2023-06-20 19:44:07

by Nischala Yelchuri

[permalink] [raw]
Subject: [PATCH] x86/hyperv: Improve code for referencing hyperv_pcpu_input_arg

Several places in code for Hyper-V reference the
per-CPU variable hyperv_pcpu_input_arg. Older code uses a multi-line
sequence to reference the variable, and usually includes a cast.
Newer code does a much simpler direct assignment. The latter is
preferable as the complexity of the older code is unnecessary.

Update older code to use the simpler direct assignment.

Signed-off-by: Nischala Yelchuri <[email protected]>
---
arch/x86/hyperv/hv_apic.c | 4 +---
arch/x86/hyperv/ivm.c | 7 +++----
arch/x86/hyperv/mmu.c | 12 ++----------
arch/x86/hyperv/nested.c | 11 ++---------
drivers/hv/hv_balloon.c | 2 +-
5 files changed, 9 insertions(+), 27 deletions(-)

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index 1fbda2f94..b21335e6a 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -107,7 +107,6 @@ static bool cpu_is_self(int cpu)
static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector,
bool exclude_self)
{
- struct hv_send_ipi_ex **arg;
struct hv_send_ipi_ex *ipi_arg;
unsigned long flags;
int nr_bank = 0;
@@ -117,9 +116,8 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector,
return false;

local_irq_save(flags);
- arg = (struct hv_send_ipi_ex **)this_cpu_ptr(hyperv_pcpu_input_arg);
+ ipi_arg = *this_cpu_ptr(hyperv_pcpu_input_arg);

- ipi_arg = *arg;
if (unlikely(!ipi_arg))
goto ipi_mask_ex_done;

diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 14f46ad2c..28be6df88 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -247,7 +247,7 @@ EXPORT_SYMBOL_GPL(hv_ghcb_msr_read);
static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
enum hv_mem_host_visibility visibility)
{
- struct hv_gpa_range_for_visibility **input_pcpu, *input;
+ struct hv_gpa_range_for_visibility *input;
u16 pages_processed;
u64 hv_status;
unsigned long flags;
@@ -263,9 +263,8 @@ static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
}

local_irq_save(flags);
- input_pcpu = (struct hv_gpa_range_for_visibility **)
- this_cpu_ptr(hyperv_pcpu_input_arg);
- input = *input_pcpu;
+ input = *this_cpu_ptr(hyperv_pcpu_input_arg);
+
if (unlikely(!input)) {
local_irq_restore(flags);
return -EINVAL;
diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
index 8460bd35e..1cc113200 100644
--- a/arch/x86/hyperv/mmu.c
+++ b/arch/x86/hyperv/mmu.c
@@ -61,7 +61,6 @@ static void hyperv_flush_tlb_multi(const struct cpumask *cpus,
const struct flush_tlb_info *info)
{
int cpu, vcpu, gva_n, max_gvas;
- struct hv_tlb_flush **flush_pcpu;
struct hv_tlb_flush *flush;
u64 status;
unsigned long flags;
@@ -74,10 +73,7 @@ static void hyperv_flush_tlb_multi(const struct cpumask *cpus,

local_irq_save(flags);

- flush_pcpu = (struct hv_tlb_flush **)
- this_cpu_ptr(hyperv_pcpu_input_arg);
-
- flush = *flush_pcpu;
+ flush = *this_cpu_ptr(hyperv_pcpu_input_arg);

if (unlikely(!flush)) {
local_irq_restore(flags);
@@ -178,17 +174,13 @@ static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
const struct flush_tlb_info *info)
{
int nr_bank = 0, max_gvas, gva_n;
- struct hv_tlb_flush_ex **flush_pcpu;
struct hv_tlb_flush_ex *flush;
u64 status;

if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
return HV_STATUS_INVALID_PARAMETER;

- flush_pcpu = (struct hv_tlb_flush_ex **)
- this_cpu_ptr(hyperv_pcpu_input_arg);
-
- flush = *flush_pcpu;
+ flush = *this_cpu_ptr(hyperv_pcpu_input_arg);

if (info->mm) {
/*
diff --git a/arch/x86/hyperv/nested.c b/arch/x86/hyperv/nested.c
index 5d70968c8..9dc259fa3 100644
--- a/arch/x86/hyperv/nested.c
+++ b/arch/x86/hyperv/nested.c
@@ -19,7 +19,6 @@

int hyperv_flush_guest_mapping(u64 as)
{
- struct hv_guest_mapping_flush **flush_pcpu;
struct hv_guest_mapping_flush *flush;
u64 status;
unsigned long flags;
@@ -30,10 +29,7 @@ int hyperv_flush_guest_mapping(u64 as)

local_irq_save(flags);

- flush_pcpu = (struct hv_guest_mapping_flush **)
- this_cpu_ptr(hyperv_pcpu_input_arg);
-
- flush = *flush_pcpu;
+ flush = *this_cpu_ptr(hyperv_pcpu_input_arg);

if (unlikely(!flush)) {
local_irq_restore(flags);
@@ -90,7 +86,6 @@ EXPORT_SYMBOL_GPL(hyperv_fill_flush_guest_mapping_list);
int hyperv_flush_guest_mapping_range(u64 as,
hyperv_fill_flush_list_func fill_flush_list_func, void *data)
{
- struct hv_guest_mapping_flush_list **flush_pcpu;
struct hv_guest_mapping_flush_list *flush;
u64 status;
unsigned long flags;
@@ -102,10 +97,8 @@ int hyperv_flush_guest_mapping_range(u64 as,

local_irq_save(flags);

- flush_pcpu = (struct hv_guest_mapping_flush_list **)
- this_cpu_ptr(hyperv_pcpu_input_arg);
+ flush = *this_cpu_ptr(hyperv_pcpu_input_arg);

- flush = *flush_pcpu;
if (unlikely(!flush)) {
local_irq_restore(flags);
goto fault;
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index dffcc894f..0d7a3ba66 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -1628,7 +1628,7 @@ static int hv_free_page_report(struct page_reporting_dev_info *pr_dev_info,
WARN_ON_ONCE(nents > HV_MEMORY_HINT_MAX_GPA_PAGE_RANGES);
WARN_ON_ONCE(sgl->length < (HV_HYP_PAGE_SIZE << page_reporting_order));
local_irq_save(flags);
- hint = *(struct hv_memory_hint **)this_cpu_ptr(hyperv_pcpu_input_arg);
+ hint = *this_cpu_ptr(hyperv_pcpu_input_arg);
if (!hint) {
local_irq_restore(flags);
return -ENOSPC;
--
2.25.1



2023-06-28 17:58:04

by Wei Liu

[permalink] [raw]
Subject: Re: [PATCH] x86/hyperv: Improve code for referencing hyperv_pcpu_input_arg

On Tue, Jun 20, 2023 at 11:40:38AM -0700, Nischala Yelchuri wrote:
> Several places in code for Hyper-V reference the
> per-CPU variable hyperv_pcpu_input_arg. Older code uses a multi-line
> sequence to reference the variable, and usually includes a cast.
> Newer code does a much simpler direct assignment. The latter is
> preferable as the complexity of the older code is unnecessary.
>
> Update older code to use the simpler direct assignment.
>
> Signed-off-by: Nischala Yelchuri <[email protected]>

Applied to hyperv-fixes. Thanks!