linux/arch/tile/kernel/head_64.S
Chris Metcalf 9ae0983847 tile: provide traceability for hypervisor calls
This change adds infrastructure (CONFIG_TILE_HVGLUE_TRACE) that
provides C code wrappers for the calls the kernel makes to the Tilera
hypervisor.  This allows standard kernel infrastructure like FTRACE to
be able to instrument hypervisor calls.

To allow direct calls to the true API, we export their names with a
leading underscore as well.  This is important for the few contexts
where we need to make hypervisor calls without touching the stack.

As part of this change, we also switch from creating the symbols
with linker magic to creating them with assembler magic.  This lets
us provide a symbol type and generally make them appear more as symbols
and less as just random values in the Elf namespace.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-08-13 16:26:31 -04:00

280 lines
7.3 KiB
ArmAsm

/*
* 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>
/* Extract two 32-bit bit values that were read into one register. */
#ifdef __BIG_ENDIAN__
#define GET_FIRST_INT(rd, rs) shrsi rd, rs, 32
#define GET_SECOND_INT(rd, rs) addxi rd, rs, 0
#else
#define GET_FIRST_INT(rd, rs) addxi rd, rs, 0
#define GET_SECOND_INT(rd, rs) shrsi rd, rs, 32
#endif
/*
* 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 */
{
#if KERNEL_PL == 1 && _HV_VERSION == 13
/* Support older hypervisors by asking for API version 12. */
movei r0, _HV_VERSION_OLD_HV_INIT
#else
movei r0, _HV_VERSION
#endif
movei r1, TILE_CHIP
}
{
movei r2, TILE_CHIP_REV
movei r3, KERNEL_PL
}
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.
*/
{
GET_FIRST_INT(r2, 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
finv 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)
}
{
moveli r3, CTX_PAGE_FLAG
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. */
jal _hv_inquire_topology
{
GET_FIRST_INT(r5, r1) /* r5 = width */
GET_SECOND_INT(r4, r0) /* r4 = y */
}
{
GET_FIRST_INT(r6, 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_PTFN(\cpa) << HV_PTE_INDEX_PTFN)
.endm
__PAGE_ALIGNED_DATA
.align PAGE_SIZE
ENTRY(swapper_pg_dir)
.org swapper_pg_dir + PGD_INDEX(PAGE_OFFSET) * HV_PTE_SIZE
.Lsv_data_pmd:
.quad 0 /* PTE temp_data_pmd - PAGE_OFFSET, 0 */
.org swapper_pg_dir + PGD_INDEX(MEM_SV_START) * HV_PTE_SIZE
.Lsv_code_pmd:
.quad 0 /* PTE temp_code_pmd - PAGE_OFFSET, 0 */
.org swapper_pg_dir + SIZEOF_PGD
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 PTRS_PER_PMD
PTE addr, HV_PTE_READABLE | HV_PTE_WRITABLE
.set addr, addr + HPAGE_SIZE
.endr
.org temp_data_pmd + SIZEOF_PMD
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 PTRS_PER_PMD
PTE addr, HV_PTE_READABLE | HV_PTE_EXECUTABLE
.set addr, addr + HPAGE_SIZE
.endr
.org temp_code_pmd + SIZEOF_PMD
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)