u-boot/arch/arm/cpu/armv8/cpu.c
Marc Zyngier 46dc542870 arm: cpu: Add optional CMOs by VA
Exposing set/way cache maintenance to a virtual machine is unsafe, not
least because the instructions are not permission-checked but also
because they are not broadcast between CPUs. Consequently, KVM traps and
emulates such maintenance in the host kernel using by-VA operations and
looping over the stage-2 page-tables. However, when running under
protected KVM, these instructions are not able to be emulated and will
instead result in an exception being delivered to the guest.

Introduce CONFIG_CMO_BY_VA_ONLY so that virtual platforms can select
this option and perform by-VA cache maintenance instead of using the
set/way instructions.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <willdeacon@google.com>
Signed-off-by: Pierre-Clément Tosi <ptosi@google.com>
[ Paul: pick from the Android tree. Fixup Pierre's commit. And fix some
  checkpatch warnings. Rebased to upstream. ]
Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Cc: Tom Rini <trini@konsulko.com>
Link: db5507f47f
Link: 2baf54e743
2023-03-06 17:03:55 -05:00

97 lines
2 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2008 Texas Insturments
*
* (C) Copyright 2002
* Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2002
* Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
*/
#include <common.h>
#include <command.h>
#include <cpu_func.h>
#include <irq_func.h>
#include <asm/cache.h>
#include <asm/system.h>
#include <asm/secure.h>
#include <linux/compiler.h>
/*
* sdelay() - simple spin loop.
*
* Will delay execution by roughly (@loops * 2) cycles.
* This is necessary to be used before timers are accessible.
*
* A value of "0" will results in 2^64 loops.
*/
void sdelay(unsigned long loops)
{
__asm__ volatile ("1:\n" "subs %0, %0, #1\n"
"b.ne 1b" : "=r" (loops) : "0"(loops) : "cc");
}
void __weak board_cleanup_before_linux(void){}
int cleanup_before_linux(void)
{
/*
* this function is called just before we call linux
* it prepares the processor for linux
*
* disable interrupt and turn off caches etc ...
*/
board_cleanup_before_linux();
disable_interrupts();
if (IS_ENABLED(CONFIG_CMO_BY_VA_ONLY)) {
/*
* Disable D-cache.
*/
dcache_disable();
} else {
/*
* Turn off I-cache and invalidate it
*/
icache_disable();
invalidate_icache_all();
/*
* turn off D-cache
* dcache_disable() in turn flushes the d-cache and disables
* MMU
*/
dcache_disable();
invalidate_dcache_all();
}
return 0;
}
#ifdef CONFIG_ARMV8_PSCI
static void relocate_secure_section(void)
{
#ifdef CONFIG_ARMV8_SECURE_BASE
size_t sz = __secure_end - __secure_start;
memcpy((void *)CONFIG_ARMV8_SECURE_BASE, __secure_start, sz);
flush_dcache_range(CONFIG_ARMV8_SECURE_BASE,
CONFIG_ARMV8_SECURE_BASE + sz + 1);
invalidate_icache_all();
#endif
}
void armv8_setup_psci(void)
{
if (current_el() != 3)
return;
relocate_secure_section();
secure_ram_addr(psci_setup_vectors)();
secure_ram_addr(psci_arch_init)();
}
#endif