* Re: Is: drivers/cpufreq/cpufreq-xen.c Was:Re: [PATCH 2 of 2] linux-xencommons: Load processor-passthru
2012-03-06 17:59 ` Dave Jones
@ 2012-03-08 2:12 ` Konrad Rzeszutek Wilk
2012-03-13 16:46 ` Konrad Rzeszutek Wilk
0 siblings, 1 reply; 5+ messages in thread
From: Konrad Rzeszutek Wilk @ 2012-03-08 2:12 UTC (permalink / raw)
To: Dave Jones
Cc: xen-devel, Ian.Campbell, stefano.stabellini,
Konrad Rzeszutek Wilk, Ian.Jackson, Jan Beulich
[-- Attachment #1: Type: text/plain, Size: 2739 bytes --]
> > I think what you are suggesting is that to write a driver in drivers/cpufreq/
> > that gets either started before the other ones (if built-in) or if as
> > a module gets
> > loaded from xencommons. That driver would then make the call
> > to acpi_processor_preregister_performance(),
> > acpi_processor_register_performance() and acpi_processor_notify_smm().
> > It would function as a cpufreq-scaling driver but
> > in reality all calls to it from cpufreq gov-* drivers would end up with nop.
> >
> > Dave, would you be Ok with a driver like that in your tree?
>
> I joined this thread half-way through, so I'm not sure what the original problem was.
> How is a driver that does nothing better than just masking out the cpufreq capabilities to guests ?
Hey Dave,
The problem statement is three-fold:
1). Parse and upload ACPI0007 (or PROCESSOR_TYPE) information to the
hypervisor - aka P-states.
2). Upload the Cx state information.
3). Inhibit CPU frequency scaling drivers from loading.
The reason for wanting to solve 1) and 2) is such that the Xen hypervisor
is the only one that knows the CPU usage of different guests and can
make the proper decision of when to put CPUs and packages in proper states.
Unfortunately the hypervisor has no support to parse ACPI DSDT tables, hence it
needs help from the initial domain to provide this information. The reason
for 3) is that we do not want the initial domain to change P-states while the
hypervisor is doing it as well - it causes rather some funny cases of P-states
transitions.
So in the past (old classic XenOLinux patches) there were patches
added in the drivers/acpi/processor_* to make the appropriate
hypercalls. And the CPUFREQ drivers
were not built for the xen kernels. Neither one of those is an option
for the upstream kernel.
I've been looking at how to leverage the existing wealth of
functionality that the
drivers/acpi/processor-* libs provide and trying to use that. The
first couple of versions would
harvest the data after the cpufreq scaling drivers had used and upload
them. But that
would not solve the 3) case. So then I went off in making a cpufreq
governor that would
be a nop and do 1) and 2).
The last incarnation, [see attached] instead uses the
drivers/acpi/processor_* libs to
fetch the ACPI information, calls "acpi_processor_notify_smm" to
inhibit the cpu freq scaling
drivers from being able to load. It actually works pretty well when it
is built-in, but not sure
how to make it work bullet-proof when CONFIG_X86_ACPI_CPUFREQ=m.
So my big question is whether could be a 'cpufreq.off=1' API, similar
to the "disable_cpuidle()"
call that inhibit the cpuidle drivers?
[-- Attachment #2: 0001-xen-acpi-processor-P-state-driver-that-uploads-said-.patch --]
[-- Type: text/x-patch, Size: 19564 bytes --]
From c9300173a6f1ed2ede35452216b109bc3a9a7e21 Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Date: Fri, 3 Feb 2012 16:03:20 -0500
Subject: [PATCH] xen/acpi-processor: P-state driver that uploads said data to
hypervisor.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This driver solves three problems:
1). Parse and upload ACPI0007 (or PROCESSOR_TYPE) information to the
hypervisor - aka P-states.
2). Upload the the Cx state information.
3). Inhibit CPU frequency scaling drivers from loading.
The reason for wanting to solve 1) and 2) is such that the Xen hypervisor
is the only one that knows the CPU usage of different guests and can
make the proper decision of when to put CPUs and packages in proper states.
Unfortunately the hypervisor has no support to parse ACPI DSDT tables, hence it
needs help from the initial domain to provide this information. The reason
for 3) is that we do not want the initial domain to change P-states while the
hypervisor is doing it as well - it causes rather some funny cases of P-states
transitions.
