Re: [PATCHv4 2/2] soc: qcom: llcc: Support chipsets that can write to llcc regs

From: Sai Prakash Ranjan
Date: Tue Sep 15 2020 - 01:22:53 EST


On 2020-09-15 00:16, Stephen Boyd wrote:
Quoting Sai Prakash Ranjan (2020-09-14 04:13:00)
From: "Isaac J. Manjarres" <isaacm@xxxxxxxxxxxxxx>

Older chipsets may not be allowed to configure certain LLCC registers
as that is handled by the secure side software. However, this is not
the case for newer chipsets and they must configure these registers
according to the contents of the SCT table, while keeping in mind that
older targets may not have these capabilities. So add support to allow
such configuration of registers to enable capacity based allocation
and power collapse retention for capable chipsets.

Reason for choosing capacity based allocation rather than the default
way based allocation is because capacity based allocation allows more
finer grain partition and provides more flexibility in configuration.
As for the retention through power collapse, it has an advantage where
the cache hits are more when we wake up from power collapse although
it does burn more power but the exact power numbers are not known at
the moment.

Signed-off-by: Isaac J. Manjarres <isaacm@xxxxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
(saiprakash.ranjan@xxxxxxxxxxxxxx: use existing config and reword commit msg)

Should be [ not (


Ok

Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
---
drivers/soc/qcom/llcc-qcom.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/qcom/llcc-qcom.c b/drivers/soc/qcom/llcc-qcom.c
index 60ee31842dea..6aedccff49bb 100644
--- a/drivers/soc/qcom/llcc-qcom.c
+++ b/drivers/soc/qcom/llcc-qcom.c
@@ -375,6 +382,22 @@ static int qcom_llcc_cfg_program(struct platform_device *pdev)
if (ret)
return ret;

+ if (cfg->need_llcc_cfg) {
+ u32 disable_cap_alloc, retain_pc;
+
+ disable_cap_alloc = llcc_table[i].dis_cap_alloc << llcc_table[i].slice_id;
+ ret = regmap_write(drv_data->bcast_regmap,
+ LLCC_TRP_SCID_DIS_CAP_ALLOC, disable_cap_alloc);
+ if (ret)
+ return ret;
+
+ retain_pc = llcc_table[i].retain_on_pc << llcc_table[i].slice_id;
+ ret = regmap_write(drv_data->bcast_regmap,
+ LLCC_TRP_PCB_ACT, retain_pc);
+ if (ret)
+ return ret;
+ }
+
if (llcc_table[i].activate_on_init) {
desc.slice_id = llcc_table[i].slice_id;
ret = llcc_slice_activate(&desc);

I thought all of this stuff would move into the config function. So the
for loop is simplified to a function call and return if failure.

The config function was specifically for attribute config
not for other llcc configs like these, so I will rename
qcom_llcc_attr_cfg() to _qcom_llcc_cfg_program() and move
everything there.

As a side note, I have your mails in my inbox but these
messages are not appearing in the list [1]. For Patch 2,
its on the list [2]. I have noticed same thing on your
messages for previous patches, where your reply for one
patch was on the list but the other one was missing, you
might have to check that.

[1] https://lore.kernel.org/patchwork/patch/1305132/
[2] https://lore.kernel.org/patchwork/patch/1305133/

Same with lore.kernel.org/lkml/ links but since url was big, I gave the
above patchwork links.

Thanks,
Sai

--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation