Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-07 Thread Vincent Chen
On Wed, Nov 07, 2018 at 07:45:52AM +0800, Palmer Dabbelt wrote: > On Sun, 04 Nov 2018 22:58:07 PST (-0800), vince...@andestech.com wrote: > > On Fri, Nov 02, 2018 at 01:48:57AM +0800, Karsten Merker wrote: > >> On Wed, Oct 31, 2018 at 10:27:05AM -0700, Palmer Dabbelt wrote: > >> > On Wed, 31 Oct

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-07 Thread Vincent Chen
On Wed, Nov 07, 2018 at 07:45:52AM +0800, Palmer Dabbelt wrote: > On Sun, 04 Nov 2018 22:58:07 PST (-0800), vince...@andestech.com wrote: > > On Fri, Nov 02, 2018 at 01:48:57AM +0800, Karsten Merker wrote: > >> On Wed, Oct 31, 2018 at 10:27:05AM -0700, Palmer Dabbelt wrote: > >> > On Wed, 31 Oct

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-07 Thread Arnd Bergmann
On 11/7/18, Palmer Dabbelt wrote: > On Mon, 05 Nov 2018 00:52:52 PST (-0800), Arnd Bergmann wrote: >> On 11/5/18, Christoph Hellwig wrote: >>> On Mon, Nov 05, 2018 at 02:58:07PM +0800, Vincent Chen wrote: Many thanks for kinds of comments. I quickly synthesize the comments and

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-07 Thread Arnd Bergmann
On 11/7/18, Palmer Dabbelt wrote: > On Mon, 05 Nov 2018 00:52:52 PST (-0800), Arnd Bergmann wrote: >> On 11/5/18, Christoph Hellwig wrote: >>> On Mon, Nov 05, 2018 at 02:58:07PM +0800, Vincent Chen wrote: Many thanks for kinds of comments. I quickly synthesize the comments and

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-06 Thread Palmer Dabbelt
On Mon, 05 Nov 2018 00:52:52 PST (-0800), Arnd Bergmann wrote: On 11/5/18, Christoph Hellwig wrote: On Mon, Nov 05, 2018 at 02:58:07PM +0800, Vincent Chen wrote: Many thanks for kinds of comments. I quickly synthesize the comments and list them as below. 1. The kernel image shall include all

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-06 Thread Palmer Dabbelt
On Sun, 04 Nov 2018 22:58:07 PST (-0800), vince...@andestech.com wrote: On Fri, Nov 02, 2018 at 01:48:57AM +0800, Karsten Merker wrote: On Wed, Oct 31, 2018 at 10:27:05AM -0700, Palmer Dabbelt wrote: > On Wed, 31 Oct 2018 04:16:10 PDT (-0700), a...@brainfault.org wrote: > > On Wed, Oct 31, 2018

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-06 Thread Palmer Dabbelt
On Mon, 05 Nov 2018 00:52:52 PST (-0800), Arnd Bergmann wrote: On 11/5/18, Christoph Hellwig wrote: On Mon, Nov 05, 2018 at 02:58:07PM +0800, Vincent Chen wrote: Many thanks for kinds of comments. I quickly synthesize the comments and list them as below. 1. The kernel image shall include all

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-06 Thread Palmer Dabbelt
On Sun, 04 Nov 2018 22:58:07 PST (-0800), vince...@andestech.com wrote: On Fri, Nov 02, 2018 at 01:48:57AM +0800, Karsten Merker wrote: On Wed, Oct 31, 2018 at 10:27:05AM -0700, Palmer Dabbelt wrote: > On Wed, 31 Oct 2018 04:16:10 PDT (-0700), a...@brainfault.org wrote: > > On Wed, Oct 31, 2018

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Christoph Hellwig
On Mon, Nov 05, 2018 at 02:51:33PM +0100, Arnd Bergmann wrote: > With the stricter policy you suggest, we'd loose the ability to support > some extensions that might be common: > > - an extension for user space that adds new registers that must be > saved and restored on a task switch, e.g.

