diff options
Diffstat (limited to 'arch/mips/mti-malta/malta-dtshim.c')
| -rw-r--r-- | arch/mips/mti-malta/malta-dtshim.c | 333 |
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; +} |