linaro-kernel March 2013

linaro-kernel@lists.linaro.org

83 participants
82 discussions

by Daniel Lezcano

When a cpu goes to a deep idle state where its local timer is shutdown, it notifies the time framework to use the broadcast timer instead. Unfortunately, the broadcast device could wake up any CPU, including an idle one which is not concerned by the wake up at all. This implies, in the worst case, an idle CPU will wake up to send an IPI to another idle cpu. This patch solves this by setting the irq affinity to the cpu concerned by the nearest timer event, by this way, the CPU which is wake up is guarantee to be the one concerned by the next event and we are safe with unnecessary wakeup for another idle CPU. As the irq affinity is not supported by all the archs, a flag is needed to specify which clocksource can handle it. Daniel Lezcano (3): time : pass broadcast parameter time : set broadcast irq affinity ARM: nomadik: add dynamic irq flag to the timer Viresh Kumar (1): ARM: timer-sp: Set dynamic irq affinity arch/arm/common/timer-sp.c | 3 ++- drivers/clocksource/nomadik-mtu.c | 3 ++- include/linux/clockchips.h | 1 + kernel/time/tick-broadcast.c | 40 +++++++++++++++++++++++++++++-------- 4 files changed, 37 insertions(+), 10 deletions(-) -- 1.7.9.5

11 years, 1 month

[PATCH v13 0/2] Add display-timing node parsing to exynos drm fimd

by Vikas Sajjan

Add display-timing node parsing to drm fimd and depends on the display helper patchset at http://lists.freedesktop.org/archives/dri-devel/2013-January/033998.html changes since v12: - Added dependency of "OF" for exynos drm fimd as suggested by Inki Dae <inki.dae(a)samsung.com> changes since v11: - Oops, there was a build error, fixed that. changes since v10: - abandoned the pinctrl patch, as commented by Linus Walleij <linus.walleij(a)linaro.org> - added new patch to enable the OF_VIDEOMODE and FB_MODE_HELPERS for EXYNOS DRM FIMD. changes since v9: - replaced IS_ERR_OR_NULL() with IS_ERR(), since IS_ERR_OR_NULL() will be depreciated, as discussed at http://lists.infradead.org/pipermail/linux-arm-kernel/2013-January/140543.h… http://www.mail-archive.com/linux-omap@vger.kernel.org/msg78030.html changes since v8: - replaced IS_ERR() with IS_ERR_OR_NULL(), because devm_pinctrl_get_select_default can return NULL, If CONFIG_PINCTRL is disabled. - modified the error log, such that it shall NOT cross 80 column. - added Acked-by. changes since v7: - addressed comments from Joonyoung Shim <jy0922.shim(a)samsung.com> to remove a unnecessary variable. changes since v6: addressed comments from Inki Dae <inki.dae(a)samsung.com> to separated out the pinctrl functionality and made a separate patch. changes since v5: - addressed comments from Inki Dae <inki.dae(a)samsung.com>, to remove the allocation of 'fbmode' and replaced '-1'in "of_get_fb_videomode(dev->of_node, fbmode, -1)" with OF_USE_NATIVE_MODE. changes since v4: - addressed comments from Paul Menzel <paulepanter(a)users.sourceforge.net>, to modify the commit message changes since v3: - addressed comments from Sean Paul <seanpaul(a)chromium.org>, to modify the return values and print messages. changes since v2: - moved 'devm_pinctrl_get_select_default' function call under 'if (pdev->dev.of_node)', this makes NON-DT code unchanged. (reported by: Rahul Sharma <r.sh.open(a)gmail.com>) changes since v1: - addressed comments from Sean Paul <seanpaul(a)chromium.org> Vikas Sajjan (2): video: drm: exynos: Add display-timing node parsing using video helper function drm/exynos: enable OF_VIDEOMODE and FB_MODE_HELPERS for exynos drm fimd drivers/gpu/drm/exynos/Kconfig | 4 +++- drivers/gpu/drm/exynos/exynos_drm_fimd.c | 24 ++++++++++++++++++++---- 2 files changed, 23 insertions(+), 5 deletions(-) -- 1.7.9.5

