cregit-Linux how code gets into the kernel

Release 4.7 drivers/misc/cxl/file.c

Directory: drivers/misc/cxl
/*
 * Copyright 2014 IBM Corp.
 *
 * 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/spinlock.h>
#include <linux/module.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/bitmap.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/pid.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <asm/cputable.h>
#include <asm/current.h>
#include <asm/copro.h>

#include "cxl.h"
#include "trace.h"


#define CXL_NUM_MINORS 256 
/* Total to reserve */


#define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))

#define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)

#define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)

#define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu))

#define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))

#define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))


#define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)


#define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)


static dev_t cxl_dev;


static struct class *cxl_class;


static int __afu_open(struct inode *inode, struct file *file, bool master) { struct cxl *adapter; struct cxl_afu *afu; struct cxl_context *ctx; int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev); int slice = CXL_DEVT_AFU(inode->i_rdev); int rc = -ENODEV; pr_devel("afu_open afu%i.%i\n", slice, adapter_num); if (!(adapter = get_cxl_adapter(adapter_num))) return -ENODEV; if (slice > adapter->slices) goto err_put_adapter; spin_lock(&adapter->afu_list_lock); if (!(afu = adapter->afu[slice])) { spin_unlock(&adapter->afu_list_lock); goto err_put_adapter; } /* * taking a ref to the afu so that it doesn't go away * for rest of the function. This ref is released before * we return. */ cxl_afu_get(afu); spin_unlock(&adapter->afu_list_lock); if (!afu->current_mode) goto err_put_afu; if (!cxl_ops->link_ok(adapter, afu)) { rc = -EIO; goto err_put_afu; } if (!(ctx = cxl_context_alloc())) { rc = -ENOMEM; goto err_put_afu; } if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping))) goto err_put_afu; pr_devel("afu_open pe: %i\n", ctx->pe); file->private_data = ctx; cxl_ctx_get(); /* indicate success */ rc = 0; err_put_afu: /* release the ref taken earlier */ cxl_afu_put(afu); err_put_adapter: put_device(&adapter->dev); return rc; }

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vaibhav jainvaibhav jain83.04%116.67%
frederic barratfrederic barrat31.14%116.67%
christophe lombardchristophe lombard20.76%116.67%
Total263100.00%6100.00%


int afu_open(struct inode *inode, struct file *file) { return __afu_open(inode, file, false); }

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static int afu_master_open(struct inode *inode, struct file *file) { return __afu_open(inode, file, true); }

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int afu_release(struct inode *inode, struct file *file) { struct cxl_context *ctx = file->private_data; pr_devel("%s: closing cxl file descriptor. pe: %i\n", __func__, ctx->pe); cxl_context_detach(ctx); /* * Delete the context's mapping pointer, unless it's created by the * kernel API, in which case leave it so it can be freed by reclaim_ctx() */ if (!ctx->kernelapi) { mutex_lock(&ctx->mapping_lock); ctx->mapping = NULL; mutex_unlock(&ctx->mapping_lock); } /* * At this this point all bottom halfs have finished and we should be * getting no more IRQs from the hardware for this context. Once it's * removed from the IDR (and RCU synchronised) it's safe to free the * sstp and context. */ cxl_context_free(ctx); return 0; }

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static long afu_ioctl_start_work(struct cxl_context *ctx, struct cxl_ioctl_start_work __user *uwork) { struct cxl_ioctl_start_work work; u64 amr = 0; int rc; pr_devel("%s: pe: %i\n", __func__, ctx->pe); /* Do this outside the status_mutex to avoid a circular dependency with * the locking in cxl_mmap_fault() */ if (copy_from_user(&work, uwork, sizeof(struct cxl_ioctl_start_work))) { rc = -EFAULT; goto out; } mutex_lock(&ctx->status_mutex); if (ctx->status != OPENED) { rc = -EIO; goto out; } /* * if any of the reserved fields are set or any of the unused * flags are set it's invalid */ if (work.reserved1 || work.reserved2 || work.reserved3 || work.reserved4 || work.reserved5 || work.reserved6 || (work.flags & ~CXL_START_WORK_ALL)) { rc = -EINVAL; goto out; } if (!(work.flags & CXL_START_WORK_NUM_IRQS)) work.num_interrupts = ctx->afu->pp_irqs; else if ((work.num_interrupts < ctx->afu->pp_irqs) || (work.num_interrupts > ctx->afu->irqs_max)) { rc = -EINVAL; goto out; } if ((rc = afu_register_irqs(ctx, work.num_interrupts))) goto out; if (work.flags & CXL_START_WORK_AMR) amr = work.amr & mfspr(SPRN_UAMOR); ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF); /* * We grab the PID here and not in the file open to allow for the case * where a process (master, some daemon, etc) has opened the chardev on * behalf of another process, so the AFU's mm gets bound to the process * that performs this ioctl and not the process that opened the file. * Also we grab the PID of the group leader so that if the task that * has performed the attach operation exits the mm context of the * process is still accessible. */ ctx->pid = get_task_pid(current, PIDTYPE_PID); ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID); trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr); if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor, amr))) { afu_release_irqs(ctx, ctx); goto out; } ctx->status = STARTED; rc = 0; out: mutex_unlock(&ctx->status_mutex); return rc; }

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frederic barratfrederic barrat30.87%112.50%
michael neulingmichael neuling20.58%112.50%
Total344100.00%8100.00%


static long afu_ioctl_process_element(struct cxl_context *ctx, int __user *upe) { pr_devel("%s: pe: %i\n", __func__, ctx->pe); if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32))) return -EFAULT; return 0; }

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christophe lombardchristophe lombard11.96%150.00%
Total51100.00%2100.00%


static long afu_ioctl_get_afu_id(struct cxl_context *ctx, struct cxl_afu_id __user *upafuid) { struct cxl_afu_id afuid = { 0 }; afuid.card_id = ctx->afu->adapter->adapter_num; afuid.afu_offset = ctx->afu->slice; afuid.afu_mode = ctx->afu->current_mode; /* set the flag bit in case the afu is a slave */ if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master) afuid.flags |= CXL_AFUID_FLAG_SLAVE; if (copy_to_user(upafuid, &afuid, sizeof(afuid))) return -EFAULT; return 0; }

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long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct cxl_context *ctx = file->private_data; if (ctx->status == CLOSED) return -EIO; if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) return -EIO; pr_devel("afu_ioctl\n"); switch (cmd) { case CXL_IOCTL_START_WORK: return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg); case CXL_IOCTL_GET_PROCESS_ELEMENT: return afu_ioctl_process_element(ctx, (__u32 __user *)arg); case CXL_IOCTL_GET_AFU_ID: return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *) arg); } return -EINVAL; }

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vaibhav jainvaibhav jain1713.49%120.00%
daniel axtensdaniel axtens1511.90%120.00%
christophe lombardchristophe lombard43.17%120.00%
frederic barratfrederic barrat32.38%120.00%
Total126100.00%5100.00%


static long afu_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { return afu_ioctl(file, cmd, arg); }

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Total29100.00%2100.00%


int afu_mmap(struct file *file, struct vm_area_struct *vm) { struct cxl_context *ctx = file->private_data; /* AFU must be started before we can MMIO */ if (ctx->status != STARTED) return -EIO; if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) return -EIO; return cxl_context_iomap(ctx, vm); }

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daniel axtensdaniel axtens1522.39%125.00%
christophe lombardchristophe lombard45.97%125.00%
frederic barratfrederic barrat34.48%125.00%
Total67100.00%4100.00%


unsigned int afu_poll(struct file *file, struct poll_table_struct *poll) { struct cxl_context *ctx = file->private_data; int mask = 0; unsigned long flags; poll_wait(file, &ctx->wq, poll); pr_devel("afu_poll wait done pe: %i\n", ctx->pe); spin_lock_irqsave(&ctx->lock, flags); if (ctx->pending_irq || ctx->pending_fault || ctx->pending_afu_err) mask |= POLLIN | POLLRDNORM; else if (ctx->status == CLOSED) /* Only error on closed when there are no futher events pending */ mask |= POLLERR; spin_unlock_irqrestore(&ctx->lock, flags); pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask); return mask; }

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static inline int ctx_event_pending(struct cxl_context *ctx) { return (ctx->pending_irq || ctx->pending_fault || ctx->pending_afu_err || (ctx->status == CLOSED)); }

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ssize_t afu_read(struct file *file, char __user *buf, size_t count, loff_t *off) { struct cxl_context *ctx = file->private_data; struct cxl_event event; unsigned long flags; int rc; DEFINE_WAIT(wait); if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) return -EIO; if (count < CXL_READ_MIN_SIZE) return -EINVAL; spin_lock_irqsave(&ctx->lock, flags); for (;;) { prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE); if (ctx_event_pending(ctx)) break; if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) { rc = -EIO; goto out; } if (file->f_flags & O_NONBLOCK) { rc = -EAGAIN; goto out; } if (signal_pending(current)) { rc = -ERESTARTSYS; goto out; } spin_unlock_irqrestore(&ctx->lock, flags); pr_devel("afu_read going to sleep...\n"); schedule(); pr_devel("afu_read woken up\n"); spin_lock_irqsave(&ctx->lock, flags); } finish_wait(&ctx->wq, &wait); memset(&event, 0, sizeof(event)); event.header.process_element = ctx->pe; event.header.size = sizeof(struct cxl_event_header); if (ctx->pending_irq) { pr_devel("afu_read delivering AFU interrupt\n"); event.header.size += sizeof(struct cxl_event_afu_interrupt); event.header.type = CXL_EVENT_AFU_INTERRUPT; event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1; clear_bit(event.irq.irq - 1, ctx->irq_bitmap); if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count)) ctx->pending_irq = false; } else if (ctx->pending_fault) { pr_devel("afu_read delivering data storage fault\n"); event.header.size += sizeof(struct cxl_event_data_storage); event.header.type = CXL_EVENT_DATA_STORAGE; event.fault.addr = ctx->fault_addr; event.fault.dsisr = ctx->fault_dsisr; ctx->pending_fault = false; } else if (ctx->pending_afu_err) { pr_devel("afu_read delivering afu error\n"); event.header.size += sizeof(struct cxl_event_afu_error); event.header.type = CXL_EVENT_AFU_ERROR; event.afu_error.error = ctx->afu_err; ctx->pending_afu_err = false; } else if (ctx->status == CLOSED) { pr_devel("afu_read fatal error\n"); spin_unlock_irqrestore(&ctx->lock, flags); return -EIO; } else WARN(1, "afu_read must be buggy\n"); spin_unlock_irqrestore(&ctx->lock, flags); if (copy_to_user(buf, &event, event.header.size)) return -EFAULT; return event.header.size; out: finish_wait(&ctx->wq, &wait); spin_unlock_irqrestore(&ctx->lock, flags); return rc; }

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christophe lombardchristophe lombard81.44%120.00%
frederic barratfrederic barrat61.08%120.00%
Total556100.00%5100.00%

