[v2,0/4] Expose GT CNTFRQ as a CPU property to support AST2600

Message

Andrew Jeffery Dec. 3, 2019, 4:14 a.m. UTC

Hello,

This is a v2 of the belated follow-up from a few of my earlier attempts to fix
up the ARM generic timer for correct behaviour on the ASPEED AST2600 SoC. The
AST2600 clocks the generic timer at the rate of HPLL, which is configured to
1125MHz.  This is significantly quicker than the currently hard-coded generic
timer rate of 62.5MHz and so we see "sticky" behaviour in the guest.

v1 can be found here:

https://patchwork.ozlabs.org/cover/1201887/

Changes since v1:

* Fix a user mode build failure from partial renaming of gt_cntfrq_period_ns()
* Add tags from Cedric and Richard

Please review.

Andrew

Andrew Jeffery (4):
  target/arm: Remove redundant scaling of nexttick
  target/arm: Abstract the generic timer frequency
  target/arm: Prepare generic timer for per-platform CNTFRQ
  ast2600: Configure CNTFRQ at 1125MHz

 hw/arm/aspeed_ast2600.c |  3 +++
 target/arm/cpu.c        | 41 +++++++++++++++++++++++++++++++++--------
 target/arm/cpu.h        | 28 ++++++++++++++++++++++++++++
 target/arm/helper.c     | 24 ++++++++++++++++++------
 4 files changed, 82 insertions(+), 14 deletions(-)

Comments

Philippe Mathieu-Daudé Dec. 3, 2019, 6:05 a.m. UTC | #1

On 12/3/19 5:14 AM, Andrew Jeffery wrote:
> Hello,
> 
> This is a v2 of the belated follow-up from a few of my earlier attempts to fix
> up the ARM generic timer for correct behaviour on the ASPEED AST2600 SoC. The
> AST2600 clocks the generic timer at the rate of HPLL, which is configured to
> 1125MHz.  This is significantly quicker than the currently hard-coded generic
> timer rate of 62.5MHz and so we see "sticky" behaviour in the guest.

Glad you fixed this! I hit the same problem with the Raspi4.