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Merge branch 'hyp-boot-mode-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into devel-stable

This commit is contained in:
Russell King
2012-09-30 09:03:44 +01:00
15 changed files with 673 additions and 27 deletions

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@@ -82,4 +82,6 @@ head-y := head$(MMUEXT).o
obj-$(CONFIG_DEBUG_LL) += debug.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_ARM_VIRT_EXT) += hyp-stub.o
extra-y := $(head-y) vmlinux.lds

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@@ -83,8 +83,12 @@ ENTRY(stext)
THUMB( .thumb ) @ switch to Thumb now.
THUMB(1: )
setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode
@ and irqs disabled
#ifdef CONFIG_ARM_VIRT_EXT
bl __hyp_stub_install
#endif
@ ensure svc mode and all interrupts masked
safe_svcmode_maskall r9
mrc p15, 0, r9, c0, c0 @ get processor id
bl __lookup_processor_type @ r5=procinfo r9=cpuid
movs r10, r5 @ invalid processor (r5=0)?
@@ -326,7 +330,11 @@ ENTRY(secondary_startup)
* the processor type - there is no need to check the machine type
* as it has already been validated by the primary processor.
*/
setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9
#ifdef CONFIG_ARM_VIRT_EXT
bl __hyp_stub_install
#endif
safe_svcmode_maskall r9
mrc p15, 0, r9, c0, c0 @ get processor id
bl __lookup_processor_type
movs r10, r5 @ invalid processor?

223
arch/arm/kernel/hyp-stub.S Normal file
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@@ -0,0 +1,223 @@
/*
* 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/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 r7, r7, #BOOT_CPU_MODE_MISMATCH
strne r7, [r5, r6] @ 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
bxne 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
bxne 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.
*/
@ 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
#ifdef CONFIG_CPU_BIG_ENDIAN
orr r7, #(1 << 9) @ HSCTLR.EE
#endif
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
1:
#endif
bic r7, r4, #MODE_MASK
orr r7, r7, #SVC_MODE
THUMB( orr r7, r7, #PSR_T_BIT )
msr spsr_cxsf, r7 @ This is SPSR_hyp.
__MSR_ELR_HYP(14) @ msr elr_hyp, lr
__ERET @ return, switching to SVC mode
@ 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)
bx 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)

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@@ -55,6 +55,7 @@
#include <asm/traps.h>
#include <asm/unwind.h>
#include <asm/memblock.h>
#include <asm/virt.h>
#if defined(CONFIG_DEPRECATED_PARAM_STRUCT)
#include "compat.h"
@@ -937,6 +938,21 @@ static int __init meminfo_cmp(const void *_a, const void *_b)
return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
}
void __init hyp_mode_check(void)
{
#ifdef CONFIG_ARM_VIRT_EXT
if (is_hyp_mode_available()) {
pr_info("CPU: All CPU(s) started in HYP mode.\n");
pr_info("CPU: Virtualization extensions available.\n");
} else if (is_hyp_mode_mismatched()) {
pr_warn("CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU mode 0x%x)\n",
__boot_cpu_mode & MODE_MASK);
pr_warn("CPU: This may indicate a broken bootloader or firmware.\n");
} else
pr_info("CPU: All CPU(s) started in SVC mode.\n");
#endif
}
void __init setup_arch(char **cmdline_p)
{
struct machine_desc *mdesc;
@@ -980,6 +996,10 @@ void __init setup_arch(char **cmdline_p)
if (is_smp())
smp_init_cpus();
#endif
if (!is_smp())
hyp_mode_check();
reserve_crashkernel();
tcm_init();

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@@ -42,6 +42,7 @@
#include <asm/ptrace.h>
#include <asm/localtimer.h>
#include <asm/smp_plat.h>
#include <asm/virt.h>
/*
* as from 2.5, kernels no longer have an init_tasks structure
@@ -290,6 +291,8 @@ void __init smp_cpus_done(unsigned int max_cpus)
num_online_cpus(),
bogosum / (500000/HZ),
(bogosum / (5000/HZ)) % 100);
hyp_mode_check();
}
void __init smp_prepare_boot_cpu(void)