linux-kernel - [PATCH 5/5] X86: Hyper-V: Consolidate the allocation of the hypercall input page

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Message-Id: <20180425181250.8740-5-kys@linuxonhyperv.com>
Date:   Wed, 25 Apr 2018 11:12:50 -0700
From:   kys@...uxonhyperv.com
To:     x86@...nel.org, gregkh@...uxfoundation.org,
        linux-kernel@...r.kernel.org, devel@...uxdriverproject.org,
        olaf@...fle.de, apw@...onical.com, jasowang@...hat.com,
        tglx@...utronix.de, hpa@...or.com, sthemmin@...rosoft.com,
        Michael.H.Kelley@...rosoft.com, vkuznets@...hat.com
Cc:     "K. Y. Srinivasan" <kys@...rosoft.com>
Subject: [PATCH 5/5] X86: Hyper-V: Consolidate the allocation of the hypercall input page

From: "K. Y. Srinivasan" <kys@...rosoft.com>

Consolidate the allocation of the hypercall input page.

Signed-off-by: K. Y. Srinivasan <kys@...rosoft.com>
---
 arch/x86/hyperv/hv_init.c       |  2 --
 arch/x86/hyperv/mmu.c           | 33 +++++++++------------------------
 arch/x86/include/asm/mshyperv.h |  1 -
 3 files changed, 9 insertions(+), 27 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index a895662b6b4c..72befd0e2c35 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -314,8 +314,6 @@ void __init hyperv_init(void)
 	hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
 	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 
-	hyper_alloc_mmu();
-
 	hv_apic_init();
 
 	/*
diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
index c9cd28f0bae4..c4466af72e77 100644
--- a/arch/x86/hyperv/mmu.c
+++ b/arch/x86/hyperv/mmu.c
@@ -32,9 +32,6 @@ struct hv_flush_pcpu_ex {
 /* Each gva in gva_list encodes up to 4096 pages to flush */
 #define HV_TLB_FLUSH_UNIT (4096 * PAGE_SIZE)
 
-static struct hv_flush_pcpu __percpu **pcpu_flush;
-
-static struct hv_flush_pcpu_ex __percpu **pcpu_flush_ex;
 
 /*
  * Fills in gva_list starting from offset. Returns the number of items added.
@@ -77,7 +74,7 @@ static void hyperv_flush_tlb_others(const struct cpumask *cpus,
 
 	trace_hyperv_mmu_flush_tlb_others(cpus, info);
 
-	if (!pcpu_flush || !hv_hypercall_pg)
+	if (!hv_hypercall_pg)
 		goto do_native;
 
 	if (cpumask_empty(cpus))
@@ -85,10 +82,8 @@ static void hyperv_flush_tlb_others(const struct cpumask *cpus,
 
 	local_irq_save(flags);
 
-	flush_pcpu = this_cpu_ptr(pcpu_flush);
-
-	if (unlikely(!*flush_pcpu))
-		*flush_pcpu = page_address(alloc_page(GFP_ATOMIC));
+	flush_pcpu = (struct hv_flush_pcpu **)
+		     this_cpu_ptr(hyperv_pcpu_input_arg);
 
 	flush = *flush_pcpu;
 
@@ -164,7 +159,7 @@ static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
 
 	trace_hyperv_mmu_flush_tlb_others(cpus, info);
 
-	if (!pcpu_flush_ex || !hv_hypercall_pg)
+	if (!hv_hypercall_pg)
 		goto do_native;
 
 	if (cpumask_empty(cpus))
@@ -172,10 +167,8 @@ static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
 
 	local_irq_save(flags);
 
-	flush_pcpu = this_cpu_ptr(pcpu_flush_ex);
-
-	if (unlikely(!*flush_pcpu))
-		*flush_pcpu = page_address(alloc_page(GFP_ATOMIC));
+	flush_pcpu = (struct hv_flush_pcpu_ex **)
+		     this_cpu_ptr(hyperv_pcpu_input_arg);
 
 	flush = *flush_pcpu;
 
@@ -249,6 +242,9 @@ void hyperv_setup_mmu_ops(void)
 	if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
 		return;
 
+	if (hyperv_pcpu_input_arg == NULL)
+		return;
+
 	if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) {
 		pr_info("Using hypercall for remote TLB flush\n");
 		pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others;
@@ -257,14 +253,3 @@ void hyperv_setup_mmu_ops(void)
 		pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others_ex;
 	}
 }
-
-void hyper_alloc_mmu(void)
-{
-	if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
-		return;
-
-	if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
-		pcpu_flush = alloc_percpu(struct hv_flush_pcpu *);
-	else
-		pcpu_flush_ex = alloc_percpu(struct hv_flush_pcpu_ex *);
-}
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 956e8603bed2..9931f9908fe2 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -300,7 +300,6 @@ static inline int cpumask_to_vpset(struct hv_vpset *vpset,
 
 void __init hyperv_init(void);
 void hyperv_setup_mmu_ops(void);
-void hyper_alloc_mmu(void);
 void hyperv_report_panic(struct pt_regs *regs, long err);
 bool hv_is_hyperv_initialized(void);
 void hyperv_cleanup(void);
-- 
2.15.1