// SPDX-License-Identifier: GPL-2.0-only /* * Broadcom STB SoCs Bus Unit Interface controls * * Copyright (C) 2015, Broadcom Corporation */ #define pr_fmt(fmt) "brcmstb: " KBUILD_MODNAME ": " fmt #include #include #include #include #include #define RACENPREF_MASK 0x3 #define RACPREFINST_SHIFT 0 #define RACENINST_SHIFT 2 #define RACPREFDATA_SHIFT 4 #define RACENDATA_SHIFT 6 #define RAC_CPU_SHIFT 8 #define RACCFG_MASK 0xff /* Bitmask to enable instruction and data prefetching with a 256-bytes stride */ #define RAC_DATA_INST_EN_MASK (1 << RACPREFINST_SHIFT | \ RACENPREF_MASK << RACENINST_SHIFT | \ 1 << RACPREFDATA_SHIFT | \ RACENPREF_MASK << RACENDATA_SHIFT) #define CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK 0x70000000 #define CPU_CREDIT_REG_MCPx_READ_CRED_MASK 0xf #define CPU_CREDIT_REG_MCPx_WRITE_CRED_MASK 0xf #define CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(x) ((x) * 8) #define CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(x) (((x) * 8) + 4) #define CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_SHIFT(x) ((x) * 8) #define CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_MASK 0xff #define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_THRESHOLD_MASK 0xf #define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_MASK 0xf #define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT 4 #define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_ENABLE BIT(8) static void __iomem *cpubiuctrl_base; static bool mcp_wr_pairing_en; static const int *cpubiuctrl_regs; enum cpubiuctrl_regs { CPU_CREDIT_REG = 0, CPU_MCP_FLOW_REG, CPU_WRITEBACK_CTRL_REG, RAC_CONFIG0_REG, NUM_CPU_BIUCTRL_REGS, }; static inline u32 cbc_readl(int reg) { int offset = cpubiuctrl_regs[reg]; if (offset == -1 || (IS_ENABLED(CONFIG_CACHE_B15_RAC) && reg == RAC_CONFIG0_REG)) return (u32)-1; return readl_relaxed(cpubiuctrl_base + offset); } static inline void cbc_writel(u32 val, int reg) { int offset = cpubiuctrl_regs[reg]; if (offset == -1 || (IS_ENABLED(CONFIG_CACHE_B15_RAC) && reg == RAC_CONFIG0_REG)) return; writel(val, cpubiuctrl_base + offset); } static const int b15_cpubiuctrl_regs[] = { [CPU_CREDIT_REG] = 0x184, [CPU_MCP_FLOW_REG] = -1, [CPU_WRITEBACK_CTRL_REG] = -1, [RAC_CONFIG0_REG] = -1, }; /* Odd cases, e.g: 7260A0 */ static const int b53_cpubiuctrl_no_wb_regs[] = { [CPU_CREDIT_REG] = 0x0b0, [CPU_MCP_FLOW_REG] = 0x0b4, [CPU_WRITEBACK_CTRL_REG] = -1, [RAC_CONFIG0_REG] = 0x78, }; static const int b53_cpubiuctrl_regs[] = { [CPU_CREDIT_REG] = 0x0b0, [CPU_MCP_FLOW_REG] = 0x0b4, [CPU_WRITEBACK_CTRL_REG] = 0x22c, [RAC_CONFIG0_REG] = 0x78, }; static const int a72_cpubiuctrl_regs[] = { [CPU_CREDIT_REG] = 0x18, [CPU_MCP_FLOW_REG] = 0x1c, [CPU_WRITEBACK_CTRL_REG] = 0x20, [RAC_CONFIG0_REG] = 0x08, }; static int __init mcp_write_pairing_set(void) { u32 creds = 0; if (!cpubiuctrl_base) return -1; creds = cbc_readl(CPU_CREDIT_REG); if (mcp_wr_pairing_en) { pr_info("MCP: Enabling write pairing\n"); cbc_writel(creds | CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK, CPU_CREDIT_REG); } else if (creds & CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK) { pr_info("MCP: Disabling write pairing\n"); cbc_writel(creds & ~CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK, CPU_CREDIT_REG); } else { pr_info("MCP: Write pairing already disabled\n"); } return 0; } static const u32 a72_b53_mach_compat[] = { 0x7211, 0x7216, 0x72164, 0x72165, 0x7255, 0x7260, 0x7268, 0x7271, 0x7278, }; /* The read-ahead cache present in the Brahma-B53 CPU is a special piece of * hardware after the integrated L2 cache of the B53 CPU complex whose purpose * is to prefetch instruction and/or data with a line size of either 64 bytes * or 256 bytes. The rationale is that the data-bus of the CPU interface is * optimized for 256-byte transactions, and enabling the read-ahead cache * provides a significant performance boost (typically twice the performance * for a memcpy benchmark application). * * The read-ahead cache is transparent for Virtual Address cache maintenance * operations: IC IVAU, DC IVAC, DC CVAC, DC CVAU and DC CIVAC. So no special * handling is needed for the DMA API above and beyond what is included in the * arm64 implementation. * * In addition, since the Point of Unification is typically between L1 and L2 * for the Brahma-B53 processor no special read-ahead cache handling is needed * for the IC IALLU and IC IALLUIS cache maintenance operations. * * However, it is not possible to specify the cache level (L3) for the cache * maintenance instructions operating by set/way to operate on the read-ahead * cache. The read-ahead cache