Messages in this thread | | | From | Rob Herring <> | Date | Mon, 27 Apr 2020 09:13:06 -0500 | Subject | Re: [PATCH v2,RESEND] misc: new driver sram_uapi for user level SRAM access |
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On Sun, Apr 19, 2020 at 10:06 PM Wang Wenhu <wenhu.wang@vivo.com> wrote: > > A generic User-Kernel interface that allows a misc device created > by it to support file-operations of ioctl and mmap to access SRAM > memory from user level. Different kinds of SRAM alloction and free > APIs could be registered by specific SRAM hardware level driver to > the available list and then be chosen by users to allocate and map > SRAM memory from user level. > > It is extremely helpful for the user space applications that require > high performance memory accesses, such as embedded networking devices > that would process data in user space, and PowerPC e500 is a case. > > Signed-off-by: Wang Wenhu <wenhu.wang@vivo.com> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Christophe Leroy <christophe.leroy@c-s.fr> > Cc: Scott Wood <oss@buserror.net> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: Randy Dunlap <rdunlap@infradead.org> > Cc: linuxppc-dev@lists.ozlabs.org > --- > Changes since v1: addressed comments from Arnd > * Changed the ioctl cmd definitions using _IO micros > * Export interfaces for HW-SRAM drivers to register apis to available list > * Modified allocation alignment to PAGE_SIZE > * Use phys_addr_t as type of SRAM resource size and offset > * Support compat_ioctl > * Misc device name:sram > > Note: From this on, the SRAM_UAPI driver is independent to any hardware > drivers, so I would only commit the patch itself as v2, while the v1 of > it was wrapped together with patches for Freescale L2-Cache-SRAM device. > Then after, I'd create patches for Freescale L2-Cache-SRAM device as > another series.
There's work to add SRAM support to dma-buf heaps[1]. Take a look and see if that works for you.
Rob
[1] https://lore.kernel.org/lkml/20200424222740.16259-1-afd@ti.com/
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