/*
   * 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/firmware.h>

  #include <asm/lppaca.h>

  #include <asm/paca.h>

  #include <asm/sections.h>

  #include <asm/pgtable.h>

  #include <asm/iseries/lpar_map.h>
  #include <asm/iseries/hv_types.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 legacy iSeries and 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 = 0xd397d781,	/* "LpPa" */
  		.size = sizeof(struct lppaca),
  		.dyn_proc_status = 2,
  		.decr_val = 0x00ff0000,
  		.fpregs_in_use = 1,
  		.end_of_quantum = 0xfffffffffffffffful,
  		.slb_count = 64,
  		.vmxregs_in_use = 0,

  		.page_ins = 0,

  	},
  };

  static struct lppaca *extra_lppacas;
  static long __initdata lppaca_size;
  
  static void 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 *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 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 = SLB_NUM_BOLTED,
  		.buffer_length = 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);

  struct paca_struct boot_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;

  #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. On iSeries they must be within the area mapped
  	 * by the HV, which is HvPagesToMap * HVPAGESIZE bytes.
  	 */

  	limit = min(0x10000000ULL, ppc64_rma_size);

  	if (firmware_has_feature(FW_FEATURE_ISERIES))
  		limit = min(limit, HvPagesToMap * HVPAGESIZE);

  	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
  ",

  		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
  ",
  		paca_size - new_size);

  	paca_size = new_size;

  
  	free_lppacas();

  }