diff options
| author | Xiang Wang <merle@hardenedlinux.org> | 2019-11-26 16:06:29 +0530 |
|---|---|---|
| committer | Anup Patel <anup@brainfault.org> | 2019-11-26 16:06:29 +0530 |
| commit | c96cc03fcc2723fa007b65e5ae6fe2673ea41413 (patch) | |
| tree | 0ba08cbedbf6cefea45618ccdaf9180c27e9929c /include/sbi/riscv_asm.h | |
| parent | 75f903dd78e2419057d04e14d6720fde764cbf78 (diff) | |
lib: Fix CPU capabilities detection function
On some platforms, misa may not be implemented. On such a platform,
reading misa will get 0. At this time, platform is required to
implement a non-standard function to detect the CPU's capabilities.
Therefore, this modification add interfaces for non-standard function.
The MXL field of misa is always at the highest two bits, whether it
is a 32-bit 64-bit or a 128-bit machine. Therefore, this modification
fixes the use of a fixed offset to detect the machine length.
Signed-off-by: Xiang Wang <merle@hardenedlinux.org>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Diffstat (limited to 'include/sbi/riscv_asm.h')
| -rw-r--r-- | include/sbi/riscv_asm.h | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/include/sbi/riscv_asm.h b/include/sbi/riscv_asm.h index 4f12c03..04502e1 100644 --- a/include/sbi/riscv_asm.h +++ b/include/sbi/riscv_asm.h @@ -159,22 +159,18 @@ void csr_write_num(int csr_num, unsigned long val); __asm__ __volatile__("wfi" ::: "memory"); \ } while (0) -static inline int misa_extension(char ext) -{ - return csr_read(CSR_MISA) & (1 << (ext - 'A')); -} +/* Determine CPU extension, return non-zero support */ +int misa_extension(char ext); -static inline int misa_xlen(void) -{ - return ((long)csr_read(CSR_MISA) < 0) ? 64 : 32; -} +/* Get MXL field of misa, return -1 on error */ +int misa_xlen(void); static inline void misa_string(char *out, unsigned int out_sz) { - unsigned long i, val = csr_read(CSR_MISA); + unsigned long i; for (i = 0; i < 26; i++) { - if (val & (1 << i)) { + if (misa_extension('A' + i)) { *out = 'A' + i; out++; } |