Michael Ellerman <mpe@xxxxxxxxxxxxxx> writes: > Daniel Axtens <dja@xxxxxxxxxx> writes: >> 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 @@ > ... >>> + >>> +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