| Alexey Brodkin | a518d63 | 2017-08-15 21:13:55 +0300 | [diff] [blame^] | 1 | /* |
| 2 | * ARC HSDK Platform support code |
| 3 | * |
| 4 | * Copyright (C) 2017 Synopsys, Inc. (www.synopsys.com) |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/smp.h> |
| 13 | #include <asm/arcregs.h> |
| 14 | #include <asm/io.h> |
| 15 | #include <asm/mach_desc.h> |
| 16 | |
| 17 | #define ARC_CCM_UNUSED_ADDR 0x60000000 |
| 18 | |
| 19 | static void __init hsdk_init_per_cpu(unsigned int cpu) |
| 20 | { |
| 21 | /* |
| 22 | * By default ICCM is mapped to 0x7z while this area is used for |
| 23 | * kernel virtual mappings, so move it to currently unused area. |
| 24 | */ |
| 25 | if (cpuinfo_arc700[cpu].iccm.sz) |
| 26 | write_aux_reg(ARC_REG_AUX_ICCM, ARC_CCM_UNUSED_ADDR); |
| 27 | |
| 28 | /* |
| 29 | * By default DCCM is mapped to 0x8z while this area is used by kernel, |
| 30 | * so move it to currently unused area. |
| 31 | */ |
| 32 | if (cpuinfo_arc700[cpu].dccm.sz) |
| 33 | write_aux_reg(ARC_REG_AUX_DCCM, ARC_CCM_UNUSED_ADDR); |
| 34 | } |
| 35 | |
| 36 | #define ARC_PERIPHERAL_BASE 0xf0000000 |
| 37 | #define CREG_BASE (ARC_PERIPHERAL_BASE + 0x1000) |
| 38 | #define CREG_PAE (CREG_BASE + 0x180) |
| 39 | #define CREG_PAE_UPDATE (CREG_BASE + 0x194) |
| 40 | |
| 41 | static void __init hsdk_init_early(void) |
| 42 | { |
| 43 | /* |
| 44 | * PAE remapping for DMA clients does not work due to an RTL bug, so |
| 45 | * CREG_PAE register must be programmed to all zeroes, otherwise it |
| 46 | * will cause problems with DMA to/from peripherals even if PAE40 is |
| 47 | * not used. |
| 48 | */ |
| 49 | |
| 50 | /* Default is 1, which means "PAE offset = 4GByte" */ |
| 51 | writel_relaxed(0, (void __iomem *) CREG_PAE); |
| 52 | |
| 53 | /* Really apply settings made above */ |
| 54 | writel(1, (void __iomem *) CREG_PAE_UPDATE); |
| 55 | } |
| 56 | |
| 57 | static const char *hsdk_compat[] __initconst = { |
| 58 | "snps,hsdk", |
| 59 | NULL, |
| 60 | }; |
| 61 | |
| 62 | MACHINE_START(SIMULATION, "hsdk") |
| 63 | .dt_compat = hsdk_compat, |
| 64 | .init_early = hsdk_init_early, |
| 65 | .init_per_cpu = hsdk_init_per_cpu, |
| 66 | MACHINE_END |