1 /* 2 * Copyright (C) 2013 Imagination Technologies 3 * Author: Paul Burton <paul.burton@imgtec.com> 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License as published by the 7 * Free Software Foundation; either version 2 of the License, or (at your 8 * option) any later version. 9 */ 10 11 #include <linux/errno.h> 12 #include <linux/percpu.h> 13 #include <linux/spinlock.h> 14 15 #include <asm/mips-cm.h> 16 #include <asm/mips-cpc.h> 17 18 void __iomem *mips_cpc_base; 19 20 static DEFINE_PER_CPU_ALIGNED(spinlock_t, cpc_core_lock); 21 22 static DEFINE_PER_CPU_ALIGNED(unsigned long, cpc_core_lock_flags); 23 24 phys_addr_t __weak mips_cpc_phys_base(void) 25 { 26 u32 cpc_base; 27 28 if (!mips_cm_present()) 29 return 0; 30 31 if (!(read_gcr_cpc_status() & CM_GCR_CPC_STATUS_EX_MSK)) 32 return 0; 33 34 /* If the CPC is already enabled, leave it so */ 35 cpc_base = read_gcr_cpc_base(); 36 if (cpc_base & CM_GCR_CPC_BASE_CPCEN_MSK) 37 return cpc_base & CM_GCR_CPC_BASE_CPCBASE_MSK; 38 39 /* Otherwise, give it the default address & enable it */ 40 cpc_base = mips_cpc_default_phys_base(); 41 write_gcr_cpc_base(cpc_base | CM_GCR_CPC_BASE_CPCEN_MSK); 42 return cpc_base; 43 } 44 45 int mips_cpc_probe(void) 46 { 47 phys_addr_t addr; 48 unsigned cpu; 49 50 for_each_possible_cpu(cpu) 51 spin_lock_init(&per_cpu(cpc_core_lock, cpu)); 52 53 addr = mips_cpc_phys_base(); 54 if (!addr) 55 return -ENODEV; 56 57 mips_cpc_base = ioremap_nocache(addr, 0x8000); 58 if (!mips_cpc_base) 59 return -ENXIO; 60 61 return 0; 62 } 63 64 void mips_cpc_lock_other(unsigned int core) 65 { 66 unsigned curr_core; 67 preempt_disable(); 68 curr_core = current_cpu_data.core; 69 spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core), 70 per_cpu(cpc_core_lock_flags, curr_core)); 71 write_cpc_cl_other(core << CPC_Cx_OTHER_CORENUM_SHF); 72 } 73 74 void mips_cpc_unlock_other(void) 75 { 76 unsigned curr_core = current_cpu_data.core; 77 spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core), 78 per_cpu(cpc_core_lock_flags, curr_core)); 79 preempt_enable(); 80 } 81