Haren Myneni <haren@xxxxxxxxxxxxx> writes:
> On power9, user space can send GZIP compression requests directly to NX
> once kernel establishes NX channel / window with VAS. This patch provides
> user space API which allows user space to establish channel using open
> VAS_TX_WIN_OPEN ioctl, mmap and close operations.
>
> Each window corresponds to file descriptor and application can open
> multiple windows. After the window is opened, VAS_TX_WIN_OPEN icoctl to
> open a window on specific VAS instance, mmap() system call to map
> the hardware address of engine's request queue into the application's
> virtual address space.
>
> Then the application can then submit one or more requests to the the
> engine by using the copy/paste instructions and pasting the CRBs to
> the virtual address (aka paste_address) returned by mmap().
>
> Only NX GZIP coprocessor type is supported right now and allow GZIP
> engine access via /dev/crypto/nx-gzip device node.
>
> Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Haren Myneni <haren@xxxxxxxxxxxxx>
> ---
> arch/powerpc/include/asm/vas.h | 11 ++
> arch/powerpc/platforms/powernv/Makefile | 2 +-
> arch/powerpc/platforms/powernv/vas-api.c | 257 ++++++++++++++++++++++++++++
> arch/powerpc/platforms/powernv/vas-window.c | 6 +-
> arch/powerpc/platforms/powernv/vas.h | 2 +
> 5 files changed, 274 insertions(+), 4 deletions(-)
> create mode 100644 arch/powerpc/platforms/powernv/vas-api.c
>
> diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
> index f93e6b0..e064953 100644
> --- a/arch/powerpc/include/asm/vas.h
> +++ b/arch/powerpc/include/asm/vas.h
> @@ -163,4 +163,15 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
> */
> int vas_paste_crb(struct vas_window *win, int offset, bool re);
>
> +/*
> + * Register / unregister coprocessor type to VAS API which will be exported
> + * to user space. Applications can use this API to open / close window
> + * which can be used to send / receive requests directly to cooprcessor.
> + *
> + * Only NX GZIP coprocessor type is supported now, but this API can be
> + * used for others in future.
> + */
> +int vas_register_coproc_api(struct module *mod);
> +void vas_unregister_coproc_api(void);
> +
> #endif /* __ASM_POWERPC_VAS_H */
> diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
> index 395789f..fe3f0fb 100644
> --- a/arch/powerpc/platforms/powernv/Makefile
> +++ b/arch/powerpc/platforms/powernv/Makefile
> @@ -17,7 +17,7 @@ obj-$(CONFIG_MEMORY_FAILURE) += opal-memory-errors.o
> obj-$(CONFIG_OPAL_PRD) += opal-prd.o
> obj-$(CONFIG_PERF_EVENTS) += opal-imc.o
> obj-$(CONFIG_PPC_MEMTRACE) += memtrace.o
> -obj-$(CONFIG_PPC_VAS) += vas.o vas-window.o vas-debug.o vas-fault.o
> +obj-$(CONFIG_PPC_VAS) += vas.o vas-window.o vas-debug.o vas-fault.o vas-api.o
> obj-$(CONFIG_OCXL_BASE) += ocxl.o
> obj-$(CONFIG_SCOM_DEBUGFS) += opal-xscom.o
> obj-$(CONFIG_PPC_SECURE_BOOT) += opal-secvar.o
> diff --git a/arch/powerpc/platforms/powernv/vas-api.c b/arch/powerpc/platforms/powernv/vas-api.c
> new file mode 100644
> index 0000000..7d049af
> --- /dev/null
> +++ b/arch/powerpc/platforms/powernv/vas-api.c
> @@ -0,0 +1,257 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * VAS user space API for its accelerators (Only NX-GZIP is supported now)
> + * Copyright (C) 2019 Haren Myneni, IBM Corp
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/cdev.h>
> +#include <linux/fs.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +#include <asm/vas.h>
> +#include <uapi/asm/vas-api.h>
> +#include "vas.h"
> +
> +/*
> + * The driver creates the device node that can be used as follows:
> + * For NX-GZIP
> + *
> + * fd = open("/dev/crypto/nx-gzip", O_RDWR);
> + * rc = ioctl(fd, VAS_TX_WIN_OPEN, &attr);
> + * paste_addr = mmap(NULL, PAGE_SIZE, prot, MAP_SHARED, fd, 0ULL).
> + * vas_copy(&crb, 0, 1);
> + * vas_paste(paste_addr, 0, 1);
> + * close(fd) or exit process to close window.
> + *
> + * where "vas_copy" and "vas_paste" are defined in copy-paste.h.
