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

Nicholas Piggin
2021-05-10T05:19:53Z

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 ?

> 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?

>
> 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.

> .../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
>
>
>