/* * CCI cache coherent interconnect driver * * Copyright (C) 2013 ARM Ltd. * Author: Lorenzo Pieralisi * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed "as is" WITHOUT ANY WARRANTY of any * kind, whether express or implied; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include #include #include #include #include #include #include #include static void __iomem *cci_ctrl_base __ro_after_init; static unsigned long cci_ctrl_phys __ro_after_init; #ifdef CONFIG_ARM_CCI400_PORT_CTRL struct cci_nb_ports { unsigned int nb_ace; unsigned int nb_ace_lite; }; static const struct cci_nb_ports cci400_ports = { .nb_ace = 2, .nb_ace_lite = 3 }; #define CCI400_PORTS_DATA (&cci400_ports) #else #define CCI400_PORTS_DATA (NULL) #endif static const struct of_device_id arm_cci_matches[] = { #ifdef CONFIG_ARM_CCI400_COMMON {.compatible = "arm,cci-400", .data = CCI400_PORTS_DATA }, #endif #ifdef CONFIG_ARM_CCI5xx_PMU { .compatible = "arm,cci-500", }, { .compatible = "arm,cci-550", }, #endif {}, }; static const struct of_dev_auxdata arm_cci_auxdata[] = { OF_DEV_AUXDATA("arm,cci-400-pmu", 0, NULL, &cci_ctrl_base), OF_DEV_AUXDATA("arm,cci-400-pmu,r0", 0, NULL, &cci_ctrl_base), OF_DEV_AUXDATA("arm,cci-400-pmu,r1", 0, NULL, &cci_ctrl_base), OF_DEV_AUXDATA("arm,cci-500-pmu,r0", 0, NULL, &cci_ctrl_base), OF_DEV_AUXDATA("arm,cci-550-pmu,r0", 0, NULL, &cci_ctrl_base), {} }; #define DRIVER_NAME "ARM-CCI" static int cci_platform_probe(struct platform_device *pdev) { if (!cci_probed()) return -ENODEV; return of_platform_populate(pdev->dev.of_node, NULL, arm_cci_auxdata, &pdev->dev); } static struct platform_driver cci_platform_driver = { .driver = { .name = DRIVER_NAME, .of_match_table = arm_cci_matches, }, .probe = cci_platform_probe, }; static int __init cci_platform_init(void) { return platform_driver_register(&cci_platform_driver); } #ifdef CONFIG_ARM_CCI400_PORT_CTRL #define CCI_PORT_CTRL 0x0 #define CCI_CTRL_STATUS 0xc #define CCI_ENABLE_SNOOP_REQ 0x1 #define CCI_ENABLE_DVM_REQ 0x2 #define CCI_ENABLE_REQ (CCI_ENABLE_SNOOP_REQ | CCI_ENABLE_DVM_REQ) enum cci_ace_port_type { ACE_INVALID_PORT = 0x0, ACE_PORT, ACE_LITE_PORT, }; struct cci_ace_port { void __iomem *base; unsigned long phys; enum cci_ace_port_type type; struct device_node *dn; }; static struct cci_ace_port *ports; static unsigned int nb_cci_ports; struct cpu_port { u64 mpidr; u32 port; }; /* * Use the port MSB as valid flag, shift can be made dynamic * by computing number of bits required for port indexes. * Code disabling CCI cpu ports runs with D-cache invalidated * and SCTLR bit clear so data accesses must be kept to a minimum * to improve performance; for now shift is left static to * avoid one more data access while disabling the CCI port. */ #define PORT_VALID_SHIFT 31 #define PORT_VALID (0x1 << PORT_VALID_SHIFT) static inline void init_cpu_port(struct cpu_port *port, u32 index, u64 mpidr) { port->port = PORT_VALID | index; port->mpidr = mpidr; } static inline bool cpu_port_is_valid(struct cpu_port *port) { return !!(port->port & PORT_VALID); } static inline bool cpu_port_match(struct cpu_port *port, u64 mpidr) { return port->mpidr == (mpidr & MPIDR_HWID_BITMASK); } static struct cpu_port cpu_port[NR_CPUS]; /** * __cci_ace_get_port - Function to retrieve the port index connected to * a cpu or device. * * @dn: device node of the device to look-up * @type: port type * * Return value: * - CCI port index if success * - -ENODEV if failure */ static int __cci_ace_get_port(struct device_node *dn, int type) { int i; bool ace_match; struct device_node *cci_portn; cci_portn = of_parse_phandle(dn, "cci-control-port", 0); for (i = 0; i < nb_cci_ports; i++) { ace_match = ports[i].type == type; if (ace_match && cci_portn == ports[i].dn) return i; } return -ENODEV; } int cci_ace_get_port(struct device_node *dn) { return __cci_ace_get_port(dn, ACE_LITE_PORT); } EXPORT_SYMBOL_GPL(cci_ace_get_port); static void cci_ace_init_ports(void) { int port, cpu; struct device_node *cpun; /* * Port index look-up speeds up the function disabling ports by CPU, * since the logical to port index mapping is done once and does * not change after system boot. * The stashed index array is initialized for all possible CPUs * at probe time. */ for_each_possible_cpu(cpu) { /* too early to use cpu->of_node */ cpun = of_get_cpu_node(cpu, NULL); if (WARN(!cpun, "Missing cpu device node\n")) continue; port = __cci_ace_get_port(cpun, ACE_PORT); if (port < 0) continue; init_cpu_port(&cpu_port[cpu], port, cpu_logical_map(cpu)); } for_each_possible_cpu(cpu) { WARN(!cpu_port_is_valid(&cpu_port[cpu]), "CPU %u does not have an associated CCI port\n", cpu); } } /* * Functions to enable/disable a CCI interconnect slave port * * They are called by low-level power management code to disable slave * interfaces snoops and DVM broadcast. * Since they may execute with cache data allocation disabled and * after the caches have been cleaned and invalidated the functions provide * no explicit locking since they may run with D-cache disabled, so normal * cacheable kernel locks based on ldrex/strex may not work. * Locking has to be provided by BSP implementations to ensure proper * operations. */ /** * cci_port_control() - function to control a CCI port * * @port: index of the port to setup * @enable: if true enables the port, if false disables it */ static void notrace cci_port_control(unsigned int port, bool enable) { void __iomem *base = ports[port].base; writel_relaxed(enable ? CCI_ENABLE_REQ : 0, base + CCI_PORT_CTRL); /* * This function is called from power down procedures * and must not execute any instruction that might * cause the processor to be put in a quiescent state * (eg wfi). Hence, cpu_relax() can not be added to this * read loop to optimize power, since it might hide possibly * disruptive operations. */ while (readl_relaxed(cci_ctrl_base + CCI_CTRL_STATUS) & 0x1) ; } /** * cci_disable_port_by_cpu() - function to disable a CCI port by CPU * reference * * @mpidr: mpidr of the CPU whose CCI port should be disabled * * Disabling a CCI port for a CPU implies disabling the CCI port * controlling that CPU cluster. Code disabling CPU CCI ports * must make sure that the CPU running the code is the last active CPU * in the cluster ie all other CPUs are quiescent in a low power state. * * Return: * 0 on success * -ENODEV on port look-up failure */ int notrace cci_disable_port_by_cpu(u64 mpidr) { int cpu; bool is_valid; for (cpu = 0; cpu < nr_cpu_ids; cpu++) { is_valid = cpu_port_is_valid(&cpu_port[cpu]); if (is_valid && cpu_port_match(&cpu_port[cpu], mpidr)) { cci_port_control(cpu_port[cpu].port, false); return 0; } } return -ENODEV; } EXPORT_SYMBOL_GPL(cci_disable_port_by_cpu); /** * cci_enable_port_for_self() - enable a CCI port for calling CPU * * Enabling a CCI port for the calling CPU implies enabling the CCI * port controlling that CPU's cluster. Caller must make sure that the * CPU running the code is the first active CPU in the cluster and all * other CPUs are quiescent in a low power state or waiting for this CPU * to complete the CCI initialization. * * Because this is called when the MMU is still off and with no stack, * the code must be position independent and ideally rely on callee * clobbered registers only. To achieve this we must code this function * entirely in assembler. * * On success this returns with the proper CCI port enabled. In case of * any