[PATCH v2 5/7] ARM: KVM: parametrize HYP page table freeing

[Marc Zyngier]

In order to prepare for having to deal with multiple HYP page tables,
pass the PGD parameter to the function performing the freeing of the
page tables.

Also move the freeing of the PGD itself there, and rename the
free_hyp_pmds to free_hyp_pgds.

Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
 arch/arm/include/asm/kvm_mmu.h |  2 +-
 arch/arm/kvm/arm.c             |  2 +-
 arch/arm/kvm/mmu.c             | 30 +++++++++++++++++-------------
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 3c71a1d..92eb20d 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -32,7 +32,7 @@
 
 int create_hyp_mappings(void *from, void *to);
 int create_hyp_io_mappings(void *from, void *to, phys_addr_t);
-void free_hyp_pmds(void);
+void free_hyp_pgds(void);
 
 int kvm_alloc_stage2_pgd(struct kvm *kvm);
 void kvm_free_stage2_pgd(struct kvm *kvm);
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 47cfcc3..8d44ef4 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -937,7 +937,7 @@ static int init_hyp_mode(void)
 out_free_context:
 	free_percpu(kvm_host_cpu_state);
 out_free_mappings:
-	free_hyp_pmds();
+	free_hyp_pgds();
 out_free_stack_pages:
 	for_each_possible_cpu(cpu)
 		free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index bfc5927..c4236e4 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -86,42 +86,46 @@ static void free_ptes(pmd_t *pmd, unsigned long addr)
 	}
 }
 
-static void free_hyp_pgd_entry(unsigned long addr)
+static void free_hyp_pgd_entry(pgd_t *pgdp, unsigned long addr)
 {
 	pgd_t *pgd;
 	pud_t *pud;
 	pmd_t *pmd;
-	unsigned long hyp_addr = KERN_TO_HYP(addr);
 
-	pgd = hyp_pgd + pgd_index(hyp_addr);
-	pud = pud_offset(pgd, hyp_addr);
+	pgd = pgdp + pgd_index(addr);
+	pud = pud_offset(pgd, addr);
 
 	if (pud_none(*pud))
 		return;
 	BUG_ON(pud_bad(*pud));
 
-	pmd = pmd_offset(pud, hyp_addr);
+	pmd = pmd_offset(pud, addr);
 	free_ptes(pmd, addr);
 	pmd_free(NULL, pmd);
 	pud_clear(pud);
 }
 
 /**
- * free_hyp_pmds - free a Hyp-mode level-2 tables and child level-3 tables
+ * free_hyp_pgds - free Hyp-mode page tables
  *
- * Assumes this is a page table used strictly in Hyp-mode and therefore contains
+ * Assumes hyp_pgd is a page table used strictly in Hyp-mode and therefore contains
  * either mappings in the kernel memory area (above PAGE_OFFSET), or
  * device mappings in the vmalloc range (from VMALLOC_START to VMALLOC_END).
  */
-void free_hyp_pmds(void)
+void free_hyp_pgds(void)
 {
 	unsigned long addr;
 
 	mutex_lock(&kvm_hyp_pgd_mutex);
-	for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
-		free_hyp_pgd_entry(addr);
-	for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
-		free_hyp_pgd_entry(addr);
+
+	if (hyp_pgd) {
+		for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
+			free_hyp_pgd_entry(hyp_pgd, KERN_TO_HYP(addr));
+		for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
+			free_hyp_pgd_entry(hyp_pgd, KERN_TO_HYP(addr));
+		kfree(hyp_pgd);
+	}
+
 	mutex_unlock(&kvm_hyp_pgd_mutex);
 }
 
@@ -741,7 +745,7 @@ int kvm_mmu_init(void)
 
 	return 0;
 out:
-	kfree(hyp_pgd);
+	free_hyp_pgds();
 	return err;
 }
 
-- 
1.8.1.4