Re: [PATCH V3 02/16] powerpc/vas: Move VAS API to common book3s platform

Haren Myneni
2021-05-10T17:13:18Z

On Mon, 2021-05-10 at 15:19 +1000, Nicholas Piggin wrote:
> Excerpts from Haren Myneni's message of April 18, 2021 7:02 am:
> > Using the same /dev/crypto/nx-gzip interface for both powerNV and
> > pseries.
>
> The pseries NX driver will use the powernv VAS API ?
Yes, both powerNV and pseries drivers use same VAS API.

>
> > So this patch creates platforms/book3s/ and moves VAS API
> > to that directory. The actual functionality is not changed.
> >
> > Common interface functions such as open, window open ioctl, mmap
> > and close are moved to arch/powerpc/platforms/book3s/vas-api.c
> > Added hooks to call platform specific code, but the underline
> > powerNV code in these functions is not changed.
>
> Even so, could you do one patch that just moves, and another that
> adds the ops struct?

Sure, I will create separate patches.

>
> > Signed-off-by: Haren Myneni <haren@linux.ibm.com>
> > ---
> > arch/powerpc/include/asm/vas.h | 22 ++++++-
> > arch/powerpc/platforms/Kconfig | 1 +
> > arch/powerpc/platforms/Makefile | 1 +
> > arch/powerpc/platforms/book3s/Kconfig | 15 +++++
> > arch/powerpc/platforms/book3s/Makefile | 2 +
>
> The usual place for these would be arch/powerpc/sysdev/vas. E.g., see
> arch/powerpc/sysdev/xive.

It was recommended to create book3s and move common vas-api code.

