[U-Boot] [PATCH v3 09/19] ARM: tegra: Support TZ-only access to PMC

Thierry Reding
2019-03-21T18:01:08Z

Some devices may restrict access to the PMC to TrustZone software only.
Non-TZ software can detect this and use SMC calls to the firmware that
runs in the TrustZone to perform accesses to PMC registers.

Note that this also fixes reset_cpu() and the enterrcm command on
Tegra186 where they were previously trying to access the PMC at a wrong
physical address.

Based on work by Kalyani Chidambaram <kalyanic@nvidia.com> and Tom
Warren <twarren@nvidia.com>.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
arch/arm/include/asm/arch-tegra/pmc.h | 20 +++++-
arch/arm/include/asm/arch-tegra/tegra.h | 6 ++
arch/arm/mach-tegra/Kconfig | 5 ++
arch/arm/mach-tegra/Makefile | 4 +-
arch/arm/mach-tegra/clock.c | 13 ++--
arch/arm/mach-tegra/cmd_enterrcm.c | 6 +-
arch/arm/mach-tegra/cpu.c | 20 +++---
arch/arm/mach-tegra/lowlevel_init.S | 39 -----------
arch/arm/mach-tegra/pmc.c | 92 +++++++++++++++++++++++++
arch/arm/mach-tegra/powergate.c | 11 +--
10 files changed, 151 insertions(+), 65 deletions(-)
delete mode 100644 arch/arm/mach-tegra/lowlevel_init.S
create mode 100644 arch/arm/mach-tegra/pmc.c

diff --git a/arch/arm/include/asm/arch-tegra/pmc.h b/arch/arm/include/asm/arch-tegra/pmc.h
index 34bbe75d5fdb..1524bf291164 100644
--- a/arch/arm/include/asm/arch-tegra/pmc.h
+++ b/arch/arm/include/asm/arch-tegra/pmc.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0+ */
/*
- * (C) Copyright 2010-2015
+ * (C) Copyright 2010-2019
* NVIDIA Corporation <www.nvidia.com>
*/

@@ -388,4 +388,22 @@ struct pmc_ctlr {
/* APBDEV_PMC_CNTRL2_0 0x440 */
#define HOLD_CKE_LOW_EN (1 << 12)

+/* PMC read/write functions */
+u32 tegra_pmc_readl(unsigned long offset);
+void tegra_pmc_writel(u32 value, unsigned long offset);
+
+#define PMC_CNTRL 0x0
+#define PMC_CNTRL_MAIN_RST BIT(4)
+
+#if IS_ENABLED(CONFIG_TEGRA186)
+# define PMC_SCRATCH0 0x32000
+#else
+# define PMC_SCRATCH0 0x00050
+#endif
+
+/* for secure PMC */
+#define TEGRA_SMC_PMC 0xc2fffe00
+#define TEGRA_SMC_PMC_READ 0xaa
+#define TEGRA_SMC_PMC_WRITE 0xbb
+
#endif /* PMC_H */
diff --git a/arch/arm/include/asm/arch-tegra/tegra.h b/arch/arm/include/asm/arch-tegra/tegra.h
index 7ae0129e2db3..7a4e0972fb76 100644
--- a/arch/arm/include/asm/arch-tegra/tegra.h
+++ b/arch/arm/include/asm/arch-tegra/tegra.h
@@ -30,7 +30,13 @@
#define NV_PA_SLINK5_BASE (NV_PA_APB_MISC_BASE + 0xDC00)
#define NV_PA_SLINK6_BASE (NV_PA_APB_MISC_BASE + 0xDE00)
#define TEGRA_DVC_BASE (NV_PA_APB_MISC_BASE + 0xD000)
+#if defined(CONFIG_TEGRA20) || defined(CONFIG_TEGRA30) || \
+ defined(CONFIG_TEGRA114) || defined(CONFIG_TEGRA124) || \
+ defined(CONFIG_TEGRA132) || defined(CONFIG_TEGRA210)
#define NV_PA_PMC_BASE (NV_PA_APB_MISC_BASE + 0xE400)
+#else
+#define NV_PA_PMC_BASE 0xc360000
+#endif
#define NV_PA_EMC_BASE (NV_PA_APB_MISC_BASE + 0xF400)
#define NV_PA_FUSE_BASE (NV_PA_APB_MISC_BASE + 0xF800)
#if defined(CONFIG_TEGRA20) || defined(CONFIG_TEGRA30) || \
diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
index db9198348d3f..28914a34a1b5 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -35,6 +35,10 @@ config TEGRA_PINCTRL
config TEGRA_PMC
bool