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Christoph Hellwig
On Mon, Nov 05, 2018 at 02:51:33PM +0100, Arnd Bergmann wrote: > With the stricter policy you suggest, we'd loose the ability to support > some extensions that might be common: > > - an extension for user space that adds new registers that must be > saved and restored on a task switch, e.g.

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Christoph Hellwig
On Mon, Nov 05, 2018 at 09:39:29PM +0200, Nick Kossifidis wrote: > a) By directly modifying your custom CSRs, it means that we will need > compiler support in order to compile a kernel with your code in it. This > will break CI systems and will introduce various issues on testing and > reviewing

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Christoph Hellwig
On Mon, Nov 05, 2018 at 09:39:29PM +0200, Nick Kossifidis wrote: > a) By directly modifying your custom CSRs, it means that we will need > compiler support in order to compile a kernel with your code in it. This > will break CI systems and will introduce various issues on testing and > reviewing

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Nick Kossifidis
Hello Vincent, Στις 2018-10-31 12:35, Vincent Chen έγραψε: RISC-V permits each vendor to develop respective extension ISA based on RISC-V standard ISA. This means that these vendor-specific features may be compatible to their compiler and CPU. Therefore, each vendor may be considered a

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Nick Kossifidis
Hello Vincent, Στις 2018-10-31 12:35, Vincent Chen έγραψε: RISC-V permits each vendor to develop respective extension ISA based on RISC-V standard ISA. This means that these vendor-specific features may be compatible to their compiler and CPU. Therefore, each vendor may be considered a

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Arnd Bergmann
On 11/5/18, Christoph Hellwig wrote: > On Mon, Nov 05, 2018 at 09:52:52AM +0100, Arnd Bergmann wrote: >> > I fundamentally disagree with this… and think it should be the >> > contrary. >> > >> > 1. The kernel shall support no vendor specific instructions whatsoever, >> > period. >> >> I think

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Arnd Bergmann
On 11/5/18, Christoph Hellwig wrote: > On Mon, Nov 05, 2018 at 09:52:52AM +0100, Arnd Bergmann wrote: >> > I fundamentally disagree with this… and think it should be the >> > contrary. >> > >> > 1. The kernel shall support no vendor specific instructions whatsoever, >> > period. >> >> I think

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Christoph Hellwig
On Mon, Nov 05, 2018 at 09:52:52AM +0100, Arnd Bergmann wrote: > > I fundamentally disagree with this… and think it should be the contrary. > > > > 1. The kernel shall support no vendor specific instructions whatsoever, > > period. > > I think what was meant above is > > 1. If a vendor extension

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Christoph Hellwig
On Mon, Nov 05, 2018 at 09:52:52AM +0100, Arnd Bergmann wrote: > > I fundamentally disagree with this… and think it should be the contrary. > > > > 1. The kernel shall support no vendor specific instructions whatsoever, > > period. > > I think what was meant above is > > 1. If a vendor extension

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Arnd Bergmann
On 11/5/18, Christoph Hellwig wrote: > On Mon, Nov 05, 2018 at 02:58:07PM +0800, Vincent Chen wrote: >> Many thanks for kinds of comments. I quickly synthesize the comments and >> list them as below. >> 1. The kernel image shall include all vendor-specific code. > > I fundamentally disagree with

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-05 Thread Arnd Bergmann
On 11/5/18, Christoph Hellwig wrote: > On Mon, Nov 05, 2018 at 02:58:07PM +0800, Vincent Chen wrote: >> Many thanks for kinds of comments. I quickly synthesize the comments and >> list them as below. >> 1. The kernel image shall include all vendor-specific code. > > I fundamentally disagree with

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-04 Thread Christoph Hellwig
On Mon, Nov 05, 2018 at 02:58:07PM +0800, Vincent Chen wrote: > Many thanks for kinds of comments. I quickly synthesize the comments and > list them as below. > 1. The kernel image shall include all vendor-specific code. I fundamentally disagree with this… and think it should be the contrary. 1.

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-04 Thread Christoph Hellwig
On Mon, Nov 05, 2018 at 02:58:07PM +0800, Vincent Chen wrote: > Many thanks for kinds of comments. I quickly synthesize the comments and > list them as below. > 1. The kernel image shall include all vendor-specific code. I fundamentally disagree with this… and think it should be the contrary. 1.

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-04 Thread Vincent Chen
On Fri, Nov 02, 2018 at 01:48:57AM +0800, Karsten Merker wrote: > On Wed, Oct 31, 2018 at 10:27:05AM -0700, Palmer Dabbelt wrote: > > On Wed, 31 Oct 2018 04:16:10 PDT (-0700), a...@brainfault.org wrote: > > > On Wed, Oct 31, 2018 at 4:06 PM Vincent Chen > > > wrote: > > > > > > > > RISC-V

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-04 Thread Vincent Chen
On Fri, Nov 02, 2018 at 01:48:57AM +0800, Karsten Merker wrote: > On Wed, Oct 31, 2018 at 10:27:05AM -0700, Palmer Dabbelt wrote: > > On Wed, 31 Oct 2018 04:16:10 PDT (-0700), a...@brainfault.org wrote: > > > On Wed, Oct 31, 2018 at 4:06 PM Vincent Chen > > > wrote: > > > > > > > > RISC-V

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-01 Thread Alan Kao
On Thu, Nov 01, 2018 at 10:50:04AM -0700, Palmer Dabbelt wrote: > On Wed, 31 Oct 2018 17:55:42 PDT (-0700), alan...@andestech.com wrote: > >On Wed, Oct 31, 2018 at 07:17:45AM -0700, Christoph Hellwig wrote: > >>On Wed, Oct 31, 2018 at 04:46:10PM +0530, Anup Patel wrote: > >>> I agree that we need

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-01 Thread Alan Kao
On Thu, Nov 01, 2018 at 10:50:04AM -0700, Palmer Dabbelt wrote: > On Wed, 31 Oct 2018 17:55:42 PDT (-0700), alan...@andestech.com wrote: > >On Wed, Oct 31, 2018 at 07:17:45AM -0700, Christoph Hellwig wrote: > >>On Wed, Oct 31, 2018 at 04:46:10PM +0530, Anup Patel wrote: > >>> I agree that we need

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-01 Thread Palmer Dabbelt
On Wed, 31 Oct 2018 17:55:42 PDT (-0700), alan...@andestech.com wrote: On Wed, Oct 31, 2018 at 07:17:45AM -0700, Christoph Hellwig wrote: On Wed, Oct 31, 2018 at 04:46:10PM +0530, Anup Patel wrote: > I agree that we need a place for vendor-specific ISA extensions and > having vendor-specific

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-11-01 Thread Palmer Dabbelt
On Wed, 31 Oct 2018 17:55:42 PDT (-0700), alan...@andestech.com wrote: On Wed, Oct 31, 2018 at 07:17:45AM -0700, Christoph Hellwig wrote: On Wed, Oct 31, 2018 at 04:46:10PM +0530, Anup Patel wrote: > I agree that we need a place for vendor-specific ISA extensions and > having vendor-specific

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Alan Kao
On Wed, Oct 31, 2018 at 07:17:45AM -0700, Christoph Hellwig wrote: > On Wed, Oct 31, 2018 at 04:46:10PM +0530, Anup Patel wrote: > > I agree that we need a place for vendor-specific ISA extensions and > > having vendor-specific directories is also good. > > The only sensible answer is that we

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Alan Kao
On Wed, Oct 31, 2018 at 07:17:45AM -0700, Christoph Hellwig wrote: > On Wed, Oct 31, 2018 at 04:46:10PM +0530, Anup Patel wrote: > > I agree that we need a place for vendor-specific ISA extensions and > > having vendor-specific directories is also good. > > The only sensible answer is that we

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Olof Johansson
On Wed, Oct 31, 2018 at 10:27 AM Palmer Dabbelt wrote: > > On Wed, 31 Oct 2018 04:16:10 PDT (-0700), a...@brainfault.org wrote: > > On Wed, Oct 31, 2018 at 4:06 PM Vincent Chen wrote: > >> > >> RISC-V permits each vendor to develop respective extension ISA based > >> on RISC-V standard ISA.

