Commit 75ca758a authored by Alastair D'Silva's avatar Alastair D'Silva Committed by Michael Ellerman
Browse files

ocxl: Create a clear delineation between ocxl backend & frontend 



The OCXL driver contains both frontend code for interacting with userspace,
as well as backend code for interacting with the hardware.

This patch separates the backend code from the frontend so that it can be
used by other device drivers that communicate via OpenCAPI.

Relocate dev, cdev & sysfs files to the frontend code to allow external
drivers to maintain their own devices.

Reference counting on the device in the backend is replaced with kref
counting.

Move file & sysfs layer initialisation from core.c (backend) to
pci.c (frontend).

Create an ocxl_function oriented interface for initing devices &
enumerating AFUs.

Signed-off-by: default avatarAlastair D'Silva <alastair@d-silva.org>
Acked-by: default avatarFrederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 2f7d3d14

drivers/misc/ocxl/context.c

+1 −1
Original line number Diff line number Diff line
@@ -238,7 +238,7 @@ int ocxl_context_detach(struct ocxl_context *ctx) 
	}

	rc = ocxl_link_remove_pe(ctx->afu->fn->link, ctx->pasid);

	if (rc) {

		dev_warn(&ctx->afu->dev,

		dev_warn(&dev->dev,

			"Couldn't remove PE entry cleanly: %d\n", rc);

	}

	return 0;

drivers/misc/ocxl/core.c

+127 −74
Original line number Diff line number Diff line
@@ -13,16 +13,6 @@ static void ocxl_fn_put(struct ocxl_fn *fn) 
	put_device(&fn->dev);

}



struct ocxl_afu *ocxl_afu_get(struct ocxl_afu *afu)

{

	return (get_device(&afu->dev) == NULL) ? NULL : afu;

}



void ocxl_afu_put(struct ocxl_afu *afu)

{

	put_device(&afu->dev);

}



static struct ocxl_afu *alloc_afu(struct ocxl_fn *fn)

{

	struct ocxl_afu *afu;
@@ -31,6 +21,7 @@ static struct ocxl_afu *alloc_afu(struct ocxl_fn *fn) 
	if (!afu)

		return NULL;



	kref_init(&afu->kref);

	mutex_init(&afu->contexts_lock);

	mutex_init(&afu->afu_control_lock);

	idr_init(&afu->contexts_idr);
@@ -39,32 +30,26 @@ static struct ocxl_afu *alloc_afu(struct ocxl_fn *fn) 
	return afu;

}



static void free_afu(struct ocxl_afu *afu)

static void free_afu(struct kref *kref)

{

	struct ocxl_afu *afu = container_of(kref, struct ocxl_afu, kref);



	idr_destroy(&afu->contexts_idr);

	ocxl_fn_put(afu->fn);

	kfree(afu);

}



static void free_afu_dev(struct device *dev)

void ocxl_afu_get(struct ocxl_afu *afu)

{

	struct ocxl_afu *afu = to_ocxl_afu(dev);



	ocxl_unregister_afu(afu);

	free_afu(afu);

	kref_get(&afu->kref);

}

EXPORT_SYMBOL_GPL(ocxl_afu_get);



static int set_afu_device(struct ocxl_afu *afu, const char *location)

void ocxl_afu_put(struct ocxl_afu *afu)

{

	struct ocxl_fn *fn = afu->fn;

	int rc;



	afu->dev.parent = &fn->dev;

	afu->dev.release = free_afu_dev;

	rc = dev_set_name(&afu->dev, "%s.%s.%hhu", afu->config.name, location,

		afu->config.idx);

	return rc;

	kref_put(&afu->kref, free_afu);

}

EXPORT_SYMBOL_GPL(ocxl_afu_put);



static int assign_afu_actag(struct ocxl_afu *afu)

{
@@ -233,28 +218,26 @@ static int configure_afu(struct ocxl_afu *afu, u8 afu_idx, struct pci_dev *dev) 
	if (rc)

		return rc;



	rc = set_afu_device(afu, dev_name(&dev->dev));

	if (rc)

		return rc;



	rc = assign_afu_actag(afu);

	if (rc)

		return rc;



	rc = assign_afu_pasid(afu);

	if (rc) {

		reclaim_afu_actag(afu);

		return rc;