For this to work, the driver parses the Power Management data and uploads said
information to the Xen hypervisor. It also calls acpi_processor_notify_smm()
to inhibit the other CPU frequency scaling drivers from being loaded.
Everything revolves around the 'struct acpi_processor' structure which
gets updated during the bootup cycle in different stages. At the startup, when
the ACPI parser starts, the C-state information is processed (processor_idle)
and saved in said structure as 'power' element. Later on, the CPU frequency
scaling driver (powernow-k8 or acpi_cpufreq), would call the the
acpi_processor_* (processor_perflib functions) to parse P-states information
and populate in the said structure the 'performance' element.
Since we do not want the CPU frequency scaling drivers from loading
we have to call the acpi_processor_* functions to parse the P-states and
call "acpi_processor_notify_smm" to stop them from loading.
There is also one oddity in this driver which is that under Xen, the
physical online CPU count can be different from the virtual online CPU count.
Meaning that the macros 'for_[online|possible]_cpu' would process only
up to virtual online CPU count. We on the other hand want to process
the full amount of physical CPUs. For that, the driver checks if the ACPI IDs
count is different from the APIC ID count - which can happen if the user
choose to use dom0_max_vcpu argument. In such a case a backup of the PM
structure is used and uploaded to the hypervisor.
[v1-v2: Initial RFC implementations that were posted]
[v3: Changed the name to passthru suggested by Pasi Kärkkäinen <pasik@iki.fi>]
[v4: Added vCPU != pCPU support - aka dom0_max_vcpus support]
[v5: Cleaned up the driver, fix bug under Athlon XP]
[v6: Changed the driver to a CPU frequency governor]
[v7: Made it a semi-cpufreq scaling type driver suggested by Jan Beulich <jbeulich@suse.com>]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
drivers/xen/Kconfig | 17 ++
drivers/xen/Makefile | 2 +-
drivers/xen/xen-acpi-processor.c | 501 ++++++++++++++++++++++++++++++++++++++
3 files changed, 519 insertions(+), 1 deletions(-)
create mode 100644 drivers/xen/xen-acpi-processor.c
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index a1ced52..648bcd4 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -178,4 +178,21 @@ config XEN_PRIVCMD
depends on XEN
default m
+config XEN_ACPI_PROCESSOR
+ tristate "Xen ACPI processor"
+ depends on XEN && X86 && ACPI_PROCESSOR
+ default y if (X86_ACPI_CPUFREQ = y || X86_POWERNOW_K8 = y)
+ default m if (X86_ACPI_CPUFREQ = m || X86_POWERNOW_K8 = m)
+ help
+ This ACPI processor uploads Power Management information to the Xen hypervisor.
+
+ To do that the driver parses the Power Management data and uploads said
+ information to the Xen hypervisor. Then the Xen hypervisor can select the
+ proper Cx and Pxx states. It also registers itslef as the SMM so that
+ other drivers (such as ACPI cpufreq scaling driver) will not load.
+
+ To compile this driver as a module, choose M here: the
+ module will be called xen_acpi_processor If you do not know what to choose,
+ select M here. If the CPUFREQ drivers are built in, select Y here.
+
endmenu
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index aa31337..9adc5be 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -20,7 +20,7 @@ obj-$(CONFIG_SWIOTLB_XEN) += swiotlb-xen.o
obj-$(CONFIG_XEN_DOM0) += pci.o
obj-$(CONFIG_XEN_PCIDEV_BACKEND) += xen-pciback/
obj-$(CONFIG_XEN_PRIVCMD) += xen-privcmd.o
-
+obj-$(CONFIG_XEN_ACPI_PROCESSOR) += xen-acpi-processor.o
xen-evtchn-y := evtchn.o
xen-gntdev-y := gntdev.o
xen-gntalloc-y := gntalloc.o
diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c
new file mode 100644
index 0000000..b6f5470
--- /dev/null
+++ b/drivers/xen/xen-acpi-processor.c
@@ -0,0 +1,501 @@
+/*
+ * Copyright 2012 by Oracle Inc
+ * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+ *
+ * This code borrows ideas from https://lkml.org/lkml/2011/11/30/249
+ * so many thanks go to Kevin Tian <kevin.tian@intel.com>
+ * and Yu Ke <ke.yu@intel.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/cpumask.h>
+#include <linux/cpufreq.h>
+#include <linux/freezer.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/processor.h>
+
+#include <xen/interface/platform.h>
+#include <asm/xen/hypercall.h>
+
+#define DRV_NAME "xen-acpi-processor"
+
+static int no_hypercall;
+MODULE_PARM_DESC(off, "Inhibit the hypercall.");
+module_param_named(off, no_hypercall, int, 0400);
+
+/*
+ * Mutex to protect the acpi_ids_done.
