1 /* 2 * c 2001 PPC 64 Team, IBM Corp 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 */ 9 10 #include <linux/threads.h> 11 #include <linux/module.h> 12 #include <linux/lmb.h> 13 14 #include <asm/firmware.h> 15 #include <asm/lppaca.h> 16 #include <asm/paca.h> 17 #include <asm/sections.h> 18 #include <asm/pgtable.h> 19 #include <asm/iseries/lpar_map.h> 20 #include <asm/iseries/hv_types.h> 21 22 /* This symbol is provided by the linker - let it fill in the paca 23 * field correctly */ 24 extern unsigned long __toc_start; 25 26 #ifdef CONFIG_PPC_BOOK3S 27 28 /* 29 * The structure which the hypervisor knows about - this structure 30 * should not cross a page boundary. The vpa_init/register_vpa call 31 * is now known to fail if the lppaca structure crosses a page 32 * boundary. The lppaca is also used on legacy iSeries and POWER5 33 * pSeries boxes. The lppaca is 640 bytes long, and cannot readily 34 * change since the hypervisor knows its layout, so a 1kB alignment 35 * will suffice to ensure that it doesn't cross a page boundary. 36 */ 37 struct lppaca lppaca[] = { 38 [0 ... (NR_CPUS-1)] = { 39 .desc = 0xd397d781, /* "LpPa" */ 40 .size = sizeof(struct lppaca), 41 .dyn_proc_status = 2, 42 .decr_val = 0x00ff0000, 43 .fpregs_in_use = 1, 44 .end_of_quantum = 0xfffffffffffffffful, 45 .slb_count = 64, 46 .vmxregs_in_use = 0, 47 .page_ins = 0, 48 }, 49 }; 50 51 #endif /* CONFIG_PPC_BOOK3S */ 52 53 #ifdef CONFIG_PPC_STD_MMU_64 54 55 /* 56 * 3 persistent SLBs are registered here. The buffer will be zero 57 * initially, hence will all be invaild until we actually write them. 58 */ 59 struct slb_shadow slb_shadow[] __cacheline_aligned = { 60 [0 ... (NR_CPUS-1)] = { 61 .persistent = SLB_NUM_BOLTED, 62 .buffer_length = sizeof(struct slb_shadow), 63 }, 64 }; 65 66 #endif /* CONFIG_PPC_STD_MMU_64 */ 67 68 /* The Paca is an array with one entry per processor. Each contains an 69 * lppaca, which contains the information shared between the 70 * hypervisor and Linux. 71 * On systems with hardware multi-threading, there are two threads 72 * per processor. The Paca array must contain an entry for each thread. 73 * The VPD Areas will give a max logical processors = 2 * max physical 74 * processors. The processor VPD array needs one entry per physical 75 * processor (not thread). 76 */ 77 struct paca_struct *paca; 78 EXPORT_SYMBOL(paca); 79 80 struct paca_struct boot_paca; 81 82 void __init initialise_paca(struct paca_struct *new_paca, int cpu) 83 { 84 /* The TOC register (GPR2) points 32kB into the TOC, so that 64kB 85 * of the TOC can be addressed using a single machine instruction. 86 */ 87 unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL; 88 89 #ifdef CONFIG_PPC_BOOK3S 90 new_paca->lppaca_ptr = &lppaca[cpu]; 91 #else 92 new_paca->kernel_pgd = swapper_pg_dir; 93 #endif 94 new_paca->lock_token = 0x8000; 95 new_paca->paca_index = cpu; 96 new_paca->kernel_toc = kernel_toc; 97 new_paca->kernelbase = (unsigned long) _stext; 98 new_paca->kernel_msr = MSR_KERNEL; 99 new_paca->hw_cpu_id = 0xffff; 100 new_paca->__current = &init_task; 101 #ifdef CONFIG_PPC_STD_MMU_64 102 new_paca->slb_shadow_ptr = &slb_shadow[cpu]; 103 #endif /* CONFIG_PPC_STD_MMU_64 */ 104 } 105 106 static int __initdata paca_size; 107 108 void __init allocate_pacas(void) 109 { 110 int nr_cpus, cpu, limit; 111 112 /* 113 * We can't take SLB misses on the paca, and we want to access them 114 * in real mode, so allocate them within the RMA and also within 115 * the first segment. On iSeries they must be within the area mapped 116 * by the HV, which is HvPagesToMap * HVPAGESIZE bytes. 117 */ 118 limit = min(0x10000000ULL, lmb.rmo_size); 119 if (firmware_has_feature(FW_FEATURE_ISERIES)) 120 limit = min(limit, HvPagesToMap * HVPAGESIZE); 121 122 nr_cpus = NR_CPUS; 123 /* On iSeries we know we can never have more than 64 cpus */ 124 if (firmware_has_feature(FW_FEATURE_ISERIES)) 125 nr_cpus = min(64, nr_cpus); 126 127 paca_size = PAGE_ALIGN(sizeof(struct paca_struct) * nr_cpus); 128 129 paca = __va(lmb_alloc_base(paca_size, PAGE_SIZE, limit)); 130 memset(paca, 0, paca_size); 131 132 printk(KERN_DEBUG "Allocated %u bytes for %d pacas at %p\n", 133 paca_size, nr_cpus, paca); 134 135 /* Can't use for_each_*_cpu, as they aren't functional yet */ 136 for (cpu = 0; cpu < nr_cpus; cpu++) 137 initialise_paca(&paca[cpu], cpu); 138 } 139 140 void __init free_unused_pacas(void) 141 { 142 int new_size; 143 144 new_size = PAGE_ALIGN(sizeof(struct paca_struct) * num_possible_cpus()); 145 146 if (new_size >= paca_size) 147 return; 148 149 lmb_free(__pa(paca) + new_size, paca_size - new_size); 150 151 printk(KERN_DEBUG "Freed %u bytes for unused pacas\n", 152 paca_size - new_size); 153 154 paca_size = new_size; 155 } 156