[00/20] hw/net/xilinx_ethlite: Map RAM buffers as RAM and remove tswap() calls

Message

Philippe Mathieu-Daudé Nov. 12, 2024, 6:10 p.m. UTC

This is the result of a long discussion with Edgar (started few
years ago!) and Paolo:
https://lore.kernel.org/qemu-devel/[e-mail]/
After clarification from Richard on MMIO/RAM accesses, I figured
strengthening the model regions would make things obvious,
eventually allowing to remove the tswap() calls for good.

This costly series mostly plays around with MemoryRegions.

The model has a mix of RAM/MMIO in its address range. Currently
they are implemented as a MMIO array of u32. Since the core
memory layer swaps accesses for MMIO, the device implementation
has to swap them back.
In order to avoid that, we'll map the RAM regions as RAM MRs.
First we move each MMIO register to new MMIO regions (RX and TX).
Then what is left are the RAM buffers; we convert them to RAM MRs,
removing the need for tswap() at all.

Once reviewed, I'll respin my "hw/microblaze: Allow running
cross-endian vCPUs" series based on this.

Please review,

Phil.

Philippe Mathieu-Daudé (20):
  hw/microblaze: Restrict MemoryRegionOps are implemented as 32-bit
  hw/net/xilinx_ethlite: Convert some debug logs to trace events
  hw/net/xilinx_ethlite: Remove unuseful debug logs
  hw/net/xilinx_ethlite: Update QOM style
  hw/net/xilinx_ethlite: Correct maximum RX buffer size
  hw/net/xilinx_ethlite: Map MDIO registers (as unimplemented)
  hw/net/xilinx_ethlite: Rename rxbuf -> port_index
  hw/net/xilinx_ethlite: Add addr_to_port_index() helper
  hw/net/xilinx_ethlite: Introduce txbuf_ptr() helper
  hw/net/xilinx_ethlite: Introduce rxbuf_ptr() helper
  hw/net/xilinx_ethlite: Access RX_CTRL register for each port
  hw/net/xilinx_ethlite: Access TX_GIE register for each port
  hw/net/xilinx_ethlite: Access TX_LEN register for each port
  hw/net/xilinx_ethlite: Access TX_CTRL register for each port
  hw/net/xilinx_ethlite: Map RX_CTRL as MMIO
  hw/net/xilinx_ethlite: Map TX_LEN as MMIO
  hw/net/xilinx_ethlite: Map TX_GIE as MMIO
  hw/net/xilinx_ethlite: Map TX_CTRL as MMIO
  hw/net/xilinx_ethlite: Map the RAM buffer as RAM memory region
  hw/net/xilinx_ethlite: Rename 'mmio' MR as 'container'

 hw/char/xilinx_uartlite.c |   4 +
 hw/intc/xilinx_intc.c     |   4 +
 hw/net/xilinx_ethlite.c   | 357 ++++++++++++++++++++++++--------------
 hw/timer/xilinx_timer.c   |   4 +
 hw/net/trace-events       |   4 +
 5 files changed, 246 insertions(+), 127 deletions(-)

Comments

Edgar E. Iglesias Nov. 13, 2024, 3:36 p.m. UTC | #1

On Tue, Nov 12, 2024 at 07:10:24PM +0100, Philippe Mathieu-Daudé wrote:
> This is the result of a long discussion with Edgar (started few
> years ago!) and Paolo:
> https://lore.kernel.org/qemu-devel/[e-mail]/
> After clarification from Richard on MMIO/RAM accesses, I figured
> strengthening the model regions would make things obvious,
> eventually allowing to remove the tswap() calls for good.
> 
> This costly series mostly plays around with MemoryRegions.
> 
> The model has a mix of RAM/MMIO in its address range. Currently
> they are implemented as a MMIO array of u32. Since the core
> memory layer swaps accesses for MMIO, the device implementation
> has to swap them back.
> In order to avoid that, we'll map the RAM regions as RAM MRs.
> First we move each MMIO register to new MMIO regions (RX and TX).
> Then what is left are the RAM buffers; we convert them to RAM MRs,
> removing the need for tswap() at all.
> 
> Once reviewed, I'll respin my "hw/microblaze: Allow running
> cross-endian vCPUs" series based on this.


Thanks Phil,

This looks good to me. Have you tested this with the Images I provied
a while back or some other way?

Cheers,
Edgar




> 
> Please review,
> 
> Phil.
> 
> Philippe Mathieu-Daudé (20):
>   hw/microblaze: Restrict MemoryRegionOps are implemented as 32-bit
>   hw/net/xilinx_ethlite: Convert some debug logs to trace events
>   hw/net/xilinx_ethlite: Remove unuseful debug logs
>   hw/net/xilinx_ethlite: Update QOM style
>   hw/net/xilinx_ethlite: Correct maximum RX buffer size
>   hw/net/xilinx_ethlite: Map MDIO registers (as unimplemented)
>   hw/net/xilinx_ethlite: Rename rxbuf -> port_index
>   hw/net/xilinx_ethlite: Add addr_to_port_index() helper
>   hw/net/xilinx_ethlite: Introduce txbuf_ptr() helper
>   hw/net/xilinx_ethlite: Introduce rxbuf_ptr() helper
>   hw/net/xilinx_ethlite: Access RX_CTRL register for each port
>   hw/net/xilinx_ethlite: Access TX_GIE register for each port
>   hw/net/xilinx_ethlite: Access TX_LEN register for each port
>   hw/net/xilinx_ethlite: Access TX_CTRL register for each port
>   hw/net/xilinx_ethlite: Map RX_CTRL as MMIO
>   hw/net/xilinx_ethlite: Map TX_LEN as MMIO
>   hw/net/xilinx_ethlite: Map TX_GIE as MMIO
>   hw/net/xilinx_ethlite: Map TX_CTRL as MMIO
>   hw/net/xilinx_ethlite: Map the RAM buffer as RAM memory region
>   hw/net/xilinx_ethlite: Rename 'mmio' MR as 'container'
> 
>  hw/char/xilinx_uartlite.c |   4 +
>  hw/intc/xilinx_intc.c     |   4 +
>  hw/net/xilinx_ethlite.c   | 357 ++++++++++++++++++++++++--------------
>  hw/timer/xilinx_timer.c   |   4 +
>  hw/net/trace-events       |   4 +
>  5 files changed, 246 insertions(+), 127 deletions(-)
> 
> -- 
> 2.45.2
>