regarding QNX structures

QNX Newsgroups (Archives) qnx.ddk
1

Hello,
I need help in replacing Linux sk_buff structure (declared
inlinux/sk_buff.h) to equivalent structure. does anybody have knowledge of
what structure and functions should I use for the same. I need to allocate
the buffer in ISR. linux provides dev_alloc_skb (uses alloc_skb with
GFP_ATOMIC flag) that makes it safe to use in ISR for memory allocation as
it is atomic and does not cause calling process to sleep. I want to know the
equivalents in QNX

Thanks in advance

regards
Moreshwar

2

There’s isn’t any direct equivalent. I think even in Linux the use of
GFP_ATOMIC is not encouraged. Basically, doing any kind of memory
allocations inside ISR is a poor design. You’re going to have to change that
design so that memory is allocated upfront.

– igor

“Moreshwar Salpekar” <moreshwars@hotmail.com> wrote in message
news:chpdun$noc$1@inn.qnx.com…

Hello,
I need help in replacing Linux sk_buff structure (declared
inlinux/sk_buff.h) to equivalent structure. does anybody have knowledge of
what structure and functions should I use for the same. I need to allocate
the buffer in ISR. linux provides dev_alloc_skb (uses alloc_skb with
GFP_ATOMIC flag) that makes it safe to use in ISR for memory allocation as
it is atomic and does not cause calling process to sleep. I want to know
the
equivalents in QNX

Thanks in advance

regards
Moreshwar
\

3

Thanks for the clarification but then how do I port the Linux code? I need
to port Linux code to QNX. Linux uses sk_buff structure and uses
dev_alloc_skb for allocation of memory. Seems I need to replace sk_buff
structure with nkpt_t, io_net_self_t and a device structure… Would that be
right? Memory buffer was being allocated for sk_buff through dev_alloc_skb
and I need to change the code I need to find replacement for this function
and the structure

Regards
Moreshwar “Igor Kovalenko” <kovalenko@comcast.net> wrote in message
news:chrn1s$hsm$1@inn.qnx.com…

There’s isn’t any direct equivalent. I think even in Linux the use of
GFP_ATOMIC is not encouraged. Basically, doing any kind of memory
allocations inside ISR is a poor design. You’re going to have to change
that
design so that memory is allocated upfront.

– igor

“Moreshwar Salpekar” <> moreshwars@hotmail.com> > wrote in message
news:chpdun$noc$> 1@inn.qnx.com> …
Hello,
I need help in replacing Linux sk_buff structure (declared
inlinux/sk_buff.h) to equivalent structure. does anybody have knowledge
of
what structure and functions should I use for the same. I need to
allocate
the buffer in ISR. linux provides dev_alloc_skb (uses alloc_skb with
GFP_ATOMIC flag) that makes it safe to use in ISR for memory allocation
as
it is atomic and does not cause calling process to sleep. I want to know
the
equivalents in QNX

Thanks in advance

regards
Moreshwar


\

4

First of all, a device driver in QNX is a user program.
You’re talking about memory allocation mechanisms used inside
the Linux kernel.

What you probably need is the source for some QNX Ethernet
device driver to look at.

John Nagle
Team Overbot

Moreshwar Salpekar wrote:

Thanks for the clarification but then how do I port the Linux code? I need
to port Linux code to QNX. Linux uses sk_buff structure and uses
dev_alloc_skb for allocation of memory. Seems I need to replace sk_buff
structure with nkpt_t, io_net_self_t and a device structure… Would that be
right? Memory buffer was being allocated for sk_buff through dev_alloc_skb
and I need to change the code I need to find replacement for this function
and the structure

Regards
Moreshwar “Igor Kovalenko” <> kovalenko@comcast.net> > wrote in message
news:chrn1s$hsm$> 1@inn.qnx.com> …

There’s isn’t any direct equivalent. I think even in Linux the use of
GFP_ATOMIC is not encouraged. Basically, doing any kind of memory
allocations inside ISR is a poor design. You’re going to have to change

that

design so that memory is allocated upfront.