>
> > .../platforms/{powernv => book3s}/vas-api.c | 64 ++++++++++-----
> > ---
> > arch/powerpc/platforms/powernv/Kconfig | 14 ----
> > arch/powerpc/platforms/powernv/Makefile | 2 +-
> > arch/powerpc/platforms/powernv/vas-window.c | 66
> > +++++++++++++++++++
> > 9 files changed, 143 insertions(+), 44 deletions(-)
> > create mode 100644 arch/powerpc/platforms/book3s/Kconfig
> > create mode 100644 arch/powerpc/platforms/book3s/Makefile
> > rename arch/powerpc/platforms/{powernv => book3s}/vas-api.c (83%)
> >
> > diff --git a/arch/powerpc/include/asm/vas.h
> > b/arch/powerpc/include/asm/vas.h
> > index 41f73fae7ab8..6bbade60d8f4 100644
> > --- a/arch/powerpc/include/asm/vas.h
> > +++ b/arch/powerpc/include/asm/vas.h
> > @@ -5,6 +5,8 @@
> >
> > #ifndef _ASM_POWERPC_VAS_H
> > #define _ASM_POWERPC_VAS_H
> > +#include <uapi/asm/vas-api.h>
> > +
> >
> > struct vas_window;
> >
> > @@ -48,6 +50,16 @@ enum vas_cop_type {
> > VAS_COP_TYPE_MAX,
> > };
> >
> > +/*
> > + * User space window operations used for powernv and powerVM
> > + */
> > +struct vas_user_win_ops {
> > + struct vas_window * (*open_win)(struct vas_tx_win_open_attr *,
> > + enum vas_cop_type);
> > + u64 (*paste_addr)(void *);
> > + int (*close_win)(void *);
> > +};
> > +
> > /*
> > * Receive window attributes specified by the (in-kernel) owner of
> > window.
> > */
> > @@ -161,6 +173,9 @@ int vas_copy_crb(void *crb, int offset);
> > * assumed to be true for NX windows.
> > */
> > int vas_paste_crb(struct vas_window *win, int offset, bool re);
> > +int vas_register_api_powernv(struct module *mod, enum vas_cop_type
> > cop_type,
> > + const char *name);
> > +void vas_unregister_api_powernv(void);
> >
> > /*
> > * Register / unregister coprocessor type to VAS API which will be
> > exported
> > @@ -170,8 +185,9 @@ 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_api_powernv(struct module *mod, enum vas_cop_type
> > cop_type,
> > - const char *name);
> > -void vas_unregister_api_powernv(void);
> > +int vas_register_coproc_api(struct module *mod, enum vas_cop_type
> > cop_type,
> > + const char *name,
> > + struct vas_user_win_ops *vops);
> > +void vas_unregister_coproc_api(void);
> >
> > #endif /* __ASM_POWERPC_VAS_H */
> > diff --git a/arch/powerpc/platforms/Kconfig
> > b/arch/powerpc/platforms/Kconfig
> > index 7a5e8f4541e3..594544a65b02 100644
> > --- a/arch/powerpc/platforms/Kconfig
> > +++ b/arch/powerpc/platforms/Kconfig
> > @@ -20,6 +20,7 @@ source
> > "arch/powerpc/platforms/embedded6xx/Kconfig"
> > source "arch/powerpc/platforms/44x/Kconfig"
> > source "arch/powerpc/platforms/40x/Kconfig"
> > source "arch/powerpc/platforms/amigaone/Kconfig"
> > +source "arch/powerpc/platforms/book3s/Kconfig"
> >
> > config KVM_GUEST
> > bool "KVM Guest support"
> > diff --git a/arch/powerpc/platforms/Makefile
> > b/arch/powerpc/platforms/Makefile
> > index 143d4417f6cc..0e75d7df387b 100644
> > --- a/arch/powerpc/platforms/Makefile
> > +++ b/arch/powerpc/platforms/Makefile
> > @@ -22,3 +22,4 @@ obj-$(CONFIG_PPC_CELL) += cell/
> > obj-$(CONFIG_PPC_PS3) += ps3/
> > obj-$(CONFIG_EMBEDDED6xx) += embedded6xx/
> > obj-$(CONFIG_AMIGAONE) += amigaone/
> > +obj-$(CONFIG_PPC_BOOK3S) += book3s/
> > diff --git a/arch/powerpc/platforms/book3s/Kconfig
> > b/arch/powerpc/platforms/book3s/Kconfig
> > new file mode 100644
> > index 000000000000..51e14db83a79
> > --- /dev/null
> > +++ b/arch/powerpc/platforms/book3s/Kconfig
> > @@ -0,0 +1,15 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +config PPC_VAS
> > + bool "IBM Virtual Accelerator Switchboard (VAS)"
> > + depends on PPC_POWERNV && PPC_64K_PAGES
> > + default y
> > + help
> > + This enables support for IBM Virtual Accelerator Switchboard
> > (VAS).
> > +
> > + VAS allows accelerators in co-processors like NX-GZIP and NX-
> > 842
> > + to be accessible to kernel subsystems and user processes.
> > + VAS adapters are found in POWER9 and later based systems.
> > + The user mode NX-GZIP support is added on P9 for powerNV and
> > on
> > + P10 for powerVM.
> > +
> > + If unsure, say "N".
> > diff --git a/arch/powerpc/platforms/book3s/Makefile
> > b/arch/powerpc/platforms/book3s/Makefile
> > new file mode 100644
> > index 000000000000..e790f1910f61
