summaryrefslogtreecommitdiffstats
path: root/arch/mips/mti-malta/malta-dtshim.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/mti-malta/malta-dtshim.c')
-rw-r--r--arch/mips/mti-malta/malta-dtshim.c333
1 files changed, 333 insertions, 0 deletions
diff --git a/arch/mips/mti-malta/malta-dtshim.c b/arch/mips/mti-malta/malta-dtshim.c
new file mode 100644
index 0000000000..f451268f6c
--- /dev/null
+++ b/arch/mips/mti-malta/malta-dtshim.c
@@ -0,0 +1,333 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Paul Burton <paul.burton@mips.com>
+ */
+
+#include <linux/bug.h>
+#include <linux/kernel.h>
+#include <linux/libfdt.h>
+#include <linux/of_fdt.h>
+#include <linux/sizes.h>
+#include <asm/addrspace.h>
+#include <asm/bootinfo.h>
+#include <asm/fw/fw.h>
+#include <asm/mips-boards/generic.h>
+#include <asm/mips-boards/malta.h>
+#include <asm/mips-cps.h>
+#include <asm/page.h>
+
+#define ROCIT_REG_BASE 0x1f403000
+#define ROCIT_CONFIG_GEN1 (ROCIT_REG_BASE + 0x04)
+#define ROCIT_CONFIG_GEN1_MEMMAP_SHIFT 8
+#define ROCIT_CONFIG_GEN1_MEMMAP_MASK (0xf << 8)
+
+static unsigned char fdt_buf[16 << 10] __initdata __aligned(8);
+
+/* determined physical memory size, not overridden by command line args */
+extern unsigned long physical_memsize;
+
+enum mem_map {
+ MEM_MAP_V1 = 0,
+ MEM_MAP_V2,
+};
+
+#define MAX_MEM_ARRAY_ENTRIES 2
+
+static __init int malta_scon(void)
+{
+ int scon = MIPS_REVISION_SCONID;
+
+ if (scon != MIPS_REVISION_SCON_OTHER)
+ return scon;
+
+ switch (MIPS_REVISION_CORID) {
+ case MIPS_REVISION_CORID_QED_RM5261:
+ case MIPS_REVISION_CORID_CORE_LV:
+ case MIPS_REVISION_CORID_CORE_FPGA:
+ case MIPS_REVISION_CORID_CORE_FPGAR2:
+ return MIPS_REVISION_SCON_GT64120;
+
+ case MIPS_REVISION_CORID_CORE_EMUL_BON:
+ case MIPS_REVISION_CORID_BONITO64:
+ case MIPS_REVISION_CORID_CORE_20K:
+ return MIPS_REVISION_SCON_BONITO;
+
+ case MIPS_REVISION_CORID_CORE_MSC:
+ case MIPS_REVISION_CORID_CORE_FPGA2:
+ case MIPS_REVISION_CORID_CORE_24K:
+ return MIPS_REVISION_SCON_SOCIT;
+
+ case MIPS_REVISION_CORID_CORE_FPGA3:
+ case MIPS_REVISION_CORID_CORE_FPGA4:
+ case MIPS_REVISION_CORID_CORE_FPGA5:
+ case MIPS_REVISION_CORID_CORE_EMUL_MSC:
+ default:
+ return MIPS_REVISION_SCON_ROCIT;
+ }
+}
+
+static unsigned __init gen_fdt_mem_array(__be32 *mem_array, unsigned long size,
+ enum mem_map map)
+{
+ unsigned long size_preio;
+ unsigned entries;
+
+ entries = 1;
+ mem_array[0] = cpu_to_be32(PHYS_OFFSET);
+ if (IS_ENABLED(CONFIG_EVA)) {
+ /*
+ * The current Malta EVA configuration is "special" in that it
+ * always makes use of addresses in the upper half of the 32 bit
+ * physical address map, which gives it a contiguous region of
+ * DDR but limits it to 2GB.
+ */
+ mem_array[1] = cpu_to_be32(size);
+ goto done;
+ }
+
+ size_preio = min_t(unsigned long, size, SZ_256M);
+ mem_array[1] = cpu_to_be32(size_preio);
+ size -= size_preio;
+ if (!size)
+ goto done;
+
+ if (map == MEM_MAP_V2) {
+ /*
+ * We have a flat 32 bit physical memory map with DDR filling
+ * all 4GB of the memory map, apart from the I/O region which
+ * obscures 256MB from 0x10000000-0x1fffffff.
