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path: root/drivers/cxl/mem.c
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Diffstat (limited to 'drivers/cxl/mem.c')
-rw-r--r--drivers/cxl/mem.c152
1 files changed, 89 insertions, 63 deletions
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 244cb7d89678..2acc6173da36 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -4,6 +4,7 @@
#include <linux/security.h>
#include <linux/debugfs.h>
#include <linux/module.h>
+#include <linux/sizes.h>
#include <linux/mutex.h>
#include <linux/cdev.h>
#include <linux/idr.h>
@@ -96,21 +97,18 @@ struct mbox_cmd {
* @dev: driver core device object
* @cdev: char dev core object for ioctl operations
* @cxlm: pointer to the parent device driver data
- * @ops_active: active user of @cxlm in ops handlers
- * @ops_dead: completion when all @cxlm ops users have exited
* @id: id number of this memdev instance.
*/
struct cxl_memdev {
struct device dev;
struct cdev cdev;
struct cxl_mem *cxlm;
- struct percpu_ref ops_active;
- struct completion ops_dead;
int id;
};
static int cxl_mem_major;
static DEFINE_IDA(cxl_memdev_ida);
+static DECLARE_RWSEM(cxl_memdev_rwsem);
static struct dentry *cxl_debugfs;
static bool cxl_raw_allow_all;
@@ -169,7 +167,7 @@ struct cxl_mem_command {
* table will be validated against the user's input. For example, if size_in is
* 0, and the user passed in 1, it is an error.
*/
-static struct cxl_mem_command mem_commands[] = {
+static struct cxl_mem_command mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
CXL_CMD(IDENTIFY, 0, 0x43, CXL_CMD_FLAG_FORCE_ENABLE),
#ifdef CONFIG_CXL_MEM_RAW_COMMANDS
CXL_CMD(RAW, ~0, ~0, 0),
@@ -776,26 +774,43 @@ static long __cxl_memdev_ioctl(struct cxl_memdev *cxlmd, unsigned int cmd,
static long cxl_memdev_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
- struct cxl_memdev *cxlmd;
- struct inode *inode;
- int rc = -ENOTTY;
+ struct cxl_memdev *cxlmd = file->private_data;
+ int rc = -ENXIO;
- inode = file_inode(file);
- cxlmd = container_of(inode->i_cdev, typeof(*cxlmd), cdev);
+ down_read(&cxl_memdev_rwsem);
+ if (cxlmd->cxlm)
+ rc = __cxl_memdev_ioctl(cxlmd, cmd, arg);
+ up_read(&cxl_memdev_rwsem);
- if (!percpu_ref_tryget_live(&cxlmd->ops_active))
- return -ENXIO;
+ return rc;
+}
- rc = __cxl_memdev_ioctl(cxlmd, cmd, arg);
+static int cxl_memdev_open(struct inode *inode, struct file *file)
+{
+ struct cxl_memdev *cxlmd =
+ container_of(inode->i_cdev, typeof(*cxlmd), cdev);
- percpu_ref_put(&cxlmd->ops_active);
+ get_device(&cxlmd->dev);
+ file->private_data = cxlmd;
- return rc;
+ return 0;
+}
+
+static int cxl_memdev_release_file(struct inode *inode, struct file *file)
+{
+ struct cxl_memdev *cxlmd =
+ container_of(inode->i_cdev, typeof(*cxlmd), cdev);
+
+ put_device(&cxlmd->dev);
+
+ return 0;
}
static const struct file_operations cxl_memdev_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = cxl_memdev_ioctl,
+ .open = cxl_memdev_open,
+ .release = cxl_memdev_release_file,
.compat_ioctl = compat_ptr_ioctl,
.llseek = noop_llseek,
};
@@ -984,7 +999,7 @@ static struct cxl_mem *cxl_mem_create(struct pci_dev *pdev, u32 reg_lo,
return NULL;
}