+ */
+static DEFINE_MUTEX(acpi_ids_mutex);
+/*
+ * Don't think convert this to cpumask_var_t or use cpumask_bit - as those
+ * shrink to nr_cpu_bits (which is dependent on possible_cpu), which can be
+ * less than what we want to put in.
+ */
+#define NR_ACPI_CPUS NR_CPUS
+#define MAX_ACPI_BITS (BITS_TO_LONGS(NR_ACPI_CPUS))
+static unsigned long *acpi_ids_done;
+/*
+ * Again, don't convert to cpumask - as we are reading the raw ACPI CPU ids
+ * which can go beyond what we presently see.
+ */
+static unsigned long *acpi_id_present;
+
+static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
+{
+ struct xen_platform_op op = {
+ .cmd = XENPF_set_processor_pminfo,
+ .interface_version = XENPF_INTERFACE_VERSION,
+ .u.set_pminfo.id = _pr->acpi_id,
+ .u.set_pminfo.type = XEN_PM_CX,
+ };
+ struct xen_processor_cx *dst_cx, *dst_cx_states = NULL;
+ struct acpi_processor_cx *cx;
+ int i, ok, ret = 0;
+
+ dst_cx_states = kcalloc(_pr->power.count,
+ sizeof(struct xen_processor_cx), GFP_KERNEL);
+ if (!dst_cx_states)
+ return -ENOMEM;
+
+ for (ok = 0, i = 1; i <= _pr->power.count; i++) {
+ cx = &_pr->power.states[i];
+ if (!cx->valid)
+ continue;
+
+ dst_cx = &(dst_cx_states[ok++]);
+
+ dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO;
+ if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
+ dst_cx->reg.bit_width = 8;
+ dst_cx->reg.bit_offset = 0;
+ dst_cx->reg.access_size = 1;
+ } else {
+ dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE;
+ if (cx->entry_method == ACPI_CSTATE_FFH) {
+ /* NATIVE_CSTATE_BEYOND_HALT */
+ dst_cx->reg.bit_offset = 2;
+ dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */
+ }
+ dst_cx->reg.access_size = 0;
+ }
+ dst_cx->reg.address = cx->address;
+
+ dst_cx->type = cx->type;
+ dst_cx->latency = cx->latency;
+ dst_cx->power = cx->power;
+
+ dst_cx->dpcnt = 0;
+ set_xen_guest_handle(dst_cx->dp, NULL);
+ }
+ if (!ok) {
+ pr_err(DRV_NAME ": No _Cx for CPU %d\n", _pr->acpi_id);
+ kfree(dst_cx_states);
+ return -EINVAL;
+ }
+ op.u.set_pminfo.power.count = ok;
+ op.u.set_pminfo.power.flags.bm_control = _pr->flags.bm_control;
+ op.u.set_pminfo.power.flags.bm_check = _pr->flags.bm_check;
+ op.u.set_pminfo.power.flags.has_cst = _pr->flags.has_cst;
+ op.u.set_pminfo.power.flags.power_setup_done =
+ _pr->flags.power_setup_done;
+
+ set_xen_guest_handle(op.u.set_pminfo.power.states, dst_cx_states);
+
+ if (!no_hypercall)
+ ret = HYPERVISOR_dom0_op(&op);
+
+ if (!ret) {
+ pr_debug("CPU%u - ACPI C-states uploaded.\n", _pr->acpi_id);
+ for (i = 1; i <= _pr->power.count; i++) {
+ cx = &_pr->power.states[i];
+ if (!cx->valid)
+ continue;
+ pr_debug(" C%d: %s, %d uS\n",
+ cx->type, cx->desc, (u32)cx->latency);
+ }
+ } else
+ pr_err(DRV_NAME "(CX): Hypervisor error (%d) for ACPI ID: %d\n",
+ ret, _pr->acpi_id);
+
+ kfree(dst_cx_states);
+
+ return ret;
+}
+static struct xen_processor_px *
+xen_copy_pss_data(struct acpi_processor *_pr,
+ struct xen_processor_performance *dst_perf)
+{
+ struct xen_processor_px *dst_states = NULL;
+ int i;
+
+ BUILD_BUG_ON(sizeof(struct xen_processor_px) !=
+ sizeof(struct acpi_processor_px));
+
+ dst_states = kcalloc(_pr->performance->state_count,
