linux-kernel - [PATCH 03/18] KVM: arm64: Make hyp

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Message-ID: <20241104133204.85208-4-qperret@google.com>
Date: Mon,  4 Nov 2024 13:31:49 +0000
From: Quentin Perret <qperret@...gle.com>
To: Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>, 
	Joey Gouly <joey.gouly@....com>, Suzuki K Poulose <suzuki.poulose@....com>, 
	Zenghui Yu <yuzenghui@...wei.com>, Catalin Marinas <catalin.marinas@....com>, 
	Will Deacon <will@...nel.org>
Cc: Fuad Tabba <tabba@...gle.com>, Vincent Donnefort <vdonnefort@...gle.com>, 
	Sebastian Ene <sebastianene@...gle.com>, linux-arm-kernel@...ts.infradead.org, 
	kvmarm@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: [PATCH 03/18] KVM: arm64: Make hyp_page::order a u8

We don't need 16 bits to store the hyp page order, and we'll need some
bits to store page ownership data soon, so let's reduce the order
member.

Signed-off-by: Quentin Perret <qperret@...gle.com>
---
 arch/arm64/kvm/hyp/include/nvhe/gfp.h    |  6 +++---
 arch/arm64/kvm/hyp/include/nvhe/memory.h |  5 +++--
 arch/arm64/kvm/hyp/nvhe/page_alloc.c     | 14 +++++++-------
 3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/kvm/hyp/include/nvhe/gfp.h b/arch/arm64/kvm/hyp/include/nvhe/gfp.h
index 97c527ef53c2..f1725bad6331 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/gfp.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/gfp.h
@@ -7,7 +7,7 @@
 #include <nvhe/memory.h>
 #include <nvhe/spinlock.h>
 
-#define HYP_NO_ORDER	USHRT_MAX
+#define HYP_NO_ORDER	0xff
 
 struct hyp_pool {
 	/*
@@ -19,11 +19,11 @@ struct hyp_pool {
 	struct list_head free_area[NR_PAGE_ORDERS];
 	phys_addr_t range_start;
 	phys_addr_t range_end;
-	unsigned short max_order;
+	u8 max_order;
 };
 
 /* Allocation */
-void *hyp_alloc_pages(struct hyp_pool *pool, unsigned short order);
+void *hyp_alloc_pages(struct hyp_pool *pool, u8 order);
 void hyp_split_page(struct hyp_page *page);
 void hyp_get_page(struct hyp_pool *pool, void *addr);
 void hyp_put_page(struct hyp_pool *pool, void *addr);
diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h
index 6dfeb000371c..88cb8ff9e769 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/memory.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h
@@ -42,8 +42,9 @@ static inline enum pkvm_page_state pkvm_getstate(enum kvm_pgtable_prot prot)
 }
 
 struct hyp_page {
-	unsigned short refcount;
-	unsigned short order;
+	u16 refcount;
+	u8 order;
+	u8 reserved;
 };
 
 extern u64 __hyp_vmemmap;
diff --git a/arch/arm64/kvm/hyp/nvhe/page_alloc.c b/arch/arm64/kvm/hyp/nvhe/page_alloc.c
index e691290d3765..a1eb27a1a747 100644
--- a/arch/arm64/kvm/hyp/nvhe/page_alloc.c
+++ b/arch/arm64/kvm/hyp/nvhe/page_alloc.c
@@ -32,7 +32,7 @@ u64 __hyp_vmemmap;
  */
 static struct hyp_page *__find_buddy_nocheck(struct hyp_pool *pool,
 					     struct hyp_page *p,
-					     unsigned short order)
+					     u8 order)
 {
 	phys_addr_t addr = hyp_page_to_phys(p);
 
@@ -51,7 +51,7 @@ static struct hyp_page *__find_buddy_nocheck(struct hyp_pool *pool,
 /* Find a buddy page currently available for allocation */
 static struct hyp_page *__find_buddy_avail(struct hyp_pool *pool,
 					   struct hyp_page *p,
-					   unsigned short order)
+					   u8 order)
 {
 	struct hyp_page *buddy = __find_buddy_nocheck(pool, p, order);
 
@@ -94,7 +94,7 @@ static void __hyp_attach_page(struct hyp_pool *pool,
 			      struct hyp_page *p)
 {
 	phys_addr_t phys = hyp_page_to_phys(p);
-	unsigned short order = p->order;
+	u8 order = p->order;
 	struct hyp_page *buddy;
 
 	memset(hyp_page_to_virt(p), 0, PAGE_SIZE << p->order);
@@ -129,7 +129,7 @@ static void __hyp_attach_page(struct hyp_pool *pool,
 
 static struct hyp_page *__hyp_extract_page(struct hyp_pool *pool,
 					   struct hyp_page *p,
-					   unsigned short order)
+					   u8 order)
 {
 	struct hyp_page *buddy;
 
@@ -183,7 +183,7 @@ void hyp_get_page(struct hyp_pool *pool, void *addr)
 
 void hyp_split_page(struct hyp_page *p)
 {
-	unsigned short order = p->order;
+	u8 order = p->order;
 	unsigned int i;
 
 	p->order = 0;
@@ -195,10 +195,10 @@ void hyp_split_page(struct hyp_page *p)
 	}
 }
 
-void *hyp_alloc_pages(struct hyp_pool *pool, unsigned short order)
+void *hyp_alloc_pages(struct hyp_pool *pool, u8 order)
 {
-	unsigned short i = order;
 	struct hyp_page *p;
+	u8 i = order;
 
 	hyp_spin_lock(&pool->lock);
 
-- 
2.47.0.163.g1226f6d8fa-goog