OpenCloudOS-Kernel/arch/arm64/kernel/paravirt.c

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// 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);
arm64: paravirt: Initialize steal time when cpu is online Steal time initialization requires mapping a memory region which invokes a memory allocation. Doing this at CPU starting time results in the following trace when CONFIG_DEBUG_ATOMIC_SLEEP is enabled: BUG: sleeping function called from invalid context at mm/slab.h:498 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #1 Call trace: dump_backtrace+0x0/0x208 show_stack+0x1c/0x28 dump_stack+0xc4/0x11c ___might_sleep+0xf8/0x130 __might_sleep+0x58/0x90 slab_pre_alloc_hook.constprop.101+0xd0/0x118 kmem_cache_alloc_node_trace+0x84/0x270 __get_vm_area_node+0x88/0x210 get_vm_area_caller+0x38/0x40 __ioremap_caller+0x70/0xf8 ioremap_cache+0x78/0xb0 memremap+0x9c/0x1a8 init_stolen_time_cpu+0x54/0xf0 cpuhp_invoke_callback+0xa8/0x720 notify_cpu_starting+0xc8/0xd8 secondary_start_kernel+0x114/0x180 CPU1: Booted secondary processor 0x0000000001 [0x431f0a11] However we don't need to initialize steal time at CPU starting time. We can simply wait until CPU online time, just sacrificing a bit of accuracy by returning zero for steal time until we know better. While at it, add __init to the functions that are only called by pv_time_init() which is __init. Signed-off-by: Andrew Jones <drjones@redhat.com> Fixes: e0685fa228fd ("arm64: Retrieve stolen time as paravirtualized guest") Cc: stable@vger.kernel.org Reviewed-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20200916154530.40809-1-drjones@redhat.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-09-16 23:45:30 +08:00
/*
* paravirt_steal_clock() may be called before the CPU
* online notification callback runs. Until the callback
* has run we just return zero.
*/
if (!reg->kaddr)
return 0;
return le64_to_cpu(READ_ONCE(reg->kaddr->stolen_time));
}
arm64: paravirt: Initialize steal time when cpu is online Steal time initialization requires mapping a memory region which invokes a memory allocation. Doing this at CPU starting time results in the following trace when CONFIG_DEBUG_ATOMIC_SLEEP is enabled: BUG: sleeping function called from invalid context at mm/slab.h:498 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #1 Call trace: dump_backtrace+0x0/0x208 show_stack+0x1c/0x28 dump_stack+0xc4/0x11c ___might_sleep+0xf8/0x130 __might_sleep+0x58/0x90 slab_pre_alloc_hook.constprop.101+0xd0/0x118 kmem_cache_alloc_node_trace+0x84/0x270 __get_vm_area_node+0x88/0x210 get_vm_area_caller+0x38/0x40 __ioremap_caller+0x70/0xf8 ioremap_cache+0x78/0xb0 memremap+0x9c/0x1a8 init_stolen_time_cpu+0x54/0xf0 cpuhp_invoke_callback+0xa8/0x720 notify_cpu_starting+0xc8/0xd8 secondary_start_kernel+0x114/0x180 CPU1: Booted secondary processor 0x0000000001 [0x431f0a11] However we don't need to initialize steal time at CPU starting time. We can simply wait until CPU online time, just sacrificing a bit of accuracy by returning zero for steal time until we know better. While at it, add __init to the functions that are only called by pv_time_init() which is __init. Signed-off-by: Andrew Jones <drjones@redhat.com> Fixes: e0685fa228fd ("arm64: Retrieve stolen time as paravirtualized guest") Cc: stable@vger.kernel.org Reviewed-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20200916154530.40809-1-drjones@redhat.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-09-16 23:45:30 +08:00
static int stolen_time_cpu_down_prepare(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;
}
arm64: paravirt: Initialize steal time when cpu is online Steal time initialization requires mapping a memory region which invokes a memory allocation. Doing this at CPU starting time results in the following trace when CONFIG_DEBUG_ATOMIC_SLEEP is enabled: BUG: sleeping function called from invalid context at mm/slab.h:498 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #1 Call trace: dump_backtrace+0x0/0x208 show_stack+0x1c/0x28 dump_stack+0xc4/0x11c ___might_sleep+0xf8/0x130 __might_sleep+0x58/0x90 slab_pre_alloc_hook.constprop.101+0xd0/0x118 kmem_cache_alloc_node_trace+0x84/0x270 __get_vm_area_node+0x88/0x210 get_vm_area_caller+0x38/0x40 __ioremap_caller+0x70/0xf8 ioremap_cache+0x78/0xb0 memremap+0x9c/0x1a8 init_stolen_time_cpu+0x54/0xf0 cpuhp_invoke_callback+0xa8/0x720 notify_cpu_starting+0xc8/0xd8 secondary_start_kernel+0x114/0x180 CPU1: Booted secondary processor 0x0000000001 [0x431f0a11] However we don't need to initialize steal time at CPU starting time. We can simply wait until CPU online time, just sacrificing a bit of accuracy by returning zero for steal time until we know better. While at it, add __init to the functions that are only called by pv_time_init() which is __init. Signed-off-by: Andrew Jones <drjones@redhat.com> Fixes: e0685fa228fd ("arm64: Retrieve stolen time as paravirtualized guest") Cc: stable@vger.kernel.org Reviewed-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20200916154530.40809-1-drjones@redhat.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-09-16 23:45:30 +08:00