+ *
+ * Therefore we discard the 256MB behind the I/O region.
+ */
+ if (size <= SZ_256M)
+ goto done;
+ size -= SZ_256M;
+
+ /* Make use of the memory following the I/O region */
+ entries++;
+ mem_array[2] = cpu_to_be32(PHYS_OFFSET + SZ_512M);
+ mem_array[3] = cpu_to_be32(size);
+ } else {
+ /*
+ * We have a 32 bit physical memory map with a 2GB DDR region
+ * aliased in the upper & lower halves of it. The I/O region
+ * obscures 256MB from 0x10000000-0x1fffffff in the low alias
+ * but the DDR it obscures is accessible via the high alias.
+ *
+ * Simply access everything beyond the lowest 256MB of DDR using
+ * the high alias.
+ */
+ entries++;
+ mem_array[2] = cpu_to_be32(PHYS_OFFSET + SZ_2G + SZ_256M);
+ mem_array[3] = cpu_to_be32(size);
+ }
+
+done:
+ BUG_ON(entries > MAX_MEM_ARRAY_ENTRIES);
+ return entries;
+}
+
+static void __init append_memory(void *fdt, int root_off)
+{
+ __be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES];
+ unsigned long memsize;
+ unsigned mem_entries;
+ int i, err, mem_off;
+ enum mem_map mem_map;
+ u32 config;
+ char *var, param_name[10], *var_names[] = {
+ "ememsize", "memsize",
+ };
+
+ /* if a memory node already exists, leave it alone */
+ mem_off = fdt_path_offset(fdt, "/memory");
+ if (mem_off >= 0)
+ return;
+
+ /* find memory size from the bootloader environment */
+ for (i = 0; i < ARRAY_SIZE(var_names); i++) {
+ var = fw_getenv(var_names[i]);
+ if (!var)
+ continue;
+
+ err = kstrtoul(var, 0, &physical_memsize);
+ if (!err)
+ break;
+
+ pr_warn("Failed to read the '%s' env variable '%s'\n",
+ var_names[i], var);
+ }
+
+ if (!physical_memsize) {
+ pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
+ physical_memsize = 32 << 20;
+ }
+
+ if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
+ /*
+ * SOC-it swaps, or perhaps doesn't swap, when DMA'ing
+ * the last word of physical memory.
+ */
+ physical_memsize -= PAGE_SIZE;
+ }
+
+ /* default to using all available RAM */
+ memsize = physical_memsize;
+
+ /* allow the user to override the usable memory */
+ for (i = 0; i < ARRAY_SIZE(var_names); i++) {
+ snprintf(param_name, sizeof(param_name), "%s=", var_names[i]);
+ var = strstr(arcs_cmdline, param_name);
+ if (!var)
+ continue;
+
+ memsize = memparse(var + strlen(param_name), NULL);
+ }
+
+ /* if the user says there's more RAM than we thought, believe them */
+ physical_memsize = max_t(unsigned long, physical_memsize, memsize);
+
+ /* detect the memory map in use */
+ if (malta_scon() == MIPS_REVISION_SCON_ROCIT) {
+ /* ROCit has a register indicating the memory map in use */
+ config = readl((void __iomem *)CKSEG1ADDR(ROCIT_CONFIG_GEN1));
+ mem_map = config & ROCIT_CONFIG_GEN1_MEMMAP_MASK;
+ mem_map >>= ROCIT_CONFIG_GEN1_MEMMAP_SHIFT;
+ } else {
+ /* if not using ROCit, presume the v1 memory map */
+ mem_map = MEM_MAP_V1;
+ }
+ if (mem_map > MEM_MAP_V2)
+ panic("Unsupported physical memory map v%u detected",
+ (unsigned int)mem_map);
+
+ /* append memory to the DT */
+ mem_off = fdt_add_subnode(fdt, root_off, "memory");
+ if (mem_off < 0)
+ panic("Unable to add memory node to DT: %d", mem_off);
+
+ err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
+ if (err)
+ panic("Unable to set memory node device_type: %d", err);
+
+ mem_entries = gen_fdt_mem_array(mem_array, physical_memsize, mem_map);
+ err = fdt_setprop(fdt, mem_off, "reg", mem_array,
+ mem_entries * 2 * sizeof(mem_array[0]));
+ if (err)
+ panic("Unable to set memory regs property: %d", err);
+
+ mem_entries = gen_fdt_mem_array(mem_array, memsize, mem_map);
+ err = fdt_setprop(fdt, mem_off, "linux,usable-memory", mem_array,
+ mem_entries * 2 * sizeof(mem_array[0]));
+ if (err)
+ panic("Unable to set linux,usable-memory property: %d", err);
+}
+
+static void __init remove_gic(void *fdt)
+{
+ int err, gic_off, i8259_off, cpu_off;
+ void __iomem *biu_base;
+ uint32_t cpu_phandle, sc_cfg;
+
+ /* if we have a CM which reports a GIC is present, leave the DT alone */
+ err = mips_cm_probe();
+ if (!err && (read_gcr_gic_status() & CM_GCR_GIC_STATUS_EX))
+ return;
+
+ if (malta_scon() == MIPS_REVISION_SCON_ROCIT) {
+ /*
+ * On systems using the RocIT system controller a GIC may be
+ * present without a CM. Detect whether that is the case.
