From: Uros Bizjak Date: Mon, 21 Oct 2024 08:07:37 +0000 (+0200) Subject: percpu: introduce PERCPU_PTR() macro X-Git-Tag: v6.13-rc1~89^2~39 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=001217defda86d0d6a5a9e6cf77a6b813857e7e3;p=thirdparty%2Fkernel%2Flinux.git percpu: introduce PERCPU_PTR() macro Introduce PERCPU_PTR() macro to cast the percpu pointer from the percpu address space to a generic (kernel) address space. Use it in per_cpu_ptr() and related SHIFT_PERCPU_PTR() macros. Also remove common knowledge from SHIFT_PERCPU_PTR() comment, "weird cast" is just a standard way to inform sparse of a cast from the percpu address space to a generic address space. Link: https://lkml.kernel.org/r/20241021080856.48746-2-ubizjak@gmail.com Signed-off-by: Uros Bizjak Acked-by: Christoph Lameter Cc: Dennis Zhou Cc: Tejun Heo Signed-off-by: Andrew Morton --- diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index 7fa88c5f4b26c..e1cf7982424f1 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -220,15 +220,17 @@ do { \ (void)__vpp_verify; \ } while (0) +#define PERCPU_PTR(__p) \ + (typeof(*(__p)) __force __kernel *)(__p); + #ifdef CONFIG_SMP /* - * Add an offset to a pointer but keep the pointer as-is. Use RELOC_HIDE() - * to prevent the compiler from making incorrect assumptions about the - * pointer value. The weird cast keeps both GCC and sparse happy. + * Add an offset to a pointer. Use RELOC_HIDE() to prevent the compiler + * from making incorrect assumptions about the pointer value. */ #define SHIFT_PERCPU_PTR(__p, __offset) \ - RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset)) + RELOC_HIDE(PERCPU_PTR(__p), (__offset)) #define per_cpu_ptr(ptr, cpu) \ ({ \ @@ -258,7 +260,7 @@ do { \ ({ \ (void)(cpu); \ __verify_pcpu_ptr(ptr); \ - (typeof(*(ptr)) __kernel __force *)(ptr); \ + PERCPU_PTR(ptr); \ }) #define raw_cpu_ptr(ptr) per_cpu_ptr(ptr, 0)