From c2226b3d1a4d9fc1daeb8dc6b9034d1fb46c1308 Mon Sep 17 00:00:00 2001
From: Michael Brown <mcb30@ipxe.org>
Date: Sun, 14 Jul 2019 15:27:01 +0100
Subject: [PATCH] [arm] Provide dummy implementations for {in,out}[s]{b,w,l}
It is currently not possible to build the all-drivers iPXE binaries
for ARM, since there is no implementation for inb(), outb(), etc.
There is no common standard for accessing I/O space on ARM platforms,
and there are almost no ARM-compatible peripherals that actually
require I/O space accesses.
Provide dummy implementations that behave as though no device is
present (i.e. ignore writes, return all bits high for reads). This is
sufficient to allow the all-drivers binaries to link, and should cause
drivers to behave as though no I/O space peripherals are present in
the system.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
src/arch/arm/include/ipxe/arm_io.h | 77 +++++++++++++++++++++++-------
1 file changed, 59 insertions(+), 18 deletions(-)
diff --git a/src/arch/arm/include/ipxe/arm_io.h b/src/arch/arm/include/ipxe/arm_io.h
index f8765af752..105f22bfbf 100644
--- a/src/arch/arm/include/ipxe/arm_io.h
+++ b/src/arch/arm/include/ipxe/arm_io.h
@@ -43,42 +43,83 @@ IOAPI_INLINE ( arm, bus_to_phys ) ( unsigned long bus_addr ) {
*
*/
-#define ARM_READX( _api_func, _type, _insn_suffix, _reg_prefix ) \
+#define ARM_READX( _suffix, _type, _insn_suffix, _reg_prefix ) \
static inline __always_inline _type \
-IOAPI_INLINE ( arm, _api_func ) ( volatile _type *io_addr ) { \
+IOAPI_INLINE ( arm, read ## _suffix ) ( volatile _type *io_addr ) { \
_type data; \
__asm__ __volatile__ ( "ldr" _insn_suffix " %" _reg_prefix "0, %1" \
: "=r" ( data ) : "Qo" ( *io_addr ) ); \
return data; \
}
#ifdef __aarch64__
-ARM_READX ( readb, uint8_t, "b", "w" );
-ARM_READX ( readw, uint16_t, "h", "w" );
-ARM_READX ( readl, uint32_t, "", "w" );
-ARM_READX ( readq, uint64_t, "", "" );
+ARM_READX ( b, uint8_t, "b", "w" );
+ARM_READX ( w, uint16_t, "h", "w" );
+ARM_READX ( l, uint32_t, "", "w" );
+ARM_READX ( q, uint64_t, "", "" );
#else
-ARM_READX ( readb, uint8_t, "b", "" );
-ARM_READX ( readw, uint16_t, "h", "" );
-ARM_READX ( readl, uint32_t, "", "" );
+ARM_READX ( b, uint8_t, "b", "" );
+ARM_READX ( w, uint16_t, "h", "" );
+ARM_READX ( l, uint32_t, "", "" );
#endif
-#define ARM_WRITEX( _api_func, _type, _insn_suffix, _reg_prefix ) \
+#define ARM_WRITEX( _suffix, _type, _insn_suffix, _reg_prefix ) \
static inline __always_inline void \
-IOAPI_INLINE ( arm, _api_func ) ( _type data, volatile _type *io_addr ) { \
+IOAPI_INLINE ( arm, write ## _suffix ) ( _type data, \
+ volatile _type *io_addr ) { \
__asm__ __volatile__ ( "str" _insn_suffix " %" _reg_prefix "0, %1" \
: : "r" ( data ), "Qo" ( *io_addr ) ); \
}
#ifdef __aarch64__
-ARM_WRITEX ( writeb, uint8_t, "b", "w" );
-ARM_WRITEX ( writew, uint16_t, "h", "w" );
-ARM_WRITEX ( writel, uint32_t, "", "w" );
-ARM_WRITEX ( writeq, uint64_t, "", "" );
+ARM_WRITEX ( b, uint8_t, "b", "w" );
+ARM_WRITEX ( w, uint16_t, "h", "w" );
+ARM_WRITEX ( l, uint32_t, "", "w" );
+ARM_WRITEX ( q, uint64_t, "", "" );
#else
-ARM_WRITEX ( writeb, uint8_t, "b", "" );
-ARM_WRITEX ( writew, uint16_t, "h", "" );
-ARM_WRITEX ( writel, uint32_t, "", "" );
+ARM_WRITEX ( b, uint8_t, "b", "" );
+ARM_WRITEX ( w, uint16_t, "h", "" );
+ARM_WRITEX ( l, uint32_t, "", "" );
#endif
+/*
+ * Dummy PIO reads and writes up to 32 bits
+ *
+ * There is no common standard for I/O-space access for ARM, and
+ * non-MMIO peripherals are vanishingly rare. Provide dummy
+ * implementations that will allow code to link and should cause
+ * drivers to simply fail to detect hardware at runtime.
+ *
+ */
+
+#define ARM_INX( _suffix, _type ) \
+static inline __always_inline _type \
+IOAPI_INLINE ( arm, in ## _suffix ) ( volatile _type *io_addr __unused) { \
+ return ~( (_type) 0 ); \
+} \
+static inline __always_inline void \
+IOAPI_INLINE ( arm, ins ## _suffix ) ( volatile _type *io_addr __unused, \
+ _type *data, unsigned int count ) { \
+ memset ( data, 0xff, count * sizeof ( *data ) ); \
+}
+ARM_INX ( b, uint8_t );
+ARM_INX ( w, uint16_t );
+ARM_INX ( l, uint32_t );
+
+#define ARM_OUTX( _suffix, _type ) \
+static inline __always_inline void \
+IOAPI_INLINE ( arm, out ## _suffix ) ( _type data __unused, \
+ volatile _type *io_addr __unused ) { \
+ /* Do nothing */ \
+} \
+static inline __always_inline void \
+IOAPI_INLINE ( arm, outs ## _suffix ) ( volatile _type *io_addr __unused, \
+ const _type *data __unused, \
+ unsigned int count __unused ) { \
+ /* Do nothing */ \
+}
+ARM_OUTX ( b, uint8_t );
+ARM_OUTX ( w, uint16_t );
+ARM_OUTX ( l, uint32_t );
+
/*
* Slow down I/O
*