11 years, 1 month

ARM architected timers question.

by dpc＠ucore.info

Hi, I'm developing a baremetal hypervisor for Cortex-A15 and I'm using Arndale Board as a reference platform. ATM, I'm working on running Linaro 13.02 as a guest. I've noticed that `arch/arm/kernel/arch_timer.c` Linux prefers the virtual IRQ timers (CNTV_): static bool arch_timer_use_virtual = false; as a timer source and I'm wondering if there's a reason for this. Is it even possible for virtual timer to be available, while physical one is not? I don't think so. So why would Linux want to default to virtual one instead of physical one, especially in the situation when it was started in SVC mode and HYP is not accessible to it? >From Hypervisor point of view, it seems natural that guest does not care about virtualization stuff, does not try to be smarter than necessary and simply uses physical timer (PL1) all the time. It's hypervisor's job to trap guest accesses to physical timer (CNTP_) and route them to virtual timer (CNTV_) so virtual offset (CNTVOFF) value can be easily switched (again, by hypervisor, not the guest) when handling multiple guests, to correctly handle virtual time for them. In opposite direction the hardware virtual timer irq is just renumbered to appear to guest as a physical one. While emulating the CNTVOFF and CNTV_ is entirely possible too and required for completeness, it seems like additional work for no apparent reason. So I wanted to clarify this. Maybe there is something that I don't understand or I misread the intentions described in reference manual. -- Dawid Ciężarkiewicz B-Labs. http://b-labs.com/

11 years, 1 month

[PATCH v12 0/2] Add display-timing node parsing to exynos drm fimd

by Vikas Sajjan

Add display-timing node parsing to drm fimd and depends on the display helper patchset at http://lists.freedesktop.org/archives/dri-devel/2013-January/033998.html changes since v11: - Oops, there was a build error, fixed that. changes since v10: - abandoned the pinctrl patch, as commented by Linus Walleij <linus.walleij(a)linaro.org> - added new patch to enable the OF_VIDEOMODE and FB_MODE_HELPERS for EXYNOS DRM FIMD. changes since v9: - replaced IS_ERR_OR_NULL() with IS_ERR(), since IS_ERR_OR_NULL() will be depreciated, as discussed at http://lists.infradead.org/pipermail/linux-arm-kernel/2013-January/140543.h… http://www.mail-archive.com/linux-omap@vger.kernel.org/msg78030.html changes since v8: - replaced IS_ERR() with IS_ERR_OR_NULL(), because devm_pinctrl_get_select_default can return NULL, If CONFIG_PINCTRL is disabled. - modified the error log, such that it shall NOT cross 80 column. - added Acked-by. changes since v7: - addressed comments from Joonyoung Shim <jy0922.shim(a)samsung.com> to remove a unnecessary variable. changes since v6: addressed comments from Inki Dae <inki.dae(a)samsung.com> to separated out the pinctrl functionality and made a separate patch. changes since v5: - addressed comments from Inki Dae <inki.dae(a)samsung.com>, to remove the allocation of 'fbmode' and replaced '-1'in "of_get_fb_videomode(dev->of_node, fbmode, -1)" with OF_USE_NATIVE_MODE. changes since v4: - addressed comments from Paul Menzel <paulepanter(a)users.sourceforge.net>, to modify the commit message changes since v3: - addressed comments from Sean Paul <seanpaul(a)chromium.org>, to modify the return values and print messages. changes since v2: - moved 'devm_pinctrl_get_select_default' function call under 'if (pdev->dev.of_node)', this makes NON-DT code unchanged. (reported by: Rahul Sharma <r.sh.open(a)gmail.com>) changes since v1: - addressed comments from Sean Paul <seanpaul(a)chromium.org> Vikas Sajjan (2): video: drm: exynos: Add display-timing node parsing using video helper function drm/exynos: enable OF_VIDEOMODE and FB_MODE_HELPERS for exynos drm fimd drivers/gpu/drm/exynos/Kconfig | 2 ++ drivers/gpu/drm/exynos/exynos_drm_fimd.c | 27 +++++++++++++++++++++++---- 2 files changed, 25 insertions(+), 4 deletions(-) -- 1.7.9.5

