diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2024-10-21 10:07:37 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-11-05 17:12:34 -0800 |
| commit | 001217defda86d0d6a5a9e6cf77a6b813857e7e3 (patch) | |
| tree | 9e6a69a137b289353ef07b54663db76f4b811e02 | |
| parent | 74ef070e325465a1b364db6a5c6859785537f835 (diff) | |
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 <ubizjak@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | include/linux/percpu-defs.h | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index 7fa88c5f4b26..e1cf7982424f 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) |