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 #include <asm/inst.h> 15 16 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 17 extern void epapr_ev_idle(void); 18 extern u32 epapr_ev_idle_start[]; 19 #endif 20 21 bool epapr_paravirt_enabled; 22 static bool __maybe_unused epapr_has_idle; 23 24 static int __init early_init_dt_scan_epapr(unsigned long node, 25 const char *uname, 26 int depth, void *data) 27 { 28 const u32 *insts; 29 int len; 30 int i; 31 32 insts = of_get_flat_dt_prop(node, "hcall-instructions", &len); 33 if (!insts) 34 return 0; 35 36 if (len % 4 || len > (4 * 4)) 37 return -1; 38 39 for (i = 0; i < (len / 4); i++) { 40 struct ppc_inst inst = ppc_inst(be32_to_cpu(insts[i])); 41 patch_instruction(epapr_hypercall_start + i, inst); 42 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 43 patch_instruction(epapr_ev_idle_start + i, inst); 44 #endif 45 } 46 47 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 48 if (of_get_flat_dt_prop(node, "has-idle", NULL)) 49 epapr_has_idle = true; 50 #endif 51 52 epapr_paravirt_enabled = true; 53 54 return 1; 55 } 56 57 int __init epapr_paravirt_early_init(void) 58 { 59 of_scan_flat_dt(early_init_dt_scan_epapr, NULL); 60 61 return 0; 62 } 63 64 static int __init epapr_idle_init(void) 65 { 66 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64) 67 if (epapr_has_idle) 68 ppc_md.power_save = epapr_ev_idle; 69 #endif 70 71 return 0; 72 } 73 74 postcore_initcall(epapr_idle_init); 75