> + * copy/paste returns to the user space directly. So refer NX hardware
> + * documententation for exact copy/paste usage and completion / error
> + * conditions.
> + */
> +
> +static char *coproc_dev_name = "nx-gzip";
> +
> +/*
> + * Wrapper object for the nx-gzip device - there is just one instance of
> + * this node for the whole system.
> + */
> +static struct coproc_dev {
> + struct cdev cdev;
> + struct device *device;
> + char *name;
> + dev_t devt;
> + struct class *class;
> +} coproc_device;
> +
> +static char *coproc_devnode(struct device *dev, umode_t *mode)
> +{
> + return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
> +}
> +
> +static int coproc_open(struct inode *inode, struct file *fp)
> +{
> + /*
> + * vas_window is allocated and assigned to fp->private_data
> + * in ioctl. Nothing to do here for NX GZIP.
> + */
> + return 0;
> +}
> +
> +static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
> +{
> + void __user *uptr = (void __user *)arg;
> + struct vas_tx_win_attr txattr = {};
> + struct vas_tx_win_open_attr uattr;
> + struct vas_window *txwin;
> + int rc, vasid;
> +
> + /*
> + * One window for file descriptor
> + */
> + if (fp->private_data)
> + return -EEXIST;
> +
> + rc = copy_from_user(&uattr, uptr, sizeof(uattr));
> + if (rc) {
> + pr_err("%s(): copy_from_user() returns %d\n", __func__, rc);
> + return -EFAULT;
> + }
> +
> + if (uattr.version != 1) {
> + pr_err("Invalid version\n");
> + return -EINVAL;
> + }
> +
> + vasid = uattr.vas_id;
> +
> + vas_init_tx_win_attr(&txattr, VAS_COP_TYPE_GZIP);
We shouldn't be hard coding GZIP in here.
I don't mind if you have a single coproc_dev for now, but we should at
least be passing the type etc. in from the driver.
Something like the patch below should work. Please test.
cheers
diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h
index 994db6f41a19..5fa65a5af095 100644
--- a/arch/powerpc/include/asm/vas.h
+++ b/arch/powerpc/include/asm/vas.h
@@ -170,7 +170,8 @@ int vas_paste_crb(struct vas_window *win, int offset, bool re);
* Only NX GZIP coprocessor type is supported now, but this API can be
* used for others in future.
*/
-int vas_register_coproc_api(struct module *mod);
+int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
+ const char *name);
void vas_unregister_coproc_api(void);
#endif /* __ASM_POWERPC_VAS_H */
diff --git a/arch/powerpc/platforms/powernv/vas-api.c b/arch/powerpc/platforms/powernv/vas-api.c
index 7d049afde63a..3537a531bec1 100644
--- a/arch/powerpc/platforms/powernv/vas-api.c
+++ b/arch/powerpc/platforms/powernv/vas-api.c
@@ -31,7 +31,6 @@
* conditions.
*/
-static char *coproc_dev_name = "nx-gzip";
/*
* Wrapper object for the nx-gzip device - there is just one instance of
@@ -43,8 +42,14 @@ static struct coproc_dev {
char *name;
dev_t devt;
struct class *class;
+ enum vas_cop_type cop_type;
} coproc_device;
+struct coproc_instance {
+ struct coproc_dev *coproc;
+ struct vas_window *txwin;
+};
+
static char *coproc_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
@@ -52,10 +57,15 @@ static char *coproc_devnode(struct device *dev, umode_t *mode)
static int coproc_open(struct inode *inode, struct file *fp)
{
- /*
- * vas_window is allocated and assigned to fp->private_data
- * in ioctl. Nothing to do here for NX GZIP.
