[PATCH v5 01/14] KVM: arm64: selftests: Add MMIO readl/writel support

Raghavendra Rao Ananta
2021-09-13T20:50:13Z

Define the readl() and writel() functions for the guests to
access (4-byte) the MMIO region.

The routines, and their dependents, are inspired from the kernel's
arch/arm64/include/asm/io.h and arch/arm64/include/asm/barrier.h.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
---
.../selftests/kvm/include/aarch64/processor.h | 46 ++++++++++++++++++-
1 file changed, 45 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
index c0273aefa63d..96578bd46a85 100644
--- a/tools/testing/selftests/kvm/include/aarch64/processor.h
+++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
@@ -9,6 +9,7 @@

#include "kvm_util.h"
#include <linux/stringify.h>
+#include <linux/types.h>

#define ARM64_CORE_REG(x) (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | \
@@ -130,6 +131,49 @@ void vm_install_sync_handler(struct kvm_vm *vm,
val; \
})

-#define isb() asm volatile("isb" : : : "memory")
+#define isb() asm volatile("isb" : : : "memory")
+#define dsb(opt) asm volatile("dsb " #opt : : : "memory")
+#define dmb(opt) asm volatile("dmb " #opt : : : "memory")
+
+#define dma_wmb() dmb(oshst)
+#define __iowmb() dma_wmb()
+
+#define dma_rmb() dmb(oshld)
+
+#define __iormb(v) \
+({ \
+ unsigned long tmp; \
+ \
+ dma_rmb(); \
+ \
+ /* \
+ * Courtesy of arch/arm64/include/asm/io.h: \
+ * Create a dummy control dependency from the IO read to any \
+ * later instructions. This ensures that a subsequent call \
+ * to udelay() will be ordered due to the ISB in __delay(). \
+ */ \
+ asm volatile("eor %0, %1, %1\n" \
+ "cbnz %0, ." \
+ : "=r" (tmp) : "r" ((unsigned long)(v)) \
+ : "memory"); \
+})
+
+static __always_inline void __raw_writel(u32 val, volatile void *addr)
+{
+ asm volatile("str %w0, [%1]" : : "rZ" (val), "r" (addr));
+}
+
+static __always_inline u32 __raw_readl(const volatile void *addr)
+{
+ u32 val;
+ asm volatile("ldr %w0, [%1]" : "=r" (val) : "r" (addr));
+ return val;
+}
+
+#define writel_relaxed(v,c) ((void)__raw_writel((__force u32)cpu_to_le32(v),(c)))
+#define readl_relaxed(c) ({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; })
+
+#define writel(v,c) ({ __iowmb(); writel_relaxed((v),(c));})
+#define readl(c) ({ u32 __v = readl_relaxed(c); __iormb(__v); __v; })

#endif /* SELFTEST_KVM_PROCESSOR_H */
--
2.33.0.309.g3052b89438-goog