11 years, 1 month

[PATCH] cpufreq: ARM big LITTLE: Add generic cpufreq driver and its DT glue

by Viresh Kumar

big LITTLE is ARM's new Architecture focussing power/performance needs of modern world. More information about big LITTLE can be found here: http://www.arm.com/products/processors/technologies/biglittleprocessing.php http://lwn.net/Articles/481055/ In order to keep cpufreq support for all big LITTLE platforms simple/generic, this patch tries to add a generic cpufreq driver layer for all big LITTLE platforms. The driver is divided into two parts: - Core driver: Generic and shared across all big LITTLE SoC's - Glue drivers: Per platform drivers providing ops to the core driver This patch adds in a generic glue driver which would extract information from Device Tree. Future SoC's can either reuse the DT glue or write their own depending on the need. Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha(a)arm.com> Signed-off-by: Viresh Kumar <viresh.kumar(a)linaro.org> --- This is pushed here: http://git.linaro.org/gitweb?p=people/vireshk/linux.git;a=shortlog;h=refs/h… .../bindings/cpufreq/arm_big_little_dt.txt | 29 +++ MAINTAINERS | 11 + drivers/cpufreq/Kconfig.arm | 13 + drivers/cpufreq/Makefile | 4 + drivers/cpufreq/arm_big_little.c | 278 +++++++++++++++++++++ drivers/cpufreq/arm_big_little.h | 40 +++ drivers/cpufreq/arm_big_little_dt.c | 125 +++++++++ 7 files changed, 500 insertions(+) create mode 100644 Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt create mode 100644 drivers/cpufreq/arm_big_little.c create mode 100644 drivers/cpufreq/arm_big_little.h create mode 100644 drivers/cpufreq/arm_big_little_dt.c diff --git a/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt b/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt new file mode 100644 index 0000000..6f534eb --- /dev/null +++ b/Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt @@ -0,0 +1,29 @@ +Generic ARM big LITTLE cpufreq driver's DT glue +----------------------------------------------- + +It is DT specific glue layer for generic cpufreq driver for big LITTLE systems. + +Both required and optional properties listed below must be defined under node +cluster*. * can be 0 or 1. + +Required properties: +- freqs: List of all supported frequencies. + +Optional properties: +- clock-latency: Specify the possible maximum transition latency for clock, in + unit of nanoseconds. + +Examples: + +cluster0: cluster@0 { + .. + + freqs = <500000000 600000000 700000000 800000000 900000000 1000000000 1100000000 1200000000>; + clock-latency = <200000>; + + .. + + cores { + .. + }; +}; diff --git a/MAINTAINERS b/MAINTAINERS index 554fd30..b14b749 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2206,6 +2206,17 @@ S: Maintained F: drivers/cpufreq/ F: include/linux/cpufreq.h +CPU FREQUENCY DRIVERS - ARM BIG LITTLE +M: Viresh Kumar <viresh.kumar(a)linaro.org> +M: Sudeep KarkadaNagesha <sudeep.karkadanagesha(a)arm.com> +L: cpufreq(a)vger.kernel.org +L: linux-pm(a)vger.kernel.org +W: http://www.arm.com/products/processors/technologies/biglittleprocessing.php +S: Maintained +F: drivers/cpufreq/arm_big_little.h +F: drivers/cpufreq/arm_big_little.c +F: drivers/cpufreq/arm_big_little_dt.c + CPUID/MSR DRIVER M: "H. Peter Anvin" <hpa(a)zytor.com> S: Maintained diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 030ddf6..fdf54a9 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -2,6 +2,19 @@ # ARM CPU Frequency scaling drivers # +config ARM_BIG_LITTLE_CPUFREQ + tristate + depends on ARM_CPU_TOPOLOGY + +config ARM_DT_BL_CPUFREQ + tristate "Generic ARM big LITTLE CPUfreq driver probed via DT" + select ARM_BIG_LITTLE_CPUFREQ + depends on OF + default n + help + This enables the Generic CPUfreq driver for ARM big.LITTLE platform. + This gets frequency tables from DT. + config ARM_OMAP2PLUS_CPUFREQ bool "TI OMAP2+" depends on ARCH_OMAP2PLUS diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index 