1 /* 2 * ePAPR para-virtualization support. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License, version 2, as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write to the Free Software 15 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 16 * 17 * Copyright (C) 2012 Freescale Semiconductor, Inc. 18 */ 19 20 #include <linux/of.h> 21 #include <linux/of_fdt.h> 22 #include <asm/epapr_hcalls.h> 23 #include <asm/cacheflush.h> 24 #include <asm/code-patching.h> 25 #include <asm/machdep.h> 26 27 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 28 extern void epapr_ev_idle(void); 29 extern u32 epapr_ev_idle_start[]; 30 #endif 31 32 bool epapr_paravirt_enabled; 33 static bool __maybe_unused epapr_has_idle; 34 35 static int __init early_init_dt_scan_epapr(unsigned long node, 36 const char *uname, 37 int depth, void *data) 38 { 39 const u32 *insts; 40 int len; 41 int i; 42 43 insts = of_get_flat_dt_prop(node, "hcall-instructions", &len); 44 if (!insts) 45 return 0; 46 47 if (len % 4 || len > (4 * 4)) 48 return -1; 49 50 for (i = 0; i < (len / 4); i++) { 51 u32 inst = be32_to_cpu(insts[i]); 52 patch_instruction(epapr_hypercall_start + i, inst); 53 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 54 patch_instruction(epapr_ev_idle_start + i, inst); 55 #endif 56 } 57 58 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 59 if (of_get_flat_dt_prop(node, "has-idle", NULL)) 60 epapr_has_idle = true; 61 #endif 62 63 epapr_paravirt_enabled = true; 64 65 return 1; 66 } 67 68 int __init epapr_paravirt_early_init(void) 69 { 70 of_scan_flat_dt(early_init_dt_scan_epapr, NULL); 71 72 return 0; 73 } 74 75 static int __init epapr_idle_init(void) 76 { 77 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 78 if (epapr_has_idle) 79 ppc_md.power_save = epapr_ev_idle; 80 #endif 81 82 return 0; 83 } 84 85 postcore_initcall(epapr_idle_init); 86