/*
* Copyright 2011 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. The relocation required to
* statically define the table is a bit too complex, so we have
* to plug in the pointer from the L0 to the L1 table by hand.
* We only do this on the first cpu to boot, though, since the
* other CPUs should see a properly-constructed page table.
*/
{
v4int_l r2, zero, r0 /* ASID for hv_install_context */
moveli r4, hw1_last(swapper_pgprot - PAGE_OFFSET)
}
{
shl16insli r4, r4, hw0(swapper_pgprot - PAGE_OFFSET)
}
{
ld r1, r4 /* access_pte for hv_install_context */
}
{
moveli r0, hw1_last(.Lsv_data_pmd - PAGE_OFFSET)
moveli r6, hw1_last(temp_data_pmd - PAGE_OFFSET)
}
{
/* After initializing swapper_pgprot, HV_PTE_GLOBAL is set. */
bfextu r7, r1, HV_PTE_INDEX_GLOBAL, HV_PTE_INDEX_GLOBAL
inv r4
}
bnez r7, .Lno_write
{
shl16insli r0, r0, hw0(.Lsv_data_pmd - PAGE_OFFSET)
shl16insli r6, r6, hw0(temp_data_pmd - PAGE_OFFSET)
}
{
/* Cut off the low bits of the PT address. */
shrui r6, r6, HV_LOG2_PAGE_TABLE_ALIGN
/* Start with our access pte. */
move r5, r1
}
{
/* Stuff the address into the page table pointer slot of the PTE. */
bfins r5, r6, HV_PTE_INDEX_PTFN, \
HV_PTE_INDEX_PTFN + HV_PTE_PTFN_BITS - 1
}
{
/* Store the L0 data PTE. */
st r0, r5
addli r6, r6, (temp_code_pmd - temp_data_pmd) >> \
HV_LOG2_PAGE_TABLE_ALIGN
}
{
addli r0, r0, .Lsv_code_pmd - .Lsv_data_pmd
bfins r5, r6, HV_PTE_INDEX_PTFN, \
HV_PTE_INDEX_PTFN + HV_PTE_PTFN_BITS - 1
}
/* Store the L0 code PTE. */
st r0, r5
.Lno_write:
moveli lr, hw2_last(1f)
{
shl16insli lr, lr, hw1(1f)
moveli r0, hw1_last(swapper_pg_dir - PAGE_OFFSET)
}
{
shl16insli lr, lr, hw0(1f)
shl16insli r0, r0, hw0(swapper_pg_dir - PAGE_OFFSET)
}
{
move r3, zero
j hv_install_context
}
1:
/* Install the interrupt base. */
moveli r0, hw2_last(MEM_SV_START)
shl16insli r0, r0, hw1(MEM_SV_START)
shl16insli r0, r0, hw0(MEM_SV_START)
mtspr SPR_INTERRUPT_VECTOR_BASE_K, r0
/*
* Get our processor number and save it away in SAVE_K_0.
* Extract stuff from the topology structure: r4 = y, r6 = x,
* r5 = width. FIXME: consider whether we want to just make these
* 64-bit values (and if so fix smp_topology write below, too).
*/
jal hv_inquire_topology
{
v4int_l r5, zero, r1 /* r5 = width */
shrui r4, r0, 32 /* r4 = y */
}
{
v4int_l r6, zero, r0 /* r6 = x */
mul_lu_lu r4, r4, r5
}
{
add r4, r4, r6 /* 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, hw2_last(__per_cpu_offset)
shl16insli r5, r5, hw1(__per_cpu_offset)
shl16insli r5, r5, hw0(__per_cpu_offset)
shl3add r5, r4, r5
ld r5, r5
bnez r5, 1f
/*
* Save the width and height to the smp_topology variable
* for later use.
*/
moveli r0, hw2_last(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
shl16insli r0, r0, hw1(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
shl16insli r0, r0, hw0(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
st r0, r1
1:
#else
move r5, zero
#endif
/* Load and go with the correct pc and sp. */
{
moveli r1, hw2_last(boot_sp)
moveli r0, hw2_last(boot_pc)
}
{
shl16insli r1, r1, hw1(boot_sp)
shl16insli r0, r0, hw1(boot_pc)
}
{
shl16insli r1, r1, hw0(boot_sp)
shl16insli r0, r0, hw0(boot_pc)
}
{
add r1, r1, r5
add r0, r0, r5
}
ld r0, r0
ld 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 cpa, bits1
.quad HV_PTE_PAGE | HV_PTE_DIRTY | HV_PTE_PRESENT | HV_PTE_ACCESSED |\
HV_PTE_GLOBAL | (HV_PTE_MODE_CACHE_NO_L3 << HV_PTE_INDEX_MODE) |\
(\bits1) | (HV_CPA_TO_PFN(\cpa) << HV_PTE_INDEX_PFN)
.endm
__PAGE_ALIGNED_DATA
.align PAGE_SIZE
ENTRY(swapper_pg_dir)
.org swapper_pg_dir + HV_L0_INDEX(PAGE_OFFSET) * HV_PTE_SIZE
.Lsv_data_pmd:
.quad 0 /* PTE temp_data_pmd - PAGE_OFFSET, 0 */
.org swapper_pg_dir + HV_L0_INDEX(MEM_SV_START) * HV_PTE_SIZE
.Lsv_code_pmd:
.quad 0 /* PTE temp_code_pmd - PAGE_OFFSET, 0 */
.org swapper_pg_dir + HV_L0_SIZE
END(swapper_pg_dir)
.align HV_PAGE_TABLE_ALIGN
ENTRY(temp_data_pmd)
/*
* We fill the PAGE_OFFSET pmd with huge pages with
* VA = PA + PAGE_OFFSET. We remap things with more precise access
* permissions later.
*/
.set addr, 0
.rept HV_L1_ENTRIES
PTE addr, HV_PTE_READABLE | HV_PTE_WRITABLE
.set addr, addr + HV_PAGE_SIZE_LARGE
.endr
.org temp_data_pmd + HV_L1_SIZE
END(temp_data_pmd)
.align HV_PAGE_TABLE_ALIGN
ENTRY(temp_code_pmd)
/*
* We fill the MEM_SV_START pmd with huge pages with
* VA = PA + PAGE_OFFSET. We remap things with more precise access
* permissions later.
*/
.set addr, 0
.rept HV_L1_ENTRIES
PTE addr, HV_PTE_READABLE | HV_PTE_EXECUTABLE
.set addr, addr + HV_PAGE_SIZE_LARGE
.endr
.org temp_code_pmd + HV_L1_SIZE
END(temp_code_pmd)
/*
* 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)
.quad HV_PTE_PRESENT | (HV_PTE_MODE_CACHE_NO_L3 << HV_PTE_INDEX_MODE)
.align CHIP_L2_LINE_SIZE()
END(swapper_pgprot)