– igor

“Moreshwar Salpekar” <> moreshwars@hotmail.com> > wrote in message
news:chpdun$noc$> 1@inn.qnx.com> …

Hello,
I need help in replacing Linux sk_buff structure (declared
inlinux/sk_buff.h) to equivalent structure. does anybody have knowledge

of

what structure and functions should I use for the same. I need to

allocate

the buffer in ISR. linux provides dev_alloc_skb (uses alloc_skb with
GFP_ATOMIC flag) that makes it safe to use in ISR for memory allocation

as

it is atomic and does not cause calling process to sleep. I want to know

the

equivalents in QNX

Thanks in advance

regards
Moreshwar




\

5

Yes I need it, I am having problems in porting Linux kernel source code and
this is my first driver for QNX so unsure. I have managed to detect the card
and replaced the card detection mechanism in my source code. I have replaced
everything except the sk_buff structure and its associated functions. I am
unable to decide how to go about it.
If I have not mentioned it earlier,I am porting HDLC driver from Linux to
QNX.
If you could let me know whether I am proceeding I correct direction, I
would be grateful
“John Nagle” <nagle@downside.com> wrote in message
news:ci3814$61f$1@inn.qnx.com…

First of all, a device driver in QNX is a user program.
You’re talking about memory allocation mechanisms used inside
the Linux kernel.

What you probably need is the source for some QNX Ethernet
device driver to look at.

John Nagle
Team Overbot

Moreshwar Salpekar wrote:

Thanks for the clarification but then how do I port the Linux code? I
need
to port Linux code to QNX. Linux uses sk_buff structure and uses
dev_alloc_skb for allocation of memory. Seems I need to replace sk_buff
structure with nkpt_t, io_net_self_t and a device structure… Would that
be
right? Memory buffer was being allocated for sk_buff through
dev_alloc_skb
and I need to change the code I need to find replacement for this
function
and the structure

Regards
Moreshwar “Igor Kovalenko” <> kovalenko@comcast.net> > wrote in message
news:chrn1s$hsm$> 1@inn.qnx.com> …

There’s isn’t any direct equivalent. I think even in Linux the use of
GFP_ATOMIC is not encouraged. Basically, doing any kind of memory
allocations inside ISR is a poor design. You’re going to have to change

that

design so that memory is allocated upfront.

– igor

“Moreshwar Salpekar” <> moreshwars@hotmail.com> > wrote in message
news:chpdun$noc$> 1@inn.qnx.com> …

Hello,
I need help in replacing Linux sk_buff structure (declared
inlinux/sk_buff.h) to equivalent structure. does anybody have knowledge

of

what structure and functions should I use for the same. I need to

allocate

the buffer in ISR. linux provides dev_alloc_skb (uses alloc_skb with
GFP_ATOMIC flag) that makes it safe to use in ISR for memory allocation

as

it is atomic and does not cause calling process to sleep. I want to
know

the

equivalents in QNX

Thanks in advance

regards
Moreshwar




\

6

Device drivers in QNX are philosophicly different. My advice is,

  1. read through the Linux driver and understand it
  2. read through any good QNX resource manager (divice driver) source code
    and understand it
  3. don’t port - redesign the QNX driver to talk to your hardware and do
    everything that the linux driver currently does.


    Moreshwar Salpekar <moreshwars@hotmail.com> wrote:
    MS > Yes I need it, I am having problems in porting Linux kernel source code and
    MS > this is my first driver for QNX so unsure. I have managed to detect the card
    MS > and replaced the card detection mechanism in my source code. I have replaced
    MS > everything except the sk_buff structure and its associated functions. I am
    MS > unable to decide how to go about it.
    MS > If I have not mentioned it earlier,I am porting HDLC driver from Linux to
    MS > QNX.
    MS > If you could let me know whether I am proceeding I correct direction, I
    MS > would be grateful
    MS > “John Nagle” <nagle@downside.com> wrote in message
    MS > news:ci3814$61f$1@inn.qnx.com…

First of all, a device driver in QNX is a user program.
You’re talking about memory allocation mechanisms used inside
the Linux kernel.

What you probably need is the source for some QNX Ethernet
device driver to look at.

John Nagle
Team Overbot

Moreshwar Salpekar wrote:

Thanks for the clarification but then how do I port the Linux code? I
MS > need
to port Linux code to QNX. Linux uses sk_buff structure and uses
dev_alloc_skb for allocation of memory. Seems I need to replace sk_buff
structure with nkpt_t, io_net_self_t and a device structure… Would that
MS > be
right? Memory buffer was being allocated for sk_buff through
MS > dev_alloc_skb
and I need to change the code I need to find replacement for this
MS > function
and the structure

Regards
Moreshwar “Igor Kovalenko” <> kovalenko@comcast.net> > wrote in message
news:chrn1s$hsm$> 1@inn.qnx.com> …

There’s isn’t any direct equivalent. I think even in Linux the use of
GFP_ATOMIC is not encouraged. Basically, doing any kind of memory
allocations inside ISR is a poor design. You’re going to have to change

that

design so that memory is allocated upfront.

