linux_dsm_epyc7002/arch/arm/kernel/hyp-stub.S
Jean-Philippe Brucker e59941b9b3 ARM: 8527/1: virt: enable GICv3 system registers
ARMv8 introduces system registers for the Generic Interrupt Controllers
CPU and virtual interfaces.  When GICv3 is implemented, EL2 needs to
allow the kernel to use those registers, by changing the value of
ICC_HSRE.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-02-16 16:33:02 +00:00

247 lines
6.8 KiB
ArmAsm

/*
* Copyright (c) 2012 Linaro Limited.
*
* 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.
*
* 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. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/init.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/virt.h>
#ifndef ZIMAGE
/*
* For the kernel proper, we need to find out the CPU boot mode long after
* boot, so we need to store it in a writable variable.
*
* This is not in .bss, because we set it sufficiently early that the boot-time
* zeroing of .bss would clobber it.
*/
.data
ENTRY(__boot_cpu_mode)
.long 0
.text
/*
* Save the primary CPU boot mode. Requires 3 scratch registers.
*/
.macro store_primary_cpu_mode reg1, reg2, reg3
mrs \reg1, cpsr
and \reg1, \reg1, #MODE_MASK
adr \reg2, .L__boot_cpu_mode_offset
ldr \reg3, [\reg2]
str \reg1, [\reg2, \reg3]
.endm
/*
* Compare the current mode with the one saved on the primary CPU.
* If they don't match, record that fact. The Z bit indicates
* if there's a match or not.
* Requires 3 additionnal scratch registers.
*/
.macro compare_cpu_mode_with_primary mode, reg1, reg2, reg3
adr \reg2, .L__boot_cpu_mode_offset
ldr \reg3, [\reg2]
ldr \reg1, [\reg2, \reg3]
cmp \mode, \reg1 @ matches primary CPU boot mode?
orrne \reg1, \reg1, #BOOT_CPU_MODE_MISMATCH
strne \reg1, [\reg2, \reg3] @ record what happened and give up
.endm
#else /* ZIMAGE */
.macro store_primary_cpu_mode reg1:req, reg2:req, reg3:req
.endm
/*
* The zImage loader only runs on one CPU, so we don't bother with mult-CPU
* consistency checking:
*/
.macro compare_cpu_mode_with_primary mode, reg1, reg2, reg3
cmp \mode, \mode
.endm
#endif /* ZIMAGE */
/*
* Hypervisor stub installation functions.
*
* These must be called with the MMU and D-cache off.
* They are not ABI compliant and are only intended to be called from the kernel
* entry points in head.S.
*/
@ Call this from the primary CPU
ENTRY(__hyp_stub_install)
store_primary_cpu_mode r4, r5, r6
ENDPROC(__hyp_stub_install)
@ fall through...
@ Secondary CPUs should call here
ENTRY(__hyp_stub_install_secondary)
mrs r4, cpsr
and r4, r4, #MODE_MASK
/*
* If the secondary has booted with a different mode, give up
* immediately.
*/
compare_cpu_mode_with_primary r4, r5, r6, r7
retne lr
/*
* Once we have given up on one CPU, we do not try to install the
* stub hypervisor on the remaining ones: because the saved boot mode
* is modified, it can't compare equal to the CPSR mode field any
* more.
*
* Otherwise...
*/
cmp r4, #HYP_MODE
retne lr @ give up if the CPU is not in HYP mode
/*
* Configure HSCTLR to set correct exception endianness/instruction set
* state etc.
* Turn off all traps
* Eventually, CPU-specific code might be needed -- assume not for now
*
* This code relies on the "eret" instruction to synchronize the
* various coprocessor accesses. This is done when we switch to SVC
* (see safe_svcmode_maskall).
