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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/bus/arm-cci.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--drivers/bus/arm-cci.c587
1 files changed, 587 insertions, 0 deletions
diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
new file mode 100644
index 000000000..b8184a903
--- /dev/null
+++ b/drivers/bus/arm-cci.c
@@ -0,0 +1,587 @@
+/*
+ * CCI cache coherent interconnect driver
+ *
+ * Copyright (C) 2013 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * 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 <linux/arm-cci.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+
+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");