Haren Myneni <haren@xxxxxxxxxxxxx> writes: > On power9, userspace 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); > + > + txattr.lpid = mfspr(SPRN_LPID); > + txattr.pidr = mfspr(SPRN_PID); > + txattr.user_win = true; > + txattr.rsvd_txbuf_count = false; > + txattr.pswid = false; > + > + 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); > + 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; > + > + return 0; > +} > + > +static int coproc_release(struct inode *inode, struct file *fp) > +{ > + struct vas_window *txwin = fp->private_data; > + > + if (txwin) { > + vas_win_close(txwin); > + 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(). > + * So, once the process calls set_thread_tidr(), the > + * TIDR value sticks around until process exits, resulting > + * in an extra copy in restore_sprs(). > + */ > + > + return 0; > +} > + > +static int coproc_mmap(struct file *fp, struct vm_area_struct *vma) > +{ > + struct vas_window *txwin = fp->private_data; > + unsigned long pfn; > + u64 paste_addr; > + pgprot_t prot; > + int rc; > + > + if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) { I think you said this should be 4096 rather than 64k, regardless of what PAGE_SIZE you are compiled with? > + pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__, > + (vma->vm_end - vma->vm_start), PAGE_SIZE); > + return -EINVAL; > + } > + > + /* Ensure instance has an open send window */ > + if (!txwin) { > + pr_err("%s(): No send window open?\n", __func__); > + return -EINVAL; > + } > + > + vas_win_paste_addr(txwin, &paste_addr, NULL); > + pfn = paste_addr >> PAGE_SHIFT; > + > + /* flags, page_prot from cxl_mmap(), except we want cachable */ > + vma->vm_flags |= VM_IO | VM_PFNMAP; > + vma->vm_page_prot = pgprot_cached(vma->vm_page_prot); > + > + prot = __pgprot(pgprot_val(vma->vm_page_prot) | _PAGE_DIRTY); > + > + rc = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff, > + vma->vm_end - vma->vm_start, prot); > + > + pr_devel("%s(): paste addr %llx at %lx, rc %d\n", __func__, > + paste_addr, vma->vm_start, rc); > + > + return rc; > +} > + > +static long coproc_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) > +{ > + switch (cmd) { > + case VAS_TX_WIN_OPEN: > + return coproc_ioc_tx_win_open(fp, arg); > + default: > + return -EINVAL; > + } > +} > + > +static struct file_operations coproc_fops = { > + .open = coproc_open, > + .release = coproc_release, > + .mmap = coproc_mmap, > + .unlocked_ioctl = coproc_ioctl, > +}; > + > +/* > + * 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 rc = -EINVAL; > + dev_t devno; > + > + rc = alloc_chrdev_region(&coproc_device.devt, 1, 1, coproc_dev_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)); > + > + coproc_device.class = class_create(mod, coproc_dev_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); > + goto err_class; > + } > + coproc_device.class->devnode = coproc_devnode; > + > + coproc_fops.owner = mod; > + cdev_init(&coproc_device.cdev, &coproc_fops); > + > + devno = MKDEV(MAJOR(coproc_device.devt), 0); > + rc = cdev_add(&coproc_device.cdev, devno, 1); > + if (rc) { > + pr_err("cdev_add() failed %d\n", rc); > + goto err_cdev; > + } > + > + coproc_device.device = device_create(coproc_device.class, NULL, > + devno, NULL, coproc_dev_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); > + goto err; > + } > + > + pr_devel("%s: Added dev [%d,%d]\n", __func__, MAJOR(devno), > + MINOR(devno)); > + > + return 0; > + > +err: > + cdev_del(&coproc_device.cdev); > +err_cdev: > + class_destroy(coproc_device.class); > +err_class: > + unregister_chrdev_region(coproc_device.devt, 1); > + return rc; > +} > +EXPORT_SYMBOL_GPL(vas_register_coproc_api); > + > +void vas_unregister_coproc_api(void) > +{ > + dev_t devno; > + > + cdev_del(&coproc_device.cdev); > + devno = MKDEV(MAJOR(coproc_device.devt), 0); > + device_destroy(coproc_device.class, devno); > + > + class_destroy(coproc_device.class); > + unregister_chrdev_region(coproc_device.devt, 1); > +} > +EXPORT_SYMBOL_GPL(vas_unregister_coproc_api); > diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c > index 4ce421f..7b5187b 100644 > --- a/arch/powerpc/platforms/powernv/vas-window.c > +++ b/arch/powerpc/platforms/powernv/vas-window.c > @@ -26,7 +26,7 @@ > * Compute the paste address region for the window @window using the > * ->paste_base_addr and ->paste_win_id_shift we got from device tree. > */ > -static void compute_paste_address(struct vas_window *window, u64 *addr, int *len) > +void vas_win_paste_addr(struct vas_window *window, u64 *addr, int *len) > { > int winid; > u64 base, shift; > @@ -80,7 +80,7 @@ static void *map_paste_region(struct vas_window *txwin) > goto free_name; > > txwin->paste_addr_name = name; > - compute_paste_address(txwin, &start, &len); > + vas_win_paste_addr(txwin, &start, &len); > > if (!request_mem_region(start, len, name)) { > pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n", > @@ -138,7 +138,7 @@ static void unmap_paste_region(struct vas_window *window) > u64 busaddr_start; > > if (window->paste_kaddr) { > - compute_paste_address(window, &busaddr_start, &len); > + vas_win_paste_addr(window, &busaddr_start, &len); > unmap_region(window->paste_kaddr, busaddr_start, len); > window->paste_kaddr = NULL; > kfree(window->paste_addr_name); > diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h > index 8c39a7d..a10abed 100644 > --- a/arch/powerpc/platforms/powernv/vas.h > +++ b/arch/powerpc/platforms/powernv/vas.h > @@ -431,6 +431,8 @@ struct vas_winctx { > extern void vas_return_credit(struct vas_window *window, bool tx); > extern struct vas_window *vas_pswid_to_window(struct vas_instance *vinst, > uint32_t pswid); > +extern void vas_win_paste_addr(struct vas_window *window, u64 *addr, > + int *len); > > static inline int vas_window_pid(struct vas_window *window) > { > -- > 1.8.3.1