On Thu, 2023-04-13 at 15:32 +0800, kernel test robot wrote:
> vim +/asm +244 arch/loongarch/include/asm/loongarch.h
>
> f2ac457a61389b Huacai Chen 2022-05-31 238
> 2c87b678639d25 Tianrui Zhao 2023-04-12 239 /* GCSR */
> 2c87b678639d25 Tianrui Zhao 2023-04-12 240 static inline u64 gcsr_read(u32 reg)
Try __always_inline instead of inline because this "function" will
definitely break up if it's not inlined.
And I guess we should have something like:
extern u64 __compiletime_error("gcsr_read parameter is not a constant")
__gcsr_read_non_const(void);
static __always_inline u64 gcsr_read(u32 reg)
{
u64 val = 0;
if (!__builtin_constant_p(reg))
return __gcsr_read_non_const();
asm volatile (
... ...
Or perhaps we should just rewrite gcsr_read to a macro.
> 2c87b678639d25 Tianrui Zhao 2023-04-12 241 {
> 2c87b678639d25 Tianrui Zhao 2023-04-12 242 u64 val = 0;
> 2c87b678639d25 Tianrui Zhao 2023-04-12 243 /* Instructions will be available in binutils later */
> 2c87b678639d25 Tianrui Zhao 2023-04-12 @244 asm volatile (
> 2c87b678639d25 Tianrui Zhao 2023-04-12 245 "parse_r __reg, %[val]\n\t"
> 2c87b678639d25 Tianrui Zhao 2023-04-12 246 /*
> 2c87b678639d25 Tianrui Zhao 2023-04-12 247 * read val from guest csr register %[reg]
> 2c87b678639d25 Tianrui Zhao 2023-04-12 248 * gcsrrd %[val], %[reg]
> 2c87b678639d25 Tianrui Zhao 2023-04-12 249 */
> 2c87b678639d25 Tianrui Zhao 2023-04-12 250 ".word 0x5 << 24 | %[reg] << 10 | 0 << 5 | __reg\n\t"
> 2c87b678639d25 Tianrui Zhao 2023-04-12 251 : [val] "+r" (val)
> 2c87b678639d25 Tianrui Zhao 2023-04-12 252 : [reg] "i" (reg)
> 2c87b678639d25 Tianrui Zhao 2023-04-12 253 : "memory");
> 2c87b678639d25 Tianrui Zhao 2023-04-12 254
> 2c87b678639d25 Tianrui Zhao 2023-04-12 255 return val;
> 2c87b678639d25 Tianrui Zhao 2023-04-12 256 }
> 2c87b678639d25 Tianrui Zhao 2023-04-12 257
>
--
Xi Ruoyao <xry111@xxxxxxxxxxx>
School of Aerospace Science and Technology, Xidian University