failure this never returns as the inability to enable the CCI is * fatal and there is no possible recovery at this stage. */ asmlinkage void __naked cci_enable_port_for_self(void) { asm volatile ("\n" " .arch armv7-a\n" " mrc p15, 0, r0, c0, c0, 5 @ get MPIDR value \n" " and r0, r0, #"__stringify(MPIDR_HWID_BITMASK)" \n" " adr r1, 5f \n" " ldr r2, [r1] \n" " add r1, r1, r2 @ &cpu_port \n" " add ip, r1, %[sizeof_cpu_port] \n" /* Loop over the cpu_port array looking for a matching MPIDR */ "1: ldr r2, [r1, %[offsetof_cpu_port_mpidr_lsb]] \n" " cmp r2, r0 @ compare MPIDR \n" " bne 2f \n" /* Found a match, now test port validity */ " ldr r3, [r1, %[offsetof_cpu_port_port]] \n" " tst r3, #"__stringify(PORT_VALID)" \n" " bne 3f \n" /* no match, loop with the next cpu_port entry */ "2: add r1, r1, %[sizeof_struct_cpu_port] \n" " cmp r1, ip @ done? \n" " blo 1b \n" /* CCI port not found -- cheaply try to stall this CPU */ "cci_port_not_found: \n" " wfi \n" " wfe \n" " b cci_port_not_found \n" /* Use matched port index to look up the corresponding ports entry */ "3: bic r3, r3, #"__stringify(PORT_VALID)" \n" " adr r0, 6f \n" " ldmia r0, {r1, r2} \n" " sub r1, r1, r0 @ virt - phys \n" " ldr r0, [r0, r2] @ *(&ports) \n" " mov r2, %[sizeof_struct_ace_port] \n" " mla r0, r2, r3, r0 @ &ports[index] \n" " sub r0, r0, r1 @ virt_to_phys() \n" /* Enable the CCI port */ " ldr r0, [r0, %[offsetof_port_phys]] \n" " mov r3, %[cci_enable_req]\n" " str r3, [r0, #"__stringify(CCI_PORT_CTRL)"] \n" /* poll the status reg for completion */ " adr r1, 7f \n" " ldr r0, [r1] \n" " ldr r0, [r0, r1] @ cci_ctrl_base \n" "4: ldr r1, [r0, #"__stringify(CCI_CTRL_STATUS)"] \n" " tst r1, %[cci_control_status_bits] \n" " bne 4b \n" " mov r0, #0 \n" " bx lr \n" " .align 2 \n" "5: .word cpu_port - . \n" "6: .word . \n" " .word ports - 6b \n" "7: .word cci_ctrl_phys - . \n" : : [sizeof_cpu_port] "i" (sizeof(cpu_port)), [cci_enable_req] "i" cpu_to_le32(CCI_ENABLE_REQ), [cci_control_status_bits] "i" cpu_to_le32(1), #ifndef __ARMEB__ [offsetof_cpu_port_mpidr_lsb] "i" (offsetof(struct cpu_port, mpidr)), #else [offsetof_cpu_port_mpidr_lsb] "i" (offsetof(struct cpu_port, mpidr)+4), #endif [offsetof_cpu_port_port] "i" (offsetof(struct cpu_port, port)), [sizeof_struct_cpu_port] "i" (sizeof(struct cpu_port)), [sizeof_struct_ace_port] "i" (sizeof(struct cci_ace_port)), [offsetof_port_phys] "i" (offsetof(struct cci_ace_port, phys)) ); } /** * __cci_control_port_by_device() - function to control a CCI port by device * reference * * @dn: device node pointer of the device whose CCI port should be * controlled * @enable: if true enables the port, if false disables it * * Return: * 0 on success * -ENODEV on port look-up failure */ int notrace __cci_control_port_by_device(struct device_node *dn, bool enable) { int port; if (!dn) return -ENODEV; port = __cci_ace_get_port(dn, ACE_LITE_PORT); if (WARN_ONCE(port < 0, "node %pOF ACE lite port look-up failure\n", dn)) return -ENODEV; cci_port_control(port, enable); return 0; } EXPORT_SYMBOL_GPL(__cci_control_port_by_device); /** * __cci_control_port_by_index() - function to control a CCI port by port index * * @port: port index previously retrieved with cci_ace_get_port() * @enable: if true enables the port, if false disables it * * Return: * 0 on success * -ENODEV on port index out of range * -EPERM if operation carried out on an ACE PORT */ int notrace __cci_control_port_by_index(u32 port, bool enable) { if (port >= nb_cci_ports || ports[port].type == ACE_INVALID_PORT) return -ENODEV; /* * CCI control for ports connected to CPUS is extremely fragile * and must be made to go through a specific and controlled * interface (ie cci_disable_port_by_cpu(); control