Replace mips/sentry5 with mips/broadcom.

[landonf]

Summary

The delta between SENTRY5 and BCM was already small due to BCM being
derived from SENTRY5; re-integrating the two avoids the maintenance
overhead of keeping them both in sync with bhnd(4) changes.

Changes:

• Re-integrate minor SENTRY5 deltas in bcm_machdep.c
• Modify uart_bus_chipc to allow uart(4) to detect the console uart; fixes multiple-uart handling.
• Modify uart_cpu_chipc to allow specifying UART debug/console flags via kenv and device hints.
• Switch SENTRY5 to std.broadcom
• Enabled CFI flash support for SENTRY5

Test Plan

Tested on:

• RT-N16, RT-N53
• WGT634U

[adrian]

if we're shifting kernel configs around, we should follow the arm tradition of std.XXXX for their base configs, not XXX_BASE. Would you mind renaming stuff appropriately?

[mizhka]

Super-nice change. I had a lot of thoughts about it.
I'm asking for few changes in inline comments, but please feel free to ask any question, argue, reject :)

sys/mips/broadcom/bcm_machdep.c

112–115 ↗

(On Diff #17704)

Please keep this debug bits, because CFE works fine not in 100% cases ;)

157–159 ↗

(On Diff #17704)

Could you please change "//" to #if 0 #endif for code and text comment to /* .... */?

236 ↗

(On Diff #17704)

"double_count" is a bit misleading variable name. What's about "clk_rate_ratio" or "clk_ratio"?

Also it will be nice to have comment with examples of chips for a half and full tick counting.

sys/mips/broadcom/uart_cpu_chipc.c

72–76 ↗

(On Diff #17704)

Could you please keep HINTS as optional thing? I.e. if there is no hints at all, we assume UART0 as Console?

sys/mips/conf/BCM47XX

1–6 ↗

(On Diff #17704)

Could you please add 53xx in description (like 5356-5358)?

I prefer to have kernel config per MIPS family, rather than BCM chip model. For example, 5358 and 4718 (74K family) are very-very close to each other in term of conf, but far from 4704 / 5350 / 5364P (aka BCM3302 or MIPS 4Kc). May be following configs:

• std.broadcom
• BCM
• BCM.4Kc?

Also I prefer to keep Sentry untouched, because there are Sentry customers & sub-freebsd-projects which use SENTRY as siba-based. It will break their codebase and force them to give up or migrate to BHND, which still in stable stage.

21–27 ↗

(On Diff #17704)

I don't see "device pci" for BCM47xx. is it correct?

32–37 ↗

(On Diff #17704)

Could you please move SPI/CFI devices to common config?

sys/mips/conf/SENTRY5

16–17 ↗

(On Diff #17704)

May be it worth to remove?

[landonf]

In D6897#144684, @adrian wrote:

if we're shifting kernel configs around, we should follow the arm tradition of std.XXXX for their base configs, not XXX_BASE. Would you mind renaming stuff appropriately?

Sure!

In D6897#144704, @mizhka_gmail.com wrote:

Super-nice change. I had a lot of thoughts about it.
I'm asking for few changes in inline comments, but please feel free to ask any question, argue, reject :)

Woot. Comment replies inlined :-)

sys/mips/broadcom/bcm_machdep.c

112–115 ↗

(On Diff #17704)

If you're OK with it, I'll rework this to be a debug macro rather than #ifdef blocks for readability.

157–159 ↗

(On Diff #17704)

Sure. I was mostly using the non-standard // so it'd stand out.

236 ↗

(On Diff #17704)

I thought the same regarding the name (I wanted to call it clockdiv), but I was just mirroring the name of the mips_timer_init_params parameter.

I'm fine changing it, though, even if it differs from mips_timer_init_params() a bit.

sys/mips/broadcom/uart_cpu_chipc.c

72–76 ↗

(On Diff #17704)

Sure; why don't I live the found case out into a function, and then call it as a fallback with a set of default uart0 values.

sys/mips/conf/BCM47XX

1–6 ↗

(On Diff #17704)

Could you please add 53xx in description (like 5356-5358)?

Sure.

I prefer to have kernel config per MIPS family, rather than BCM chip model. For example, 5358 and 4718 (74K family) are very-very close to each other in term of conf, but far from 4704 / 5350 / 5364P (aka BCM3302 or MIPS 4Kc).

If we can get away with two generic configurations (74K, 4K) and rely on product-specific configurations in the cases where necessary, and/or modules for device drivers, I'd be pretty happy.

However, I'm wary of laying claim to "BCM"/"broadcom" ; eventually we'll need to support the ARM bcma-based SoCs, and there's already an arm/broadcom containing the bcm2835 RPI code.

I am ambivalent about the 47xx naming; but I'm not sure what else to call this family of bcma/siba-based MIPS SoCs.

Also I prefer to keep Sentry untouched, because there are Sentry customers & sub-freebsd-projects which use SENTRY as siba-based. It will break their codebase and force them to give up or migrate to BHND, which still in stable stage.

I switched SENTRY5 over to bhnd(4) once it was at feature parity with the existing code; I've been operating under the assumption that folks aren't using using the SENTRY5 code, since the port was incomplete and non-functional without updates, and most drivers (uart, pcib, usb, etc) were unimplemented or stubbed out.

32–37 ↗

(On Diff #17704)

I'd like to save that flash space if the drivers aren't required, especially on the smaller hardware.

sys/mips/conf/SENTRY5

16–17 ↗

(On Diff #17704)

Seems to be unused, so may as well.

[landonf]

sys/mips/broadcom/bcm_machdep.c

236 ↗

(On Diff #17704)

Revisiting this, I misspoke. Here's the actual usage in mips_timer_init_params:

/*
  * XXX: Some MIPS32 cores update the Count register only every two
  * pipeline cycles.
  * We know this because of status registers in CP0, make it automatic.
  */
if (double_count != 0)
	counter_freq /= 2;

[landonf]

Changes:

• Drop unused references to sentry5's s5reg.h in mips/atheros.
• Re-introduce CFE memory map debugging using a local BCM_TRACE() macro.
• style(9) fixes for non-PMU reset TODO.
• Fall back to uart0 if no uart hints are available.
• Revert the BCM/BCM_BASE rename in favor of minimal changes to allow existing SENTRY5/BCM to both use std.broadcom.

The BCM/BCM_BASE rename wasn't necessary for the mips/sentry5 -> mips/broadcom transition, and we're probably better off tackling changes to naming/config separately.

[mizhka]

Superb!

sys/mips/broadcom/bcm_machdep.c

236 ↗

(On Diff #17704)

Could you please add comment like "Wanted for single_counting SoC model" :)

[adrian]

ok, get approval from re@ and then push it in!