ad5a57dfe4
Instead of maintaining 2 sets of enums/macros for tracking SMCCC version, let us drop smccc_version enum and use ARM_SMCCC_VERSION_1_x directly instead. This is in preparation to drop smccc_version here and move it separately under drivers/firmware/smccc. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Etienne Carriere <etienne.carriere@st.com> Reviewed-by: Steven Price <steven.price@arm.com> Reviewed-by: Etienne Carriere <etienne.carriere@st.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200518091222.27467-5-sudeep.holla@arm.com Signed-off-by: Will Deacon <will@kernel.org>
159 lines
3.3 KiB
C
159 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
*
|
|
* Copyright (C) 2013 Citrix Systems
|
|
*
|
|
* Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "arm-pv: " fmt
|
|
|
|
#include <linux/arm-smccc.h>
|
|
#include <linux/cpuhotplug.h>
|
|
#include <linux/export.h>
|
|
#include <linux/io.h>
|
|
#include <linux/jump_label.h>
|
|
#include <linux/printk.h>
|
|
#include <linux/psci.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/types.h>
|
|
|
|
#include <asm/paravirt.h>
|
|
#include <asm/pvclock-abi.h>
|
|
#include <asm/smp_plat.h>
|
|
|
|
struct static_key paravirt_steal_enabled;
|
|
struct static_key paravirt_steal_rq_enabled;
|
|
|
|
struct paravirt_patch_template pv_ops;
|
|
EXPORT_SYMBOL_GPL(pv_ops);
|
|
|
|
struct pv_time_stolen_time_region {
|
|
struct pvclock_vcpu_stolen_time *kaddr;
|
|
};
|
|
|
|
static DEFINE_PER_CPU(struct pv_time_stolen_time_region, stolen_time_region);
|
|
|
|
static bool steal_acc = true;
|
|
static int __init parse_no_stealacc(char *arg)
|
|
{
|
|
steal_acc = false;
|
|
return 0;
|
|
}
|
|
|
|
early_param("no-steal-acc", parse_no_stealacc);
|
|
|
|
/* return stolen time in ns by asking the hypervisor */
|
|
static u64 pv_steal_clock(int cpu)
|
|
{
|
|
struct pv_time_stolen_time_region *reg;
|
|
|
|
reg = per_cpu_ptr(&stolen_time_region, cpu);
|
|
if (!reg->kaddr) {
|
|
pr_warn_once("stolen time enabled but not configured for cpu %d\n",
|
|
cpu);
|
|
return 0;
|
|
}
|
|
|
|
return le64_to_cpu(READ_ONCE(reg->kaddr->stolen_time));
|
|
}
|
|
|
|
static int stolen_time_dying_cpu(unsigned int cpu)
|
|
{
|
|
struct pv_time_stolen_time_region *reg;
|
|
|
|
reg = this_cpu_ptr(&stolen_time_region);
|
|
if (!reg->kaddr)
|
|
return 0;
|
|
|
|
memunmap(reg->kaddr);
|
|
memset(reg, 0, sizeof(*reg));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int init_stolen_time_cpu(unsigned int cpu)
|
|
{
|
|
struct pv_time_stolen_time_region *reg;
|
|
struct arm_smccc_res res;
|
|
|
|
reg = this_cpu_ptr(&stolen_time_region);
|
|
|
|
arm_smccc_1_1_invoke(ARM_SMCCC_HV_PV_TIME_ST, &res);
|
|
|
|
if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
|
|
return -EINVAL;
|
|
|
|
reg->kaddr = memremap(res.a0,
|
|
sizeof(struct pvclock_vcpu_stolen_time),
|
|
MEMREMAP_WB);
|
|
|
|
if (!reg->kaddr) {
|
|
pr_warn("Failed to map stolen time data structure\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (le32_to_cpu(reg->kaddr->revision) != 0 ||
|
|
le32_to_cpu(reg->kaddr->attributes) != 0) {
|
|
pr_warn_once("Unexpected revision or attributes in stolen time data\n");
|
|
return -ENXIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pv_time_init_stolen_time(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = cpuhp_setup_state(CPUHP_AP_ARM_KVMPV_STARTING,
|
|
"hypervisor/arm/pvtime:starting",
|
|
init_stolen_time_cpu, stolen_time_dying_cpu);
|
|
if (ret < 0)
|
|
return ret;
|
|
return 0;
|
|
}
|
|
|
|
static bool has_pv_steal_clock(void)
|
|
{
|
|
struct arm_smccc_res res;
|
|
|
|
/* To detect the presence of PV time support we require SMCCC 1.1+ */
|
|
if (arm_smccc_1_1_get_conduit() == SMCCC_CONDUIT_NONE)
|
|
return false;
|
|
|
|
arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
|
|
ARM_SMCCC_HV_PV_TIME_FEATURES, &res);
|
|
|
|
if (res.a0 != SMCCC_RET_SUCCESS)
|
|
return false;
|
|
|
|
arm_smccc_1_1_invoke(ARM_SMCCC_HV_PV_TIME_FEATURES,
|
|
ARM_SMCCC_HV_PV_TIME_ST, &res);
|
|
|
|
return (res.a0 == SMCCC_RET_SUCCESS);
|
|
}
|
|
|
|
int __init pv_time_init(void)
|
|
{
|
|
int ret;
|
|
|
|
if (!has_pv_steal_clock())
|
|
return 0;
|
|
|
|
ret = pv_time_init_stolen_time();
|
|
if (ret)
|
|
return ret;
|
|
|
|
pv_ops.time.steal_clock = pv_steal_clock;
|
|
|
|
static_key_slow_inc(¶virt_steal_enabled);
|
|
if (steal_acc)
|
|
static_key_slow_inc(¶virt_steal_rq_enabled);
|
|
|
|
pr_info("using stolen time PV\n");
|
|
|
|
return 0;
|
|
}
|