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authorLinus Torvalds <torvalds@linux-foundation.org>2025-09-29 19:14:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-09-29 19:14:25 -0700
commit9cc220a422113f665e13364be1411c7bba9e3e30 (patch)
treeb5040ec3821b0812b70daa2c102a375b1b53f3a1 /include/linux
parentf1004b2f19d7e9add9d707f64d9fcbc50f67921b (diff)
parent088bb10e37252034ec58a6152f20bfdc8a837f54 (diff)
Merge tag 's390-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Alexander Gordeev: - Refactor SCLP memory hotplug code - Introduce common boot_panic() decompressor helper macro and use it to get rid of nearly few identical implementations - Take into account additional key generation flags and forward it to the ep11 implementation. With that allow users to modify the key generation process, e.g. provide valid combinations of XCP_BLOB_* flags - Replace kmalloc() + copy_from_user() with memdup_user_nul() in s390 debug facility and HMC driver - Add DAX support for DCSS memory block devices - Make the compiler statement attribute "assume" available with a new __assume macro - Rework ffs() and fls() family bitops functions, including source code improvements and generated code optimizations. Use the newly introduced __assume macro for that - Enable additional network features in default configurations - Use __GFP_ACCOUNT flag for user page table allocations to add missing kmemcg accounting - Add WQ_PERCPU flag to explicitly request the use of the per-CPU workqueue for 3590 tape driver - Switch power reading to the per-CPU and the Hiperdispatch to the default workqueue - Add memory allocation profiling hooks to allow better profiling data and the /proc/allocinfo output similar to other architectures * tag 's390-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (21 commits) s390/mm: Add memory allocation profiling hooks s390: Replace use of system_wq with system_dfl_wq s390/diag324: Replace use of system_wq with system_percpu_wq s390/tape: Add WQ_PERCPU to alloc_workqueue users s390/bitops: Switch to generic ffs() if supported by compiler s390/bitops: Switch to generic fls(), fls64(), etc. s390/mm: Use __GFP_ACCOUNT for user page table allocations s390/configs: Enable additional network features s390/bitops: Cleanup __flogr() s390/bitops: Use __assume() for __flogr() inline assembly return value compiler_types: Add __assume macro s390/bitops: Limit return value range of __flogr() s390/dcssblk: Add DAX support s390/hmcdrv: Replace kmalloc() + copy_from_user() with memdup_user_nul() s390/debug: Replace kmalloc() + copy_from_user() with memdup_user_nul() s390/pkey: Forward keygenflags to ep11_unwrapkey s390/boot: Add common boot_panic() code s390/bitops: Optimize inlining s390/bitops: Slightly optimize ffs() and fls64() s390/sclp: Move memory hotplug code for better modularity ...
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/compiler_types.h23
1 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 16755431fc11..2f3e80bf9f35 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -330,6 +330,29 @@ struct ftrace_likely_data {
#endif
/*
+ * The assume attribute is used to indicate that a certain condition is
+ * assumed to be true. If this condition is violated at runtime, the behavior
+ * is undefined. Compilers may or may not use this indication to generate
+ * optimized code.
+ *
+ * Note that the clang documentation states that optimizers may react
+ * differently to this attribute, and this may even have a negative
+ * performance impact. Therefore this attribute should be used with care.
+ *
+ * Optional: only supported since gcc >= 13
+ * Optional: only supported since clang >= 19
+ *
+ * gcc: https://gcc.gnu.org/onlinedocs/gcc/Statement-Attributes.html#index-assume-statement-attribute
+ * clang: https://clang.llvm.org/docs/AttributeReference.html#id13
+ *
+ */
+#ifdef CONFIG_CC_HAS_ASSUME
+# define __assume(expr) __attribute__((__assume__(expr)))
+#else
+# define __assume(expr)
+#endif
+
+/*
* Optional: only supported since gcc >= 15
* Optional: only supported since clang >= 18
*