rpi4: Amend DTB to advertise PSCI
The device tree provided by the official Raspberry Pi firmware uses
spin tables for SMP bringup.
One of the benefit of having TF-A is that it provides PSCI services, so
let's rewrite the DTB to advertise PSCI instead of spin tables.
This uses the (newly exported) routine from the QEMU platform port.
Change-Id: Ifddcb14041ca253a333f8c2d5e97a42db152470c
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/plat/rpi/rpi4/platform.mk b/plat/rpi/rpi4/platform.mk
index 6ac2169..2038021 100644
--- a/plat/rpi/rpi4/platform.mk
+++ b/plat/rpi/rpi4/platform.mk
@@ -25,6 +25,7 @@
plat/rpi/common/rpi3_pm.c \
plat/common/plat_psci_common.c \
plat/rpi/common/rpi3_topology.c \
+ common/fdt_fixup.c \
${LIBFDT_SRCS}
# For now we only support BL31, using the kernel loaded by the GPU firmware.
diff --git a/plat/rpi/rpi4/rpi4_bl31_setup.c b/plat/rpi/rpi4/rpi4_bl31_setup.c
index f5f74bd..e1b6c89 100644
--- a/plat/rpi/rpi4/rpi4_bl31_setup.c
+++ b/plat/rpi/rpi4/rpi4_bl31_setup.c
@@ -9,12 +9,15 @@
#include <libfdt.h>
#include <platform_def.h>
+#include <arch_helpers.h>
#include <common/bl_common.h>
#include <lib/mmio.h>
#include <lib/xlat_tables/xlat_mmu_helpers.h>
#include <lib/xlat_tables/xlat_tables_defs.h>
#include <lib/xlat_tables/xlat_tables_v2.h>
#include <plat/common/platform.h>
+#include <common/fdt_fixup.h>
+#include <libfdt.h>
#include <drivers/arm/gicv2.h>
@@ -180,6 +183,18 @@
void bl31_plat_arch_setup(void)
{
/*
+ * Is the dtb_ptr32 pointer valid? If yes, map the DTB region.
+ * We map the 2MB region the DTB start address lives in, plus
+ * the next 2MB, to have enough room for expansion.
+ */
+ if (stub_magic == 0) {
+ unsigned long long dtb_region = dtb_ptr32;
+
+ dtb_region &= ~0x1fffff; /* Align to 2 MB. */
+ mmap_add_region(dtb_region, dtb_region, 4U << 20,
+ MT_MEMORY | MT_RW | MT_NS);
+ }
+ /*
* Add the first page of memory, which holds the stub magic,
* the kernel and the DT address.
* This is read-only, as the GPU already populated the header,
@@ -198,8 +213,50 @@
enable_mmu_el3(0);
}
+static uint32_t dtb_size(const void *dtb)
+{
+ const uint32_t *dtb_header = dtb;
+
+ return fdt32_to_cpu(dtb_header[1]);
+}
+
+static void rpi4_prepare_dtb(void)
+{
+ void *dtb = (void *)rpi4_get_dtb_address();
+ int ret;
+
+ /* Return if no device tree is detected */
+ if (fdt_check_header(dtb) != 0)
+ return;
+
+ ret = fdt_open_into(dtb, dtb, 0x100000);
+ if (ret < 0) {
+ ERROR("Invalid Device Tree at %p: error %d\n", dtb, ret);
+ return;
+ }
+
+ if (dt_add_psci_node(dtb)) {
+ ERROR("Failed to add PSCI Device Tree node\n");
+ return;
+ }
+
+ if (dt_add_psci_cpu_enable_methods(dtb)) {
+ ERROR("Failed to add PSCI cpu enable methods in Device Tree\n");
+ return;
+ }
+
+ ret = fdt_pack(dtb);
+ if (ret < 0)
+ ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret);
+
+ clean_dcache_range((uintptr_t)dtb, dtb_size(dtb));
+ INFO("Changed device tree to advertise PSCI.\n");
+}
+
void bl31_platform_setup(void)
{
+ rpi4_prepare_dtb();
+
/* Configure the interrupt controller */
gicv2_driver_init(&rpi4_gic_data);
gicv2_distif_init();