+ sizeof(struct xen_processor_px), GFP_KERNEL);
+ if (!dst_states)
+ return ERR_PTR(-ENOMEM);
+
+ dst_perf->state_count = _pr->performance->state_count;
+ for (i = 0; i < _pr->performance->state_count; i++) {
+ /* Fortunatly for us, they are both the same size */
+ memcpy(&(dst_states[i]), &(_pr->performance->states[i]),
+ sizeof(struct acpi_processor_px));
+ }
+ return dst_states;
+}
+static int xen_copy_psd_data(struct acpi_processor *_pr,
+ struct xen_processor_performance *dst)
+{
+ BUILD_BUG_ON(sizeof(struct xen_psd_package) !=
+ sizeof(struct acpi_psd_package));
+
+ if (_pr->performance->shared_type != CPUFREQ_SHARED_TYPE_NONE) {
+ dst->shared_type = _pr->performance->shared_type;
+
+ memcpy(&(dst->domain_info), &(_pr->performance->domain_info),
+ sizeof(struct acpi_psd_package));
+ return 0;
+ }
+ return -EINVAL;
+}
+static int xen_copy_pct_data(struct acpi_pct_register *pct,
+ struct xen_pct_register *dst_pct)
+{
+ /* It would be nice if you could just do 'memcpy(pct, dst_pct') but
+ * sadly the Xen structure did not have the proper padding so the
+ * descriptor field takes two (dst_pct) bytes instead of one (pct).
+ */
+ dst_pct->descriptor = pct->descriptor;
+ dst_pct->length = pct->length;
+ dst_pct->space_id = pct->space_id;
+ dst_pct->bit_width = pct->bit_width;
+ dst_pct->bit_offset = pct->bit_offset;
+ dst_pct->reserved = pct->reserved;
+ dst_pct->address = pct->address;
+ return 0;
+}
+static int push_pxx_to_hypervisor(struct acpi_processor *_pr)
+{
+ int ret = 0;
+ struct xen_platform_op op = {
+ .cmd = XENPF_set_processor_pminfo,
+ .interface_version = XENPF_INTERFACE_VERSION,
+ .u.set_pminfo.id = _pr->acpi_id,
+ .u.set_pminfo.type = XEN_PM_PX,
+ };
+ struct xen_processor_performance *dst_perf;
+ struct xen_processor_px *dst_states = NULL;
+
+ dst_perf = &op.u.set_pminfo.perf;
+
+ dst_perf->platform_limit = _pr->performance_platform_limit;
+ dst_perf->flags |= XEN_PX_PPC;
+ xen_copy_pct_data(&(_pr->performance->control_register),
+ &dst_perf->control_register);
+ xen_copy_pct_data(&(_pr->performance->status_register),
+ &dst_perf->status_register);
+ dst_perf->flags |= XEN_PX_PCT;
+ dst_states = xen_copy_pss_data(_pr, dst_perf);
+ if (!IS_ERR_OR_NULL(dst_states)) {
+ set_xen_guest_handle(dst_perf->states, dst_states);
+ dst_perf->flags |= XEN_PX_PSS;
+ }
+ if (!xen_copy_psd_data(_pr, dst_perf))
+ dst_perf->flags |= XEN_PX_PSD;
+
+ if (dst_perf->flags != (XEN_PX_PSD | XEN_PX_PSS | XEN_PX_PCT | XEN_PX_PPC)) {
+ ret = -ENODEV;
+ goto clean;
+ }
+
+ if (!no_hypercall)
+ ret = HYPERVISOR_dom0_op(&op);
+
+ if (!ret) {
+ struct acpi_processor_performance *perf;
+ int i;
+
+ perf = _pr->performance;
+ pr_debug("CPU%u - ACPI P-states uploaded.\n", _pr->acpi_id);
+ for (i = 0; i < perf->state_count; i++) {
+ pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n",
+ (i == perf->state ? '*' : ' '), i,
+ (u32) perf->states[i].core_frequency,
+ (u32) perf->states[i].power,
+ (u32) perf->states[i].transition_latency);
+ }
+ } else
+ pr_err(DRV_NAME "(_PXX): Hypervisor error (%d) for ACPI ID %d\n",
+ ret, _pr->acpi_id);
+clean:
+ if (!IS_ERR_OR_NULL(dst_states))