+config TEGRA_PMC_SECURE
+ bool
+ depends on TEGRA_PMC
+
config TEGRA_COMMON
bool "Tegra common options"
select BINMAN
@@ -127,6 +131,7 @@ config TEGRA210
select TEGRA_NO_BPMP
select TEGRA_PINCTRL
select TEGRA_PMC
+ select TEGRA_PMC_SECURE

config TEGRA186
bool "Tegra186 family"
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index 517be21ee5f5..f8bc65aa8b18 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0+
#
-# (C) Copyright 2010-2015 Nvidia Corporation.
+# (C) Copyright 2010-2019 Nvidia Corporation.
#
# (C) Copyright 2000-2008
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
@@ -27,11 +27,11 @@ obj-y += dt-setup.o
obj-$(CONFIG_TEGRA_CLOCK_SCALING) += emc.o
obj-$(CONFIG_TEGRA_GPU) += gpu.o
obj-$(CONFIG_TEGRA_IVC) += ivc.o
-obj-y += lowlevel_init.o
ifndef CONFIG_SPL_BUILD
obj-$(CONFIG_ARMV7_PSCI) += psci.o
endif
obj-$(CONFIG_DISPLAY_CPUINFO) += sys_info.o
+obj-y += pmc.o

obj-$(CONFIG_TEGRA20) += tegra20/
obj-$(CONFIG_TEGRA30) += tegra30/
diff --git a/arch/arm/mach-tegra/clock.c b/arch/arm/mach-tegra/clock.c
index 096330748f2b..c9cd4e6aaeb7 100644
--- a/arch/arm/mach-tegra/clock.c
+++ b/arch/arm/mach-tegra/clock.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (c) 2010-2015, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (c) 2010-2019, NVIDIA CORPORATION. All rights reserved.
*/

/* Tegra SoC common clock control functions */
@@ -814,11 +814,16 @@ void tegra30_set_up_pllp(void)

int clock_external_output(int clk_id)
{
- struct pmc_ctlr *pmc = (struct pmc_ctlr *)NV_PA_PMC_BASE;
+ u32 val;

if (clk_id >= 1 && clk_id <= 3) {
- setbits_le32(&pmc->pmc_clk_out_cntrl,
- 1 << (2 + (clk_id - 1) * 8));
+ val = tegra_pmc_readl(offsetof(struct pmc_ctlr,
+ pmc_clk_out_cntrl));
+ val |= 1 << (2 + (clk_id - 1) * 8);
+ tegra_pmc_writel(val,
+ offsetof(struct pmc_ctlr,
+ pmc_clk_out_cntrl));
+
} else {
printf("%s: Unknown output clock id %d\n", __func__, clk_id);
return -EINVAL;
diff --git a/arch/arm/mach-tegra/cmd_enterrcm.c b/arch/arm/mach-tegra/cmd_enterrcm.c
index 4e6beb3e5bb4..4a889f0e3422 100644
--- a/arch/arm/mach-tegra/cmd_enterrcm.c
+++ b/arch/arm/mach-tegra/cmd_enterrcm.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0+
/*
- * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (c) 2012-2019, NVIDIA CORPORATION. All rights reserved.
*
* Derived from code (arch/arm/lib/reset.c) that is:
*
@@ -31,12 +31,10 @@
static int do_enterrcm(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
- struct pmc_ctlr *pmc = (struct pmc_ctlr *)NV_PA_PMC_BASE;
-
puts("Entering RCM...\n");
udelay(50000);

- pmc->pmc_scratch0 = 2;
+ tegra_pmc_writel(2, PMC_SCRATCH0);
disable_interrupts();
reset_cpu(0);

diff --git a/arch/arm/mach-tegra/cpu.c b/arch/arm/mach-tegra/cpu.c
index 1b6ad074ed8f..3d140760e68f 100644
--- a/arch/arm/mach-tegra/cpu.c
+++ b/arch/arm/mach-tegra/cpu.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (c) 2010-2015, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (c) 2010-2019, NVIDIA CORPORATION. All rights reserved.
*/

