomics: Add compiler barrier to atomic operations...

ARC: define ASM_NL and __ALIGN(_STR) outside #ifdef __ASSEMBLY__ guard

mm/fault: convert remaining simple cases to lock_mm_and_find_vma()

ARC: mm: fix leakage of memory allocated for PTE

arc: update config files

arc: iounmap() arg is volatile

arc: dts: Harmonize EHCI/OHCI DT nodes name

ARC: bitops: Change __fls to return unsigned long

ARC: define ASM_NL and __ALIGN(_STR) outside #ifdef ASSEMBLY guard