will maintain coherency when inner cache lines * are cleaned by set/way, but if it is necessary to invalidate inner cache * lines by set/way to maintain coherency with system masters operating on * shared memory that does not have hardware support for coherency, then it * will also be necessary to explicitly invalidate the read-ahead cache. */ static void __init a72_b53_rac_enable_all(struct device_node *np) { unsigned int cpu; u32 enable = 0; if (IS_ENABLED(CONFIG_CACHE_B15_RAC)) return; if (WARN(num_possible_cpus() > 4, "RAC only supports 4 CPUs\n")) return; for_each_possible_cpu(cpu) enable |= RAC_DATA_INST_EN_MASK << (cpu * RAC_CPU_SHIFT); cbc_writel(enable, RAC_CONFIG0_REG); pr_info("%pOF: Broadcom %s read-ahead cache\n", np, cpubiuctrl_regs == a72_cpubiuctrl_regs ? "Cortex-A72" : "Brahma-B53"); } static void __init mcp_a72_b53_set(void) { unsigned int i; u32 reg; reg = brcmstb_get_family_id(); for (i = 0; i < ARRAY_SIZE(a72_b53_mach_compat); i++) { if (BRCM_ID(reg) == a72_b53_mach_compat[i]) break; } if (i == ARRAY_SIZE(a72_b53_mach_compat)) return; /* Set all 3 MCP interfaces to 8 credits */ reg = cbc_readl(CPU_CREDIT_REG); for (i = 0; i < 3; i++) { reg &= ~(CPU_CREDIT_REG_MCPx_WRITE_CRED_MASK << CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(i)); reg &= ~(CPU_CREDIT_REG_MCPx_READ_CRED_MASK << CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(i)); reg |= 8 << CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(i); reg |= 8 << CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(i); } cbc_writel(reg, CPU_CREDIT_REG); /* Max out the number of in-flight Jwords reads on the MCP interface */ reg = cbc_readl(CPU_MCP_FLOW_REG); for (i = 0; i < 3; i++) reg |= CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_MASK << CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_SHIFT(i); cbc_writel(reg, CPU_MCP_FLOW_REG); /* Enable writeback throttling, set timeout to 128 cycles, 256 cycles * threshold */ reg = cbc_readl(CPU_WRITEBACK_CTRL_REG); reg |= CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_ENABLE; reg &= ~CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_THRESHOLD_MASK; reg &= ~(CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_MASK << CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT); reg |= 8; reg |= 7 << CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT; cbc_writel(reg, CPU_WRITEBACK_CTRL_REG); } static int __init setup_hifcpubiuctrl_regs(struct device_node *np) { struct device_node *cpu_dn; u32 family_id; int ret = 0; cpubiuctrl_base = of_iomap(np, 0); if (!cpubiuctrl_base) { pr_err("failed to remap BIU control base\n"); ret = -ENOMEM; goto out; } mcp_wr_pairing_en = of_property_read_bool(np, "brcm,write-pairing"); cpu_dn = of_get_cpu_node(0, NULL); if (!cpu_dn) { pr_err("failed to obtain CPU device node\n"); ret = -ENODEV; goto out; } if (of_device_is_compatible(cpu_dn, "brcm,brahma-b15")) cpubiuctrl_regs = b15_cpubiuctrl_regs; else if (of_device_is_compatible(cpu_dn, "brcm,brahma-b53")) cpubiuctrl_regs = b53_cpubiuctrl_regs; else if (of_device_is_compatible(cpu_dn, "arm,cortex-a72")) cpubiuctrl_regs = a72_cpubiuctrl_regs; else { pr_err("unsupported CPU\n"); ret = -EINVAL; } of_node_put(cpu_dn); family_id = brcmstb_get_family_id(); if (BRCM_ID(family_id) == 0x7260 && BRCM_REV(family_id) == 0) cpubiuctrl_regs = b53_cpubiuctrl_no_wb_regs; out: of_node_put(np); return ret; } #ifdef CONFIG_PM_SLEEP static u32 cpubiuctrl_reg_save[NUM_CPU_BIUCTRL_REGS]; static int brcmstb_cpu_credit_reg_suspend(void) { unsigned int i; if (!cpubiuctrl_base) return 0; for (i = 0; i < NUM_CPU_BIUCTRL_REGS; i++) cpubiuctrl_reg_save[i] = cbc_readl(i); return 0; } static void brcmstb_cpu_credit_reg_resume(void) { unsigned int i; if (!cpubiuctrl_base) return; for (i = 0; i < NUM_CPU_BIUCTRL_REGS; i++) cbc_writel(cpubiuctrl_reg_save[i], i); } static struct syscore_ops brcmstb_cpu_credit_syscore_ops = { .suspend = brcmstb_cpu_credit_reg_suspend, .resume = brcmstb_cpu_credit_reg_resume, }; #endif static int __init brcmstb_biuctrl_init(void) { struct device_node *np; int ret; /* We might be running on a multi-platform kernel, don't make this a * fatal error, just bail out early */ np = of_find_compatible_node(NULL, NULL, "brcm,brcmstb-cpu-biu-ctrl"); if (!np) return 0; ret = setup_hifcpubiuctrl_regs(np); if (ret) return ret; ret = mcp_write_pairing_set(); if (ret) { pr_err("MCP: Unable to disable write pairing!\n"); return ret; } a72_b53_rac_enable_all(np); mcp_a72_b53_set(); #ifdef CONFIG_PM_SLEEP register_syscore_ops(&brcmstb_cpu_credit_syscore_ops); #endif return 0; } early_initcall(brcmstb_biuctrl_init);