Re: [PATCH v3 2/2] drivers: soc: Add LLCC driver

From: Channa
Date: Mon Apr 02 2018 - 15:03:14 EST

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On 2018-04-02 02:11, Stanimir Varbanov wrote:

Hi,

Please adjust your mail client to drop on new line on 80 column!

On 03/29/2018 08:55 PM, Channa wrote:

On 2018-03-29 01:08, Stanimir Varbanov wrote:

Hi,

On 03/27/2018 09:52 PM, Rishabh Bhatnagar wrote:

LLCC (Last Level Cache Controller) provides additional cache memory
in the system. LLCC is partitioned into muliple slices and each
slice getting its own priority, size, ID and other config parameters.
LLCC driver programs these parameters for each slice. Clients that
are assigned to use LLCC need to get information such size & ID of the
Âslice they get and activate or deactivate the slice as needed. LLCC
driver
provides API interfaces for the clients to perform these operations.

Signed-off-by: Channagoud Kadabi <ckadabi@xxxxxxxxxxxxxx>
Signed-off-by: Rishabh Bhatnagar <rishabhb@xxxxxxxxxxxxxx>
---
Âdrivers/soc/qcom/KconfigÂÂÂÂÂÂÂÂÂÂ |Â 16 ++
Âdrivers/soc/qcom/MakefileÂÂÂÂÂÂÂÂÂ |ÂÂ 2 +
Âdrivers/soc/qcom/llcc-sdm845.cÂÂÂÂ | 120 ++++++++++
Âdrivers/soc/qcom/llcc-slice.cÂÂÂÂÂ | 454
+++++++++++++++++++++++++++++++++++++

I'd name it just llcc.c, slice suffix didn't add any value.

Âinclude/linux/soc/qcom/llcc-qcom.h | 178 +++++++++++++++
Â5 files changed, 770 insertions(+)
Âcreate mode 100644 drivers/soc/qcom/llcc-sdm845.c
Âcreate mode 100644 drivers/soc/qcom/llcc-slice.c
Âcreate mode 100644 include/linux/soc/qcom/llcc-qcom.h

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index e050eb8..28237fc 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -21,6 +21,22 @@ config QCOM_GSBI
ÂÂÂÂÂÂÂÂÂÂ functions for connecting the underlying serial UART, SPI,
and I2C
ÂÂÂÂÂÂÂÂÂÂ devices to the output pins.

