linux/arch/mips/include/asm/mach-cavium-octeon/kernel-entry-init.h
Steven J. Hill 3ff72be4c9 MIPS: Octeon: Enable KASLR
This patch enables KASLR for Octeon systems. The SMP startup code is
such that the secondaries monitor the volatile variable
'octeon_processor_relocated_kernel_entry' for any non-zero value.
The 'plat_post_relocation hook' is used to set that value to the
kernel entry point of the relocated kernel. The secondary CPUs will
then jusmp to the new kernel, perform their initialization again
and begin waiting for the boot CPU to start them via the relocated
loop 'octeon_spin_wait_boot'. Inspired by Steven's code from Cavium.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Signed-off-by: Steven J. Hill <steven.hill@cavium.com>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14669/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-01-03 16:34:35 +01:00

161 lines
3.8 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2005-2008 Cavium Networks, Inc
*/
#ifndef __ASM_MACH_CAVIUM_OCTEON_KERNEL_ENTRY_H
#define __ASM_MACH_CAVIUM_OCTEON_KERNEL_ENTRY_H
#define CP0_CVMCTL_REG $9, 7
#define CP0_CVMMEMCTL_REG $11,7
#define CP0_PRID_REG $15, 0
#define CP0_DCACHE_ERR_REG $27, 1
#define CP0_PRID_OCTEON_PASS1 0x000d0000
#define CP0_PRID_OCTEON_CN30XX 0x000d0200
.macro kernel_entry_setup
# Registers set by bootloader:
# (only 32 bits set by bootloader, all addresses are physical
# addresses, and need to have the appropriate memory region set
# by the kernel
# a0 = argc
# a1 = argv (kseg0 compat addr)
# a2 = 1 if init core, zero otherwise
# a3 = address of boot descriptor block
.set push
.set arch=octeon
# Read the cavium mem control register
dmfc0 v0, CP0_CVMMEMCTL_REG
# Clear the lower 6 bits, the CVMSEG size
dins v0, $0, 0, 6
ori v0, CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE
dmtc0 v0, CP0_CVMMEMCTL_REG # Write the cavium mem control register
dmfc0 v0, CP0_CVMCTL_REG # Read the cavium control register
# Disable unaligned load/store support but leave HW fixup enabled
# Needed for octeon specific memcpy
or v0, v0, 0x5001
xor v0, v0, 0x1001
# First clear off CvmCtl[IPPCI] bit and move the performance
# counters interrupt to IRQ 6
dli v1, ~(7 << 7)
and v0, v0, v1
ori v0, v0, (6 << 7)
mfc0 v1, CP0_PRID_REG
and t1, v1, 0xfff8
xor t1, t1, 0x9000 # 63-P1
beqz t1, 4f
and t1, v1, 0xfff8
xor t1, t1, 0x9008 # 63-P2
beqz t1, 4f
and t1, v1, 0xfff8
xor t1, t1, 0x9100 # 68-P1
beqz t1, 4f
and t1, v1, 0xff00
xor t1, t1, 0x9200 # 66-PX
bnez t1, 5f # Skip WAR for others.
and t1, v1, 0x00ff
slti t1, t1, 2 # 66-P1.2 and later good.
beqz t1, 5f
4: # core-16057 work around
or v0, v0, 0x2000 # Set IPREF bit.
5: # No core-16057 work around
# Write the cavium control register
dmtc0 v0, CP0_CVMCTL_REG
sync
# Flush dcache after config change
cache 9, 0($0)
# Zero all of CVMSEG to make sure parity is correct
dli v0, CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE
dsll v0, 7
beqz v0, 2f
1: dsubu v0, 8
sd $0, -32768(v0)
bnez v0, 1b
2:
mfc0 v0, CP0_PRID_REG
bbit0 v0, 15, 1f
# OCTEON II or better have bit 15 set. Clear the error bits.
and t1, v0, 0xff00
dli v0, 0x9500
bge t1, v0, 1f # OCTEON III has no DCACHE_ERR_REG COP0
dli v0, 0x27
dmtc0 v0, CP0_DCACHE_ERR_REG
1:
# Get my core id
rdhwr v0, $0
# Jump the master to kernel_entry
bne a2, zero, octeon_main_processor
nop
#ifdef CONFIG_SMP
#
# All cores other than the master need to wait here for SMP bootstrap
# to begin
#
octeon_spin_wait_boot:
#ifdef CONFIG_RELOCATABLE
PTR_LA t0, octeon_processor_relocated_kernel_entry
LONG_L t0, (t0)
beq zero, t0, 1f
nop
jr t0
nop
1:
#endif /* CONFIG_RELOCATABLE */
# This is the variable where the next core to boot is stored
PTR_LA t0, octeon_processor_boot
# Get the core id of the next to be booted
LONG_L t1, (t0)
# Keep looping if it isn't me
bne t1, v0, octeon_spin_wait_boot
nop
# Get my GP from the global variable
PTR_LA t0, octeon_processor_gp
LONG_L gp, (t0)
# Get my SP from the global variable
PTR_LA t0, octeon_processor_sp
LONG_L sp, (t0)
# Set the SP global variable to zero so the master knows we've started
LONG_S zero, (t0)
#ifdef __OCTEON__
syncw
syncw
#else
sync
#endif
# Jump to the normal Linux SMP entry point
j smp_bootstrap
nop
#else /* CONFIG_SMP */
#
# Someone tried to boot SMP with a non SMP kernel. All extra cores
# will halt here.
#
octeon_wait_forever:
wait
b octeon_wait_forever
nop
#endif /* CONFIG_SMP */
octeon_main_processor:
.set pop
.endm
/*
* Do SMP slave processor setup necessary before we can safely execute C code.
*/
.macro smp_slave_setup
.endm
#endif /* __ASM_MACH_CAVIUM_OCTEON_KERNEL_ENTRY_H */