diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/kernel/pj4-cp0.c | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/arch/arm/kernel/pj4-cp0.c b/arch/arm/kernel/pj4-cp0.c index 12352cd30ab2..8153e36b2491 100644 --- a/arch/arm/kernel/pj4-cp0.c +++ b/arch/arm/kernel/pj4-cp0.c @@ -72,6 +72,33 @@ static void __init pj4_cp_access_write(u32 value) : "=r" (temp) : "r" (value)); } +static int __init pj4_get_iwmmxt_version(void) +{ + u32 cp_access, wcid; + + cp_access = pj4_cp_access_read(); + pj4_cp_access_write(cp_access | 0xf); + + /* check if coprocessor 0 and 1 are available */ + if ((pj4_cp_access_read() & 0xf) != 0xf) { + pj4_cp_access_write(cp_access); + return -ENODEV; + } + + /* read iWMMXt coprocessor id register p1, c0 */ + __asm__ __volatile__ ("mrc p1, 0, %0, c0, c0, 0\n" : "=r" (wcid)); + + pj4_cp_access_write(cp_access); + + /* iWMMXt v1 */ + if ((wcid & 0xffffff00) == 0x56051000) + return 1; + /* iWMMXt v2 */ + if ((wcid & 0xffffff00) == 0x56052000) + return 2; + + return -EINVAL; +} /* * Disable CP0/CP1 on boot, and let call_fpe() and the iWMMXt lazy @@ -80,17 +107,22 @@ static void __init pj4_cp_access_write(u32 value) static int __init pj4_cp0_init(void) { u32 __maybe_unused cp_access; + int vers; if (!cpu_is_pj4()) return 0; + vers = pj4_get_iwmmxt_version(); + if (vers < 0) + return 0; + #ifndef CONFIG_IWMMXT pr_info("PJ4 iWMMXt coprocessor detected, but kernel support is missing.\n"); #else cp_access = pj4_cp_access_read() & ~0xf; pj4_cp_access_write(cp_access); - printk(KERN_INFO "PJ4 iWMMXt coprocessor enabled.\n"); + pr_info("PJ4 iWMMXt v%d coprocessor enabled.\n", vers); elf_hwcap |= HWCAP_IWMMXT; thread_register_notifier(&iwmmxt_notifier_block); #endif |