+config QCOM_LLCC
+ÂÂÂ tristate "Qualcomm Technologies, Inc. LLCC driver"
+ÂÂÂ depends on ARCH_QCOM
+ÂÂÂ help
+ÂÂÂÂÂ Qualcomm Technologies, Inc. platform specific LLCC driver for
Last
+ÂÂÂÂÂ Level Cache. This provides interfaces to client's that use the
LLCC.
+ÂÂÂÂÂ Say yes here to enable LLCC slice driver.
+
+config QCOM_SDM845_LLCC
+ÂÂÂ tristate "Qualcomm Technologies, Inc. SDM845 LLCC driver"
+ÂÂÂ depends on QCOM_LLCC
+ÂÂÂ help
+ÂÂÂÂÂ Say yes here to enable the LLCC driver for SDM845. This is
provides
+ÂÂÂÂÂ data required to configure LLCC so that clients can start
using the
+ÂÂÂÂÂ LLCC slices.
+
Âconfig QCOM_MDT_LOADER
ÂÂÂÂ tristate
ÂÂÂÂ select QCOM_SCM
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index dcebf28..e16d6a2 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -12,3 +12,5 @@ obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
Âobj-$(CONFIG_QCOM_SMP2P)ÂÂÂ += smp2p.o
Âobj-$(CONFIG_QCOM_SMSM)ÂÂÂ += smsm.o
Âobj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o
+obj-$(CONFIG_QCOM_LLCC) += llcc-slice.o
+obj-$(CONFIG_QCOM_SDM845_LLCC) += llcc-sdm845.o
diff --git a/drivers/soc/qcom/llcc-sdm845.c
b/drivers/soc/qcom/llcc-sdm845.c
new file mode 100644
index 0000000..cd431d9
--- /dev/null
+++ b/drivers/soc/qcom/llcc-sdm845.c
@@ -0,0 +1,120 @@
+/* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.Â See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/soc/qcom/llcc-qcom.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+
+/*
+ * SCT entry contains of the following parameters
+ * name: Name of the client's use case for which the llcc slice is used
+ * uid: Unique id for the client's use case
+ * slice_id: llcc slice id for each client
+ * max_cap: The maximum capacity of the cache slice provided in KB
+ * priority: Priority of the client used to select victim line for
replacement
+ * fixed_size: Determine of the slice has a fixed capacity
+ * bonus_ways: Bonus ways to be used by any slice, bonus way is used
only if
+ *ÂÂÂÂÂÂÂÂÂÂÂÂ it't not a reserved way.
+ * res_ways: Reserved ways for the cache slice, the reserved ways
cannot be used
+ *ÂÂÂÂÂÂÂÂÂÂ by any other client than the one its assigned to.
+ * cache_mode: Each slice operates as a cache, this controls the
mode of the
+ *ÂÂÂÂÂÂÂÂÂÂÂÂ slice normal or TCM
+ * probe_target_ways: Determines what ways to probe for access hit.
When
+ *ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ configured to 1 only bonus and reseved ways
are probed.
+ *ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ when configured to 0 all ways in llcc are probed.
+ * dis_cap_alloc: Disable capacity based allocation for a client
+ * retain_on_pc: If this bit is set and client has maitained active
vote
+ *ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ then the ways assigned to this client are not
flushed on power
+ *ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ collapse.
+ * activate_on_init: Activate the slice immidiately after the SCT is
programmed
+ */
+#define SCT_ENTRY(n, uid, sid, mc, p, fs, bway, rway, cmod, ptw,
dca, rp, a) \
+ÂÂÂ {ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .name = n,ÂÂÂÂÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .usecase_id = uid,ÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .slice_id = sid,ÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .max_cap = mc,ÂÂÂÂÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .priority = p,ÂÂÂÂÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .fixed_size = fs,ÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .bonus_ways = bway,ÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .res_ways = rway,ÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .cache_mode = cmod,ÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .probe_target_ways = ptw,ÂÂÂ \
