head_32.S
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/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* 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, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*
* TILE startup code.
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/thread_info.h>
#include <asm/processor.h>
#include <asm/asm-offsets.h>
#include <hv/hypervisor.h>
#include <arch/chip.h>
#include <arch/spr_def.h>
/*
* This module contains the entry code for kernel images. It performs the
* minimal setup needed to call the generic C routines.
*/
__HEAD
ENTRY(_start)
/* Notify the hypervisor of what version of the API we want */
{
movei r1, TILE_CHIP
movei r2, TILE_CHIP_REV
}
{
moveli r0, _HV_VERSION
jal hv_init
}
/* Get a reasonable default ASID in r0 */
{
move r0, zero
jal hv_inquire_asid
}
/* Install the default page table */
{
moveli r6, lo16(swapper_pgprot - PAGE_OFFSET)
move r4, r0 /* use starting ASID of range for this page table */
}
{
moveli r0, lo16(swapper_pg_dir - PAGE_OFFSET)
auli r6, r6, ha16(swapper_pgprot - PAGE_OFFSET)
}
{
lw r2, r6
addi r6, r6, 4
}
{
lw r3, r6
auli r0, r0, ha16(swapper_pg_dir - PAGE_OFFSET)
}
{
inv r6
move r1, zero /* high 32 bits of CPA is zero */
}
{
moveli lr, lo16(1f)
move r5, zero
}
{
auli lr, lr, ha16(1f)
j hv_install_context
}
1:
/* Get our processor number and save it away in SAVE_K_0. */
jal hv_inquire_topology
mulll_uu r4, r1, r2 /* r1 == y, r2 == width */
add r4, r4, r0 /* r0 == x, so r4 == cpu == y*width + x */
#ifdef CONFIG_SMP
/*
* Load up our per-cpu offset. When the first (master) tile
* boots, this value is still zero, so we will load boot_pc
* with start_kernel, and boot_sp with init_stack + THREAD_SIZE.
* The master tile initializes the per-cpu offset array, so that
* when subsequent (secondary) tiles boot, they will instead load
* from their per-cpu versions of boot_sp and boot_pc.
*/
moveli r5, lo16(__per_cpu_offset)
auli r5, r5, ha16(__per_cpu_offset)
s2a r5, r4, r5
lw r5, r5
bnz r5, 1f
/*
* Save the width and height to the smp_topology variable
* for later use.
*/
moveli r0, lo16(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
auli r0, r0, ha16(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
{
sw r0, r2
addi r0, r0, (HV_TOPOLOGY_HEIGHT_OFFSET - HV_TOPOLOGY_WIDTH_OFFSET)
}
sw r0, r3
1:
#else
move r5, zero
#endif
/* Load and go with the correct pc and sp. */
{
addli r1, r5, lo16(boot_sp)
addli r0, r5, lo16(boot_pc)
}
{
auli r1, r1, ha16(boot_sp)
auli r0, r0, ha16(boot_pc)
}
lw r0, r0
lw sp, r1
or r4, sp, r4
mtspr SPR_SYSTEM_SAVE_K_0, r4 /* save ksp0 + cpu */
addi sp, sp, -STACK_TOP_DELTA
{
move lr, zero /* stop backtraces in the called function */
jr r0
}
ENDPROC(_start)
__PAGE_ALIGNED_BSS
.align PAGE_SIZE
ENTRY(empty_zero_page)
.fill PAGE_SIZE,1,0
END(empty_zero_page)
.macro PTE va, cpa, bits1, no_org=0
.ifeq \no_org
.org swapper_pg_dir + HV_L1_INDEX(\va) * HV_PTE_SIZE
.endif
.word HV_PTE_PAGE | HV_PTE_DIRTY | HV_PTE_PRESENT | HV_PTE_ACCESSED | \
(HV_PTE_MODE_CACHE_NO_L3 << HV_PTE_INDEX_MODE)
.word (\bits1) | (HV_CPA_TO_PFN(\cpa) << (HV_PTE_INDEX_PFN - 32))
.endm
__PAGE_ALIGNED_DATA
.align PAGE_SIZE
ENTRY(swapper_pg_dir)
/*
* All data pages from PAGE_OFFSET to MEM_USER_INTRPT are mapped as
* VA = PA + PAGE_OFFSET. We remap things with more precise access
* permissions and more respect for size of RAM later.
*/
.set addr, 0
.rept (MEM_USER_INTRPT - PAGE_OFFSET) >> PGDIR_SHIFT
PTE addr + PAGE_OFFSET, addr, (1 << (HV_PTE_INDEX_READABLE - 32)) | \
(1 << (HV_PTE_INDEX_WRITABLE - 32))
.set addr, addr + PGDIR_SIZE
.endr
/* The true text VAs are mapped as VA = PA + MEM_SV_INTRPT */
PTE MEM_SV_INTRPT, 0, (1 << (HV_PTE_INDEX_READABLE - 32)) | \
(1 << (HV_PTE_INDEX_EXECUTABLE - 32))
.org swapper_pg_dir + HV_L1_SIZE
END(swapper_pg_dir)
/*
* Isolate swapper_pgprot to its own cache line, since each cpu
* starting up will read it using VA-is-PA and local homing.
* This would otherwise likely conflict with other data on the cache
* line, once we have set its permanent home in the page tables.
*/
__INITDATA
.align CHIP_L2_LINE_SIZE()
ENTRY(swapper_pgprot)
PTE 0, 0, (1 << (HV_PTE_INDEX_READABLE - 32)) | \
(1 << (HV_PTE_INDEX_WRITABLE - 32)), 1
.align CHIP_L2_LINE_SIZE()
END(swapper_pgprot)