863fd18..d1b0832 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -44,6 +44,10 @@ obj-$(CONFIG_X86_INTEL_PSTATE) += intel_pstate.o ################################################################################## # ARM SoC drivers +obj-$(CONFIG_ARM_BIG_LITTLE_CPUFREQ) += arm_big_little.o +# big LITTLE per platform glues. Keep DT_BL_CPUFREQ as the last entry in all big +# LITTLE drivers, so that it is probed last. +obj-$(CONFIG_ARM_DT_BL_CPUFREQ) += arm_big_little_dt.o obj-$(CONFIG_UX500_SOC_DB8500) += dbx500-cpufreq.o obj-$(CONFIG_ARM_S3C2416_CPUFREQ) += s3c2416-cpufreq.o obj-$(CONFIG_ARM_S3C64XX_CPUFREQ) += s3c64xx-cpufreq.o diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c new file mode 100644 index 0000000..0d6de0e --- /dev/null +++ b/drivers/cpufreq/arm_big_little.c @@ -0,0 +1,278 @@ +/* + * ARM big.LITTLE Platforms CPUFreq support + * + * Copyright (C) 2013 ARM Ltd. + * Sudeep KarkadaNagesha <sudeep.karkadanagesha(a)arm.com> + * + * Copyright (C) 2013 Linaro. + * Viresh Kumar <viresh.kumar(a)linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/clk.h> +#include <linux/cpufreq.h> +#include <linux/cpumask.h> +#include <linux/export.h> +#include <linux/of_platform.h> +#include <linux/slab.h> +#include <linux/topology.h> +#include <linux/types.h> + +#include "arm_big_little.h" + +/* Currently we support only two clusters */ +#define MAX_CLUSTERS 2 + +static struct cpufreq_arm_bL_ops *arm_bL_ops; +static struct clk *clk[MAX_CLUSTERS]; +static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS]; +static atomic_t cluster_usage[MAX_CLUSTERS] = {ATOMIC_INIT(0), ATOMIC_INIT(0)}; + +static int cpu_to_cluster(int cpu) +{ + return topology_physical_package_id(cpu); +} + +static unsigned int bL_cpufreq_get(unsigned int cpu) +{ + u32 cur_cluster = cpu_to_cluster(cpu); + + return clk_get_rate(clk[cur_cluster]) / 1000; +} + +/* Validate policy frequency range */ +static int bL_cpufreq_verify_policy(struct cpufreq_policy *policy) +{ + u32 cur_cluster = cpu_to_cluster(policy->cpu); + + return cpufreq_frequency_table_verify(policy, freq_table[cur_cluster]); +} + +/* Set clock frequency */ +static int bL_cpufreq_set_target(struct cpufreq_policy *policy, + unsigned int target_freq, unsigned int relation) +{ + struct cpufreq_freqs freqs; + u32 cpu = policy->cpu, freq_tab_idx, cur_cluster; + int ret = 0; + + cur_cluster = cpu_to_cluster(policy->cpu); + + freqs.old = bL_cpufreq_get(policy->cpu); + + /* Determine valid target frequency using freq_table */ + cpufreq_frequency_table_target(policy, freq_table[cur_cluster], + target_freq, relation, &freq_tab_idx); + freqs.new = freq_table[cur_cluster][freq_tab_idx].frequency; + + freqs.cpu = policy->cpu; + + pr_debug("%s: cpu: %d, cluster: %d, oldfreq: %d, target freq: %d, new freq: %d\n", + __func__, cpu, cur_cluster, freqs.old, target_freq, + freqs.new); + + if (freqs.old == freqs.new) + return 0; + + for_each_cpu(freqs.cpu, policy->cpus) + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + + ret = clk_set_rate(clk[cur_cluster], freqs.new * 1000); + if (ret) { + pr_err("clk_set_rate failed: %d\n", ret); + return ret; + } + + policy->cur = freqs.new; + + for_each_cpu(freqs.cpu, policy->cpus) + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + + return ret; +} + +/* translate the integer array into cpufreq_frequency_table entries */ +struct cpufreq_frequency_table * +arm_bL_copy_table_from_array(unsigned int *table, int count) +{ + int i; + + struct cpufreq_frequency_table *freq_table; + + pr_debug("%s: table: %p, count: %d\n", __func__, table, count); + + freq_table = kmalloc(sizeof(*freq_table) * (count + 1), GFP_KERNEL); + if (!freq_table) + return NULL; + + for (i = 0; i < count; i++) { + pr_debug("%s: index: %d, freq: %d\n", __func__, i, table[i]); + freq_table[i].index = i; + freq_table[i].frequency = table[i]; /* in kHZ */ + } + + freq_table[i].index = count; + freq_table[i].frequency = CPUFREQ_TABLE_END; + + return freq_table; +} +EXPORT_SYMBOL_GPL(arm_bL_copy_table_from_array); + +void arm_bL_free_freq_table(u32 cluster) +{ + pr_debug("%s: free freq table\n", __func__); + + kfree(freq_table[cluster]); +} +EXPORT_SYMBOL_GPL(arm_bL_free_freq_table); + +static void put_cluster_clk_and_freq_table(u32 cluster) +{ + if (!atomic_dec_return(&cluster_usage[cluster])) { + clk_put(clk[cluster]); + clk[cluster] = NULL; + arm_bL_ops->put_freq_tbl(cluster); + freq_table[cluster] = NULL; + pr_debug("%s: cluster: %d\n", __func__, cluster); + } +} + +static int get_cluster_clk_and_freq_table(u32 cluster) +{ + char name[9] = "cluster"; + int count; + + if (atomic_inc_return(&cluster_usage[cluster]) != 1) + return 0; + + freq_table[cluster] = arm_bL_ops->get_freq_tbl(cluster, &count); + if (!freq_table[cluster]) + goto atomic_dec; + + name[7] = cluster + '0'; + clk[cluster] = clk_get(NULL, name); + if (!IS_ERR_OR_NULL(clk[cluster])) { + pr_debug("%s: clk: %p & freq table: %p, cluster: %d\n", + __func__, clk[cluster], freq_table[cluster], + cluster); + return 0; + } + + arm_bL_ops->put_freq_tbl(cluster); + +atomic_dec: + atomic_dec(&cluster_usage[cluster]); + pr_err("%s: Failed to get data for cluster: %d\n", __func__, cluster); + return -ENODATA; +} + +/* Per-CPU initialization */ +static int bL_cpufreq_init(struct cpufreq_policy *policy) +{ + u32 cur_cluster = cpu_to_cluster(policy->cpu); + int result; + + result = get_cluster_clk_and_freq_table(cur_cluster); + if (result) + return result; + + result = cpufreq_frequency_table_cpuinfo(policy, + freq_table[cur_cluster]); + if (result) { + pr_err("CPU %d, cluster: %d invalid freq table\n", policy->cpu, + cur_cluster); + put_cluster_clk_and_freq_table(cur_cluster); + return result; + } + + cpufreq_frequency_table_get_attr(freq_table[cur_cluster], policy->cpu); + + policy->cpuinfo.transition_latency = + arm_bL_ops->get_transition_latency(cur_cluster); + policy->cur = bL_cpufreq_get(policy->cpu); + + cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu)); + + pr_info("CPU %d initialized\n", policy->cpu); + return 0; +} + +static int bL_cpufreq_exit(struct cpufreq_policy *policy) +{ + put_cluster_clk_and_freq_table(cpu_to_cluster(policy->cpu)); + pr_debug("%s: Exited, cpu: %d\n", __func__, policy->cpu); + + return 0; +} + +/* Export freq_table to sysfs */ +static struct freq_attr *bL_cpufreq_attr[] = { + &cpufreq_freq_attr_scaling_available_freqs, + NULL, +}; + +static struct cpufreq_driver bL_cpufreq_driver = { + .name = "arm-big-little", + .flags = CPUFREQ_STICKY, + .verify = bL_cpufreq_verify_policy, + .target = bL_cpufreq_set_target, + .get = bL_cpufreq_get, + .init = bL_cpufreq_init, + .exit = bL_cpufreq_exit, + .attr = bL_cpufreq_attr, +}; + +int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops) +{ + int ret; + + if (arm_bL_ops) { + pr_debug("%s: Already registered: %s, exiting\n", __func__, + arm_bL_ops->name); + return -EBUSY; + } + + if (!ops || !strlen(ops->name) || !ops->get_freq_tbl) { + pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__); + return -ENODEV; + } + + arm_bL_ops = ops; + + ret = cpufreq_register_driver(&bL_cpufreq_driver); + if (ret) { + pr_info("%s: Failed registering platform driver: %s, err: %d\n", + __func__, ops->name, ret); + arm_bL_ops = NULL; + } else { + pr_info("%s: Registered platform driver: %s\n", __func__, + ops->name); + } + + return ret; +} +EXPORT_SYMBOL_GPL(bL_cpufreq_register); + +void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops) +{ + if (arm_bL_ops != ops) { + pr_info("%s: Registered with: %s, can't unregister, exiting\n", + __func__, arm_bL_ops->name); + } + + cpufreq_unregister_driver(&bL_cpufreq_driver); + pr_info("%s: Un-registered platform driver: %s\n", __func__, + arm_bL_ops->name); + arm_bL_ops = NULL; +} +EXPORT_SYMBOL_GPL(bL_cpufreq_unregister); diff --git a/drivers/cpufreq/arm_big_little.h b/drivers/cpufreq/arm_big_little.h