+ÂÂÂÂÂÂÂ .dis_cap_alloc = dca,ÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .retain_on_pc = rp,ÂÂÂÂÂÂÂ \
+ÂÂÂÂÂÂÂ .activate_on_init = a,ÂÂÂÂÂÂÂ \
+ÂÂÂ }
+
+
+static struct llcc_slice_config sdm845_data[] =Â {
+ÂÂÂ SCT_ENTRY("cpuss",ÂÂÂÂÂÂ 1, 1, 2816, 1, 0, 0xFFC, 0x2, 0, 0, 1,
1, 1),
+ÂÂÂ SCT_ENTRY("vidsc0",ÂÂÂÂÂ 2, 2, 512, 2, 1, 0x0,Â 0x0F0, 0, 0, 1,
1, 0),
+ÂÂÂ SCT_ENTRY("vidsc1",ÂÂÂÂÂ 3, 3, 512, 2, 1, 0x0,Â 0x0F0, 0, 0, 1,
1, 0),
+ÂÂÂ SCT_ENTRY("rotator",ÂÂÂÂ 4, 4, 563, 2, 1, 0x0,Â 0x00e, 2, 0, 1,
1, 0),
+ÂÂÂ SCT_ENTRY("voice",ÂÂÂÂÂÂ 5, 5, 2816, 1, 0, 0xFFC, 0x2, 0, 0, 1,
1, 0),
+ÂÂÂ SCT_ENTRY("audio",ÂÂÂÂÂÂ 6, 6, 2816, 1, 0, 0xFFC, 0x2, 0, 0, 1,
1, 0),
+ÂÂÂ SCT_ENTRY("modemhp_grow", 7, 7, 1024, 2, 0, 0x0FC, 0xF00, 0, 0,
1, 1, 0),
+ÂÂÂ SCT_ENTRY("modem",ÂÂÂÂÂÂ 8, 8, 2816, 1, 0, 0xFFC, 0x2, 0, 0, 1,
1, 0),
+ÂÂÂ SCT_ENTRY("compute",ÂÂÂÂ 10, 10, 2816, 1, 0, 0xFFC, 0x2, 0, 0,
1, 1, 0),
+ÂÂÂ SCT_ENTRY("gpuhtw",ÂÂÂÂÂ 11, 11, 512, 1, 1, 0xC,Â 0x0, 0, 0, 1,
1, 0),
+ÂÂÂ SCT_ENTRY("gpu",ÂÂÂÂÂÂÂÂ 12, 12, 2304, 1, 0, 0xFF0, 0x2, 0, 0,
1, 1, 0),
+ÂÂÂ SCT_ENTRY("mmuhwt",ÂÂÂÂÂ 13, 13, 256, 2, 0, 0x0,Â 0x1, 0, 0, 1,
0, 1),
+ÂÂÂ SCT_ENTRY("compute_dma", 15, 15, 2816, 1, 0, 0xFFC, 0x2, 0, 0,
1, 1, 0),
+ÂÂÂ SCT_ENTRY("display",ÂÂÂÂ 16, 16, 2816, 1, 0, 0xFFC, 0x2, 0, 0,
1, 1, 0),
+ÂÂÂ SCT_ENTRY("videofw",ÂÂÂÂ 17, 17, 2816, 1, 0, 0xFFC, 0x2, 0, 0,
1, 1, 0),
+ÂÂÂ SCT_ENTRY("modemhp_fix", 20, 20, 1024, 2, 1, 0x0,Â 0xF00, 0, 0,
1, 1, 0),
+ÂÂÂ SCT_ENTRY("modem_paging", 21, 21, 1024, 0, 1, 0x1e, 0x0, 0, 0,
1, 1, 0),
+ÂÂÂ SCT_ENTRY("audiohw",ÂÂÂÂ 22, 22, 1024, 1, 1, 0xFFC, 0x2, 0, 0,
1, 1, 0),
+};
+
+
+static int sdm845_qcom_llcc_probe(struct platform_device *pdev)
+{
+ÂÂÂ return qcom_llcc_probe(pdev, sdm845_data, ARRAY_SIZE(sdm845_data));

I think having separate driver just for this config structure is
pointless. Please move this in llcc driver and select the configuration
based on compatible string.

Thanks Stan for your review.

Wanted to highlight the reason we chose this approach. The System cache
table data
changes from chipset to chipset and overtime the table could have more
parameters.
Adding it as part of the core driver and selecting the table based on
compatible
would clutter the core driver. If we have 4 chipsets supporting system
cache then
core driver would have 4 tables as above and we select one of them based
on compatible
string. That is why we followed the pin control approach to have data in
per chipset
driver and pass it to common driver.

OK, do you plan to extend this with some more code?

Not this particular file, this is chipset specific file. We don't expect
more changes to this file.
A new driver is added for every chipset, so the data maintained here could
change in future. So the idea is to keep the chipset driver separate
from core driver.

--
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Next message: Dominik Brodowski: "[GIT PULL] remove in-kernel calls to syscalls"
Previous message: Tejun Heo: "[PATCH 2/2] blk-mq: Fix request handover from timeout path to normal execution"
In reply to: Stanimir Varbanov: "Re: [PATCH v3 2/2] drivers: soc: Add LLCC driver"
Next in thread: rishabhb: "Re: [PATCH v3 2/2] drivers: soc: Add LLCC driver"
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