linux/arch/powerpc/kernel/paca.c

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/*
* 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>
2008-08-30 01:43:47 +00:00
#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.
*/
static struct slb_shadow *slb_shadow;
static void __init allocate_slb_shadows(int nr_cpus, int limit)
{
int size = PAGE_ALIGN(sizeof(struct slb_shadow) * nr_cpus);
slb_shadow = __va(memblock_alloc_base(size, PAGE_SIZE, limit));
memset(slb_shadow, 0, size);
}
static struct slb_shadow * __init init_slb_shadow(int cpu)
{
struct slb_shadow *s = &slb_shadow[cpu];
s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
s->buffer_length = cpu_to_be32(sizeof(*s));
return s;
}
#else /* CONFIG_PPC_STD_MMU_64 */
static void __init allocate_slb_shadows(int nr_cpus, int limit) { }
#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;
/* Only set MSR:IR/DR when MMU is initialized */
new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
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 = init_slb_shadow(cpu);
#endif /* CONFIG_PPC_STD_MMU_64 */
#ifdef CONFIG_PPC_BOOK3E
/* For now -- if we have threads this will be adjusted later */
new_paca->tcd_ptr = &new_paca->tcd;
#endif
}
/* 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);
allocate_slb_shadows(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();
}