+ kfree(dst_states);
+
+ return ret;
+}
+static int upload_pm_data(struct acpi_processor *_pr)
+{
+ int err = 0;
+
+ mutex_lock(&acpi_ids_mutex);
+ if (__test_and_set_bit(_pr->acpi_id, acpi_ids_done)) {
+ mutex_unlock(&acpi_ids_mutex);
+ return -EBUSY;
+ }
+ if (_pr->flags.power)
+ err = push_cxx_to_hypervisor(_pr);
+
+ if (_pr->performance && _pr->performance->states)
+ err |= push_pxx_to_hypervisor(_pr);
+
+ mutex_unlock(&acpi_ids_mutex);
+ return err;
+}
+static int xen_cpu_soft_notify(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+ struct acpi_processor *_pr = per_cpu(processors, cpu);
+
+ if (action == CPU_ONLINE && _pr)
+ (void)upload_pm_data(_pr);
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block xen_cpu_notifier = {
+ .notifier_call = xen_cpu_soft_notify,
+ .priority = -1, /* Be the last one */
+};
+
+static acpi_status __init
+read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+ u32 acpi_id;
+ acpi_status status;
+ acpi_object_type acpi_type;
+ unsigned long long tmp;
+ union acpi_object object = { 0 };
+ struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
+
+ status = acpi_get_type(handle, &acpi_type);
+ if (ACPI_FAILURE(status))
+ return AE_OK;
+
+ switch (acpi_type) {
+ case ACPI_TYPE_PROCESSOR:
+ status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
+ if (ACPI_FAILURE(status))
+ return AE_OK;
+ acpi_id = object.processor.proc_id;
+ break;
+ case ACPI_TYPE_DEVICE:
+ status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
+ if (ACPI_FAILURE(status))
+ return AE_OK;
+ acpi_id = tmp;
+ break;
+ default:
+ return AE_OK;
+ }
+ if (acpi_id > NR_ACPI_CPUS) {
+ WARN_ONCE(1, "There are %d ACPI processors, but kernel can only do %d!\n",
+ acpi_id, NR_ACPI_CPUS);
+ return AE_OK;
+ }
+ __set_bit(acpi_id, acpi_id_present);
+
+ return AE_OK;
+}
+static int __init check_acpi_ids(struct acpi_processor *pr_backup)
+{
+ if (!pr_backup)
+ return -ENODEV;
+
+ /* All online CPUs have been processed at this stage. Now verify
+ * whether in fact "online CPUs" == physical CPUs.
+ */
+ acpi_id_present = kcalloc(MAX_ACPI_BITS, sizeof(unsigned long), GFP_KERNEL);
+ if (!acpi_id_present)
+ return -ENOMEM;
+
+ memset(acpi_id_present, 0, MAX_ACPI_BITS * sizeof(unsigned long));
+
+ acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX,
+ read_acpi_id, NULL, NULL, NULL);
+ acpi_get_devices("ACPI0007", read_acpi_id, NULL, NULL);
+
+ if (!bitmap_equal(acpi_id_present, acpi_ids_done, MAX_ACPI_BITS)) {
+ int cpu;
+
+ for_each_set_bit(cpu, acpi_id_present, MAX_ACPI_BITS) {
+ pr_backup->acpi_id = cpu;
+ (void)upload_pm_data(pr_backup);
+ }
+ }
+ kfree(acpi_id_present);
+ acpi_id_present = NULL;
+
+ return 0;
+}
+static int __init check_prereq(void)
+{
+ struct cpuinfo_x86 *c = &cpu_data(0);
+
+ if (!xen_initial_domain())
+ return -ENODEV;
+
+ if (!acpi_gbl_FADT.smi_command)
+ return -ENODEV;
+
+ if (c->x86_vendor == X86_VENDOR_INTEL) {
+ if (!cpu_has(c, X86_FEATURE_EST))
+ return -ENODEV;
+
+ return 0;
+ }
+ if (c->x86_vendor == X86_VENDOR_AMD) {
+ /* Copied from powernow-k8.h, can't include ../xen-acpi-processor/powernow
+ * as we get compile warnings for the static functions.