	}

	if (rc)

		goto err_free_actag;



	rc = map_mmio_areas(afu);

	if (rc) {

	if (rc)

		goto err_free_pasid;



	return 0;



err_free_pasid:

	reclaim_afu_pasid(afu);

err_free_actag:

	reclaim_afu_actag(afu);

	return rc;

}

	return 0;

}



static void deconfigure_afu(struct ocxl_afu *afu)

{
@@ -265,16 +248,8 @@ static void deconfigure_afu(struct ocxl_afu *afu) 


static int activate_afu(struct pci_dev *dev, struct ocxl_afu *afu)

{

	int rc;



	ocxl_config_set_afu_state(dev, afu->config.dvsec_afu_control_pos, 1);

	/*

	 * Char device creation is the last step, as processes can

	 * call our driver immediately, so all our inits must be finished.

	 */

	rc = ocxl_create_cdev(afu);

	if (rc)

		return rc;



	return 0;

}
@@ -282,11 +257,10 @@ static void deactivate_afu(struct ocxl_afu *afu) 
{

	struct pci_dev *dev = to_pci_dev(afu->fn->dev.parent);



	ocxl_destroy_cdev(afu);

	ocxl_config_set_afu_state(dev, afu->config.dvsec_afu_control_pos, 0);

}



int init_afu(struct pci_dev *dev, struct ocxl_fn *fn, u8 afu_idx)

static int init_afu(struct pci_dev *dev, struct ocxl_fn *fn, u8 afu_idx)

{

	int rc;

	struct ocxl_afu *afu;
@@ -297,41 +271,29 @@ int init_afu(struct pci_dev *dev, struct ocxl_fn *fn, u8 afu_idx) 


	rc = configure_afu(afu, afu_idx, dev);

	if (rc) {

		free_afu(afu);

		ocxl_afu_put(afu);

		return rc;

	}



	rc = ocxl_register_afu(afu);

	if (rc)

		goto err;



	rc = ocxl_sysfs_add_afu(afu);

	if (rc)

		goto err;



	rc = activate_afu(dev, afu);

	if (rc)

		goto err_sys;

	if (rc) {

		deconfigure_afu(afu);

		ocxl_afu_put(afu);

		return rc;

	}



	list_add_tail(&afu->list, &fn->afu_list);

	return 0;



err_sys:

	ocxl_sysfs_remove_afu(afu);

err:

	deconfigure_afu(afu);

	device_unregister(&afu->dev);

	return rc;

	return 0;

}



void remove_afu(struct ocxl_afu *afu)

static void remove_afu(struct ocxl_afu *afu)

{

	list_del(&afu->list);

	ocxl_context_detach_all(afu);

	deactivate_afu(afu);

	ocxl_sysfs_remove_afu(afu);

	deconfigure_afu(afu);

	device_unregister(&afu->dev);

	ocxl_afu_put(afu); // matches the implicit get in alloc_afu

}



static struct ocxl_fn *alloc_function(void)
@@ -358,7 +320,7 @@ static void free_function(struct ocxl_fn *fn) 


static void free_function_dev(struct device *dev)

{

	struct ocxl_fn *fn = to_ocxl_function(dev);

	struct ocxl_fn *fn = container_of(dev, struct ocxl_fn, dev);



	free_function(fn);

}
@@ -372,7 +334,6 @@ static int set_function_device(struct ocxl_fn *fn, struct pci_dev *dev) 
	rc = dev_set_name(&fn->dev, "ocxlfn.%s", dev_name(&dev->dev));

	if (rc)

		return rc;

	pci_set_drvdata(dev, fn);

	return 0;

}
@@ -490,7 +451,7 @@ static void deconfigure_function(struct ocxl_fn *fn) 
	pci_disable_device(dev);

}



struct ocxl_fn *init_function(struct pci_dev *dev)

static struct ocxl_fn *init_function(struct pci_dev *dev)