static int stolen_time_cpu_online(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;
}
arm64: paravirt: Initialize steal time when cpu is online Steal time initialization requires mapping a memory region which invokes a memory allocation. Doing this at CPU starting time results in the following trace when CONFIG_DEBUG_ATOMIC_SLEEP is enabled: BUG: sleeping function called from invalid context at mm/slab.h:498 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #1 Call trace: dump_backtrace+0x0/0x208 show_stack+0x1c/0x28 dump_stack+0xc4/0x11c ___might_sleep+0xf8/0x130 __might_sleep+0x58/0x90 slab_pre_alloc_hook.constprop.101+0xd0/0x118 kmem_cache_alloc_node_trace+0x84/0x270 __get_vm_area_node+0x88/0x210 get_vm_area_caller+0x38/0x40 __ioremap_caller+0x70/0xf8 ioremap_cache+0x78/0xb0 memremap+0x9c/0x1a8 init_stolen_time_cpu+0x54/0xf0 cpuhp_invoke_callback+0xa8/0x720 notify_cpu_starting+0xc8/0xd8 secondary_start_kernel+0x114/0x180 CPU1: Booted secondary processor 0x0000000001 [0x431f0a11] However we don't need to initialize steal time at CPU starting time. We can simply wait until CPU online time, just sacrificing a bit of accuracy by returning zero for steal time until we know better. While at it, add __init to the functions that are only called by pv_time_init() which is __init. Signed-off-by: Andrew Jones <drjones@redhat.com> Fixes: e0685fa228fd ("arm64: Retrieve stolen time as paravirtualized guest") Cc: stable@vger.kernel.org Reviewed-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20200916154530.40809-1-drjones@redhat.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-09-16 23:45:30 +08:00
static int __init pv_time_init_stolen_time(void)
{
int ret;
arm64: paravirt: Initialize steal time when cpu is online Steal time initialization requires mapping a memory region which invokes a memory allocation. Doing this at CPU starting time results in the following trace when CONFIG_DEBUG_ATOMIC_SLEEP is enabled: BUG: sleeping function called from invalid context at mm/slab.h:498 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #1 Call trace: dump_backtrace+0x0/0x208 show_stack+0x1c/0x28 dump_stack+0xc4/0x11c ___might_sleep+0xf8/0x130 __might_sleep+0x58/0x90 slab_pre_alloc_hook.constprop.101+0xd0/0x118 kmem_cache_alloc_node_trace+0x84/0x270 __get_vm_area_node+0x88/0x210 get_vm_area_caller+0x38/0x40 __ioremap_caller+0x70/0xf8 ioremap_cache+0x78/0xb0 memremap+0x9c/0x1a8 init_stolen_time_cpu+0x54/0xf0 cpuhp_invoke_callback+0xa8/0x720 notify_cpu_starting+0xc8/0xd8 secondary_start_kernel+0x114/0x180 CPU1: Booted secondary processor 0x0000000001 [0x431f0a11] However we don't need to initialize steal time at CPU starting time. We can simply wait until CPU online time, just sacrificing a bit of accuracy by returning zero for steal time until we know better. While at it, add __init to the functions that are only called by pv_time_init() which is __init. Signed-off-by: Andrew Jones <drjones@redhat.com> Fixes: e0685fa228fd ("arm64: Retrieve stolen time as paravirtualized guest") Cc: stable@vger.kernel.org Reviewed-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20200916154530.40809-1-drjones@redhat.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-09-16 23:45:30 +08:00
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
"hypervisor/arm/pvtime:online",
stolen_time_cpu_online,
stolen_time_cpu_down_prepare);
if (ret < 0)
return ret;
return 0;
}
arm64: paravirt: Initialize steal time when cpu is online Steal time initialization requires mapping a memory region which invokes a memory allocation. Doing this at CPU starting time results in the following trace when CONFIG_DEBUG_ATOMIC_SLEEP is enabled: BUG: sleeping function called from invalid context at mm/slab.h:498 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #1 Call trace: dump_backtrace+0x0/0x208 show_stack+0x1c/0x28 dump_stack+0xc4/0x11c ___might_sleep+0xf8/0x130 __might_sleep+0x58/0x90 slab_pre_alloc_hook.constprop.101+0xd0/0x118 kmem_cache_alloc_node_trace+0x84/0x270 __get_vm_area_node+0x88/0x210 get_vm_area_caller+0x38/0x40 __ioremap_caller+0x70/0xf8 ioremap_cache+0x78/0xb0 memremap+0x9c/0x1a8 init_stolen_time_cpu+0x54/0xf0 cpuhp_invoke_callback+0xa8/0x720 notify_cpu_starting+0xc8/0xd8 secondary_start_kernel+0x114/0x180 CPU1: Booted secondary processor 0x0000000001 [0x431f0a11] However we don't need to initialize steal time at CPU starting time. We can simply wait until CPU online time, just sacrificing a bit of accuracy by returning zero for steal time until we know better. While at it, add __init to the functions that are only called by pv_time_init() which is __init. Signed-off-by: Andrew Jones <drjones@redhat.com> Fixes: e0685fa228fd ("arm64: Retrieve stolen time as paravirtualized guest") Cc: stable@vger.kernel.org Reviewed-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20200916154530.40809-1-drjones@redhat.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-09-16 23:45:30 +08:00
static bool __init 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(&paravirt_steal_enabled);
if (steal_acc)
static_key_slow_inc(&paravirt_steal_rq_enabled);
pr_info("using stolen time PV\n");
return 0;
}