- */
+ struct coproc_instance *cp_inst;
+
+ cp_inst = kzalloc(sizeof(*cp_inst), GFP_KERNEL);
+ if (!cp_inst)
+ return -ENOMEM;
+
+ cp_inst->coproc = container_of(inode->i_cdev, struct coproc_dev, cdev);
+ fp->private_data = cp_inst;
+
return 0;
}
@@ -64,13 +74,16 @@ static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
void __user *uptr = (void __user *)arg;
struct vas_tx_win_attr txattr = {};
struct vas_tx_win_open_attr uattr;
+ struct coproc_instance *cp_inst;
struct vas_window *txwin;
int rc, vasid;
+ cp_inst = fp->private_data;
+
/*
* One window for file descriptor
*/
- if (fp->private_data)
+ if (cp_inst->txwin)
return -EEXIST;
rc = copy_from_user(&uattr, uptr, sizeof(uattr));
@@ -86,7 +99,7 @@ static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
vasid = uattr.vas_id;
- vas_init_tx_win_attr(&txattr, VAS_COP_TYPE_GZIP);
+ vas_init_tx_win_attr(&txattr, cp_inst->coproc->cop_type);
txattr.lpid = mfspr(SPRN_LPID);
txattr.pidr = mfspr(SPRN_PID);
@@ -97,27 +110,30 @@ static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
pr_devel("Pid %d: Opening txwin, PIDR %ld\n", txattr.pidr,
mfspr(SPRN_PID));
- txwin = vas_tx_win_open(vasid, VAS_COP_TYPE_GZIP, &txattr);
+ txwin = vas_tx_win_open(vasid, cp_inst->coproc->cop_type, &txattr);
if (IS_ERR(txwin)) {
pr_err("%s() vas_tx_win_open() failed, %ld\n", __func__,
PTR_ERR(txwin));
return PTR_ERR(txwin);
}
- fp->private_data = txwin;
+ cp_inst->txwin = txwin;
return 0;
}
static int coproc_release(struct inode *inode, struct file *fp)
{
- struct vas_window *txwin = fp->private_data;
+ struct coproc_instance *cp_inst = fp->private_data;
- if (txwin) {
- vas_win_close(txwin);
- fp->private_data = NULL;
+ if (cp_inst->txwin) {
+ vas_win_close(cp_inst->txwin);
+ cp_inst->txwin = NULL;
}
+ kfree(cp_inst);
+ fp->private_data = NULL;
+
/*
* We don't know here if user has other receive windows
* open, so we can't really call clear_thread_tidr().
@@ -131,12 +147,15 @@ static int coproc_release(struct inode *inode, struct file *fp)
static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
{
- struct vas_window *txwin = fp->private_data;
+ struct coproc_instance *cp_inst = fp->private_data;
+ struct vas_window *txwin;
unsigned long pfn;
u64 paste_addr;
pgprot_t prot;
int rc;
+ txwin = cp_inst->txwin;
+
if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__,
(vma->vm_end - vma->vm_start), PAGE_SIZE);
@@ -188,28 +207,30 @@ static struct file_operations coproc_fops = {
* Supporting only nx-gzip coprocessor type now, but this API code
* extended to other coprocessor types later.
*/
-int vas_register_coproc_api(struct module *mod)
+int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
+ const char *name)
{
int rc = -EINVAL;
dev_t devno;
- rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, coproc_dev_name);
+ rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, name);
if (rc) {
pr_err("Unable to allocate coproc major number: %i\n", rc);
return rc;
}
- pr_devel("%s device allocated, dev [%i,%i]\n", coproc_dev_name,
- MAJOR(coproc_device.devt), MINOR(coproc_device.devt));
+ pr_devel("%s device allocated, dev [%i,%i]\n", name,
+ MAJOR(coproc_device.devt), MINOR(coproc_device.devt));
- coproc_device.class = class_create(mod, coproc_dev_name);
+ coproc_device.class = class_create(mod, name);
if (IS_ERR(coproc_device.class)) {
rc = PTR_ERR(coproc_device.class);
- pr_err("Unable to create %s class %d\n", coproc_dev_name, rc);
+ pr_err("Unable to create %s class %d\n", name, rc);
goto err_class;
}
coproc_device.class->devnode = coproc_devnode;
+ coproc_device.cop_type = cop_type;
coproc_fops.owner = mod;
cdev_init(&coproc_device.cdev, &coproc_fops);
@@ -221,7 +242,7 @@ int vas_register_coproc_api(struct module *mod)
}
coproc_device.device = device_create(coproc_device.class, NULL,
- devno, NULL, coproc_dev_name, MINOR(devno));
+ devno, NULL, name, MINOR(devno));
if (IS_ERR(coproc_device.device)) {
rc = PTR_ERR(coproc_device.device);
pr_err("Unable to create coproc-%d %d\n", MINOR(devno), rc);
diff --git a/drivers/crypto/nx/nx-common-powernv.c b/drivers/crypto/nx/nx-common-powernv.c
index 38333e475097..1979fa6055de 100644
--- a/drivers/crypto/nx/nx-common-powernv.c
+++ b/drivers/crypto/nx/nx-common-powernv.c
@@ -1088,7 +1088,7 @@ static __init int nx_compress_powernv_init(void)
* that user space can use GZIP engine.
* 842 compression is supported only in kernel.
*/
- ret = vas_register_coproc_api(THIS_MODULE);
+ ret = vas_register_coproc_api(THIS_MODULE, VAS_COP_TYPE_GZIP, "nx-gzip");
/*
* GZIP is not supported in kernel right now.