{

	struct ocxl_fn *fn;

	int rc;
@@ -514,8 +475,100 @@ struct ocxl_fn *init_function(struct pci_dev *dev) 
	return fn;

}



void remove_function(struct ocxl_fn *fn)

// Device detection & initialisation



struct ocxl_fn *ocxl_function_open(struct pci_dev *dev)

{

	int rc, afu_count = 0;

	u8 afu;

	struct ocxl_fn *fn;



	if (!radix_enabled()) {

		dev_err(&dev->dev, "Unsupported memory model (hash)\n");

		return ERR_PTR(-ENODEV);

	}



	fn = init_function(dev);

	if (IS_ERR(fn)) {

		dev_err(&dev->dev, "function init failed: %li\n",

			PTR_ERR(fn));

		return fn;

	}



	for (afu = 0; afu <= fn->config.max_afu_index; afu++) {

		rc = ocxl_config_check_afu_index(dev, &fn->config, afu);

		if (rc > 0) {

			rc = init_afu(dev, fn, afu);

			if (rc) {

				dev_err(&dev->dev,

					"Can't initialize AFU index %d\n", afu);

				continue;

			}

			afu_count++;

		}

	}

	dev_info(&dev->dev, "%d AFU(s) configured\n", afu_count);

	return fn;

}

EXPORT_SYMBOL_GPL(ocxl_function_open);



struct list_head *ocxl_function_afu_list(struct ocxl_fn *fn)

{

	return &fn->afu_list;

}

EXPORT_SYMBOL_GPL(ocxl_function_afu_list);



struct ocxl_afu *ocxl_function_fetch_afu(struct ocxl_fn *fn, u8 afu_idx)

{

	struct ocxl_afu *afu;



	list_for_each_entry(afu, &fn->afu_list, list) {

		if (afu->config.idx == afu_idx)

			return afu;

	}



	return NULL;

}

EXPORT_SYMBOL_GPL(ocxl_function_fetch_afu);



const struct ocxl_fn_config *ocxl_function_config(struct ocxl_fn *fn)

{

	return &fn->config;

}

EXPORT_SYMBOL_GPL(ocxl_function_config);



void ocxl_function_close(struct ocxl_fn *fn)

{

	struct ocxl_afu *afu, *tmp;



	list_for_each_entry_safe(afu, tmp, &fn->afu_list, list) {

		remove_afu(afu);

	}



	deconfigure_function(fn);

	device_unregister(&fn->dev);

}

EXPORT_SYMBOL_GPL(ocxl_function_close);



// AFU Metadata



struct ocxl_afu_config *ocxl_afu_config(struct ocxl_afu *afu)

{

	return &afu->config;

}

EXPORT_SYMBOL_GPL(ocxl_afu_config);



void ocxl_afu_set_private(struct ocxl_afu *afu, void *private)

{

	afu->private = private;

}

EXPORT_SYMBOL_GPL(ocxl_afu_set_private);



void *ocxl_afu_get_private(struct ocxl_afu *afu)

{

	if (afu)

		return afu->private;



	return NULL;

}

EXPORT_SYMBOL_GPL(ocxl_afu_get_private);

drivers/misc/ocxl/file.c

+100 −42
Original line number Diff line number Diff line
@@ -17,70 +17,60 @@ static struct class *ocxl_class; 
static struct mutex minors_idr_lock;

static struct idr minors_idr;



static struct ocxl_afu *find_and_get_afu(dev_t devno)

static struct ocxl_file_info *find_file_info(dev_t devno)

{

	struct ocxl_afu *afu;

	int afu_minor;

	struct ocxl_file_info *info;



	afu_minor = MINOR(devno);

	/*

	 * We don't declare an RCU critical section here, as our AFU

	 * is protected by a reference counter on the device. By the time the

	 * minor number of a device is removed from the idr, the ref count of

	 * info reference is removed from the idr, the ref count of

	 * the device is already at 0, so no user API will access that AFU and

	 * this function can't return it.

