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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-02 13:43:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-02 13:43:38 -0700
commit3883cbb6c1bda013a3ce2dbdab7dc97c52e4a232 (patch)
tree5b69f83b049d24ac81123ac954ca8c9128e48443 /drivers/bus
parentd2033f2c1d1de2239ded15e478ddb4028f192a15 (diff)
parent1eb92b24e243085d242cf5ffd64829bba70972e1 (diff)
downloadlwn-3883cbb6c1bda013a3ce2dbdab7dc97c52e4a232.tar.gz
lwn-3883cbb6c1bda013a3ce2dbdab7dc97c52e4a232.zip
Merge tag 'soc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC specific changes from Arnd Bergmann: "These changes are all to SoC-specific code, a total of 33 branches on 17 platforms were pulled into this. Like last time, Renesas sh-mobile is now the platform with the most changes, followed by OMAP and EXYNOS. Two new platforms, TI Keystone and Rockchips RK3xxx are added in this branch, both containing almost no platform specific code at all, since they are using generic subsystem interfaces for clocks, pinctrl, interrupts etc. The device drivers are getting merged through the respective subsystem maintainer trees. One more SoC (u300) is now multiplatform capable and several others (shmobile, exynos, msm, integrator, kirkwood, clps711x) are moving towards that goal with this series but need more work. Also noteworthy is the work on PCI here, which is traditionally part of the SoC specific code. With the changes done by Thomas Petazzoni, we can now more easily have PCI host controller drivers as loadable modules and keep them separate from the platform code in drivers/pci/host. This has already led to the discovery that three platforms (exynos, spear and imx) are actually using an identical PCIe host controller and will be able to share a driver once support for spear and imx is added." * tag 'soc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (480 commits) ARM: integrator: let pciv3 use mem/premem from device tree ARM: integrator: set local side PCI addresses right ARM: dts: Add pcie controller node for exynos5440-ssdk5440 ARM: dts: Add pcie controller node for Samsung EXYNOS5440 SoC ARM: EXYNOS: Enable PCIe support for Exynos5440 pci: Add PCIe driver for Samsung Exynos ARM: OMAP5: voltagedomain data: remove temporary OMAP4 voltage data ARM: keystone: Move CPU bringup code to dedicated asm file ARM: multiplatform: always pick one CPU type ARM: imx: select syscon for IMX6SL ARM: keystone: select ARM_ERRATA_798181 only for SMP ARM: imx: Synertronixx scb9328 needs to select SOC_IMX1 ARM: OMAP2+: AM43x: resolve SMP related build error dmaengine: edma: enable build for AM33XX ARM: edma: Add EDMA crossbar event mux support ARM: edma: Add DT and runtime PM support to the private EDMA API dmaengine: edma: Add TI EDMA device tree binding arm: add basic support for Rockchip RK3066a boards arm: add debug uarts for rockchip rk29xx and rk3xxx series arm: Add basic clocks for Rockchip rk3066a SoCs ...
Diffstat (limited to 'drivers/bus')
-rw-r--r--drivers/bus/Kconfig7
-rw-r--r--drivers/bus/Makefile2
-rw-r--r--drivers/bus/arm-cci.c533
3 files changed, 542 insertions, 0 deletions
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index b05ecab915c4..5286e2d333b0 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -26,4 +26,11 @@ config OMAP_INTERCONNECT
help
Driver to enable OMAP interconnect error handling driver.
+
+config ARM_CCI
+ bool "ARM CCI driver support"
+ depends on ARM
+ help
+ Driver supporting the CCI cache coherent interconnect for ARM
+ platforms.
endmenu
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index 3c7b53c12091..670cea443802 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -7,3 +7,5 @@ obj-$(CONFIG_OMAP_OCP2SCP) += omap-ocp2scp.o
# Interconnect bus driver for OMAP SoCs.
obj-$(CONFIG_OMAP_INTERCONNECT) += omap_l3_smx.o omap_l3_noc.o
+# CCI cache coherent interconnect for ARM platforms
+obj-$(CONFIG_ARM_CCI) += arm-cci.o
diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
new file mode 100644
index 000000000000..733288967d4d
--- /dev/null
+++ b/drivers/bus/arm-cci.c
@@ -0,0 +1,533 @@
+/*
+ * 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/slab.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+
+#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)
+
+struct cci_nb_ports {
+ unsigned int nb_ace;
+ unsigned int nb_ace_lite;
+};
+
+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;
+
+static void __iomem *cci_ctrl_base;
+static unsigned long cci_ctrl_phys;
+
+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 __init cci_ace_init_ports(void)
+{
+ int port, ac, cpu;
+ u64 hwid;
+ const u32 *cell;
+ struct device_node *cpun, *cpus;
+
+ cpus = of_find_node_by_path("/cpus");
+ if (WARN(!cpus, "Missing cpus node, bailing out\n"))
+ return;
+
+ if (WARN_ON(of_property_read_u32(cpus, "#address-cells", &ac)))
+ ac = of_n_addr_cells(cpus);
+
+ /*
+ * 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_child_of_node(cpus, cpun) {
+ if (of_node_cmp(cpun->type, "cpu"))
+ continue;
+ cell = of_get_property(cpun, "reg", NULL);
+ if (WARN(!cell, "%s: missing reg property\n", cpun->full_name))
+ continue;
+
+ hwid = of_read_number(cell, ac);
+ cpu = get_logical_index(hwid & MPIDR_HWID_BITMASK);
+
+ if (cpu < 0 || !cpu_possible(cpu))
+ 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, #"__stringify(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, #1 \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)),
+#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)) );
+
+ unreachable();
+}
+
+/**
+ * __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 %s ACE lite port look-up failure\n",
+ dn->full_name))
+ 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 cci_nb_ports cci400_ports = {
+ .nb_ace = 2,
+ .nb_ace_lite = 3
+};
+
+static const struct of_device_id arm_cci_matches[] = {
+ {.compatible = "arm,cci-400", .data = &cci400_ports },
+ {},
+};
+
+static const struct of_device_id arm_cci_ctrl_if_matches[] = {
+ {.compatible = "arm,cci-400-ctrl-if", },
+ {},
+};
+
+static int __init cci_probe(void)
+{
+ struct cci_nb_ports const *cci_config;
+ int ret, i, nb_ace = 0, nb_ace_lite = 0;
+ struct device_node *np, *cp;
+ struct resource res;
+ const char *match_str;
+ bool is_ace;
+
+ np = of_find_matching_node(NULL, arm_cci_matches);
+ if (!np)
+ return -ENODEV;
+
+ 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(sizeof(*ports), nb_cci_ports, GFP_KERNEL);
+ if (!ports)
+ return -ENOMEM;
+
+ 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");
+ ret = -ENXIO;
+ goto memalloc_err;
+ }
+
+ for_each_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 %s missing interface-type property\n",
+ cp->full_name);
+ continue;
+ }
+ is_ace = strcmp(match_str, "ace") == 0;
+ if (!is_ace && strcmp(match_str, "ace-lite")) {
+ WARN(1, "node %s containing invalid interface-type property, skipping it\n",
+ cp->full_name);
+ 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;
+ }
+
+ /* 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;
+
+memalloc_err:
+
+ kfree(ports);
+ return ret;
+}
+
+static int cci_init_status = -EAGAIN;
+static DEFINE_MUTEX(cci_probing);
+
+static int __init 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 __init cci_probed(void)
+{
+ return cci_init() == 0;
+}
+EXPORT_SYMBOL_GPL(cci_probed);
+
+early_initcall(cci_init);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ARM CCI support");