> > --- /dev/null
> > +++ b/arch/powerpc/platforms/book3s/Makefile
> > @@ -0,0 +1,2 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +obj-$(CONFIG_PPC_VAS) += vas-api.o
> > diff --git a/arch/powerpc/platforms/powernv/vas-api.c
> > b/arch/powerpc/platforms/book3s/vas-api.c
> > similarity index 83%
> > rename from arch/powerpc/platforms/powernv/vas-api.c
> > rename to arch/powerpc/platforms/book3s/vas-api.c
> > index 72d8ce39e56c..05d7b99acf41 100644
> > --- a/arch/powerpc/platforms/powernv/vas-api.c
> > +++ b/arch/powerpc/platforms/book3s/vas-api.c
> > @@ -4,15 +4,20 @@
> > * Copyright (C) 2019 Haren Myneni, IBM Corp
> > */
> >
> > +#include <linux/module.h>
> > #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 <linux/kthread.h>
> > +#include <linux/sched/signal.h>
> > +#include <linux/sched/mm.h>
> > +#include <linux/mmu_context.h>
> > #include <asm/vas.h>
> > +#include <asm/icswx.h>
> > #include <uapi/asm/vas-api.h>
> > -#include "vas.h"
> >
> > /*
> > * The driver creates the device node that can be used as follows:
> > @@ -42,6 +47,7 @@ static struct coproc_dev {
> > dev_t devt;
> > struct class *class;
> > enum vas_cop_type cop_type;
> > + struct vas_user_win_ops *vops;
> > } coproc_device;
> >
> > struct coproc_instance {
> > @@ -72,11 +78,10 @@ static int coproc_open(struct inode *inode,
> > struct file *fp)
> > 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;
> > + int rc;
> >
> > cp_inst = fp->private_data;
> >
> > @@ -93,27 +98,20 @@ static int coproc_ioc_tx_win_open(struct file
> > *fp, unsigned long arg)
> > }
> >
> > if (uattr.version != 1) {
> > - pr_err("Invalid version\n");
> > + pr_err("Invalid window open API version\n");
> > return -EINVAL;
> > }
> >
> > - vasid = uattr.vas_id;
> > -
> > - vas_init_tx_win_attr(&txattr, cp_inst->coproc->cop_type);
> > -
> > - 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));
> > + if (!cp_inst->coproc->vops && !cp_inst->coproc->vops->open_win)
> > {
> > + pr_err("VAS API is not registered\n");
> > + return -EACCES;
> > + }
> >
> > - txwin = vas_tx_win_open(vasid, cp_inst->coproc->cop_type,
> > &txattr);
> > + txwin = cp_inst->coproc->vops->open_win(&uattr,
> > + cp_inst->coproc->cop_type);
> > if (IS_ERR(txwin)) {
> > - pr_err("%s() vas_tx_win_open() failed, %ld\n",
> > __func__,
> > - PTR_ERR(txwin));
> > + pr_err("%s() VAS window open failed, %ld\n", __func__,
> > + PTR_ERR(txwin));
> > return PTR_ERR(txwin);
> > }
> >
> > @@ -125,9 +123,14 @@ static int coproc_ioc_tx_win_open(struct file
> > *fp, unsigned long arg)
> > static int coproc_release(struct inode *inode, struct file *fp)
> > {
> > struct coproc_instance *cp_inst = fp->private_data;
> > + int rc = 0;
> >
> > if (cp_inst->txwin) {
> > - vas_win_close(cp_inst->txwin);
> > + if (cp_inst->coproc->vops && cp_inst->coproc->vops-
> > >close_win) {
> > + rc = cp_inst->coproc->vops->close_win(cp_inst-
> > >txwin);
> > + if (rc)
> > + return rc;
> > + }
> > cp_inst->txwin = NULL;
> > }
> >
> > @@ -168,7 +171,17 @@ static int coproc_mmap(struct file *fp, struct
> > vm_area_struct *vma)
> > return -EINVAL;
> > }
> >
> > - vas_win_paste_addr(txwin, &paste_addr, NULL);
> > + if (!cp_inst->coproc->vops && !cp_inst->coproc->vops-
> > >paste_addr) {
> > + pr_err("%s(): VAS API is not registered\n", __func__);
> > + return -EACCES;
> > + }
> > +
> > + paste_addr = cp_inst->coproc->vops->paste_addr(txwin);
> > + if (!paste_addr) {
> > + pr_err("%s(): Window paste address failed\n",
> > __func__);
> > + return -EINVAL;
> > + }
> > +
> > pfn = paste_addr >> PAGE_SHIFT;
> >
> > /* flags, page_prot from cxl_mmap(), except we want cachable */
> > @@ -207,8 +220,8 @@ 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_api_powernv(struct module *mod, enum vas_cop_type
> > cop_type,
> > - const char *name)
> > +int vas_register_coproc_api(struct module *mod, enum vas_cop_type
> > cop_type,
> > + const char *name, struct vas_user_win_ops
> > *vops)
> > {
> > int rc = -EINVAL;
> > dev_t devno;
> > @@ -230,6 +243,7 @@ int vas_register_api_powernv(struct module
> > *mod, enum vas_cop_type cop_type,
> > }
> > coproc_device.class->devnode = coproc_devnode;
> > coproc_device.cop_type = cop_type;
> > + coproc_device.vops = vops;
> >