+ */
+#define CPUID_FREQ_VOLT_CAPABILITIES 0x80000007
+#define USE_HW_PSTATE 0x00000080
+ u32 eax, ebx, ecx, edx;
+ cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
+ if ((edx & USE_HW_PSTATE) != USE_HW_PSTATE)
+ return -ENODEV;
+ return 0;
+ }
+ return -ENODEV;
+}
+/* acpi_perf_data is a pointer to percpu data. */
+static struct acpi_processor_performance __percpu *acpi_perf_data;
+
+static void free_acpi_perf_data(void)
+{
+ unsigned int i;
+
+ /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
+ for_each_possible_cpu(i)
+ free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
+ ->shared_cpu_map);
+ free_percpu(acpi_perf_data);
+}
+
+static int __init xen_acpi_processor_init(void)
+{
+ struct acpi_processor *pr_backup = NULL;
+ int i, rc = check_prereq();
+
+ if (rc)
+ return rc;
+
+ acpi_ids_done = kcalloc(MAX_ACPI_BITS, sizeof(unsigned long), GFP_KERNEL);
+ if (!acpi_ids_done)
+ return -ENOMEM;
+
+ memset(acpi_ids_done, 0, MAX_ACPI_BITS * sizeof(unsigned long));
+
+ acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
+ if (!acpi_perf_data) {
+ pr_debug("Memory allocation error for acpi_perf_data.\n");
+ kfree(acpi_ids_done);
+ return -ENOMEM;
+ }
+ for_each_possible_cpu(i) {
+ if (!zalloc_cpumask_var_node(
+ &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
+ GFP_KERNEL, cpu_to_node(i))) {
+ rc = -ENOMEM;
+ goto err_out;
+ }
+ }
+
+ /* Do initialization in ACPI core */
+ rc = acpi_processor_preregister_performance(acpi_perf_data);
+ if (rc)
+ goto err_out;
+
+ for_each_possible_cpu(i) {
+ struct acpi_processor_performance *perf;
+
+ perf = per_cpu_ptr(acpi_perf_data, i);
+ rc = acpi_processor_register_performance(perf, i);
+ if (rc)
+ goto err_out;
+ }
+ rc = acpi_processor_notify_smm(THIS_MODULE);
+ if (rc)
+ goto err_unregister;
+
+ for_each_possible_cpu(i) {
+ struct acpi_processor *_pr;
+ _pr = per_cpu(processors, i /* APIC ID */);
+ if (!_pr)
+ continue;
+
+ if (!pr_backup) {
+ pr_backup = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
+ memcpy(pr_backup, _pr, sizeof(struct acpi_processor));
+ }
+ (void)upload_pm_data(_pr);
+ }
+ rc = check_acpi_ids(pr_backup);
+ if (rc)
+ goto err_unregister;
+
+ kfree(pr_backup);
+ register_hotcpu_notifier(&xen_cpu_notifier);
+
+ return 0;
+err_unregister:
+ for_each_possible_cpu(i) {
+ struct acpi_processor_performance *perf;
+ perf = per_cpu_ptr(acpi_perf_data, i);
+ acpi_processor_unregister_performance(perf, i);
+ }
+err_out:
+ /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
+ free_acpi_perf_data();
+ kfree(acpi_ids_done);
+ return rc;
+}
+static void __exit xen_acpi_processor_exit(void)
+{
+ int i;
+
+ unregister_hotcpu_notifier(&xen_cpu_notifier);
+ kfree(acpi_ids_done);
+ for_each_possible_cpu(i) {
+ struct acpi_processor_performance *perf;
+ perf = per_cpu_ptr(acpi_perf_data, i);
+ acpi_processor_unregister_performance(perf, i);
+ }
+ free_acpi_perf_data();
+}
+
+MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>");
+MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor");
+MODULE_LICENSE("GPL");
+
+/* We want to be loaded before the CPU freq scaling drivers are loaded. */
+device_initcall(xen_acpi_processor_init);
+module_exit(xen_acpi_processor_exit);
--
1.7.9.48.g85da4d
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