armv8/fsl-lsch3: device tree fixups for PCI stream IDs

This patch adds the infrastructure to update device
tree nodes to convey SMMU stream IDs in the device
tree.  Fixups are implemented for PCI controllers
initially.

Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>

2 files changed, 120 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv8/fsl-lsch3/fdt.c b/arch/arm/cpu/armv8/fsl-lsch3/fdt.c
index b9fd559356..567c41927a 100644
--- a/arch/arm/cpu/armv8/fsl-lsch3/fdt.c
+++ b/arch/arm/cpu/armv8/fsl-lsch3/fdt.c
@@ -7,6 +7,7 @@
 #include <common.h>
 #include <libfdt.h>
 #include <fdt_support.h>
+#include <asm/arch-fsl-lsch3/fdt.h>
 #ifdef CONFIG_FSL_ESDHC
 #include <fsl_esdhc.h>
 #endif
@@ -58,6 +59,113 @@ void ft_fixup_cpu(void *blob)
 }
 #endif
 
+/*
+ * the burden is on the the caller to not request a count
+ * exceeding the bounds of the stream_ids[] array
+ */
+void alloc_stream_ids(int start_id, int count, u32 *stream_ids, int max_cnt)
+{
+	int i;
+
+	if (count > max_cnt) {
+		printf("\n%s: ERROR: max per-device stream ID count exceed\n",
+		       __func__);
+		return;
+	}
+
+	for (i = 0; i < count; i++)
+		stream_ids[i] = start_id++;
+}
+
+/*
+ * This function updates the mmu-masters property on the SMMU
+ * node as per the SMMU binding-- phandle and list of stream IDs
+ * for each MMU master.
+ */
+void append_mmu_masters(void *blob, const char *smmu_path,
+			const char *master_name, u32 *stream_ids, int count)
+{
+	u32 phandle;
+	int smmu_nodeoffset;
+	int master_nodeoffset;
+	int i;
+
+	/* get phandle of mmu master device */
+	master_nodeoffset = fdt_path_offset(blob, master_name);
+	if (master_nodeoffset < 0) {
+		printf("\n%s: ERROR: master not found\n", __func__);
+		return;
+	}
+	phandle = fdt_get_phandle(blob, master_nodeoffset);
+	if (!phandle) { /* if master has no phandle, create one */
+		phandle = fdt_create_phandle(blob, master_nodeoffset);
+		if (!phandle) {
+			printf("\n%s: ERROR: unable to create phandle\n",
+			       __func__);
+			return;
+		}
+	}
+
+	/* append it to mmu-masters */
+	smmu_nodeoffset = fdt_path_offset(blob, smmu_path);
+	if (fdt_appendprop_u32(blob, smmu_nodeoffset, "mmu-masters",
+			       phandle) < 0) {
+		printf("\n%s: ERROR: unable to update SMMU node\n", __func__);
+		return;
+	}
+
+	/* for each stream ID, append to mmu-masters */
+	for (i = 0; i < count; i++) {
+		fdt_appendprop_u32(blob, smmu_nodeoffset, "mmu-masters",
+				   stream_ids[i]);
+	}
+
+	/* fix up #stream-id-cells with stream ID count */
+	if (fdt_setprop_u32(blob, master_nodeoffset, "#stream-id-cells",
+			    count) < 0)
+		printf("\n%s: ERROR: unable to update #stream-id-cells\n",
+		       __func__);
+}
+
+
+/*
+ * The info below summarizes how streamID partitioning works
+ * for ls2085a and how it is conveyed to the OS via the device tree.
+ *
+ *  -non-PCI legacy, platform devices (USB, SD/MMC, SATA, DMA)
+ *     -all legacy devices get a unique ICID assigned and programmed in
+ *      their AMQR registers by u-boot
+ *     -u-boot updates the hardware device tree with streamID properties
+ *      for each platform/legacy device (smmu-masters property)
+ *
+ *  -PCIe
+ *     -for each PCI controller that is active (as per RCW settings),
+ *      u-boot will allocate a range of ICID and convey that to Linux via
+ *      the device tree (smmu-masters property)
+ *
+ *  -DPAA2
+ *     -u-boot will allocate a range of ICIDs to be used by the Management
+ *      Complex for containers and will set these values in the MC DPC image.
+ *     -the MC is responsible for allocating and setting up ICIDs
+ *      for all DPAA2 devices.
+ *
+ */
+static void fdt_fixup_smmu(void *blob)
+{
+	int nodeoffset;
+
+	nodeoffset = fdt_path_offset(blob, "/iommu@5000000");
+	if (nodeoffset < 0) {
+		printf("\n%s: WARNING: no SMMU node found\n", __func__);
+		return;
+	}
+
+	/* fixup for all PCI controllers */
+#ifdef CONFIG_PCI
+	fdt_fixup_smmu_pcie(blob);
+#endif
+}
+
 void ft_cpu_setup(void *blob, bd_t *bd)
 {
 #ifdef CONFIG_MP
@@ -76,4 +184,6 @@ void ft_cpu_setup(void *blob, bd_t *bd)
 #if defined(CONFIG_FSL_ESDHC)
 	fdt_fixup_esdhc(blob, bd);
 #endif
+
+	fdt_fixup_smmu(blob);
 }
diff --git a/arch/arm/include/asm/arch-fsl-lsch3/fdt.h b/arch/arm/include/asm/arch-fsl-lsch3/fdt.h
new file mode 100644
index 0000000000..21d20fba21
--- /dev/null
+++ b/arch/arm/include/asm/arch-fsl-lsch3/fdt.h
@@ -0,0 +1,10 @@
+/*
+ * Copyright 2015 Freescale Semiconductor
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+void alloc_stream_ids(int start_id, int count, u32 *stream_ids, int max_cnt);
+void append_mmu_masters(void *blob, const char *smmu_path,
+			const char *master_name, u32 *stream_ids, int count);
+void fdt_fixup_smmu_pcie(void *blob);