- offset = ((u64)reg_hi << 32) | FIELD_GET(CXL_REGLOC_ADDR_MASK, reg_lo);
+ offset = ((u64)reg_hi << 32) | (reg_lo & CXL_REGLOC_ADDR_MASK);
bar = FIELD_GET(CXL_REGLOC_BIR_MASK, reg_lo);
/* Basic sanity check that BAR is big enough */
@@ -1049,7 +1064,6 @@ static void cxl_memdev_release(struct device *dev)
{
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
- percpu_ref_exit(&cxlmd->ops_active);
ida_free(&cxl_memdev_ida, cxlmd->id);
kfree(cxlmd);
}
@@ -1066,7 +1080,7 @@ static ssize_t firmware_version_show(struct device *dev,
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
struct cxl_mem *cxlm = cxlmd->cxlm;
- return sprintf(buf, "%.16s\n", cxlm->firmware_version);
+ return sysfs_emit(buf, "%.16s\n", cxlm->firmware_version);
}
static DEVICE_ATTR_RO(firmware_version);
@@ -1076,7 +1090,7 @@ static ssize_t payload_max_show(struct device *dev,
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
struct cxl_mem *cxlm = cxlmd->cxlm;
- return sprintf(buf, "%zu\n", cxlm->payload_size);
+ return sysfs_emit(buf, "%zu\n", cxlm->payload_size);
}
static DEVICE_ATTR_RO(payload_max);
@@ -1087,7 +1101,7 @@ static ssize_t ram_size_show(struct device *dev, struct device_attribute *attr,
struct cxl_mem *cxlm = cxlmd->cxlm;
unsigned long long len = range_len(&cxlm->ram_range);
- return sprintf(buf, "%#llx\n", len);
+ return sysfs_emit(buf, "%#llx\n", len);
}
static struct device_attribute dev_attr_ram_size =
@@ -1100,7 +1114,7 @@ static ssize_t pmem_size_show(struct device *dev, struct device_attribute *attr,
struct cxl_mem *cxlm = cxlmd->cxlm;
unsigned long long len = range_len(&cxlm->pmem_range);
- return sprintf(buf, "%#llx\n", len);
+ return sysfs_emit(buf, "%#llx\n", len);
}
static struct device_attribute dev_attr_pmem_size =
@@ -1150,27 +1164,24 @@ static const struct device_type cxl_memdev_type = {
.groups = cxl_memdev_attribute_groups,
};
-static void cxlmdev_unregister(void *_cxlmd)
+static void cxl_memdev_shutdown(struct cxl_memdev *cxlmd)
{
- struct cxl_memdev *cxlmd = _cxlmd;
- struct device *dev = &cxlmd->dev;
-
- percpu_ref_kill(&cxlmd->ops_active);
- cdev_device_del(&cxlmd->cdev, dev);
- wait_for_completion(&cxlmd->ops_dead);
+ down_write(&cxl_memdev_rwsem);
cxlmd->cxlm = NULL;
- put_device(dev);
+ up_write(&cxl_memdev_rwsem);
}
-static void cxlmdev_ops_active_release(struct percpu_ref *ref)
+static void cxl_memdev_unregister(void *_cxlmd)
{
- struct cxl_memdev *cxlmd =
- container_of(ref, typeof(*cxlmd), ops_active);
+ struct cxl_memdev *cxlmd = _cxlmd;
+ struct device *dev = &cxlmd->dev;
- complete(&cxlmd->ops_dead);
+ cdev_device_del(&cxlmd->cdev, dev);
+ cxl_memdev_shutdown(cxlmd);
+ put_device(dev);
}
-static int cxl_mem_add_memdev(struct cxl_mem *cxlm)
+static struct cxl_memdev *cxl_memdev_alloc(struct cxl_mem *cxlm)
{
struct pci_dev *pdev = cxlm->pdev;
struct cxl_memdev *cxlmd;
@@ -1180,22 +1191,11 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm)
cxlmd = kzalloc(sizeof(*cxlmd), GFP_KERNEL);
if (!cxlmd)
- return -ENOMEM;
- init_completion(&cxlmd->ops_dead);
-
- /*
- * @cxlm is deallocated when the driver unbinds so operations
- * that are using it need to hold a live reference.