– igor

“Moreshwar Salpekar” <> moreshwars@hotmail.com> > wrote in message
news:chpdun$noc$> 1@inn.qnx.com> …

Hello,
I need help in replacing Linux sk_buff structure (declared
inlinux/sk_buff.h) to equivalent structure. does anybody have knowledge

of

what structure and functions should I use for the same. I need to

allocate

the buffer in ISR. linux provides dev_alloc_skb (uses alloc_skb with
GFP_ATOMIC flag) that makes it safe to use in ISR for memory allocation

as

it is atomic and does not cause calling process to sleep. I want to
MS > know

the

equivalents in QNX

Thanks in advance

regards
Moreshwar





\

–
Bill Caroselli – Q-TPS Consulting
1-(708) 308-4956 <== Note: New Number
qtps@earthlink.net

7

Having written device drivers for 2 A/D cards for QNX from a linux starting
point, I concur with Bill. I also found that Rob Krten’s book “Getting
Started with QNX Neutrino 2” (www.parse.com) was extremely helpful.
“Bill Caroselli” <qtps@earthlink.net> wrote in message
news:ci459d$rbp$1@inn.qnx.com…

Device drivers in QNX are philosophicly different. My advice is,

  1. read through the Linux driver and understand it
  2. read through any good QNX resource manager (divice driver) source code
    and understand it
  3. don’t port - redesign the QNX driver to talk to your hardware and do
    everything that the linux driver currently does.


    Moreshwar Salpekar <> moreshwars@hotmail.com> > wrote:
    MS > Yes I need it, I am having problems in porting Linux kernel source
    code and
    MS > this is my first driver for QNX so unsure. I have managed to detect
    the card
    MS > and replaced the card detection mechanism in my source code. I have
    replaced
    MS > everything except the sk_buff structure and its associated functions.
    I am
    MS > unable to decide how to go about it.
    MS > If I have not mentioned it earlier,I am porting HDLC driver from
    Linux to
    MS > QNX.
    MS > If you could let me know whether I am proceeding I correct direction,
    I
    MS > would be grateful
    MS > “John Nagle” <> nagle@downside.com> > wrote in message
    MS > news:ci3814$61f$> 1@inn.qnx.com> …
    First of all, a device driver in QNX is a user program.
    You’re talking about memory allocation mechanisms used inside
    the Linux kernel.

What you probably need is the source for some QNX Ethernet
device driver to look at.

John Nagle
Team Overbot

Moreshwar Salpekar wrote:

Thanks for the clarification but then how do I port the Linux code? I
MS > need
to port Linux code to QNX. Linux uses sk_buff structure and uses
dev_alloc_skb for allocation of memory. Seems I need to replace
sk_buff
structure with nkpt_t, io_net_self_t and a device structure… Would
that
MS > be
right? Memory buffer was being allocated for sk_buff through
MS > dev_alloc_skb
and I need to change the code I need to find replacement for this
MS > function
and the structure

Regards
Moreshwar “Igor Kovalenko” <> kovalenko@comcast.net> > wrote in message
news:chrn1s$hsm$> 1@inn.qnx.com> …

There’s isn’t any direct equivalent. I think even in Linux the use of
GFP_ATOMIC is not encouraged. Basically, doing any kind of memory
allocations inside ISR is a poor design. You’re going to have to
change

that

design so that memory is allocated upfront.

– igor

“Moreshwar Salpekar” <> moreshwars@hotmail.com> > wrote in message
news:chpdun$noc$> 1@inn.qnx.com> …

Hello,
I need help in replacing Linux sk_buff structure (declared
inlinux/sk_buff.h) to equivalent structure. does anybody have
knowledge

of

what structure and functions should I use for the same. I need to

allocate

the buffer in ISR. linux provides dev_alloc_skb (uses alloc_skb with
GFP_ATOMIC flag) that makes it safe to use in ISR for memory
allocation

as

it is atomic and does not cause calling process to sleep. I want to
MS > know

the

equivalents in QNX

Thanks in advance

regards
Moreshwar










\

Bill Caroselli – Q-TPS Consulting
1-(708) 308-4956 <== Note: New Number
qtps@earthlink.net

8

Having ported some Linux drivers too, I would not say that philosophycal
difference is not all that relevant.