by general purpose * indexing is therefore disabled for ACE ports. */ if (ports[port].type == ACE_PORT) return -EPERM; cci_port_control(port, enable); return 0; } EXPORT_SYMBOL_GPL(__cci_control_port_by_index); static const struct of_device_id arm_cci_ctrl_if_matches[] = { {.compatible = "arm,cci-400-ctrl-if", }, {}, }; static int cci_probe_ports(struct device_node *np) { struct cci_nb_ports const *cci_config; int ret, i, nb_ace = 0, nb_ace_lite = 0; struct device_node *cp; struct resource res; const char *match_str; bool is_ace; cci_config = of_match_node(arm_cci_matches, np)->data; if (!cci_config) return -ENODEV; nb_cci_ports = cci_config->nb_ace + cci_config->nb_ace_lite; ports = kcalloc(nb_cci_ports, sizeof(*ports), GFP_KERNEL); if (!ports) return -ENOMEM; for_each_available_child_of_node(np, cp) { if (!of_match_node(arm_cci_ctrl_if_matches, cp)) continue; i = nb_ace + nb_ace_lite; if (i >= nb_cci_ports) break; if (of_property_read_string(cp, "interface-type", &match_str)) { WARN(1, "node %pOF missing interface-type property\n", cp); continue; } is_ace = strcmp(match_str, "ace") == 0; if (!is_ace && strcmp(match_str, "ace-lite")) { WARN(1, "node %pOF containing invalid interface-type property, skipping it\n", cp); continue; } ret = of_address_to_resource(cp, 0, &res); if (!ret) { ports[i].base = ioremap(res.start, resource_size(&res)); ports[i].phys = res.start; } if (ret || !ports[i].base) { WARN(1, "unable to ioremap CCI port %d\n", i); continue; } if (is_ace) { if (WARN_ON(nb_ace >= cci_config->nb_ace)) continue; ports[i].type = ACE_PORT; ++nb_ace; } else { if (WARN_ON(nb_ace_lite >= cci_config->nb_ace_lite)) continue; ports[i].type = ACE_LITE_PORT; ++nb_ace_lite; } ports[i].dn = cp; } /* * If there is no CCI port that is under kernel control * return early and report probe status. */ if (!nb_ace && !nb_ace_lite) return -ENODEV; /* initialize a stashed array of ACE ports to speed-up look-up */ cci_ace_init_ports(); /* * Multi-cluster systems may need this data when non-coherent, during * cluster power-up/power-down. Make sure it reaches main memory. */ sync_cache_w(&cci_ctrl_base); sync_cache_w(&cci_ctrl_phys); sync_cache_w(&ports); sync_cache_w(&cpu_port); __sync_cache_range_w(ports, sizeof(*ports) * nb_cci_ports); pr_info("ARM CCI driver probed\n"); return 0; } #else /* !CONFIG_ARM_CCI400_PORT_CTRL */ static inline int cci_probe_ports(struct device_node *np) { return 0; } #endif /* CONFIG_ARM_CCI400_PORT_CTRL */ static int cci_probe(void) { int ret; struct device_node *np; struct resource res; np = of_find_matching_node(NULL, arm_cci_matches); if (!of_device_is_available(np)) return -ENODEV; ret = of_address_to_resource(np, 0, &res); if (!ret) { cci_ctrl_base = ioremap(res.start, resource_size(&res)); cci_ctrl_phys = res.start; } if (ret || !cci_ctrl_base) { WARN(1, "unable to ioremap CCI ctrl\n"); return -ENXIO; } return cci_probe_ports(np); } static int cci_init_status = -EAGAIN; static DEFINE_MUTEX(cci_probing); static int cci_init(void) { if (cci_init_status != -EAGAIN) return cci_init_status; mutex_lock(&cci_probing); if (cci_init_status == -EAGAIN) cci_init_status = cci_probe(); mutex_unlock(&cci_probing); return cci_init_status; } /* * To sort out early init calls ordering a helper function is provided to * check if the CCI driver has beed initialized. Function check if the driver * has been initialized, if not it calls the init function that probes * the driver and updates the return value. */ bool cci_probed(void) { return cci_init() == 0; } EXPORT_SYMBOL_GPL(cci_probed); early_initcall(cci_init); core_initcall(cci_platform_init); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("ARM CCI support");