new file mode 100644 index 0000000..049e15d --- /dev/null +++ b/drivers/cpufreq/arm_big_little.h @@ -0,0 +1,40 @@ +/* + * ARM big.LITTLE platform's CPUFreq header file + * + * Copyright (C) 2013 ARM Ltd. + * Sudeep KarkadaNagesha <sudeep.karkadanagesha(a)arm.com> + * + * Copyright (C) 2013 Linaro. + * Viresh Kumar <viresh.kumar(a)linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#ifndef CPUFREQ_ARM_BIG_LITTLE_H +#define CPUFREQ_ARM_BIG_LITTLE_H + +#include <linux/cpufreq.h> +#include <linux/types.h> + +struct cpufreq_arm_bL_ops { + char name[CPUFREQ_NAME_LEN]; + u32 (*get_transition_latency)(u32 cluster); + struct cpufreq_frequency_table *(*get_freq_tbl)(u32 cluster, + int *count); + void (*put_freq_tbl)(u32 cluster); +}; + +struct cpufreq_frequency_table * +arm_bL_copy_table_from_array(unsigned int *table, int count); +void arm_bL_free_freq_table(u32 cluster); + +int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops); +void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops); + +#endif /* CPUFREQ_ARM_BIG_LITTLE_H */ diff --git a/drivers/cpufreq/arm_big_little_dt.c b/drivers/cpufreq/arm_big_little_dt.c new file mode 100644 index 0000000..c1eee50 --- /dev/null +++ b/drivers/cpufreq/arm_big_little_dt.c @@ -0,0 +1,125 @@ +/* + * Generic big.LITTLE CPUFreq Interface driver + * + * It provides necessary ops to arm_big_little cpufreq driver and gets + * Frequency information from Device Tree. Freq table in DT must be in KHz. + * + * Copyright (C) 2013 Linaro. + * Viresh Kumar <viresh.kumar(a)linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cpufreq.h> +#include <linux/export.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/types.h> +#include "arm_big_little.h" + +static struct cpufreq_frequency_table *generic_get_freq_tbl(u32 cluster, + int *count) +{ + struct device_node *np = NULL; + const struct property *pp; + unsigned int *table = NULL; + int cluster_id; + struct cpufreq_frequency_table *cpufreq_table; + + while ((np = of_find_node_by_name(np, "cluster"))) { + if (of_property_read_u32(np, "reg", &cluster_id)) + continue; + + if (cluster_id != cluster) + continue; + + pp = of_find_property(np, "freqs", NULL); + if (!pp) + continue; + + *count = pp->length / sizeof(u32); + if (!*count) + continue; + + table = kmalloc(sizeof(*table) * (*count), GFP_KERNEL); + if (!table) { + pr_err("%s: Failed to allocate memory for table\n", + __func__); + return NULL; + } + + of_property_read_u32_array(np, "freqs", table, *count); + break; + } + + if (!table) { + pr_err("%s: Unable to retrieve Freq table from Device Tree", + __func__); + return NULL; + } + + cpufreq_table = arm_bL_copy_table_from_array(table, *count); + kfree(table); + + return cpufreq_table; +} + +static void generic_put_freq_tbl(u32 cluster) +{ + arm_bL_free_freq_table(cluster); +} + +static u32 get_transition_latency(u32 cluster) +{ + struct device_node *np = NULL; + u32 transition_latency = CPUFREQ_ETERNAL; + int cluster_id; + + while ((np = of_find_node_by_name(np, "cluster"))) { + if (of_property_read_u32(np, "reg", &cluster_id)) + continue; + + if (cluster_id != cluster) + continue; + + of_property_read_u32(np, "clock-latency", &transition_latency); + return transition_latency; + } + + pr_err("%s: Unable to get clock-latency from DT, use CPUFREQ_ETERNAL", + __func__); + + return transition_latency; +} + +static struct cpufreq_arm_bL_ops generic_bL_ops = { + .name = "generic-bl", + .get_transition_latency = get_transition_latency, + .get_freq_tbl = generic_get_freq_tbl, + .put_freq_tbl = generic_put_freq_tbl, +}; + +static int generic_bL_init(void) +{ + return bL_cpufreq_register(&generic_bL_ops); +} +module_init(generic_bL_init); + +static void generic_bL_exit(void) +{ + return bL_cpufreq_unregister(&generic_bL_ops); +} +module_exit(generic_bL_exit); + +MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver"); +MODULE_LICENSE("GPL"); -- 1.7.12.rc2.18.g61b472e

