ping again ... Ralf On Mon, Apr 03, 2017 at 11:11:04AM +0100, Matt Redfearn wrote: > Hi Bjorn, > > Please could you provide any comments / review on this driver? > > Thanks, > > Matt > > > On 23/03/17 16:37, Matt Redfearn wrote: > > This driver allows a MIPS processor offlined from Linux to be used as a > > remote processor. The processor can then handle real-time tasks or > > perform coprocessing while remaining processors are available to Linux, > > effectively making the system hybrid of SMP Linux and AMP. > > > > A sysfs interface is provided to allow control of which system CPUs may > > be acquired by the driver when offlined from Linux. > > > > Coprocessor firmware must abide by the remoteproc standard, i.e. > > implement the resource table containing memory layouts and virtio device > > descriptions, and additionally abide by the MIPS UHI coprocessor boot > > protocol in the startup code. > > > > Example firmware and host executables to test them are located at [1]. > > > > [1] https://github.com/MIPS/mips-rproc-example > > > > Signed-off-by: Lisa Parratt <lisa.parratt@xxxxxxxxxx> > > Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxxxx> > > > > --- > > > > Changes in v6: > > Change to set_current_state() as set_task_state has been removed. > > > > Changes in v5: > > Depend on !64bit since this driver only works with 32bit kernels > > Set mproc->tsk state to TASK_DEAD before freeing it to avoid warning > > Flush icache of each carveout so that icache sees latest data written > > > > Changes in v4: > > Have a single mips-rproc device to be parent to each CPU's rproc device. > > Support per-device coherence introduced in v4.9 > > Add a sysfs interface to control the mask of cpus available to rproc > > > > Changes in v3: > > Update MIPS remoteproc driver to use CPU hotplug state machine > > Remove sysfs interface from MIPS rproc driver, now provided by the core. > > Drop patches that Ralf has already merged to mips-next > > > > Changes in v2: None > > > > Documentation/ABI/testing/sysfs-devices-mips-rproc | 13 + > > drivers/remoteproc/Kconfig | 11 + > > drivers/remoteproc/Makefile | 1 + > > drivers/remoteproc/mips_remoteproc.c | 599 +++++++++++++++++++++ > > 4 files changed, 624 insertions(+) > > create mode 100644 Documentation/ABI/testing/sysfs-devices-mips-rproc > > create mode 100644 drivers/remoteproc/mips_remoteproc.c > > > > diff --git a/Documentation/ABI/testing/sysfs-devices-mips-rproc b/Documentation/ABI/testing/sysfs-devices-mips-rproc > > new file mode 100644 > > index 000000000000..b06f6671807a > > --- /dev/null > > +++ b/Documentation/ABI/testing/sysfs-devices-mips-rproc > > @@ -0,0 +1,13 @@ > > +What: /sys/devices/mips-rproc/cpus > > +Date: October 2016 > > +Contact: Matt Redfearn <matt.redfearn@xxxxxxxxxx> > > +Description: > > + CPU topology file describing which CPUs may be used by the > > + MIPS remote processor driver when offline from Linux. > > + > > + This can be read to observe the current setting, or written to > > + change the allowed CPUs. > > + > > + The format is compatible with cpulist_parse() > > + [see <linux/cpumask.h>], for example to enable the MIPS remote > > + processor driver on CPUs 1,2 & 3, write "1-3" into this file. > > diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig > > index 65f86bc24c07..558b67184723 100644 > > --- a/drivers/remoteproc/Kconfig > > +++ b/drivers/remoteproc/Kconfig > > @@ -71,6 +71,17 @@ config DA8XX_REMOTEPROC > > It's safe to say n here if you're not interested in multimedia > > offloading. > > +config MIPS_REMOTEPROC > > + tristate "MIPS remoteproc support" > > + depends on MIPS_CPS && HAS_DMA && !64BIT > > + depends on REMOTEPROC > > + select CMA > > + select MIPS_CPU_STEAL > > + help > > + Say y here to support using offline cores/VPEs as remote processors > > + via the remote processor framework. > > + If unsure say N. > > + > > config QCOM_ADSP_PIL > > tristate "Qualcomm ADSP Peripheral Image Loader" > > depends on OF && ARCH_QCOM > > diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile > > index ffc5e430df27..9525debba686 100644 > > --- a/drivers/remoteproc/Makefile > > +++ b/drivers/remoteproc/Makefile > > @@ -11,6 +11,7 @@ remoteproc-y += remoteproc_elf_loader.o > > obj-$(CONFIG_OMAP_REMOTEPROC) += omap_remoteproc.o > > obj-$(CONFIG_WKUP_M3_RPROC) += wkup_m3_rproc.o > > obj-$(CONFIG_DA8XX_REMOTEPROC) += da8xx_remoteproc.o > > +obj-$(CONFIG_MIPS_REMOTEPROC) += mips_remoteproc.o > > obj-$(CONFIG_QCOM_ADSP_PIL) += qcom_adsp_pil.o > > obj-$(CONFIG_QCOM_RPROC_COMMON) += qcom_common.o > > obj-$(CONFIG_QCOM_Q6V5_PIL) += qcom_q6v5_pil.o > > diff --git a/drivers/remoteproc/mips_remoteproc.c b/drivers/remoteproc/mips_remoteproc.c > > new file mode 100644 > > index 000000000000..9a0e5e06c0b1 > > --- /dev/null > > +++ b/drivers/remoteproc/mips_remoteproc.c > > @@ -0,0 +1,599 @@ > > +/* > > + * MIPS Remote Processor driver > > + * > > + * Copyright (C) 2016 Imagination Technologies > > + * Lisa Parratt <lisa.parratt@xxxxxxxxxx> > > + * Matt Redfearn <matt.redfearn@xxxxxxxxxx> > > + * > > + * This program is free software; you can redistribute it and/or modify it > > + * under the terms of the GNU General Public License as published by the > > + * Free Software Foundation; either version 2 of the License, or (at your > > + * option) any later version. > > + */ > > + > > +#include <linux/cpu.h> > > +#include <linux/dma-mapping.h> > > +#include <linux/interrupt.h> > > +#include <linux/io.h> > > +#include <linux/irq.h> > > +#include <linux/module.h> > > +#include <linux/of_irq.h> > > +#include <linux/platform_device.h> > > +#include <linux/remoteproc.h> > > +#include <linux/sched/task.h> > > + > > +#include <asm/cacheflush.h> > > +#include <asm/smp-cps.h> > > +#include <asm/tlbflush.h> > > +#include <asm/tlbmisc.h> > > + > > +#include "remoteproc_internal.h" > > + > > +struct mips_rproc { > > + char name[16]; > > + struct rproc *rproc; > > + struct task_struct *tsk; > > + unsigned int cpu; > > + int ipi_linux; > > + int ipi_remote; > > +}; > > + > > +/* Parent device for MIPS remoteproc */ > > +static struct device mips_rproc_dev; > > + > > +/* Array of allocated MIPS remote processor instances */ > > +static struct mips_rproc *mips_rprocs[NR_CPUS]; > > + > > +/* Bitmap used to identify which CPUs are available to rproc */ > > +static cpumask_var_t mips_rproc_cpumask; > > + > > +/* Dynamic CPU hotplug state associated with this driver */ > > +static int cpuhp_state; > > + > > +/* Add wired entry to map a device address to physical memory */ > > +static void mips_map_page(unsigned long da, unsigned long pa, int c, > > + unsigned long pagesize) > > +{ > > + unsigned long pa2 = pa + (pagesize / 2); > > + unsigned long entryhi, entrylo0, entrylo1; > > + unsigned long pagemask = pagesize - 0x2000; > > + > > + pa = (pa >> 6) & (ULONG_MAX << MIPS_ENTRYLO_PFN_SHIFT); > > + pa2 = (pa2 >> 6) & (ULONG_MAX << MIPS_ENTRYLO_PFN_SHIFT); > > + entryhi = da & 0xfffffe000; > > + entrylo0 = (c << ENTRYLO_C_SHIFT) | ENTRYLO_D | ENTRYLO_V | pa; > > + entrylo1 = (c << ENTRYLO_C_SHIFT) | ENTRYLO_D | ENTRYLO_V | pa2; > > + > > + pr_debug("Create wired entry %d, CCA %d\n", read_c0_wired(), c); > > + pr_debug(" EntryHi: 0x%016lx\n", entryhi); > > + pr_debug(" EntryLo0: 0x%016lx\n", entrylo0); > > + pr_debug(" EntryLo1: 0x%016lx\n", entrylo1); > > + pr_debug(" Pagemask: 0x%016lx\n", pagemask); > > + pr_debug("\n"); > > + > > + add_wired_entry(entrylo0, entrylo1, entryhi, pagemask); > > +} > > + > > +/* Compute the largest page mask a physical address can be mapped with */ > > +static unsigned long mips_rproc_largest_pm(unsigned long pa, > > + unsigned long maxmask) > > +{ > > + unsigned long mask; > > + /* Find address bits limiting alignment */ > > + unsigned long shift = ffs(pa); > > + > > + /* Obey MIPS restrictions on page sizes */ > > + if (pa) { > > + if (shift & 1) > > + shift -= 2; > > + else > > + shift--; > > + } > > + mask = ULONG_MAX << shift; > > + return maxmask & ~mask; > > +} > > + > > +/* Compute the page mask one step larger than a given page mask */ > > +static unsigned long mips_rproc_next_pm(unsigned long pm, unsigned long maxmask) > > +{ > > +#define PM_SHIFT 13 > > + return ((pm << 2) | (0x3 << PM_SHIFT)) & maxmask; > > +} > > + > > +/* > > + * Add mappings to the TLB such that memory allocated by the kernel for a > > + * firmware component appears at the right virtual address > > + */ > > +static inline void mips_rproc_map(unsigned long da, unsigned long pa, int c, > > + unsigned long size, unsigned long maxmask) > > +{ > > + /* minimum mappable size is 2 * 4k pages */ > > + const unsigned long min_map_sz = 0x2000; > > + unsigned long bigmask, nextmask; > > + unsigned long distance, target; > > + unsigned long page2_size; /* Size of the 2 buddy pages */ > > + > > + do { > > + /* Compute the current largest page mask */ > > + bigmask = mips_rproc_largest_pm(pa, maxmask); > > + /* Compute the next largest pagesize */ > > + nextmask = mips_rproc_next_pm(bigmask, maxmask); > > + /* > > + * Compute the distance from our current physical address to > > + * the next page boundary. > > + */ > > + distance = (nextmask + min_map_sz) - (pa & nextmask); > > + /* > > + * Decide between searching to get to the next highest page > > + * boundary or finishing. > > + */ > > + target = distance < size ? distance : size; > > + while (target) { > > + /* Find the largest supported page size that will fit */ > > + for (page2_size = maxmask + min_map_sz; > > + (page2_size > min_map_sz) && (page2_size > target); > > + page2_size /= 4) { > > + } > > + /* Emit it */ > > + mips_map_page(da, pa, c, page2_size); > > + /* Move to next step */ > > + size -= page2_size; > > + da += page2_size; > > + pa += page2_size; > > + target -= page2_size; > > + } > > + } while (size); > > +} > > + > > +static int mips_rproc_carveouts(struct rproc *rproc, int max_pagemask) > > +{ > > + struct rproc_mem_entry *carveout; > > + > > + list_for_each_entry(carveout, &rproc->carveouts, node) { > > + int