+ */
+ biu_base = ioremap(MSC01_BIU_REG_BASE,
+ MSC01_BIU_ADDRSPACE_SZ);
+ sc_cfg = __raw_readl(biu_base + MSC01_SC_CFG_OFS);
+ if (sc_cfg & MSC01_SC_CFG_GICPRES_MSK) {
+ /* enable the GIC at the system controller level */
+ sc_cfg |= BIT(MSC01_SC_CFG_GICENA_SHF);
+ __raw_writel(sc_cfg, biu_base + MSC01_SC_CFG_OFS);
+ return;
+ }
+ }
+
+ gic_off = fdt_node_offset_by_compatible(fdt, -1, "mti,gic");
+ if (gic_off < 0) {
+ pr_warn("malta-dtshim: unable to find DT GIC node: %d\n",
+ gic_off);
+ return;
+ }
+
+ err = fdt_nop_node(fdt, gic_off);
+ if (err)
+ pr_warn("malta-dtshim: unable to nop GIC node\n");
+
+ i8259_off = fdt_node_offset_by_compatible(fdt, -1, "intel,i8259");
+ if (i8259_off < 0) {
+ pr_warn("malta-dtshim: unable to find DT i8259 node: %d\n",
+ i8259_off);
+ return;
+ }
+
+ cpu_off = fdt_node_offset_by_compatible(fdt, -1,
+ "mti,cpu-interrupt-controller");
+ if (cpu_off < 0) {
+ pr_warn("malta-dtshim: unable to find CPU intc node: %d\n",
+ cpu_off);
+ return;
+ }
+
+ cpu_phandle = fdt_get_phandle(fdt, cpu_off);
+ if (!cpu_phandle) {
+ pr_warn("malta-dtshim: unable to get CPU intc phandle\n");
+ return;
+ }
+
+ err = fdt_setprop_u32(fdt, i8259_off, "interrupt-parent", cpu_phandle);
+ if (err) {
+ pr_warn("malta-dtshim: unable to set i8259 interrupt-parent: %d\n",
+ err);
+ return;
+ }
+
+ err = fdt_setprop_u32(fdt, i8259_off, "interrupts", 2);
+ if (err) {
+ pr_warn("malta-dtshim: unable to set i8259 interrupts: %d\n",
+ err);
+ return;
+ }
+}
+
+void __init *malta_dt_shim(void *fdt)
+{
+ int root_off, len, err;
+ const char *compat;
+
+ if (fdt_check_header(fdt))
+ panic("Corrupt DT");
+
+ err = fdt_open_into(fdt, fdt_buf, sizeof(fdt_buf));
+ if (err)
+ panic("Unable to open FDT: %d", err);
+
+ root_off = fdt_path_offset(fdt_buf, "/");
+ if (root_off < 0)
+ panic("No / node in DT");
+
+ compat = fdt_getprop(fdt_buf, root_off, "compatible", &len);
+ if (!compat)
+ panic("No root compatible property in DT: %d", len);
+
+ /* if this isn't Malta, leave the DT alone */
+ if (strncmp(compat, "mti,malta", len))
+ return fdt;
+
+ append_memory(fdt_buf, root_off);
+ remove_gic(fdt_buf);
+
+ err = fdt_pack(fdt_buf);
+ if (err)
+ panic("Unable to pack FDT: %d\n", err);
+
+ return fdt_buf;
+}