11 years, 1 month

64k page support for ARM v7

by David Betz

Has anyone worked on adding 64k page support to the ARM v7 architecture, in particular the ARM Cortex A9? I know that there is HugeTLB support available but I'm wondering if anyone has tried making the native page size 64k rather than 4k. In other words, make PAGE_SHIFT 16 instead of 12 and all of the corresponding changes to the way page tables are handled. Has this been attempted already? Can someone point me to a patch? Thanks! David Betz

11 years, 1 month

[PATCH v11 0/2] Add display-timing node parsing to exynos drm fimd

by Vikas Sajjan

Add display-timing node parsing to drm fimd and depends on the display helper patchset at http://lists.freedesktop.org/archives/dri-devel/2013-January/033998.html changes since v10: - abandoned the pinctrl patch, as commented by Linus Walleij <linus.walleij(a)linaro.org> - added new patch to enable the OF_VIDEOMODE and FB_MODE_HELPERS for EXYNOS DRM FIMD. changes since v9: - replaced IS_ERR_OR_NULL() with IS_ERR(), since IS_ERR_OR_NULL() will be depreciated, as discussed at http://lists.infradead.org/pipermail/linux-arm-kernel/2013-January/140543.h… http://www.mail-archive.com/linux-omap@vger.kernel.org/msg78030.html changes since v8: - replaced IS_ERR() with IS_ERR_OR_NULL(), because devm_pinctrl_get_select_default can return NULL, If CONFIG_PINCTRL is disabled. - modified the error log, such that it shall NOT cross 80 column. - added Acked-by. changes since v7: - addressed comments from Joonyoung Shim <jy0922.shim(a)samsung.com> to remove a unnecessary variable. changes since v6: addressed comments from Inki Dae <inki.dae(a)samsung.com> to separated out the pinctrl functionality and made a separate patch. changes since v5: - addressed comments from Inki Dae <inki.dae(a)samsung.com>, to remove the allocation of 'fbmode' and replaced '-1'in "of_get_fb_videomode(dev->of_node, fbmode, -1)" with OF_USE_NATIVE_MODE. changes since v4: - addressed comments from Paul Menzel <paulepanter(a)users.sourceforge.net>, to modify the commit message changes since v3: - addressed comments from Sean Paul <seanpaul(a)chromium.org>, to modify the return values and print messages. changes since v2: - moved 'devm_pinctrl_get_select_default' function call under 'if (pdev->dev.of_node)', this makes NON-DT code unchanged. (reported by: Rahul Sharma <r.sh.open(a)gmail.com>) changes since v1: - addressed comments from Sean Paul <seanpaul(a)chromium.org> Vikas Sajjan (2): video: drm: exynos: Add display-timing node parsing using video helper function drm/exynos: enable OF_VIDEOMODE and FB_MODE_HELPERS for exynos drm fimd drivers/gpu/drm/exynos/Kconfig | 2 ++ drivers/gpu/drm/exynos/exynos_drm_fimd.c | 27 +++++++++++++++++++++++---- 2 files changed, 25 insertions(+), 4 deletions(-) -- 1.7.9.5