c = CONF_CM_CACHABLE_COW; > > + > > + dev_dbg(&rproc->dev, > > + "carveout mapping da 0x%x -> %pad length 0x%x, CCA %d", > > + carveout->da, &carveout->dma, carveout->len, c); > > + > > + mips_rproc_map(carveout->da, carveout->dma, c, > > + carveout->len, max_pagemask); > > + flush_icache_range((unsigned long)carveout->va, > > + (unsigned long)carveout->va + carveout->len); > > + } > > + return 0; > > +} > > + > > +static int mips_rproc_vdevs(struct rproc *rproc, int max_pagemask) > > +{ > > + struct rproc_vdev *rvdev; > > + > > + list_for_each_entry(rvdev, &rproc->rvdevs, node) { > > + int i, size; > > + > > + for (i = 0; i < ARRAY_SIZE(rvdev->vring); i++) { > > + struct rproc_vring *vring = &rvdev->vring[i]; > > + unsigned long pa = vring->dma; > > + int c; > > + > > + if (plat_device_is_coherent(&mips_rproc_dev)) { > > + /* > > + * The DMA API will allocate cacheable buffers > > + * for shared resources, so the firmware should > > + * also access those buffers cached > > + */ > > + c = (_page_cachable_default >> _CACHE_SHIFT); > > + } else { > > + /* > > + * Otherwise, shared buffers should be accessed > > + * uncached > > + */ > > + c = CONF_CM_UNCACHED; > > + } > > + > > + /* actual size of vring (in bytes) */ > > + size = PAGE_ALIGN(vring_size(vring->len, vring->align)); > > + > > + dev_dbg(&rproc->dev, > > + "vring mapping da %pad -> %pad length 0x%x, CCA %d", > > + &vring->dma, &vring->dma, size, c); > > + > > + mips_rproc_map(pa, pa, c, size, max_pagemask); > > + } > > + } > > + return 0; > > +} > > + > > +static void mips_rproc_cpu_entry(void) > > +{ > > + struct mips_rproc *mproc = mips_rprocs[smp_processor_id()]; > > + struct rproc *rproc = mproc->rproc; > > + int ipi_to_remote = ipi_get_hwirq(mproc->ipi_remote, mproc->cpu); > > + int ipi_from_remote = ipi_get_hwirq(mproc->ipi_linux, 0); > > + unsigned long old_pagemask, max_pagemask; > > + void (*fw_entry)(int, int ipi_to_remote, int ipi_from_remote, int); > > + > > + dev_info(&rproc->dev, "%s booting firmware %s\n", > > + rproc->name, rproc->firmware); > > + > > + /* Get the maximum pagemask supported on this CPU */ > > + old_pagemask = read_c0_pagemask(); > > + write_c0_pagemask(~0); > > + back_to_back_c0_hazard(); > > + max_pagemask = read_c0_pagemask(); > > + write_c0_pagemask(old_pagemask); > > + back_to_back_c0_hazard(); > > + > > + /* Start with no wired entries */ > > + write_c0_wired(0); > > + > > + /* Flush all previous TLB entries */ > > + local_flush_tlb_all(); > > + > > + /* Set ASID 0 */ > > + write_c0_entryhi(0); > > + > > + /* Map firmware resources into virtual memory */ > > + mips_rproc_carveouts(rproc, max_pagemask); > > + mips_rproc_vdevs(rproc, max_pagemask); > > + > > + dev_dbg(&rproc->dev, "IPI to remote: %d\n", ipi_to_remote); > > + dev_dbg(&rproc->dev, "IPI from remote: %d\n", ipi_from_remote); > > + > > + /* Hand off the CPU to the firmware */ > > + dev_dbg(&rproc->dev, "Jumping to firmware at 0x%x\n", rproc->bootaddr); > > + > > + /* We're done with the task struct that provided the stack we've used */ > > + set_current_state(TASK_DEAD); > > + > > + /* Jump into the firmware, obeying the firmware protocol. */ > > + fw_entry = (void *)rproc->bootaddr; > > + fw_entry(-3, ipi_to_remote, ipi_from_remote, 0); > > +} > > + > > +static irqreturn_t mips_rproc_ipi_handler(int irq, void *dev_id) > > +{ > > + /* Synthetic interrupts shouldn't need acking */ > > + return IRQ_WAKE_THREAD; > > +} > > + > > +static irqreturn_t mips_rproc_vq_int(int irq, void *p) > > +{ > > + struct rproc *rproc = (struct rproc *)p; > > + void *entry; > > + int id; > > + > > + /* We don't have a mailbox, so iterate over all vqs and kick them. */ > > + idr_for_each_entry(&rproc->notifyids, entry, id) > > + rproc_vq_interrupt(rproc, id); > > + > > + return IRQ_HANDLED; > > +} > > + > > +/* Helper function to find the IPI domain */ > > +static struct irq_domain *ipi_domain(void) > > +{ > > + struct device_node *node = of_irq_find_parent(of_root); > > + struct irq_domain *ipidomain; > > + > > + ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI); > > + /* > > + * Some platforms have half DT setup. So if we found irq node but > > + * didn't find an ipidomain, try to search for one that is not in the > > + * DT. > > + */ > > + if (node && !ipidomain) > > + ipidomain = irq_find_matching_host(NULL, DOMAIN_BUS_IPI); > > + > > + return ipidomain; > > +} > > + > > +int mips_rproc_op_start(struct rproc *rproc) > > +{ > > + struct mips_rproc *mproc = rproc->priv; > > + int err; > > + int cpu = mproc->cpu; > > + > > + /* Create task for the CPU to use before handing off to firmware */ > > + mproc->tsk = fork_idle(cpu); > > + if (IS_ERR(mproc->tsk)) { > > + dev_err(&rproc->dev, "fork_idle() failed for CPU%d\n", cpu); > > + return -ENOMEM; > > + } > > + > > + /* We won't be needing the Linux IPIs anymore */ > > + if (mips_smp_ipi_free(get_cpu_mask(cpu))) { > > + dev_err(&rproc->dev, "Failed to reserve incoming kick\n"); > > + goto exit_free_tsk; > > + } > > + > > + /* > > + * Direct IPIs from the remote processor to CPU0 since that can't be > > + * offlined while the remote CPU is running. > > + */ > > + mproc->ipi_linux = irq_reserve_ipi(ipi_domain(), get_cpu_mask(0)); > > + if (!mproc->ipi_linux) { > > + dev_err(&rproc->dev, "Failed to reserve incoming kick\n"); > > + goto exit_restore_ipi; > > + } > > + > > + mproc->ipi_remote = irq_reserve_ipi(ipi_domain(), get_cpu_mask(cpu)); > > + if (!mproc->ipi_remote) { > > + dev_err(&rproc->dev, "Failed to reserve outgoing kick\n"); > > + goto exit_destroy_ipi_linux; > > + } > > + > > + /* register incoming ipi */ > > + err = request_threaded_irq(mproc->ipi_linux, mips_rproc_ipi_handler, > > + mips_rproc_vq_int, 0, > > + "mips-rproc IPI in", rproc); > > + if (err) { > > + dev_err(&rproc->dev, "Failed to register incoming kick: %d\n", > > + err); > > + goto exit_destroy_ipi_remote; > > + } > > + > > + if (mips_cps_steal_cpu_and_execute(cpu, &mips_rproc_cpu_entry, > > + mproc->tsk)) { > > + dev_err(&rproc->dev, "Failed to steal CPU%d for remote\n", cpu); > > + goto exit_free_irq; > > + } > > + > > + return 0; > > + > > +exit_free_irq: > > + free_irq(mproc->ipi_linux, rproc); > > +exit_destroy_ipi_remote: > > + irq_destroy_ipi(mproc->ipi_remote, get_cpu_mask(cpu)); > > +exit_destroy_ipi_linux: > > + irq_destroy_ipi(mproc->ipi_linux, get_cpu_mask(0)); > > +exit_restore_ipi: > > + /* Set up the Linux IPIs again */ > > + mips_smp_ipi_allocate(get_cpu_mask(cpu)); > > +exit_free_tsk: > > + free_task(mproc->tsk); > > + > > + return -EINVAL; > > +} > > + > > +int mips_rproc_op_stop(struct rproc *rproc) > > +{ > > + struct mips_rproc *mproc = rproc->priv; > > + > > + free_irq(mproc->ipi_linux, rproc); > > + > > + irq_destroy_ipi(mproc->ipi_linux, get_cpu_mask(0)); > > + irq_destroy_ipi(mproc->ipi_remote, get_cpu_mask(mproc->cpu)); > > + > > + /* Set up the Linux IPIs again */ > > + mips_smp_ipi_allocate(get_cpu_mask(mproc->cpu)); > > + > > + free_task(mproc->tsk); > > + > > + return mips_cps_halt_and_return_cpu(mproc->cpu); > > +} > > + > > +void mips_rproc_op_kick(struct rproc *rproc, int vqid) > > +{ > > + struct mips_rproc *mproc = rproc->priv; > > + > > + if (rproc->state == RPROC_RUNNING) > > + ipi_send_single(mproc->ipi_remote, mproc->cpu); > > +} > > + > > +static const struct rproc_ops mips_rproc_proc_ops = { > > + .start = mips_rproc_op_start, > > + .stop = mips_rproc_op_stop, > > + .kick = mips_rproc_op_kick, > > +}; > > + > > +/* Create an rproc instance in response to CPU down */ > > +static int mips_rproc_device_register(unsigned int cpu) > > +{ > > + char *template = "mips-cpu%u"; > > + struct rproc *rproc; > > + struct mips_rproc *mproc; > > + int err; > > + > > + if (!cpumask_test_cpu(cpu, mips_rproc_cpumask)) > > + /* The CPU is not in the mask, so don't register rproc on it */ > > + return 0; > > + > > + pr_debug("Allocating MIPS rproc for cpu%d\n", cpu); > > + > > + if (mips_rprocs[cpu]) { > > + dev_err(&mips_rproc_dev, "CPU%d in use\n", cpu); > > + return 0; > > + } > > + > > + mproc = kzalloc(sizeof(struct mips_rproc), GFP_KERNEL); > > + if (!mproc) { > > + err = -ENOMEM; > > + goto exit; > > + } > > + > > + snprintf(mproc->name, sizeof(mproc->name), template, cpu); > > + mproc->cpu = cpu; > > + > > + rproc = rproc_alloc(&mips_rproc_dev, mproc->name, > > + &mips_rproc_proc_ops, NULL, > > + sizeof(struct mips_rproc *)); > > + if (!rproc) { > > + dev_err(&mips_rproc_dev, "Error allocating rproc\n"); > > + err = -ENOMEM; > > + goto exit_free_mproc; > > + } > > + > > + mproc->rproc = rproc; > > + rproc->priv = (void *)mproc; > > + > > + err = rproc_add(rproc); > > + if (err) { > > + dev_err(&mips_rproc_dev, "Failed to add rproc: %d\n", err); > > + goto exit_free_rproc; > > + } > > + > > + mips_rprocs[cpu] = mproc; > > + return 0; > > + > > +exit_free_rproc: > > + rproc_free(rproc); > > +exit_free_mproc: > > + kfree(mproc); > > +exit: > > + return err; > > +} > > + > > +/* Destroy rproc instance in response to CPU up */ > > +static int mips_rproc_device_unregister(unsigned int cpu) > > +{ > > + struct mips_rproc *mproc = mips_rprocs[cpu]; > > + > > + if (!mproc) > > + /* No rproc instance has been created for this CPU */ > > + return 0; > > + > > + pr_debug("Deallocating MIPS rproc for cpu%d\n", cpu); > > + > > + rproc_del(mproc->rproc); > > + rproc_put(mproc->rproc); > > + kfree(mproc); > > + > > + mips_rprocs[cpu] = NULL; > > + return 0; > > +} > > + > > +/* Show MIPS CPUs available to rproc */ > > +static ssize_t cpus_show(struct device *dev, struct device_attribute *attr, > > + char *buf) > > +{ > > + return cpumap_print_to_pagebuf(true, buf, mips_rproc_cpumask); > > +} > > + > > +/* Allow MIPS CPUs to be made available to rproc */ > > +static ssize_t cpus_store(struct device *dev, > > + struct device_attribute *attr, > > + const char *buf, size_t count) > > +{ > > + static cpumask_var_t new_mask; > > + int err, cpu; > > + > > + err = cpulist_parse(buf, new_mask); > > + if (err) > > + return err; > > + > > + /* Prevent