ti: k3: common: Add support for runtime detection of GICR base address
Valid addresses for GICR base are always a set calculable distance from
the GICD and is based on the number of cores a given instance of GICv3 IP
can support. The formula for the number of address bits is given by the
ARM GIC-500 TRM section 3.2 as 2^(18+log2(cores)) with the MSB set to
one for GICR instances. Holes in the GIC address space are also
guaranteed to safely return 0 on reads. This allows us to support runtime
detection of the GICR base address by starting from GIC base address plus
BIT(18) and walking until the GICR ID register (IIDR) is detected. We
stop searching after BIT(20) to prevent searching out into space if
something goes wrong. This can be extended out if we ever have a device
with 16 or more cores.
Signed-off-by: Andrew F. Davis <afd@ti.com>
diff --git a/plat/ti/k3/common/k3_gicv3.c b/plat/ti/k3/common/k3_gicv3.c
index b7c7880..1932eaa 100644
--- a/plat/ti/k3/common/k3_gicv3.c
+++ b/plat/ti/k3/common/k3_gicv3.c
@@ -6,10 +6,12 @@
#include <platform_def.h>
+#include <assert.h>
#include <common/bl_common.h>
#include <common/interrupt_props.h>
#include <drivers/arm/gicv3.h>
#include <lib/utils.h>
+#include <lib/mmio.h>
#include <plat/common/platform.h>
#include <k3_gicv3.h>
@@ -35,8 +37,25 @@
.mpidr_to_core_pos = k3_mpidr_to_core_pos,
};
-void k3_gic_driver_init(uintptr_t gicd_base, uintptr_t gicr_base)
+void k3_gic_driver_init(uintptr_t gic_base)
{
+ /* GIC Distributor is always at the base of the IP */
+ uintptr_t gicd_base = gic_base;
+ /* GIC Redistributor base is run-time detected */
+ uintptr_t gicr_base = 0;
+
+ for (unsigned int gicr_shift = 18; gicr_shift < 21; gicr_shift++) {
+ uintptr_t gicr_check = gic_base + BIT(gicr_shift);
+ uint32_t iidr = mmio_read_32(gicr_check + GICR_IIDR);
+ if (iidr != 0) {
+ /* Found the GICR base */
+ gicr_base = gicr_check;
+ break;
+ }
+ }
+ /* Assert if we have not found the GICR base */
+ assert(gicr_base != 0);
+
/*
* The GICv3 driver is initialized in EL3 and does not need
* to be initialized again in SEL1. This is because the S-EL1