/* * Note: if this is updated, we need to update api.c to patch the new ones in * too */ const struct file_operations afu_fops = { .owner = THIS_MODULE, .open = afu_open, .poll = afu_poll, .read = afu_read, .release = afu_release, .unlocked_ioctl = afu_ioctl, .compat_ioctl = afu_compat_ioctl, .mmap = afu_mmap, }; static const struct file_operations afu_master_fops = { .owner = THIS_MODULE, .open = afu_master_open, .poll = afu_poll, .read = afu_read, .release = afu_release, .unlocked_ioctl = afu_ioctl, .compat_ioctl = afu_compat_ioctl, .mmap = afu_mmap, };
static char *cxl_devnode(struct device *dev, umode_t *mode) { if (cpu_has_feature(CPU_FTR_HVMODE) && CXL_DEVT_IS_CARD(dev->devt)) { /* * These minor numbers will eventually be used to program the * PSL and AFUs once we have dynamic reprogramming support */ return NULL; } return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev)); }

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extern struct class *cxl_class;
static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev, struct device **chardev, char *postfix, char *desc, const struct file_operations *fops) { struct device *dev; int rc; cdev_init(cdev, fops); if ((rc = cdev_add(cdev, devt, 1))) { dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc); return rc; } dev = device_create(cxl_class, &afu->dev, devt, afu, "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix); if (IS_ERR(dev)) { dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc); rc = PTR_ERR(dev); goto err; } *chardev = dev; return 0; err: cdev_del(cdev); return rc; }

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int cxl_chardev_d_afu_add(struct cxl_afu *afu) { return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d, &afu->chardev_d, "d", "dedicated", &afu_master_fops); /* Uses master fops */ }

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int cxl_chardev_m_afu_add(struct cxl_afu *afu) { return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m, &afu->chardev_m, "m", "master", &afu_master_fops); }

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int cxl_chardev_s_afu_add(struct cxl_afu *afu) { return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s, &afu->chardev_s, "s", "shared", &afu_fops); }

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void cxl_chardev_afu_remove(struct cxl_afu *afu) { if (afu->chardev_d) { cdev_del(&afu->afu_cdev_d); device_unregister(afu->chardev_d); afu->chardev_d = NULL; } if (afu->chardev_m) { cdev_del(&afu->afu_cdev_m); device_unregister(afu->chardev_m); afu->chardev_m = NULL; } if (afu->chardev_s) { cdev_del(&afu->afu_cdev_s); device_unregister(afu->chardev_s); afu->chardev_s = NULL; } }

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int cxl_register_afu(struct cxl_afu *afu) { afu->dev.class = cxl_class; return device_register(&afu->dev); }

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int cxl_register_adapter(struct cxl *adapter) { adapter->dev.class = cxl_class; /* * Future: When we support dynamically reprogramming the PSL & AFU we * will expose the interface to do that via a chardev: * adapter->dev.devt = CXL_CARD_MKDEV(adapter); */ return device_register(&adapter->dev); }

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dev_t cxl_get_dev(void) { return cxl_dev; }

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christophe lombardchristophe lombard10100.00%1100.00%
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int __init cxl_file_init(void) { int rc; /* * If these change we really need to update API. Either change some * flags or update API version number CXL_API_VERSION. */ BUILD_BUG_ON(CXL_API_VERSION != 2); BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64); BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8); BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8); BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32); BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16); if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) { pr_err("Unable to allocate CXL major number: %i\n", rc); return rc; } pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev)); cxl_class = class_create(THIS_MODULE, "cxl"); if (IS_ERR(cxl_class)) { pr_err("Unable to create CXL class\n"); rc = PTR_ERR(cxl_class); goto err; } cxl_class->devnode = cxl_devnode; return 0; err: unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS); return rc; }

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void cxl_file_exit(void) { unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS); class_destroy(cxl_class); }

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ian munsieian munsie244289.42%736.84%
vaibhav jainvaibhav jain1395.09%315.79%
daniel axtensdaniel axtens853.11%210.53%
christophe lombardchristophe lombard341.24%315.79%
frederic barratfrederic barrat180.66%15.26%
andrew donnellanandrew donnellan100.37%15.26%
michael neulingmichael neuling30.11%210.53%
Total2731100.00%19100.00%
Directory: drivers/misc/cxl
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