#include <common.h>
@@ -299,21 +299,19 @@ void enable_cpu_clock(int enable)

static int is_cpu_powered(void)
{
- struct pmc_ctlr *pmc = (struct pmc_ctlr *)NV_PA_PMC_BASE;
-
- return (readl(&pmc->pmc_pwrgate_status) & CPU_PWRED) ? 1 : 0;
+ return (tegra_pmc_readl(offsetof(struct pmc_ctlr,
+ pmc_pwrgate_status)) & CPU_PWRED) ? 1 : 0;
}

static void remove_cpu_io_clamps(void)
{
- struct pmc_ctlr *pmc = (struct pmc_ctlr *)NV_PA_PMC_BASE;
u32 reg;
debug("%s entry\n", __func__);

/* Remove the clamps on the CPU I/O signals */
- reg = readl(&pmc->pmc_remove_clamping);
+ reg = tegra_pmc_readl(offsetof(struct pmc_ctlr, pmc_remove_clamping));
reg |= CPU_CLMP;
- writel(reg, &pmc->pmc_remove_clamping);
+ tegra_pmc_writel(reg, offsetof(struct pmc_ctlr, pmc_remove_clamping));

/* Give I/O signals time to stabilize */
udelay(IO_STABILIZATION_DELAY);
@@ -321,17 +319,19 @@ static void remove_cpu_io_clamps(void)

void powerup_cpu(void)
{
- struct pmc_ctlr *pmc = (struct pmc_ctlr *)NV_PA_PMC_BASE;
u32 reg;
int timeout = IO_STABILIZATION_DELAY;
debug("%s entry\n", __func__);

if (!is_cpu_powered()) {
/* Toggle the CPU power state (OFF -> ON) */
- reg = readl(&pmc->pmc_pwrgate_toggle);
+ reg = tegra_pmc_readl(offsetof(struct pmc_ctlr,
+ pmc_pwrgate_toggle));
reg &= PARTID_CP;
reg |= START_CP;
- writel(reg, &pmc->pmc_pwrgate_toggle);
+ tegra_pmc_writel(reg,
+ offsetof(struct pmc_ctlr,
+ pmc_pwrgate_toggle));