*/
@ Now install the hypervisor stub:
adr r7, __hyp_stub_vectors
mcr p15, 4, r7, c12, c0, 0 @ set hypervisor vector base (HVBAR)
@ Disable all traps, so we don't get any nasty surprise
mov r7, #0
mcr p15, 4, r7, c1, c1, 0 @ HCR
mcr p15, 4, r7, c1, c1, 2 @ HCPTR
mcr p15, 4, r7, c1, c1, 3 @ HSTR
THUMB( orr r7, #(1 << 30) ) @ HSCTLR.TE
ARM_BE8(orr r7, r7, #(1 << 25)) @ HSCTLR.EE
mcr p15, 4, r7, c1, c0, 0 @ HSCTLR
mrc p15, 4, r7, c1, c1, 1 @ HDCR
and r7, #0x1f @ Preserve HPMN
mcr p15, 4, r7, c1, c1, 1 @ HDCR
#if !defined(ZIMAGE) && defined(CONFIG_ARM_ARCH_TIMER)
@ make CNTP_* and CNTPCT accessible from PL1
mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1
lsr r7, #16
and r7, #0xf
cmp r7, #1
bne 1f
mrc p15, 4, r7, c14, c1, 0 @ CNTHCTL
orr r7, r7, #3 @ PL1PCEN | PL1PCTEN
mcr p15, 4, r7, c14, c1, 0 @ CNTHCTL
mov r7, #0
mcrr p15, 4, r7, r7, c14 @ CNTVOFF
@ Disable virtual timer in case it was counting
mrc p15, 0, r7, c14, c3, 1 @ CNTV_CTL
bic r7, #1 @ Clear ENABLE
mcr p15, 0, r7, c14, c3, 1 @ CNTV_CTL
1:
#endif
#ifdef CONFIG_ARM_GIC_V3
@ Check whether GICv3 system registers are available
mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1
ubfx r7, r7, #28, #4
cmp r7, #1
bne 2f
@ Enable system register accesses
mrc p15, 4, r7, c12, c9, 5 @ ICC_HSRE
orr r7, r7, #(ICC_SRE_EL2_ENABLE | ICC_SRE_EL2_SRE)
mcr p15, 4, r7, c12, c9, 5 @ ICC_HSRE
isb
@ SRE bit could be forced to 0 by firmware.
@ Check whether it sticks before accessing any other sysreg
mrc p15, 4, r7, c12, c9, 5 @ ICC_HSRE
tst r7, #ICC_SRE_EL2_SRE
beq 2f
mov r7, #0
mcr p15, 4, r7, c12, c11, 0 @ ICH_HCR
2:
#endif
bx lr @ The boot CPU mode is left in r4.
ENDPROC(__hyp_stub_install_secondary)
__hyp_stub_do_trap:
cmp r0, #-1
mrceq p15, 4, r0, c12, c0, 0 @ get HVBAR
mcrne p15, 4, r0, c12, c0, 0 @ set HVBAR
__ERET
ENDPROC(__hyp_stub_do_trap)
/*
* __hyp_set_vectors: Call this after boot to set the initial hypervisor
* vectors as part of hypervisor installation. On an SMP system, this should
* be called on each CPU.
*
* r0 must be the physical address of the new vector table (which must lie in
* the bottom 4GB of physical address space.
*
* r0 must be 32-byte aligned.
*
* Before calling this, you must check that the stub hypervisor is installed
* everywhere, by waiting for any secondary CPUs to be brought up and then
* checking that BOOT_CPU_MODE_HAVE_HYP(__boot_cpu_mode) is true.
*
* If not, there is a pre-existing hypervisor, some CPUs failed to boot, or
* something else went wrong... in such cases, trying to install a new
* hypervisor is unlikely to work as desired.
*
* When you call into your shiny new hypervisor, sp_hyp will contain junk,
* so you will need to set that to something sensible at the new hypervisor's
* initialisation entry point.
*/
ENTRY(__hyp_get_vectors)
mov r0, #-1
ENDPROC(__hyp_get_vectors)
@ fall through
ENTRY(__hyp_set_vectors)
__HVC(0)
ret lr
ENDPROC(__hyp_set_vectors)
#ifndef ZIMAGE
.align 2
.L__boot_cpu_mode_offset:
.long __boot_cpu_mode - .
#endif
.align 5
__hyp_stub_vectors:
__hyp_stub_reset: W(b) .
__hyp_stub_und: W(b) .
__hyp_stub_svc: W(b) .
__hyp_stub_pabort: W(b) .
__hyp_stub_dabort: W(b) .
__hyp_stub_trap: W(b) __hyp_stub_do_trap
__hyp_stub_irq: W(b) .
__hyp_stub_fiq: W(b) .
ENDPROC(__hyp_stub_vectors)