	 */

	afu = idr_find(&minors_idr, afu_minor);

	if (afu)

		ocxl_afu_get(afu);

	return afu;

	info = idr_find(&minors_idr, MINOR(devno));

	return info;

}



static int allocate_afu_minor(struct ocxl_afu *afu)

static int allocate_minor(struct ocxl_file_info *info)

{

	int minor;



	mutex_lock(&minors_idr_lock);

	minor = idr_alloc(&minors_idr, afu, 0, OCXL_NUM_MINORS, GFP_KERNEL);

	minor = idr_alloc(&minors_idr, info, 0, OCXL_NUM_MINORS, GFP_KERNEL);

	mutex_unlock(&minors_idr_lock);

	return minor;

}



static void free_afu_minor(struct ocxl_afu *afu)

static void free_minor(struct ocxl_file_info *info)

{

	mutex_lock(&minors_idr_lock);

	idr_remove(&minors_idr, MINOR(afu->dev.devt));

	idr_remove(&minors_idr, MINOR(info->dev.devt));

	mutex_unlock(&minors_idr_lock);

}



static int afu_open(struct inode *inode, struct file *file)

{

	struct ocxl_afu *afu;

	struct ocxl_file_info *info;

	struct ocxl_context *ctx;

	int rc;



	pr_debug("%s for device %x\n", __func__, inode->i_rdev);



	afu = find_and_get_afu(inode->i_rdev);

	if (!afu)

	info = find_file_info(inode->i_rdev);

	if (!info)

		return -ENODEV;



	ctx = ocxl_context_alloc();

	if (!ctx) {

		rc = -ENOMEM;

		goto put_afu;

	}

	if (!ctx)

		return -ENOMEM;



	rc = ocxl_context_init(ctx, afu, inode->i_mapping);

	rc = ocxl_context_init(ctx, info->afu, inode->i_mapping);

	if (rc)

		goto put_afu;

		return rc;



	file->private_data = ctx;

	ocxl_afu_put(afu);

	return 0;



put_afu:

	ocxl_afu_put(afu);

	return rc;

}



static long afu_ioctl_attach(struct ocxl_context *ctx,
@@ -204,11 +194,16 @@ static long afu_ioctl(struct file *file, unsigned int cmd, 
	struct ocxl_ioctl_irq_fd irq_fd;

	u64 irq_offset;

	long rc;

	bool closed;



	pr_debug("%s for context %d, command %s\n", __func__, ctx->pasid,

		CMD_STR(cmd));



	if (ctx->status == CLOSED)

	mutex_lock(&ctx->status_mutex);

	closed = (ctx->status == CLOSED);

	mutex_unlock(&ctx->status_mutex);



	if (closed)

		return -EIO;



	switch (cmd) {
@@ -468,39 +463,102 @@ static const struct file_operations ocxl_afu_fops = { 
	.release        = afu_release,

};



int ocxl_create_cdev(struct ocxl_afu *afu)

// Free the info struct

static void info_release(struct device *dev)

{

	struct ocxl_file_info *info = container_of(dev, struct ocxl_file_info, dev);



	free_minor(info);

	ocxl_afu_put(info->afu);

	kfree(info);

}



static int ocxl_file_make_visible(struct ocxl_file_info *info)

{

	int rc;



	cdev_init(&afu->cdev, &ocxl_afu_fops);

	rc = cdev_add(&afu->cdev, afu->dev.devt, 1);

	cdev_init(&info->cdev, &ocxl_afu_fops);

	rc = cdev_add(&info->cdev, info->dev.devt, 1);

	if (rc) {

		dev_err(&afu->dev, "Unable to add afu char device: %d\n", rc);

		dev_err(&info->dev, "Unable to add afu char device: %d\n", rc);

		return rc;

	}



	return 0;

}



void ocxl_destroy_cdev(struct ocxl_afu *afu)

static void ocxl_file_make_invisible(struct ocxl_file_info *info)

{

	cdev_del(&afu->cdev);

	cdev_del(&info->cdev);

}



int ocxl_register_afu(struct ocxl_afu *afu)

int ocxl_file_register_afu(struct ocxl_afu *afu)