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Olof Johansson
On Wed, Oct 31, 2018 at 10:27 AM Palmer Dabbelt wrote: > > On Wed, 31 Oct 2018 04:16:10 PDT (-0700), a...@brainfault.org wrote: > > On Wed, Oct 31, 2018 at 4:06 PM Vincent Chen wrote: > >> > >> RISC-V permits each vendor to develop respective extension ISA based > >> on RISC-V standard ISA.

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Palmer Dabbelt
On Wed, 31 Oct 2018 04:16:10 PDT (-0700), a...@brainfault.org wrote: On Wed, Oct 31, 2018 at 4:06 PM Vincent Chen wrote: RISC-V permits each vendor to develop respective extension ISA based on RISC-V standard ISA. This means that these vendor-specific features may be compatible to their

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Palmer Dabbelt
On Wed, 31 Oct 2018 04:16:10 PDT (-0700), a...@brainfault.org wrote: On Wed, Oct 31, 2018 at 4:06 PM Vincent Chen wrote: RISC-V permits each vendor to develop respective extension ISA based on RISC-V standard ISA. This means that these vendor-specific features may be compatible to their

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Christoph Hellwig
On Wed, Oct 31, 2018 at 04:46:10PM +0530, Anup Patel wrote: > I agree that we need a place for vendor-specific ISA extensions and > having vendor-specific directories is also good. The only sensible answer is that we should not allow vendor specific extensions in the kernel at all. We need to

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Christoph Hellwig
On Wed, Oct 31, 2018 at 04:46:10PM +0530, Anup Patel wrote: > I agree that we need a place for vendor-specific ISA extensions and > having vendor-specific directories is also good. The only sensible answer is that we should not allow vendor specific extensions in the kernel at all. We need to

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Arnd Bergmann
On 10/31/18, Anup Patel wrote: > On Wed, Oct 31, 2018 at 4:06 PM Vincent Chen > wrote: >> >> RISC-V permits each vendor to develop respective extension ISA based >> on RISC-V standard ISA. This means that these vendor-specific features >> may be compatible to their compiler and CPU. Therefore,

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Arnd Bergmann
On 10/31/18, Anup Patel wrote: > On Wed, Oct 31, 2018 at 4:06 PM Vincent Chen > wrote: >> >> RISC-V permits each vendor to develop respective extension ISA based >> on RISC-V standard ISA. This means that these vendor-specific features >> may be compatible to their compiler and CPU. Therefore,

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Anup Patel
On Wed, Oct 31, 2018 at 4:06 PM Vincent Chen wrote: > > RISC-V permits each vendor to develop respective extension ISA based > on RISC-V standard ISA. This means that these vendor-specific features > may be compatible to their compiler and CPU. Therefore, each vendor may > be considered a

Re: [RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Anup Patel
On Wed, Oct 31, 2018 at 4:06 PM Vincent Chen wrote: > > RISC-V permits each vendor to develop respective extension ISA based > on RISC-V standard ISA. This means that these vendor-specific features > may be compatible to their compiler and CPU. Therefore, each vendor may > be considered a

[RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Vincent Chen
RISC-V permits each vendor to develop respective extension ISA based on RISC-V standard ISA. This means that these vendor-specific features may be compatible to their compiler and CPU. Therefore, each vendor may be considered a sub-architecture of RISC-V. Currently, vendors do not have the

[RFC 0/2] RISC-V: A proposal to add vendor-specific code

2018-10-31 Thread Vincent Chen
RISC-V permits each vendor to develop respective extension ISA based on RISC-V standard ISA. This means that these vendor-specific features may be compatible to their compiler and CPU. Therefore, each vendor may be considered a sub-architecture of RISC-V. Currently, vendors do not have the