[Skiboot] [PATCH 3/3] ibm-fsp: Use finalise_dt() for DT fixups

[Gautham R Shenoy]

Hello Oliver,

On Thu, Jul 11, 2019 at 05:41:44PM +1000, Oliver O'Halloran wrote:
> >From Gautham's patch to fix pstates_init() that this was based on:
> 
> > On FSP based systems (particularly POWER8), we perform
> > occ_pstates_init() late in the boot to allow OCC to be loaded. Hence
> > this was being performed in platform.exit(). occ_pstates_init() would
> > add pstate information into the device-tree.
> >
> > A recent commit 9fc0c1287ada ("Move FSP specific op-panel calls to
> > platform.exit()") moved the invocation of platform.exit() after the
> > creation of device-tree blob. As a result, on FSP based systems, we
> > don't have the pstate information in the device-tree, and thus the
> > Kernel is unable to perform frequency scaling.
> >
> > Fix this by moving occ_pstates_init() out of ibm_fsp_exit() and call
> > it before the creation of the device-tree blob.
> 
> The same patch also broke fast-reboot on ZZ. Without this patch applied
> we get the following assert() fail when fast rebooting:
> 
> [ 1153.398889405,5] CUPD: Waiting read marker LID and in flight parsm completion...
> [ 1153.398892228,3] Duplicate property "mi-version" in node /ibm,opal/firmware
> [ 1153.398894036,0] Aborting!
> CPU 0054 Backtrace:
>  S: 0000000031ea39b0 R: 0000000030013828   .backtrace+0x34
>  S: 0000000031ea3a70 R: 000000003001b268   ._abort+0x4c
>  S: 0000000031ea3af0 R: 0000000030027788   .new_property+0x80
>  S: 0000000031ea3b80 R: 00000000300278d0   .dt_add_property+0xa8
>  S: 0000000031ea3c10 R: 0000000030081a98   .fsp_code_update_wait_vpd+0x19c
>  S: 0000000031ea3d10 R: 000000003008ff98   .ibm_fsp_exit+0x1c
>  S: 0000000031ea3d80 R: 0000000030014864   .load_and_boot_kernel+0xb14
>  S: 0000000031ea3e60 R: 000000003002685c   .fast_reboot_entry+0x38c
>  S: 0000000031ea3f00 R: 0000000030002988   reset_fast_reboot_wakeup+0x40
> 
> This happens because fsp_code_update_wait_vpd(true) adds some properties
> to the DT so moving it to finalise_dt fixes that crash too.
> 
> Cc: Vasant Hegde <hegdevasant at linux.vnet.ibm.com>
> Cc: Gautham R. Shenoy <ego at linux.vnet.ibm.com>
> Cc: Vaidyanathan Srinivasan <svaidy at linux.ibm.com>
> Fixes: 9fc0c1287ada ("Move FSP specific op-panel calls to platform.exit()")
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>

This fixes the cpufreq problem on Firenze and ZZ.

Tested-by: Gautham R. Shenoy <ego at linux.vnet.ibm.com>

> ---
>  platforms/ibm-fsp/common.c  | 17 +++++++++++------
>  platforms/ibm-fsp/firenze.c |  1 +
>  platforms/ibm-fsp/ibm-fsp.h |  1 +
>  platforms/ibm-fsp/zz.c      |  1 +
>  4 files changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/platforms/ibm-fsp/common.c b/platforms/ibm-fsp/common.c
> index 7f7a1f246206..6f9d57a8fb6b 100644
> --- a/platforms/ibm-fsp/common.c
> +++ b/platforms/ibm-fsp/common.c
> @@ -174,8 +174,11 @@ void ibm_fsp_init(void)
>  	preload_io_vpd();
>  }
> 
> -void ibm_fsp_exit(void)
> +void ibm_fsp_finalise_dt(bool is_reboot)
>  {
> +	if (is_reboot)
> +		return;
> +
>  	/*
>  	 * LED related SPCN commands might take a while to
>  	 * complete. Call this as late as possible to
> @@ -183,18 +186,20 @@ void ibm_fsp_exit(void)
>  	 */
>  	create_led_device_nodes();
> 
> -	/* Wait for FW VPD data read to complete */
> -	fsp_code_update_wait_vpd(true);
> -
>  	/*
>  	 * OCC takes few secs to boot.  Call this as late as
>  	 * as possible to avoid delay.
>  	 */
> -	if (fsp_present())
> -		occ_pstates_init();
> +	occ_pstates_init();
> +
> +	/* Wait for FW VPD data read to complete */
> +	fsp_code_update_wait_vpd(true);
> 
>  	fsp_console_select_stdout();
> +}
> 
> +void ibm_fsp_exit(void)
> +{
>  	op_panel_disable_src_echo();
> 
>  	/* Clear SRCs on the op-panel when Linux starts */
> diff --git a/platforms/ibm-fsp/firenze.c b/platforms/ibm-fsp/firenze.c
> index 232833480f75..db18e2ff4eba 100644
> --- a/platforms/ibm-fsp/firenze.c
> +++ b/platforms/ibm-fsp/firenze.c
> @@ -214,6 +214,7 @@ DECLARE_PLATFORM(firenze) = {
>  	.probe			= firenze_probe,
>  	.init			= firenze_init,
>  	.fast_reboot_init	= fsp_console_reset,
> +	.finalise_dt		= ibm_fsp_finalise_dt,
>  	.exit			= ibm_fsp_exit,
>  	.cec_power_down		= ibm_fsp_cec_power_down,
>  	.cec_reboot		= ibm_fsp_cec_reboot,
> diff --git a/platforms/ibm-fsp/ibm-fsp.h b/platforms/ibm-fsp/ibm-fsp.h
> index dc3969ec688d..c055d4a3e6f9 100644
> --- a/platforms/ibm-fsp/ibm-fsp.h
> +++ b/platforms/ibm-fsp/ibm-fsp.h
> @@ -20,6 +20,7 @@
> 
>  extern void ibm_fsp_init(void);
>  extern void ibm_fsp_exit(void);
> +void ibm_fsp_finalise_dt(bool is_reboot);
> 
>  extern int64_t ibm_fsp_cec_power_down(uint64_t request);
>  extern int64_t ibm_fsp_cec_reboot(void);
> diff --git a/platforms/ibm-fsp/zz.c b/platforms/ibm-fsp/zz.c
> index f44c618c0ec1..e369f8d1fc5b 100644
> --- a/platforms/ibm-fsp/zz.c
> +++ b/platforms/ibm-fsp/zz.c
> @@ -79,6 +79,7 @@ DECLARE_PLATFORM(zz) = {
>  	.probe			= zz_probe,
>  	.init			= zz_init,
>  	.fast_reboot_init	= fsp_console_reset,
> +	.finalise_dt		= ibm_fsp_finalise_dt,
>  	.exit			= ibm_fsp_exit,
>  	.cec_power_down		= ibm_fsp_cec_power_down,
>  	.cec_reboot		= ibm_fsp_cec_reboot,
> -- 
> 2.21.0
>