Tegra: memctrl_v1: disable AHB redirection after cold boot
During boot, USB3 and flash media (SDMMC/SATA) devices need access to
IRAM. Because these clients connect to the MC and do not have a direct
path to the IRAM, the MC implements AHB redirection during boot to allow
path to IRAM. In this mode, accesses to a programmed memory address aperture
are directed to the AHB bus, allowing access to the IRAM. The AHB aperture
is defined by the IRAM_BASE_LO and IRAM_BASE_HI registers, which are
initialized to disable this aperture. Once bootup is complete, we must
program IRAM base/top, thus disabling access to IRAM.
This patch provides functionality to disable this access. The tegra port
calls this new function before jumping to the non-secure world during
cold boot.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/plat/nvidia/tegra/common/drivers/memctrl/memctrl_v1.c b/plat/nvidia/tegra/common/drivers/memctrl/memctrl_v1.c
index 859ecd5..fc70727 100644
--- a/plat/nvidia/tegra/common/drivers/memctrl/memctrl_v1.c
+++ b/plat/nvidia/tegra/common/drivers/memctrl/memctrl_v1.c
@@ -218,3 +218,29 @@
video_mem_base = phys_base;
video_mem_size = size_in_bytes >> 20;
}
+
+/*
+ * During boot, USB3 and flash media (SDMMC/SATA) devices need access to
+ * IRAM. Because these clients connect to the MC and do not have a direct
+ * path to the IRAM, the MC implements AHB redirection during boot to allow
+ * path to IRAM. In this mode, accesses to a programmed memory address aperture
+ * are directed to the AHB bus, allowing access to the IRAM. The AHB aperture
+ * is defined by the IRAM_BASE_LO and IRAM_BASE_HI registers, which are
+ * initialized to disable this aperture.
+ *
+ * Once bootup is complete, we must program IRAM base to 0xffffffff and
+ * IRAM top to 0x00000000, thus disabling access to IRAM. DRAM is then
+ * potentially accessible in this address range. These aperture registers
+ * also have an access_control/lock bit. After disabling the aperture, the
+ * access_control register should be programmed to lock the registers.
+ */
+void tegra_memctrl_disable_ahb_redirection(void)
+{
+ /* program the aperture registers */
+ tegra_mc_write_32(MC_IRAM_BASE_LO, 0xFFFFFFFF);
+ tegra_mc_write_32(MC_IRAM_TOP_LO, 0);
+ tegra_mc_write_32(MC_IRAM_BASE_TOP_HI, 0);
+
+ /* lock the aperture registers */
+ tegra_mc_write_32(MC_IRAM_REG_CTRL, MC_DISABLE_IRAM_CFG_WRITES);
+}
diff --git a/plat/nvidia/tegra/common/drivers/memctrl/memctrl_v2.c b/plat/nvidia/tegra/common/drivers/memctrl/memctrl_v2.c
index d3c3e87..7cf54b5 100644
--- a/plat/nvidia/tegra/common/drivers/memctrl/memctrl_v2.c
+++ b/plat/nvidia/tegra/common/drivers/memctrl/memctrl_v2.c
@@ -581,3 +581,11 @@
*/
mce_update_gsc_videomem();
}
+
+/*
+ * This feature exists only for v1 of the Tegra Memory Controller.
+ */
+void tegra_memctrl_disable_ahb_redirection(void)
+{
+ ; /* do nothing */
+}
diff --git a/plat/nvidia/tegra/common/tegra_bl31_setup.c b/plat/nvidia/tegra/common/tegra_bl31_setup.c
index 9e7e576..d2a6be5 100644
--- a/plat/nvidia/tegra/common/tegra_bl31_setup.c
+++ b/plat/nvidia/tegra/common/tegra_bl31_setup.c
@@ -299,7 +299,16 @@
******************************************************************************/
void bl31_plat_runtime_setup(void)
{
- ; /* do nothing */
+ /*
+ * During boot, USB3 and flash media (SDMMC/SATA) devices need
+ * access to IRAM. Because these clients connect to the MC and
+ * do not have a direct path to the IRAM, the MC implements AHB
+ * redirection during boot to allow path to IRAM. In this mode
+ * accesses to a programmed memory address aperture are directed
+ * to the AHB bus, allowing access to the IRAM. This mode must be
+ * disabled before we jump to the non-secure world.
+ */
+ tegra_memctrl_disable_ahb_redirection();
}
/*******************************************************************************
diff --git a/plat/nvidia/tegra/include/drivers/memctrl.h b/plat/nvidia/tegra/include/drivers/memctrl.h
index a3f0875..1557bbf 100644
--- a/plat/nvidia/tegra/include/drivers/memctrl.h
+++ b/plat/nvidia/tegra/include/drivers/memctrl.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
@@ -36,5 +36,6 @@
void tegra_memctrl_tzdram_setup(uint64_t phys_base, uint32_t size_in_bytes);
void tegra_memctrl_tzram_setup(uint64_t phys_base, uint32_t size_in_bytes);
void tegra_memctrl_videomem_setup(uint64_t phys_base, uint32_t size_in_bytes);
+void tegra_memctrl_disable_ahb_redirection(void);
#endif /* __MEMCTRL_H__ */
diff --git a/plat/nvidia/tegra/include/drivers/memctrl_v1.h b/plat/nvidia/tegra/include/drivers/memctrl_v1.h
index b504594..8b8ce79 100644
--- a/plat/nvidia/tegra/include/drivers/memctrl_v1.h
+++ b/plat/nvidia/tegra/include/drivers/memctrl_v1.h
@@ -60,6 +60,13 @@
#define MC_SMMU_TRANSLATION_ENABLE_4_0 0xb98
#define MC_SMMU_TRANSLATION_ENABLE (~0)
+/* MC IRAM aperture registers */
+#define MC_IRAM_BASE_LO 0x65CU
+#define MC_IRAM_TOP_LO 0x660U
+#define MC_IRAM_BASE_TOP_HI 0x980U
+#define MC_IRAM_REG_CTRL 0x964U
+#define MC_DISABLE_IRAM_CFG_WRITES 1U
+
static inline uint32_t tegra_mc_read_32(uint32_t off)
{
return mmio_read_32(TEGRA_MC_BASE + off);