> > coproc_fops.owner = mod;
> > cdev_init(&coproc_device.cdev, &coproc_fops);
> > @@ -262,9 +276,8 @@ int vas_register_api_powernv(struct module
> > *mod, enum vas_cop_type cop_type,
> > unregister_chrdev_region(coproc_device.devt, 1);
> > return rc;
> > }
> > -EXPORT_SYMBOL_GPL(vas_register_api_powernv);
> >
> > -void vas_unregister_api_powernv(void)
> > +void vas_unregister_coproc_api(void)
> > {
> > dev_t devno;
> >
> > @@ -275,4 +288,3 @@ void vas_unregister_api_powernv(void)
> > class_destroy(coproc_device.class);
> > unregister_chrdev_region(coproc_device.devt, 1);
> > }
> > -EXPORT_SYMBOL_GPL(vas_unregister_api_powernv);
> > diff --git a/arch/powerpc/platforms/powernv/Kconfig
> > b/arch/powerpc/platforms/powernv/Kconfig
> > index 619b093a0657..043eefbbdd28 100644
> > --- a/arch/powerpc/platforms/powernv/Kconfig
> > +++ b/arch/powerpc/platforms/powernv/Kconfig
> > @@ -33,20 +33,6 @@ config PPC_MEMTRACE
> > Enabling this option allows for runtime allocation of memory
> > (RAM)
> > for hardware tracing.
> >
> > -config PPC_VAS
> > - bool "IBM Virtual Accelerator Switchboard (VAS)"
> > - depends on PPC_POWERNV && PPC_64K_PAGES
> > - default y
> > - help
> > - This enables support for IBM Virtual Accelerator Switchboard
> > (VAS).
> > -
> > - VAS allows accelerators in co-processors like NX-GZIP and NX-
> > 842
> > - to be accessible to kernel subsystems and user processes.
> > -
> > - VAS adapters are found in POWER9 based systems.
> > -
> > - If unsure, say N.
> > -
> > config SCOM_DEBUGFS
> > bool "Expose SCOM controllers via debugfs"
> > depends on DEBUG_FS
> > diff --git a/arch/powerpc/platforms/powernv/Makefile
> > b/arch/powerpc/platforms/powernv/Makefile
> > index 2eb6ae150d1f..c747a1f1d25b 100644
> > --- a/arch/powerpc/platforms/powernv/Makefile
> > +++ b/arch/powerpc/platforms/powernv/Makefile
> > @@ -18,7 +18,7 @@ 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-$(CONFIG_PPC_VAS) += vas.o vas-window.o vas-debug.o vas-
> > fault.o vas-api.o
> > +obj-$(CONFIG_PPC_VAS) += vas.o vas-window.o vas-debug.o vas-
> > fault.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-window.c
> > b/arch/powerpc/platforms/powernv/vas-window.c
> > index 5f5fe63a3d1c..b973dd574b47 100644
> > --- a/arch/powerpc/platforms/powernv/vas-window.c
> > +++ b/arch/powerpc/platforms/powernv/vas-window.c
> > @@ -16,6 +16,8 @@
> > #include <linux/mmu_context.h>
> > #include <asm/switch_to.h>
> > #include <asm/ppc-opcode.h>
> > +#include <asm/vas.h>
> > +#include <uapi/asm/vas-api.h>
> > #include "vas.h"
> > #include "copy-paste.h"
> >
> > @@ -1441,3 +1443,67 @@ struct vas_window
> > *vas_pswid_to_window(struct vas_instance *vinst,
> >
> > return window;
> > }
> > +
> > +static struct vas_window *vas_user_win_open(struct
> > vas_tx_win_open_attr *uattr,
> > + enum vas_cop_type cop_type)
> > +{
> > + struct vas_tx_win_attr txattr = {};
> > +
> > + vas_init_tx_win_attr(&txattr, cop_type);
> > +
> > + 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));
> > +
> > + return vas_tx_win_open(uattr->vas_id, cop_type, &txattr);
> > +}
> > +
> > +static u64 vas_user_win_paste_addr(void *addr)
> > +{
> > + u64 paste_addr;
> > +
> > + vas_win_paste_addr((struct vas_window *)addr, &paste_addr,
> > NULL);
> > +
> > + return paste_addr;
> > +}
> > +
> > +static int vas_user_win_close(void *addr)
> > +{
> > + struct vas_window *txwin = addr;
> > +
> > + vas_win_close(txwin);
> > +
> > + return 0;
> > +}
> > +
> > +static struct vas_user_win_ops vops = {
> > + .open_win = vas_user_win_open,
> > + .paste_addr = vas_user_win_paste_addr,
> > + .close_win = vas_user_win_close,
> > +};
> > +
> > +/*
> > + * Supporting only nx-gzip coprocessor type now, but this API code
> > + * extended to other coprocessor types later.
> > + */
> > +int vas_register_api_powernv(struct module *mod, enum vas_cop_type
> > cop_type,
> > + const char *name)
> > +{
> > + int rc;
> > +
> > + rc = vas_register_coproc_api(mod, cop_type, name, &vops);
> > +
> > + return rc;
> > +}
> > +EXPORT_SYMBOL_GPL(vas_register_api_powernv);
> > +
> > +void vas_unregister_api_powernv(void)
> > +{
> > + vas_unregister_coproc_api();
> > +}
> > +EXPORT_SYMBOL_GPL(vas_unregister_api_powernv);
> > --
> > 2.18.2
> >
> >
> >