Yes, QNX drivers are processes, whereas Linux drivers are modules. However
if you look at the framework for writing char/block drivers in Linux, it is
quite similar to QNX ‘resource manager’ framework. Some things are simpler
in QNX (no need to care about kernel vs user space, ability to use all
standard POSIX API in the drivers, no stupid limits on DMA buffers), some
are easier in Linux (I’d say their framework is easier to use because it
includes wait queues management). However major concepts are very similar.
The network drivers of course are different story, since they follow a
separate model. I did not write any so I can not really comment on that …
but from a brief reading I did not see a lot of differences either.

“John McClurkin” <jwm@lsr.nei.nih.gov> wrote in message
news:ci6sib$1t7$1@inn.qnx.com…

Having written device drivers for 2 A/D cards for QNX from a linux
starting
point, I concur with Bill. I also found that Rob Krten’s book “Getting
Started with QNX Neutrino 2” (> www.parse.com> ) was extremely helpful.
“Bill Caroselli” <> qtps@earthlink.net> > wrote in message
news:ci459d$rbp$> 1@inn.qnx.com> …
Device drivers in QNX are philosophicly different. My advice is,

  1. read through the Linux driver and understand it
  2. read through any good QNX resource manager (divice driver) source
    code
    and understand it
  3. don’t port - redesign the QNX driver to talk to your hardware and do
    everything that the linux driver currently does.


    Moreshwar Salpekar <> moreshwars@hotmail.com> > wrote:
    MS > Yes I need it, I am having problems in porting Linux kernel source
    code and
    MS > this is my first driver for QNX so unsure. I have managed to detect
    the card
    MS > and replaced the card detection mechanism in my source code. I have
    replaced
    MS > everything except the sk_buff structure and its associated
    functions.
    I am
    MS > unable to decide how to go about it.
    MS > If I have not mentioned it earlier,I am porting HDLC driver from
    Linux to
    MS > QNX.
    MS > If you could let me know whether I am proceeding I correct
    direction,
    I
    MS > would be grateful
    MS > “John Nagle” <> nagle@downside.com> > wrote in message
    MS > news:ci3814$61f$> 1@inn.qnx.com> …
    First of all, a device driver in QNX is a user program.
    You’re talking about memory allocation mechanisms used inside
    the Linux kernel.

What you probably need is the source for some QNX Ethernet
device driver to look at.

John Nagle
Team Overbot

Moreshwar Salpekar wrote:

Thanks for the clarification but then how do I port the Linux code?
I
MS > need
to port Linux code to QNX. Linux uses sk_buff structure and uses
dev_alloc_skb for allocation of memory. Seems I need to replace
sk_buff
structure with nkpt_t, io_net_self_t and a device structure… Would
that
MS > be
right? Memory buffer was being allocated for sk_buff through
MS > dev_alloc_skb
and I need to change the code I need to find replacement for this
MS > function
and the structure

Regards
Moreshwar “Igor Kovalenko” <> kovalenko@comcast.net> > wrote in message
news:chrn1s$hsm$> 1@inn.qnx.com> …

There’s isn’t any direct equivalent. I think even in Linux the use
of
GFP_ATOMIC is not encouraged. Basically, doing any kind of memory
allocations inside ISR is a poor design. You’re going to have to
change

that

design so that memory is allocated upfront.

– igor

“Moreshwar Salpekar” <> moreshwars@hotmail.com> > wrote in message
news:chpdun$noc$> 1@inn.qnx.com> …

Hello,
I need help in replacing Linux sk_buff structure (declared
inlinux/sk_buff.h) to equivalent structure. does anybody have
knowledge

of

what structure and functions should I use for the same. I need to

allocate

the buffer in ISR. linux provides dev_alloc_skb (uses alloc_skb
with
GFP_ATOMIC flag) that makes it safe to use in ISR for memory
allocation

as

it is atomic and does not cause calling process to sleep. I want
to
MS > know

the

equivalents in QNX

Thanks in advance

regards
Moreshwar










\

Bill Caroselli – Q-TPS Consulting
1-(708) 308-4956 <== Note: New Number
qtps@earthlink.net