Implement the previously defined ioremap/iounmap hooks for arm64,
calling into KVM's MMIO guard if available.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/mm/ioremap.c | 56 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 56 insertions(+)
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
index b7c81dacabf0..0801fd92f0e3 100644
--- a/arch/arm64/mm/ioremap.c
+++ b/arch/arm64/mm/ioremap.c
@@ -9,13 +9,69 @@
* Copyright (C) 2012 ARM Ltd.
*/
+#define pr_fmt(fmt) "ioremap: " fmt
+
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/io.h>
+#include <linux/arm-smccc.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
+#include <asm/hypervisor.h>
+
+static DEFINE_STATIC_KEY_FALSE(ioremap_guard_key);
+
+void ioremap_page_range_hook(unsigned long addr, unsigned long end,
+ phys_addr_t phys_addr, pgprot_t prot)
+{
+ size_t size = end - addr;
+
+ if (!static_branch_unlikely(&ioremap_guard_key))
+ return;
+
+ if (pfn_valid(__phys_to_pfn(phys_addr)))
+ return;
+
+ while (size) {
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_hvc(ARM_SMCCC_VENDOR_HYP_KVM_MMIO_GUARD_MAP_FUNC_ID,
+ phys_addr, prot, &res);
+ if (res.a0 != SMCCC_RET_SUCCESS) {
+ pr_warn_ratelimited("Failed to register %llx\n",
+ phys_addr);
+ return;
+ }
+
+ size -= PAGE_SIZE;
+ phys_addr += PAGE_SIZE;
+ }
+}
+
+void iounmap_page_range_hook(phys_addr_t phys_addr, size_t size)
+{
+ if (!static_branch_unlikely(&ioremap_guard_key))
+ return;
+
+ VM_BUG_ON(phys_addr & ~PAGE_MASK || size & ~PAGE_MASK);
+
+ while (size) {
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_hvc(ARM_SMCCC_VENDOR_HYP_KVM_MMIO_GUARD_UNMAP_FUNC_ID,
+ phys_addr, &res);
+ if (res.a0 != SMCCC_RET_SUCCESS) {
+ pr_warn_ratelimited("Failed to unregister %llx\n",
+ phys_addr);
+ return;
+ }
+
+ size -= PAGE_SIZE;
+ phys_addr += PAGE_SIZE;
+ }
+}
static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
pgprot_t prot, void *caller)
--
2.30.2