CPU hotplug on/offlining CPUs while we do this */ > > + get_online_cpus(); > > + > > + for_each_possible_cpu(cpu) { > > + if (cpumask_test_cpu(cpu, mips_rproc_cpumask) && > > + !cpumask_test_cpu(cpu, new_mask)) { > > + /* CPU no longer allowed. Release any instance on it */ > > + cpumask_clear_cpu(cpu, mips_rproc_cpumask); > > + mips_rproc_device_unregister(cpu); > > + > > + } else if (!cpumask_test_cpu(cpu, mips_rproc_cpumask) && > > + cpumask_test_cpu(cpu, new_mask)) { > > + /* If the CPU isn't online, start an instance */ > > + cpumask_set_cpu(cpu, mips_rproc_cpumask); > > + if (!cpu_online(cpu)) > > + mips_rproc_device_register(cpu); > > + } > > + } > > + put_online_cpus(); > > + return count; > > +} > > +static DEVICE_ATTR_RW(cpus); > > + > > +static struct attribute *mips_rproc_attrs[] = { > > + &dev_attr_cpus.attr, > > + NULL > > +}; > > + > > +static const struct attribute_group mips_rproc_devgroup = { > > + .attrs = mips_rproc_attrs > > +}; > > + > > +static const struct attribute_group *mips_rproc_devgroups[] = { > > + &mips_rproc_devgroup, > > + NULL > > +}; > > +static struct device_type mips_rproc_type = { > > + .groups = mips_rproc_devgroups, > > +}; > > + > > +static struct platform_driver mips_rproc_driver = { > > + .driver = { > > + .name = "mips-rproc", > > + }, > > +}; > > + > > +static int __init mips_rproc_init(void) > > +{ > > + int err; > > + > > + if ((!cpu_has_mipsmt) && (!cpu_has_vp)) { > > + pr_debug("MIPS rproc not supported on this cpu\n"); > > + return -EIO; > > + } > > + > > + mips_rproc_dev.driver = &mips_rproc_driver.driver; > > + mips_rproc_dev.type = &mips_rproc_type; > > + dev_set_name(&mips_rproc_dev, "mips-rproc"); > > + > > + /* Set device to have coherent DMA ops */ > > + arch_setup_dma_ops(&mips_rproc_dev, 0, 0, NULL, 1); > > + > > + err = device_register(&mips_rproc_dev); > > + if (err) { > > + dev_err(&mips_rproc_dev, "Error adding MIPS rproc: %d\n", err); > > + return err; > > + } > > + > > + /* > > + * Register with the cpu hotplug state machine. > > + * This driver requires opposite sense to "normal" drivers, since the > > + * driver is activated for offline CPUs via the teardown callback and > > + * deactivated via the online callback. > > + */ > > + err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "MIPS:REMOTEPROC", > > + mips_rproc_device_unregister, > > + mips_rproc_device_register); > > + if (err < 0) { > > + device_unregister(&mips_rproc_dev); > > + return err; > > + } > > + > > + cpuhp_state = err; > > + > > + return 0; > > +} > > + > > +static void __exit mips_rproc_exit(void) > > +{ > > + int cpu; > > + > > + if (cpuhp_state) { > > + /* > > + * Unregister with the cpu hotplug state machine, but don't call > > + * the teardown callback, since that would try to start the > > + * remote processor device. > > + */ > > + __cpuhp_remove_state(cpuhp_state, false); > > + cpuhp_state = 0; > > + } > > + > > + get_online_cpus(); > > + /* Unregister devices created for any offline CPUs */ > > + for_each_possible_cpu(cpu) > > + mips_rproc_device_unregister(cpu); > > + put_online_cpus(); > > +} > > + > > +late_initcall(mips_rproc_init); > > +module_exit(mips_rproc_exit); > > + > > +module_platform_driver(mips_rproc_driver); > > + > > +MODULE_LICENSE("GPL v2"); > > +MODULE_DESCRIPTION("MIPS Remote Processor control driver");