/* Wait for the power to come up */
while (!is_cpu_powered()) {
diff --git a/arch/arm/mach-tegra/lowlevel_init.S b/arch/arm/mach-tegra/lowlevel_init.S
deleted file mode 100644
index 626f1b642745..000000000000
--- a/arch/arm/mach-tegra/lowlevel_init.S
+++ /dev/null
@@ -1,39 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
-/*
- * SoC-specific setup info
- *
- * (C) Copyright 2010,2011
- * NVIDIA Corporation <www.nvidia.com>
- */
-
-#include <config.h>
-#include <linux/linkage.h>
-
-#ifdef CONFIG_ARM64
- .align 5
-ENTRY(reset_cpu)
- /* get address for global reset register */
- ldr x1, =PRM_RSTCTRL
- ldr w3, [x1]
- /* force reset */
- orr w3, w3, #0x10
- str w3, [x1]
- mov w0, w0
-1:
- b 1b
-ENDPROC(reset_cpu)
-#else
- .align 5
-ENTRY(reset_cpu)
- ldr r1, rstctl @ get addr for global reset
- @ reg
- ldr r3, [r1]
- orr r3, r3, #0x10
- str r3, [r1] @ force reset
- mov r0, r0
-_loop_forever:
- b _loop_forever
-rstctl:
- .word PRM_RSTCTRL
-ENDPROC(reset_cpu)
-#endif
diff --git a/arch/arm/mach-tegra/pmc.c b/arch/arm/mach-tegra/pmc.c
new file mode 100644
index 000000000000..afd3c54179c1
--- /dev/null
+++ b/arch/arm/mach-tegra/pmc.c
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018-2019, NVIDIA CORPORATION. All rights reserved.
+ */
+
+#include <common.h>
+
+#include <linux/arm-smccc.h>
+
+#include <asm/io.h>
+#include <asm/arch-tegra/pmc.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#if IS_ENABLED(CONFIG_TEGRA_PMC_SECURE)
+static bool tegra_pmc_detect_tz_only(void)
+{
+ static bool initialized = false;
+ static bool is_tz_only = false;
+ u32 value, saved;
+
+ if (!initialized) {
+ saved = readl(NV_PA_PMC_BASE + PMC_SCRATCH0);
+ value = saved ^ 0xffffffff;
+
+ if (value == 0xffffffff)
+ value = 0xdeadbeef;
+
+ /* write pattern and read it back */
+ writel(value, NV_PA_PMC_BASE + PMC_SCRATCH0);
+ value = readl(NV_PA_PMC_BASE + PMC_SCRATCH0);
+
+ /* if we read all-zeroes, access is restricted to TZ only */
+ if (value == 0) {
+ debug("access to PMC is restricted to TZ\n");
+ is_tz_only = true;
+ } else {
+ /* restore original value */
+ writel(saved, NV_PA_PMC_BASE + PMC_SCRATCH0);
+ }
+
+ initialized = true;
+ }
+
+ return is_tz_only;
+}
+#endif
+
+uint32_t tegra_pmc_readl(unsigned long offset)
+{
+#if IS_ENABLED(CONFIG_TEGRA_PMC_SECURE)
+ if (tegra_pmc_detect_tz_only()) {
+ struct arm_smccc_res res;
+
+ arm_smccc_smc(TEGRA_SMC_PMC, TEGRA_SMC_PMC_READ, offset, 0, 0,
+ 0, 0, 0, &res);
+ if (res.a0)
+ printf("%s(): SMC failed: %lu\n", __func__, res.a0);
+
+ return res.a1;
+ }
+#endif
+
+ return readl(NV_PA_PMC_BASE + offset);
+}
+
+void tegra_pmc_writel(u32 value, unsigned long offset)
+{
+#if IS_ENABLED(CONFIG_TEGRA_PMC_SECURE)
+ if (tegra_pmc_detect_tz_only()) {
+ struct arm_smccc_res res;
+
+ arm_smccc_smc(TEGRA_SMC_PMC, TEGRA_SMC_PMC_WRITE, offset,
+ value, 0, 0, 0, 0, &res);
+ if (res.a0)
+ printf("%s(): SMC failed: %lu\n", __func__, res.a0);
+
+ return;
+ }
+#endif
+
+ writel(value, NV_PA_PMC_BASE + offset);
+}
+
+void reset_cpu(ulong addr)
+{
+ u32 value;
+
+ value = tegra_pmc_readl(PMC_CNTRL);
+ value |= PMC_CNTRL_MAIN_RST;
+ tegra_pmc_writel(value, PMC_CNTRL);
+}
diff --git a/arch/arm/mach-tegra/powergate.c b/arch/arm/mach-tegra/powergate.c
index e45f0961b242..761c9ef19e3b 100644
--- a/arch/arm/mach-tegra/powergate.c
+++ b/arch/arm/mach-tegra/powergate.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (c) 2014-2019, NVIDIA CORPORATION. All rights reserved.
*/

#include <common.h>
@@ -11,6 +11,7 @@

#include <asm/arch/powergate.h>
#include <asm/arch/tegra.h>
+#include <asm/arch-tegra/pmc.h>

#define PWRGATE_TOGGLE 0x30
#define PWRGATE_TOGGLE_START (1 << 8)
@@ -24,18 +25,18 @@ static int tegra_powergate_set(enum tegra_powergate id, bool state)
u32 value, mask = state ? (1 << id) : 0, old_mask;
unsigned long start, timeout = 25;

- value = readl(NV_PA_PMC_BASE + PWRGATE_STATUS);
+ value = tegra_pmc_readl(PWRGATE_STATUS);
old_mask = value & (1 << id);

if (mask == old_mask)
return 0;

- writel(PWRGATE_TOGGLE_START | id, NV_PA_PMC_BASE + PWRGATE_TOGGLE);
+ tegra_pmc_writel(PWRGATE_TOGGLE_START | id, PWRGATE_TOGGLE);

start = get_timer(0);

while (get_timer(start) < timeout) {
- value = readl(NV_PA_PMC_BASE + PWRGATE_STATUS);
+ value = tegra_pmc_readl(PWRGATE_STATUS);
if ((value & (1 << id)) == mask)
return 0;
}
@@ -69,7 +70,7 @@ static int tegra_powergate_remove_clamping(enum tegra_powergate id)
else
value = 1 << id;

- writel(value, NV_PA_PMC_BASE + REMOVE_CLAMPING);
+ tegra_pmc_writel(value, REMOVE_CLAMPING);

return 0;
}
--
2.21.0