feat(libfdt): also allow changing base address

For platforms where we don't know the number of cores at compile time,
the size of the GIC redistributor frame is then also undetermined, since
it depends on this number of cores.
On top of this the GICR base address can also change, when an unknown
number of ITS frames (including zero) take up space between the
distributor and redistributor.

So while those two adjustments are done for independent reasons, the
code for doing so is very similar, so we should utilise the existing
fdt_adjust_gic_redist() function.

Add an (optional) gicr_base parameters to the prototype, so callers can
choose to also adjust this base address later, if needed.

Change-Id: Id39c0ba83e7401fdff1944e86950bb7121f210e8
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

common/fdt_fixup.c

@@ -398,6 +398,7 @@ int fdt_add_cpus_node(void *dtb, unsigned int afflv0,
  * fdt_adjust_gic_redist() - Adjust GICv3 redistributor size
  * @dtb: Pointer to the DT blob in memory
  * @nr_cores: Number of CPU cores on this system.
+ * @gicr_base: Base address of the first GICR frame, or ~0 if unchanged
  * @gicr_frame_size: Size of the GICR frame per core
  *
  * On a GICv3 compatible interrupt controller, the redistributor provides
@@ -410,17 +411,19 @@ int fdt_add_cpus_node(void *dtb, unsigned int afflv0,
  * A GICv4 compatible redistributor uses four 64K pages per core, whereas GICs
  * without support for direct injection of virtual interrupts use two 64K pages.
  * The @gicr_frame_size parameter should be 262144 and 131072, respectively.
+ * Also optionally allow adjusting the GICR frame base address, when this is
+ * different due to ITS frames between distributor and redistributor.
  *
  * Return: 0 on success, negative error value otherwise.
  */
 int fdt_adjust_gic_redist(void *dtb, unsigned int nr_cores,
-			  unsigned int gicr_frame_size)
+			  uintptr_t gicr_base, unsigned int gicr_frame_size)
 {
 	int offset = fdt_node_offset_by_compatible(dtb, 0, "arm,gic-v3");
-	uint64_t redist_size_64;
-	uint32_t redist_size_32;
+	uint64_t reg_64;
+	uint32_t reg_32;
 	void *val;
-	int parent;
+	int parent, ret;
 	int ac, sc;
 
 	if (offset < 0) {
@@ -437,13 +440,34 @@ int fdt_adjust_gic_redist(void *dtb, unsigned int nr_cores,
 		return -EINVAL;
 	}
 
+	if (gicr_base != INVALID_BASE_ADDR) {
+		if (ac == 1) {
+			reg_32 = cpu_to_fdt32(gicr_base);
+			val = &reg_32;
+		} else {
+			reg_64 = cpu_to_fdt64(gicr_base);
+			val = &reg_64;
+		}
+		/*
+		 * The redistributor base address is the second address in
+		 * the "reg" entry, so we have to skip one address and one
+		 * size cell.
+		 */
+		ret = fdt_setprop_inplace_namelen_partial(dtb, offset,
+							  "reg", 3,
+							  (ac + sc) * 4,
+							  val, ac * 4);
+		if (ret < 0) {
+			return ret;
+		}
+	}
+
 	if (sc == 1) {
-		redist_size_32 = cpu_to_fdt32(nr_cores * gicr_frame_size);
-		val = &redist_size_32;
+		reg_32 = cpu_to_fdt32(nr_cores * gicr_frame_size);
+		val = &reg_32;
 	} else {
-		redist_size_64 = cpu_to_fdt64(nr_cores *
-					      (uint64_t)gicr_frame_size);
-		val = &redist_size_64;
+		reg_64 = cpu_to_fdt64(nr_cores * (uint64_t)gicr_frame_size);
+		val = &reg_64;
 	}
 
 	/*

include/common/fdt_fixup.h

@@ -7,13 +7,15 @@
 #ifndef FDT_FIXUP_H
 #define FDT_FIXUP_H
 
+#define INVALID_BASE_ADDR	((uintptr_t)~0UL)
+
 int dt_add_psci_node(void *fdt);
 int dt_add_psci_cpu_enable_methods(void *fdt);
 int fdt_add_reserved_memory(void *dtb, const char *node_name,
 			    uintptr_t base, size_t size);
 int fdt_add_cpus_node(void *dtb, unsigned int afflv0,
 		      unsigned int afflv1, unsigned int afflv2);
-int fdt_adjust_gic_redist(void *dtb, unsigned int nr_cores,
+int fdt_adjust_gic_redist(void *dtb, unsigned int nr_cores, uintptr_t gicr_base,
 			  unsigned int gicr_frame_size);
 
 #endif /* FDT_FIXUP_H */

plat/arm/board/arm_fpga/fpga_bl31_setup.c

@@ -224,6 +224,7 @@ static void fpga_prepare_dtb(void)
 			INFO("Adjusting GICR DT region to cover %u cores\n",
 			      nr_cores);
 			err = fdt_adjust_gic_redist(fdt, nr_cores,
+						    INVALID_BASE_ADDR,
 						    fpga_get_redist_size());
 			if (err < 0) {
 				ERROR("Error %d fixing up GIC DT node\n", err);