Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 58a8e739 authored by Arun KS's avatar Arun KS
Browse files

soc: qcom: pasr: Add MSM PASR driver 



Partial Array Self-Refresh driver is used to interface
with rpm to vote/unvote on memory self-refresh from HLOS.

Driver listens to memory hotplug notifications and decides
to vote or unvote depending on memory online and offline.
This vote is considered by RPM to avoid self-refresh on
offlined DDR segments. And hence a reduce in power consumption.

Change-Id: Ida2b36d671c6379dc3c07258a95cf15ae07a4bc0
Signed-off-by: default avatarArun KS <arunks@codeaurora.org>
parent d0d5319f

drivers/soc/qcom/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -2,6 +2,13 @@ 
# QCOM Soc drivers

#

source "drivers/soc/qcom/hab/Kconfig"

config MSM_PASR

	bool "MSM DDR Partial Array Self-Refresh Driver"

	help

	  RPM controls DDR functionaliy. This driver

	  is an interface for linux memory hotplug to RPM

	  for start/stop self-refresh of hot added or removed

	  memory in DDR.



config MSM_INRUSH_CURRENT_MITIGATION

	bool "Inrush-current mitigation Driver"

drivers/soc/qcom/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ obj-$(CONFIG_MSM_PFE_WA) += pfe-wa.o 
obj-$(CONFIG_ARCH_MSM8996) += msm_cpu_voltage.o



obj-$(CONFIG_MSM_PERFORMANCE) += msm_performance.o

obj-$(CONFIG_MSM_PASR) += pasr.o



ifdef CONFIG_MSM_SUBSYSTEM_RESTART

	obj-y += subsystem_notif.o

drivers/soc/qcom/pasr.c

0 → 100644
+95 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 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.  See the

 * GNU General Public License for more details.

 */



#include <linux/memory.h>

#include <linux/module.h>

#include <soc/qcom/rpm-smd.h>



struct memory_refresh_request {

	u64 start;	/* Lower bit signifies action

			 * 0 - disable self-refresh

			 * 1 - enable self-refresh

			 * upper bits are for base address

			 */

	size_t size;	/* size of memory region */

};

#define RPM_DDR_REQ 0x726464



static void mem_region_refresh_control(unsigned long pfn,

		unsigned long nr_pages, bool enable)

{

	struct memory_refresh_request mem_req;

	struct msm_rpm_kvp rpm_kvp;

	int ret;



	mem_req.start = enable;

	mem_req.start |= pfn << PAGE_SHIFT;

	mem_req.size = nr_pages * PAGE_SIZE;



	rpm_kvp.key = RPM_DDR_REQ;

	rpm_kvp.data = (void *)&mem_req;

	rpm_kvp.length = sizeof(mem_req);



	ret = msm_rpm_send_message(MSM_RPM_CTX_ACTIVE_SET, RPM_DDR_REQ, 0,

					&rpm_kvp, 1);

	if (ret)

		pr_err("PASR: Failed to send rpm message\n");

}



static int pasr_callback(struct notifier_block *self,

				unsigned long action, void *arg)

{

	struct memory_notify *mn = arg;

	unsigned long start, end;



	start = SECTION_ALIGN_DOWN(mn->start_pfn);

	end = SECTION_ALIGN_UP(mn->start_pfn + mn->nr_pages);



	if ((start != mn->start_pfn) || (end != mn->start_pfn + mn->nr_pages)) {

		pr_err("PASR: %s pfn not aligned to section\n", __func__);

		pr_err("PASR: start pfn = %lu end pfn = %lu\n",

			mn->start_pfn, mn->start_pfn + mn->nr_pages);

		return -EINVAL;

	}



	switch (action) {

	case MEM_GOING_ONLINE:

		pr_debug("PASR: MEM_GOING_ONLINE : start = %lx end = %lx",

			mn->start_pfn << PAGE_SHIFT,

			(mn->start_pfn + mn->nr_pages) << PAGE_SHIFT);

		mem_region_refresh_control(mn->start_pfn, mn->nr_pages, true);

		break;

	case MEM_OFFLINE:

		pr_debug("PASR: MEM_OFFLINE: start = %lx end = %lx",

			mn->start_pfn << PAGE_SHIFT,

			(mn->start_pfn + mn->nr_pages) << PAGE_SHIFT);

		mem_region_refresh_control(mn->start_pfn, mn->nr_pages, false);

		break;

	case MEM_CANCEL_ONLINE:

		pr_debug("PASR: MEM_CANCEL_ONLINE: start = %lx end = %lx",

			mn->start_pfn << PAGE_SHIFT,

			(mn->start_pfn + mn->nr_pages) << PAGE_SHIFT);

		mem_region_refresh_control(mn->start_pfn, mn->nr_pages, false);

		break;

	default:

		break;

	}



	return NOTIFY_OK;

}



static int __init pasr_module_init(void)

{

	return hotplug_memory_notifier(pasr_callback, 0);

}

late_initcall(pasr_module_init);