Re: [PATCH v4 3/9] powerpc/vas: Add VAS user space API
On Tue, 2020-03-24 at 14:41 +1100, Michael Ellerman wrote:
> Daniel Axtens writes:
> > Michael Ellerman writes:
> >> Daniel Axtens writes:
> >>> Haren Myneni writes:
> diff --git a/arch/powerpc/platforms/powernv/vas-api.c
> b/arch/powerpc/platforms/powernv/vas-api.c
> new file mode 100644
> index 000..7d049af
> --- /dev/null
> +++ b/arch/powerpc/platforms/powernv/vas-api.c
> @@ -0,0 +1,257 @@
> >> ...
> +
> +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?
> >>
> >> You can't mmap less than a page, a page is PAGE_SIZE bytes.
> >>
> >> So if that checked for 4K explicitly it would prevent mmap on 64K
> >> kernels always, which seems like not what you want?
> >
> > Ah. My bad. Carry on then :)
>
> Well you were just quoting something from Haren, so I think it's over to
> him.
Sorry my mistake.
I should change in documentation. vas_win_paste_addr() always returns 1
page. Restriction should be PAGE_SIZE.
>
> cheers
Re: [PATCH v4 3/9] powerpc/vas: Add VAS user space API
Daniel Axtens writes:
> Michael Ellerman writes:
>> Daniel Axtens writes:
>>> Haren Myneni writes:
diff --git a/arch/powerpc/platforms/powernv/vas-api.c
b/arch/powerpc/platforms/powernv/vas-api.c
new file mode 100644
index 000..7d049af
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/vas-api.c
@@ -0,0 +1,257 @@
>> ...
+
+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?
>>
>> You can't mmap less than a page, a page is PAGE_SIZE bytes.
>>
>> So if that checked for 4K explicitly it would prevent mmap on 64K
>> kernels always, which seems like not what you want?
>
> Ah. My bad. Carry on then :)
Well you were just quoting something from Haren, so I think it's over to
him.
cheers
Re: [PATCH v4 3/9] powerpc/vas: Add VAS user space API
Michael Ellerman writes:
> Daniel Axtens writes:
>> Haren Myneni 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
>>> Signed-off-by: Haren Myneni
>>> ---
>>> 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 000..7d049af
>>> --- /dev/null
>>> +++ b/arch/powerpc/platforms/powernv/vas-api.c
>>> @@ -0,0 +1,257 @@
> ...
>>> +
>>> +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?
>
> You can't mmap less than a page, a page is PAGE_SIZE bytes.
>
> So if that checked for 4K explicitly it would prevent mmap on 64K
> kernels always, which seems like not what you want?
Ah. My bad. Carry on then :)
Regards,
Daniel
>
> cheers
Re: [PATCH v4 3/9] powerpc/vas: Add VAS user space API
Daniel Axtens writes:
> Haren Myneni 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
>> Signed-off-by: Haren Myneni
>> ---
>> 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 000..7d049af
>> --- /dev/null
>> +++ b/arch/powerpc/platforms/powernv/vas-api.c
>> @@ -0,0 +1,257 @@
...
>> +
>> +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?
You can't mmap less than a page, a page is PAGE_SIZE bytes.
So if that checked for 4K explicitly it would prevent mmap on 64K
kernels always, which seems like not what you want?
cheers
Re: [PATCH v4 3/9] powerpc/vas: Add VAS user space API
Haren Myneni 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
> Signed-off-by: Haren Myneni
> ---
> 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 000..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
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#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, );
> + * paste_addr = mmap(NULL, PAGE_SIZE, prot, MAP_SHARED, fd, 0ULL).
> + * vas_copy(, 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
