text: /*
   * c 2001 PPC 64 Team, IBM Corp
   *
   *      This program is free software; you can redistribute it and/or
   *      modify it under the terms of the GNU General Public License
   *      as published by the Free Software Foundation; either version
   *      2 of the License, or (at your option) any later version.
   */
  
  #include <linux/smp.h>
  #include <linux/export.h>
  #include <linux/memblock.h>
  
  #include <asm/lppaca.h>
  #include <asm/paca.h>
  #include <asm/sections.h>
  #include <asm/pgtable.h>
  #include <asm/kexec.h>
  
  /* This symbol is provided by the linker - let it fill in the paca
   * field correctly */
  extern unsigned long __toc_start;
  
  #ifdef CONFIG_PPC_BOOK3S
  
  /*
   * The structure which the hypervisor knows about - this structure
   * should not cross a page boundary.  The vpa_init/register_vpa call
   * is now known to fail if the lppaca structure crosses a page
   * boundary.  The lppaca is also used on POWER5 pSeries boxes.
   * The lppaca is 640 bytes long, and cannot readily
   * change since the hypervisor knows its layout, so a 1kB alignment
   * will suffice to ensure that it doesn't cross a page boundary.
   */
  struct lppaca lppaca[] = {
  	[0 ... (NR_LPPACAS-1)] = {
  		.desc = cpu_to_be32(0xd397d781),	/* "LpPa" */
  		.size = cpu_to_be16(sizeof(struct lppaca)),
  		.fpregs_in_use = 1,
  		.slb_count = cpu_to_be16(64),
  		.vmxregs_in_use = 0,
  		.page_ins = 0,
  	},
  };
  
  static struct lppaca *extra_lppacas;
  static long __initdata lppaca_size;
  
  static void __init allocate_lppacas(int nr_cpus, unsigned long limit)
  {
  	if (nr_cpus <= NR_LPPACAS)
  		return;
  
  	lppaca_size = PAGE_ALIGN(sizeof(struct lppaca) *
  				 (nr_cpus - NR_LPPACAS));
  	extra_lppacas = __va(memblock_alloc_base(lppaca_size,
  						 PAGE_SIZE, limit));
  }
  
  static struct lppaca * __init new_lppaca(int cpu)
  {
  	struct lppaca *lp;
  
  	if (cpu < NR_LPPACAS)
  		return &lppaca[cpu];
  
  	lp = extra_lppacas + (cpu - NR_LPPACAS);
  	*lp = lppaca[0];
  
  	return lp;
  }
  
  static void __init free_lppacas(void)
  {
  	long new_size = 0, nr;
  
  	if (!lppaca_size)
  		return;
  	nr = num_possible_cpus() - NR_LPPACAS;
  	if (nr > 0)
  		new_size = PAGE_ALIGN(nr * sizeof(struct lppaca));
  	if (new_size >= lppaca_size)
  		return;
  
  	memblock_free(__pa(extra_lppacas) + new_size, lppaca_size - new_size);
  	lppaca_size = new_size;
  }
  
  #else
  
  static inline void allocate_lppacas(int nr_cpus, unsigned long limit) { }
  static inline void free_lppacas(void) { }
  
  #endif /* CONFIG_PPC_BOOK3S */
  
  #ifdef CONFIG_PPC_STD_MMU_64
  
  /*
   * 3 persistent SLBs are registered here.  The buffer will be zero
   * initially, hence will all be invaild until we actually write them.
   */
  struct slb_shadow slb_shadow[] __cacheline_aligned = {
  	[0 ... (NR_CPUS-1)] = {
  		.persistent = cpu_to_be32(SLB_NUM_BOLTED),
  		.buffer_length = cpu_to_be32(sizeof(struct slb_shadow)),
  	},
  };
  
  #endif /* CONFIG_PPC_STD_MMU_64 */
  
  /* The Paca is an array with one entry per processor.  Each contains an
   * lppaca, which contains the information shared between the
   * hypervisor and Linux.
   * On systems with hardware multi-threading, there are two threads
   * per processor.  The Paca array must contain an entry for each thread.
   * The VPD Areas will give a max logical processors = 2 * max physical
   * processors.  The processor VPD array needs one entry per physical
   * processor (not thread).
   */
  struct paca_struct *paca;
  EXPORT_SYMBOL(paca);
  
  void __init initialise_paca(struct paca_struct *new_paca, int cpu)
  {
         /* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
  	* of the TOC can be addressed using a single machine instruction.
  	*/
  	unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
  
  #ifdef CONFIG_PPC_BOOK3S
  	new_paca->lppaca_ptr = new_lppaca(cpu);
  #else
  	new_paca->kernel_pgd = swapper_pg_dir;
  #endif
  	new_paca->lock_token = 0x8000;
  	new_paca->paca_index = cpu;
  	new_paca->kernel_toc = kernel_toc;
  	new_paca->kernelbase = (unsigned long) _stext;
  	new_paca->kernel_msr = MSR_KERNEL;
  	new_paca->hw_cpu_id = 0xffff;
  	new_paca->kexec_state = KEXEC_STATE_NONE;
  	new_paca->__current = &init_task;
  	new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
  #ifdef CONFIG_PPC_STD_MMU_64
  	new_paca->slb_shadow_ptr = &slb_shadow[cpu];
  #endif /* CONFIG_PPC_STD_MMU_64 */
  }
  
  /* Put the paca pointer into r13 and SPRG_PACA */
  void setup_paca(struct paca_struct *new_paca)
  {
  	/* Setup r13 */
  	local_paca = new_paca;
  
  #ifdef CONFIG_PPC_BOOK3E
  	/* On Book3E, initialize the TLB miss exception frames */
  	mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
  #else
  	/* In HV mode, we setup both HPACA and PACA to avoid problems
  	 * if we do a GET_PACA() before the feature fixups have been
  	 * applied
  	 */
  	if (cpu_has_feature(CPU_FTR_HVMODE))
  		mtspr(SPRN_SPRG_HPACA, local_paca);
  #endif
  	mtspr(SPRN_SPRG_PACA, local_paca);
  
  }
  
  static int __initdata paca_size;
  
  void __init allocate_pacas(void)
  {
  	int cpu, limit;
  
  	/*
  	 * We can't take SLB misses on the paca, and we want to access them
  	 * in real mode, so allocate them within the RMA and also within
  	 * the first segment.
  	 */
  	limit = min(0x10000000ULL, ppc64_rma_size);
  
  	paca_size = PAGE_ALIGN(sizeof(struct paca_struct) * nr_cpu_ids);
  
  	paca = __va(memblock_alloc_base(paca_size, PAGE_SIZE, limit));
  	memset(paca, 0, paca_size);
  
  	printk(KERN_DEBUG "Allocated %u bytes for %d pacas at %p\n",
  		paca_size, nr_cpu_ids, paca);
  
  	allocate_lppacas(nr_cpu_ids, limit);
  
  	/* Can't use for_each_*_cpu, as they aren't functional yet */
  	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
  		initialise_paca(&paca[cpu], cpu);
  }
  
  void __init free_unused_pacas(void)
  {
  	int new_size;
  
  	new_size = PAGE_ALIGN(sizeof(struct paca_struct) * nr_cpu_ids);
  
  	if (new_size >= paca_size)
  		return;
  
  	memblock_free(__pa(paca) + new_size, paca_size - new_size);
  
  	printk(KERN_DEBUG "Freed %u bytes for unused pacas\n",
  		paca_size - new_size);
  
  	paca_size = new_size;
  
  	free_lppacas();
  }
  