diff options
Diffstat (limited to 'arch/mips/kernel/mips-cpc.c')
-rw-r--r-- | arch/mips/kernel/mips-cpc.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c new file mode 100644 index 000000000..11964501c --- /dev/null +++ b/arch/mips/kernel/mips-cpc.c @@ -0,0 +1,80 @@ +/* + * Copyright (C) 2013 Imagination Technologies + * Author: Paul Burton <paul.burton@imgtec.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/errno.h> +#include <linux/percpu.h> +#include <linux/spinlock.h> + +#include <asm/mips-cm.h> +#include <asm/mips-cpc.h> + +void __iomem *mips_cpc_base; + +static DEFINE_PER_CPU_ALIGNED(spinlock_t, cpc_core_lock); + +static DEFINE_PER_CPU_ALIGNED(unsigned long, cpc_core_lock_flags); + +phys_addr_t __weak mips_cpc_phys_base(void) +{ + u32 cpc_base; + + if (!mips_cm_present()) + return 0; + + if (!(read_gcr_cpc_status() & CM_GCR_CPC_STATUS_EX_MSK)) + return 0; + + /* If the CPC is already enabled, leave it so */ + cpc_base = read_gcr_cpc_base(); + if (cpc_base & CM_GCR_CPC_BASE_CPCEN_MSK) + return cpc_base & CM_GCR_CPC_BASE_CPCBASE_MSK; + + /* Otherwise, give it the default address & enable it */ + cpc_base = mips_cpc_default_phys_base(); + write_gcr_cpc_base(cpc_base | CM_GCR_CPC_BASE_CPCEN_MSK); + return cpc_base; +} + +int mips_cpc_probe(void) +{ + phys_addr_t addr; + unsigned cpu; + + for_each_possible_cpu(cpu) + spin_lock_init(&per_cpu(cpc_core_lock, cpu)); + + addr = mips_cpc_phys_base(); + if (!addr) + return -ENODEV; + + mips_cpc_base = ioremap_nocache(addr, 0x8000); + if (!mips_cpc_base) + return -ENXIO; + + return 0; +} + +void mips_cpc_lock_other(unsigned int core) +{ + unsigned curr_core; + preempt_disable(); + curr_core = current_cpu_data.core; + spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core), + per_cpu(cpc_core_lock_flags, curr_core)); + write_cpc_cl_other(core << CPC_Cx_OTHER_CORENUM_SHF); +} + +void mips_cpc_unlock_other(void) +{ + unsigned curr_core = current_cpu_data.core; + spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core), + per_cpu(cpc_core_lock_flags, curr_core)); + preempt_enable(); +} |