[PATCH v9 5/7] ARM: tegra: Don't apply CPU erratas in insecure mode

Dmitry Osipenko
2019-03-03T17:14:01Z

CPU isn't allowed to touch secure registers while running under secure
monitor. Hence skip applying of CPU erratas in the reset handler if
Trusted Foundations firmware presents.

Partially based on work done by Michał Mirosław [1].

[1] https://www.spinics.net/lists/arm-kernel/msg594768.html

Tested-by: Robert Yang <decatf@gmail.com>
Tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
arch/arm/mach-tegra/reset-handler.S | 23 ++++++++++++-----------
arch/arm/mach-tegra/reset.c | 3 +++
arch/arm/mach-tegra/reset.h | 9 +++++++--
arch/arm/mach-tegra/sleep-tegra20.S | 4 ++++
4 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
index e22ccf87eded..809fbc200cef 100644
--- a/arch/arm/mach-tegra/reset-handler.S
+++ b/arch/arm/mach-tegra/reset-handler.S
@@ -29,8 +29,6 @@

#define PMC_SCRATCH41 0x140

-#define RESET_DATA(x) ((TEGRA_RESET_##x)*4)
-
#ifdef CONFIG_PM_SLEEP
/*
* tegra_resume
@@ -121,6 +119,12 @@ ENTRY(__tegra_cpu_reset_handler)
cpsid aif, 0x13 @ SVC mode, interrupts disabled

tegra_get_soc_id TEGRA_APB_MISC_BASE, r6
+
+ adr r12, __tegra_cpu_reset_handler_data
+ ldr r5, [r12, #RESET_DATA(TF_PRESENT)]
+ cmp r5, #0
+ bne after_errata
+
#ifdef CONFIG_ARCH_TEGRA_2x_SOC
t20_check:
cmp r6, #TEGRA20
@@ -155,7 +159,6 @@ after_errata:
and r10, r10, #0x3 @ R10 = CPU number
mov r11, #1
mov r11, r11, lsl r10 @ R11 = CPU mask
- adr r12, __tegra_cpu_reset_handler_data

#ifdef CONFIG_SMP
/* Does the OS know about this CPU? */
@@ -169,10 +172,9 @@ after_errata:
cmp r6, #TEGRA20
bne 1f
/* If not CPU0, don't let CPU0 reset CPU1 now that CPU1 is coming up. */
- mov32 r5, TEGRA_IRAM_BASE + TEGRA_IRAM_RESET_HANDLER_OFFSET
mov r0, #CPU_NOT_RESETTABLE
cmp r10, #0
- strbne r0, [r5, #__tegra20_cpu1_resettable_status_offset]
+ strbne r0, [r12, #RESET_DATA(RESETTABLE_STATUS)]
1:
#endif

@@ -277,14 +279,13 @@ ENDPROC(__tegra_cpu_reset_handler)
.align L1_CACHE_SHIFT
.type __tegra_cpu_reset_handler_data, %object
.globl __tegra_cpu_reset_handler_data
+ .globl __tegra_cpu_reset_handler_data_offset
+ .equ __tegra_cpu_reset_handler_data_offset, \
+ . - __tegra_cpu_reset_handler_start
__tegra_cpu_reset_handler_data:
- .rept TEGRA_RESET_DATA_SIZE
- .long 0
+ .rept TEGRA_RESET_DATA_SIZE
+ .long 0
.endr
- .globl __tegra20_cpu1_resettable_status_offset
- .equ __tegra20_cpu1_resettable_status_offset, \
- . - __tegra_cpu_reset_handler_start
- .byte 0
.align L1_CACHE_SHIFT

ENTRY(__tegra_cpu_reset_handler_end)
diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
index dc558892753c..b02ae7699842 100644
--- a/arch/arm/mach-tegra/reset.c
+++ b/arch/arm/mach-tegra/reset.c
@@ -24,6 +24,7 @@
#include <asm/cacheflush.h>
#include <asm/firmware.h>
#include <asm/hardware/cache-l2x0.h>
+#include <asm/trusted_foundations.h>

#include "iomap.h"
#include "irammap.h"
@@ -89,6 +90,8 @@ static void __init tegra_cpu_reset_handler_enable(void)

void __init tegra_cpu_reset_handler_init(void)
{
+ __tegra_cpu_reset_handler_data[TEGRA_RESET_TF_PRESENT] =
+ trusted_foundations_registered();

#ifdef CONFIG_SMP
__tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_PRESENT] =
diff --git a/arch/arm/mach-tegra/reset.h b/arch/arm/mach-tegra/reset.h
index 9c479c7925b8..db0e6b3097ab 100644
--- a/arch/arm/mach-tegra/reset.h
+++ b/arch/arm/mach-tegra/reset.h
@@ -25,7 +25,11 @@
#define TEGRA_RESET_STARTUP_SECONDARY 3
#define TEGRA_RESET_STARTUP_LP2 4
#define TEGRA_RESET_STARTUP_LP1 5
-#define TEGRA_RESET_DATA_SIZE 6
+#define TEGRA_RESET_RESETTABLE_STATUS 6
+#define TEGRA_RESET_TF_PRESENT 7
+#define TEGRA_RESET_DATA_SIZE 8
+
+#define RESET_DATA(x) ((TEGRA_RESET_##x)*4)

#ifndef __ASSEMBLY__

@@ -49,7 +53,8 @@ void __tegra_cpu_reset_handler_end(void);
(u32)__tegra_cpu_reset_handler_start)))
#define tegra20_cpu1_resettable_status \
(IO_ADDRESS(TEGRA_IRAM_BASE + TEGRA_IRAM_RESET_HANDLER_OFFSET + \
- (u32)__tegra20_cpu1_resettable_status_offset))
+ ((u32)&__tegra_cpu_reset_handler_data[TEGRA_RESET_RESETTABLE_STATUS] - \
+ (u32)__tegra_cpu_reset_handler_start)))
#endif

#define tegra_cpu_reset_handler_offset \
diff --git a/arch/arm/mach-tegra/sleep-tegra20.S b/arch/arm/mach-tegra/sleep-tegra20.S
index dedeebfccc55..50d51d3465f6 100644
--- a/arch/arm/mach-tegra/sleep-tegra20.S
+++ b/arch/arm/mach-tegra/sleep-tegra20.S
@@ -28,6 +28,7 @@
#include <asm/cache.h>

#include "irammap.h"
+#include "reset.h"
#include "sleep.h"

#define EMC_CFG 0xc
@@ -53,6 +54,9 @@
#define APB_MISC_XM2CFGCPADCTRL2 0x8e4
#define APB_MISC_XM2CFGDPADCTRL2 0x8e8

+#define __tegra20_cpu1_resettable_status_offset \
+ (__tegra_cpu_reset_handler_data_offset + RESET_DATA(RESETTABLE_STATUS))
+
.macro pll_enable, rd, r_car_base, pll_base
ldr \rd, [\r_car_base, #\pll_base]
tst \rd, #(1 << 30)
--
2.20.1