- */
- cxlmd->cxlm = cxlm;
- rc = percpu_ref_init(&cxlmd->ops_active, cxlmdev_ops_active_release, 0,
- GFP_KERNEL);
- if (rc)
- goto err_ref;
+ return ERR_PTR(-ENOMEM);
rc = ida_alloc_range(&cxl_memdev_ida, 0, CXL_MEM_MAX_DEVS, GFP_KERNEL);
if (rc < 0)
- goto err_id;
+ goto err;
cxlmd->id = rc;
dev = &cxlmd->dev;
@@ -1204,30 +1204,54 @@ static int cxl_mem_add_memdev(struct cxl_mem *cxlm)
dev->bus = &cxl_bus_type;
dev->devt = MKDEV(cxl_mem_major, cxlmd->id);
dev->type = &cxl_memdev_type;
- dev_set_name(dev, "mem%d", cxlmd->id);
+ device_set_pm_not_required(dev);
cdev = &cxlmd->cdev;
cdev_init(cdev, &cxl_memdev_fops);
+ return cxlmd;
+
+err:
+ kfree(cxlmd);
+ return ERR_PTR(rc);
+}
+
+static int cxl_mem_add_memdev(struct cxl_mem *cxlm)
+{
+ struct cxl_memdev *cxlmd;
+ struct device *dev;
+ struct cdev *cdev;
+ int rc;
+
+ cxlmd = cxl_memdev_alloc(cxlm);
+ if (IS_ERR(cxlmd))
+ return PTR_ERR(cxlmd);
+
+ dev = &cxlmd->dev;
+ rc = dev_set_name(dev, "mem%d", cxlmd->id);
+ if (rc)
+ goto err;
+
+ /*
+ * Activate ioctl operations, no cxl_memdev_rwsem manipulation
+ * needed as this is ordered with cdev_add() publishing the device.
+ */
+ cxlmd->cxlm = cxlm;
+ cdev = &cxlmd->cdev;
rc = cdev_device_add(cdev, dev);
if (rc)
- goto err_add;
+ goto err;
- return devm_add_action_or_reset(dev->parent, cxlmdev_unregister, cxlmd);
+ return devm_add_action_or_reset(dev->parent, cxl_memdev_unregister,
+ cxlmd);
-err_add:
- ida_free(&cxl_memdev_ida, cxlmd->id);
-err_id:
+err:
/*
- * Theoretically userspace could have already entered the fops,
- * so flush ops_active.
+ * The cdev was briefly live, shutdown any ioctl operations that
+ * saw that state.
*/
- percpu_ref_kill(&cxlmd->ops_active);
- wait_for_completion(&cxlmd->ops_dead);
- percpu_ref_exit(&cxlmd->ops_active);
-err_ref:
- kfree(cxlmd);
-
+ cxl_memdev_shutdown(cxlmd);
+ put_device(dev);
return rc;
}
@@ -1396,6 +1420,7 @@ out:
*/
static int cxl_mem_identify(struct cxl_mem *cxlm)
{
+ /* See CXL 2.0 Table 175 Identify Memory Device Output Payload */
struct cxl_mbox_identify {
char fw_revision[0x10];
__le64 total_capacity;
@@ -1424,10 +1449,11 @@ static int cxl_mem_identify(struct cxl_mem *cxlm)
* For now, only the capacity is exported in sysfs
*/
cxlm->ram_range.start = 0;
- cxlm->ram_range.end = le64_to_cpu(id.volatile_capacity) - 1;
+ cxlm->ram_range.end = le64_to_cpu(id.volatile_capacity) * SZ_256M - 1;
cxlm->pmem_range.start = 0;
- cxlm->pmem_range.end = le64_to_cpu(id.persistent_capacity) - 1;
+ cxlm->pmem_range.end =
+ le64_to_cpu(id.persistent_capacity) * SZ_256M - 1;
memcpy(cxlm->firmware_version, id.fw_revision, sizeof(id.fw_revision));