{

	int minor;

	int rc;

	struct ocxl_file_info *info;

	struct ocxl_fn *fn = afu->fn;

	struct pci_dev *pci_dev = to_pci_dev(fn->dev.parent);



	info = kzalloc(sizeof(*info), GFP_KERNEL);

	if (info == NULL)

		return -ENOMEM;



	minor = allocate_afu_minor(afu);

	if (minor < 0)

	minor = allocate_minor(info);

	if (minor < 0) {

		kfree(info);

		return minor;

	afu->dev.devt = MKDEV(MAJOR(ocxl_dev), minor);

	afu->dev.class = ocxl_class;

	return device_register(&afu->dev);

	}



void ocxl_unregister_afu(struct ocxl_afu *afu)

	info->dev.parent = &fn->dev;

	info->dev.devt = MKDEV(MAJOR(ocxl_dev), minor);

	info->dev.class = ocxl_class;

	info->dev.release = info_release;



	info->afu = afu;

	ocxl_afu_get(afu);



	rc = dev_set_name(&info->dev, "%s.%s.%hhu",

		afu->config.name, dev_name(&pci_dev->dev), afu->config.idx);

	if (rc)

		goto err_put;



	rc = device_register(&info->dev);

	if (rc)

		goto err_put;



	rc = ocxl_sysfs_register_afu(info);

	if (rc)

		goto err_unregister;



	rc = ocxl_file_make_visible(info);

	if (rc)

		goto err_unregister;



	ocxl_afu_set_private(afu, info);



	return 0;



err_unregister:

	ocxl_sysfs_unregister_afu(info); // safe to call even if register failed

	device_unregister(&info->dev);

err_put:

	ocxl_afu_put(afu);

	free_minor(info);

	kfree(info);

	return rc;

}



void ocxl_file_unregister_afu(struct ocxl_afu *afu)

{

	free_afu_minor(afu);

	struct ocxl_file_info *info = ocxl_afu_get_private(afu);



	if (!info)

		return;



	ocxl_file_make_invisible(info);

	ocxl_sysfs_unregister_afu(info);

	device_unregister(&info->dev);

}



static char *ocxl_devnode(struct device *dev, umode_t *mode)

drivers/misc/ocxl/ocxl_internal.h

+13 −18
Original line number Diff line number Diff line
@@ -11,9 +11,6 @@ 
#define MAX_IRQ_PER_LINK	2000

#define MAX_IRQ_PER_CONTEXT	MAX_IRQ_PER_LINK



#define to_ocxl_function(d) container_of(d, struct ocxl_fn, dev)

#define to_ocxl_afu(d) container_of(d, struct ocxl_afu, dev)



extern struct pci_driver ocxl_pci_driver;



struct ocxl_fn {
@@ -30,11 +27,17 @@ struct ocxl_fn { 
	void *link;

};



struct ocxl_file_info {

	struct ocxl_afu *afu;

	struct device dev;

	struct cdev cdev;

	struct bin_attribute attr_global_mmio;

};



struct ocxl_afu {

	struct kref kref;

	struct ocxl_fn *fn;

	struct list_head list;

	struct device dev;

	struct cdev cdev;

	struct ocxl_afu_config config;

	int pasid_base;

	int pasid_count; /* opened contexts */
@@ -48,7 +51,7 @@ struct ocxl_afu { 
	u64 irq_base_offset;

	void __iomem *global_mmio_ptr;

	u64 pp_mmio_start;

	struct bin_attribute attr_global_mmio;

	void *private;

};



enum ocxl_context_status {
@@ -91,13 +94,10 @@ struct ocxl_process_element { 
	__be32 software_state;

