1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ePAPR para-virtualization support. 4 * 5 * Copyright (C) 2012 Freescale Semiconductor, Inc. 6 */ 7 8 #include <linux/of.h> 9 #include <linux/of_fdt.h> 10 #include <asm/epapr_hcalls.h> 11 #include <asm/cacheflush.h> 12 #include <asm/code-patching.h> 13 #include <asm/machdep.h> 14 15 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 16 extern void epapr_ev_idle(void); 17 extern u32 epapr_ev_idle_start[]; 18 #endif 19 20 bool epapr_paravirt_enabled; 21 static bool __maybe_unused epapr_has_idle; 22 23 static int __init early_init_dt_scan_epapr(unsigned long node, 24 const char *uname, 25 int depth, void *data) 26 { 27 const u32 *insts; 28 int len; 29 int i; 30 31 insts = of_get_flat_dt_prop(node, "hcall-instructions", &len); 32 if (!insts) 33 return 0; 34 35 if (len % 4 || len > (4 * 4)) 36 return -1; 37 38 for (i = 0; i < (len / 4); i++) { 39 u32 inst = be32_to_cpu(insts[i]); 40 patch_instruction(epapr_hypercall_start + i, inst); 41 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 42 patch_instruction(epapr_ev_idle_start + i, inst); 43 #endif 44 } 45 46 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 47 if (of_get_flat_dt_prop(node, "has-idle", NULL)) 48 epapr_has_idle = true; 49 #endif 50 51 epapr_paravirt_enabled = true; 52 53 return 1; 54 } 55 56 int __init epapr_paravirt_early_init(void) 57 { 58 of_scan_flat_dt(early_init_dt_scan_epapr, NULL); 59 60 return 0; 61 } 62 63 static int __init epapr_idle_init(void) 64 { 65 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 66 if (epapr_has_idle) 67 ppc_md.power_save = epapr_ev_idle; 68 #endif 69 70 return 0; 71 } 72 73 postcore_initcall(epapr_idle_init); 74