11 years, 1 month

[PATCH V2 0/2] cpufreq: governors: Avoid unnecessary per cpu timer interrupts

by Viresh Kumar

Following patch has introduced per cpu timers or works for ondemand and conservative governors. commit 2abfa876f1117b0ab45f191fb1f82c41b1cbc8fe Author: Rickard Andersson <rickard.andersson(a)stericsson.com> Date: Thu Dec 27 14:55:38 2012 +0000 cpufreq: handle SW coordinated CPUs This causes additional unnecessary interrupts on all cpus when the load is recently evaluated by any other cpu. i.e. When load is recently evaluated by cpu x, we don't really need any other cpu to evaluate this load again for the next sampling_rate time. Some sort of code is present to avoid that but we are still getting timer interrupts for all cpus. A good way of avoiding this would be to modify delays for all cpus (policy->cpus) whenever any cpu has evaluated load. This patchset tries to fix this issue. These patches are applied here: http://git.linaro.org/gitweb?p=people/vireshk/linux.git;a=shortlog;h=refs/h… V1->V2: - Dropped Workqueue modifications and use system_wq directly. Viresh Kumar (2): cpufreq: ondemand: Don't update sample_type if we don't evaluate load again cpufreq: governors: Avoid unnecessary per cpu timer interrupts drivers/cpufreq/cpufreq_conservative.c | 8 ++++--- drivers/cpufreq/cpufreq_governor.c | 39 ++++++++++++++++++++++++---------- drivers/cpufreq/cpufreq_governor.h | 2 ++ drivers/cpufreq/cpufreq_ondemand.c | 34 ++++++++++++++--------------- 4 files changed, 52 insertions(+), 31 deletions(-) -- 1.7.12.rc2.18.g61b472e

11 years, 1 month

[ACTIVITY] 2013-2-23 - 2012-03-3-1

by David Long

=== David Long === === Highlights === * I'm unfortunately still trying to sort out what chat in basic uprobes support is causing the upleveled ARM uprobe patch to behave incorrectly. I still think it's a small issue, it's just a matter of tracking it down. * Spent a little time getting ready for Connect. === Plans === * Connect-specific activities will occupy most of my time in the coming week. * Find the problem in the upleved patch and move forward. === Issues === -dl

11 years, 1 month

[ACTIVITY] (John Stultz) Feb 25 - Mar 1

by John Stultz

=== Highlights === * Got my slides ready for connect * Acked Serban's reduced scope ashmem compat_ioctl patch * Saw the experimental/android-3.8 branch showed up and send Arve a build fix patch * Reviewed the android-3.8 branch and found some staging fixes that should probably go upstream. After consulting the Google devs, sent them on to lkml. Little bit of contention on the list, so I may have to drop one and resend the rest. * Sorted out ABS travel expenses * Pinged Jason Wessel on Anton's KDB patches * Updated blueprints and held bi-weekly Android Upstreaming hangout meeting. * Sent out RFD on submitting the sync driver to staging. Got no objections, so submitted the patches. Greg seemed ok with most of it, likely to be merged for 3.10 * Got invited to, but declined a conference on the future of UTC. * Spent some time testing valid-interval lock concept for timekeeping * Did packing and prep for connect. === Plans === * Linaro Connect mostly. * Still need to review Serban's binder patches * Still need Look into Androids support of large-files with 32bit applications * Need to look into some community bugs I've been ignoring. === Issues === * NA

11 years, 1 month

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