};



struct ocxl_afu *ocxl_afu_get(struct ocxl_afu *afu);

void ocxl_afu_put(struct ocxl_afu *afu);



int ocxl_create_cdev(struct ocxl_afu *afu);

void ocxl_destroy_cdev(struct ocxl_afu *afu);

int ocxl_register_afu(struct ocxl_afu *afu);

void ocxl_unregister_afu(struct ocxl_afu *afu);

int ocxl_file_register_afu(struct ocxl_afu *afu);

void ocxl_file_unregister_afu(struct ocxl_afu *afu);



int ocxl_file_init(void);

void ocxl_file_exit(void);
@@ -140,8 +140,8 @@ int ocxl_context_detach(struct ocxl_context *ctx); 
void ocxl_context_detach_all(struct ocxl_afu *afu);

void ocxl_context_free(struct ocxl_context *ctx);



int ocxl_sysfs_add_afu(struct ocxl_afu *afu);

void ocxl_sysfs_remove_afu(struct ocxl_afu *afu);

int ocxl_sysfs_register_afu(struct ocxl_file_info *info);

void ocxl_sysfs_unregister_afu(struct ocxl_file_info *info);



int ocxl_afu_irq_alloc(struct ocxl_context *ctx, u64 *irq_offset);

int ocxl_afu_irq_free(struct ocxl_context *ctx, u64 irq_offset);
@@ -150,9 +150,4 @@ int ocxl_afu_irq_set_fd(struct ocxl_context *ctx, u64 irq_offset, 
			int eventfd);

u64 ocxl_afu_irq_get_addr(struct ocxl_context *ctx, u64 irq_offset);



struct ocxl_fn *init_function(struct pci_dev *dev);

void remove_function(struct ocxl_fn *fn);

int init_afu(struct pci_dev *dev, struct ocxl_fn *fn, u8 afu_idx);

void remove_afu(struct ocxl_afu *afu);



#endif /* _OCXL_INTERNAL_H_ */

drivers/misc/ocxl/pci.c

+27 −29
Original line number Diff line number Diff line
@@ -16,47 +16,45 @@ MODULE_DEVICE_TABLE(pci, ocxl_pci_tbl); 


static int ocxl_probe(struct pci_dev *dev, const struct pci_device_id *id)

{

	int rc, afu_count = 0;

	u8 afu;

	int rc;

	struct ocxl_afu *afu, *tmp;

	struct ocxl_fn *fn;

	struct list_head *afu_list;



	if (!radix_enabled()) {

		dev_err(&dev->dev, "Unsupported memory model (hash)\n");

		return -ENODEV;

	}



	fn = init_function(dev);

	if (IS_ERR(fn)) {

		dev_err(&dev->dev, "function init failed: %li\n",

			PTR_ERR(fn));

	fn = ocxl_function_open(dev);

	if (IS_ERR(fn))

		return PTR_ERR(fn);

	}



	for (afu = 0; afu <= fn->config.max_afu_index; afu++) {

		rc = ocxl_config_check_afu_index(dev, &fn->config, afu);

		if (rc > 0) {

			rc = init_afu(dev, fn, afu);

	pci_set_drvdata(dev, fn);



	afu_list = ocxl_function_afu_list(fn);



	list_for_each_entry_safe(afu, tmp, afu_list, list) {

		// Cleanup handled within ocxl_file_register_afu()

		rc = ocxl_file_register_afu(afu);

		if (rc) {

				dev_err(&dev->dev,

					"Can't initialize AFU index %d\n", afu);

				continue;

			dev_err(&dev->dev, "Failed to register AFU '%s' index %d",

					afu->config.name, afu->config.idx);

		}

			afu_count++;

	}

	}

	dev_info(&dev->dev, "%d AFU(s) configured\n", afu_count);



	return 0;

}



static void ocxl_remove(struct pci_dev *dev)

void ocxl_remove(struct pci_dev *dev)

{

	struct ocxl_afu *afu, *tmp;

	struct ocxl_fn *fn = pci_get_drvdata(dev);

	struct ocxl_fn *fn;

	struct ocxl_afu *afu;

	struct list_head *afu_list;



	fn = pci_get_drvdata(dev);

	afu_list = ocxl_function_afu_list(fn);



	list_for_each_entry_safe(afu, tmp, &fn->afu_list, list) {

		remove_afu(afu);

	list_for_each_entry(afu, afu_list, list) {

		ocxl_file_unregister_afu(afu);

	}

	remove_function(fn);



	ocxl_function_close(fn);

}



struct pci_driver ocxl_pci_driver = {

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