[PATCH v2 1/2] smc91x: always use 8-bit access if necessary

Arnd Bergmann
2016-08-25T15:39:00Z

As Russell King found out the hard way, a change I did to fix multiplatform
builds with this driver broke the old Assabet/Neponset platform: It turns
out that while the driver is runtime configurable in principle, the
runtime configuration does not cover the specific case of machines that
can not do any 16-bit I/O on the smc91x registers.

The driver currently provides helpers to access 16-bit registers for
architectures that are known at compile-time to only have 8-bit I/O,
but my patch changed it to a runtime flag that never gets consulted
most register accesses.

This introduces new SMC_out16()/SMC_in16 helpers (if anyone can suggest
a better name, I'm glad to modify this) that behaves like SMC_outw()/SMC_inw()
most of the time, but uses a pair of 8-bit accesses on platforms that
have no support for wider register accesses.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Russell King <linux@armlinux.org.uk>
Fixes: b70661c70830d ("net: smc91x: use run-time configuration on all ARM machines")
---
Having bad luck streak with this patch, the version I sent
had a couple of mistakes from the last rebase before sending
it out, this version should actually apply and build.

diff --git a/drivers/net/ethernet/smsc/smc91x.h b/drivers/net/ethernet/smsc/smc91x.h
index 1a55c7976df0..497411ed6de2 100644
--- a/drivers/net/ethernet/smsc/smc91x.h
+++ b/drivers/net/ethernet/smsc/smc91x.h
@@ -414,30 +414,32 @@ smc_pxa_dma_insw(void __iomem *ioaddr, struct smc_local *lp, int reg, int dma,
#define SMC_outsl(a, r, p, l) BUG()
#endif

-#if ! SMC_CAN_USE_16BIT
-
/*
- * Any 16-bit access is performed with two 8-bit accesses if the hardware
- * can't do it directly. Most registers are 16-bit so those are mandatory.
+ * Any 16-bit register access is performed with two 8-bit accesses if the
+ * hardware can't do it directly.
*/
-#define SMC_outw(x, ioaddr, reg) \
- do { \
- unsigned int __val16 = (x); \
- SMC_outb( __val16, ioaddr, reg ); \
- SMC_outb( __val16 >> 8, ioaddr, reg + (1 << SMC_IO_SHIFT));\
- } while (0)
-#define SMC_inw(ioaddr, reg) \
- ({ \
- unsigned int __val16; \
- __val16 = SMC_inb( ioaddr, reg ); \
+#define SMC_out16(x, ioaddr, reg) \
+do { \
+ if (SMC_CAN_USE_8BIT && !SMC_16BIT(lp)) { \
+ unsigned int __val16 = (x); \
+ SMC_outb(__val16, ioaddr, reg ); \
+ SMC_outb(__val16 >> 8, ioaddr, reg + (1 << SMC_IO_SHIFT)); \
+ } else { \
+ SMC_outw(x, ioaddr, reg); \
+ } \
+} while (0)
+
+#define SMC_in16(ioaddr, reg) \
+({ \
+ unsigned int __val16; \
+ if (SMC_CAN_USE_8BIT && !SMC_16BIT(lp)) { \
+ __val16 = SMC_inb( ioaddr, reg ); \
__val16 |= SMC_inb( ioaddr, reg + (1 << SMC_IO_SHIFT)) << 8; \
- __val16; \
- })
-
-#define SMC_insw(a, r, p, l) BUG()
-#define SMC_outsw(a, r, p, l) BUG()
-
-#endif
+ } else { \
+ __val16 = SMC_inw(ioaddr, reg); \
+ } \
+ __val16; \
+})

#if !defined(SMC_insw) || !defined(SMC_outsw)
#define SMC_insw(a, r, p, l) BUG()
@@ -927,113 +929,113 @@ static const char * chip_ids[ 16 ] = {
SMC_outw((x) << 8, ioaddr, INT_REG(lp)); \
} while (0)

-#define SMC_CURRENT_BANK(lp) SMC_inw(ioaddr, BANK_SELECT)
+#define SMC_CURRENT_BANK(lp) SMC_in16(ioaddr, BANK_SELECT)

#define SMC_SELECT_BANK(lp, x) \
do { \
if (SMC_MUST_ALIGN_WRITE(lp)) \
SMC_outl((x)<<16, ioaddr, 12<<SMC_IO_SHIFT); \
else \
- SMC_outw(x, ioaddr, BANK_SELECT); \
+ SMC_out16(x, ioaddr, BANK_SELECT); \
} while (0)

-#define SMC_GET_BASE(lp) SMC_inw(ioaddr, BASE_REG(lp))
+#define SMC_GET_BASE(lp) SMC_in16(ioaddr, BASE_REG(lp))

-#define SMC_SET_BASE(lp, x) SMC_outw(x, ioaddr, BASE_REG(lp))
+#define SMC_SET_BASE(lp, x) SMC_out16(x, ioaddr, BASE_REG(lp))

-#define SMC_GET_CONFIG(lp) SMC_inw(ioaddr, CONFIG_REG(lp))
+#define SMC_GET_CONFIG(lp) SMC_in16(ioaddr, CONFIG_REG(lp))

-#define SMC_SET_CONFIG(lp, x) SMC_outw(x, ioaddr, CONFIG_REG(lp))
+#define SMC_SET_CONFIG(lp, x) SMC_out16(x, ioaddr, CONFIG_REG(lp))

-#define SMC_GET_COUNTER(lp) SMC_inw(ioaddr, COUNTER_REG(lp))
+#define SMC_GET_COUNTER(lp) SMC_in16(ioaddr, COUNTER_REG(lp))

-#define SMC_GET_CTL(lp) SMC_inw(ioaddr, CTL_REG(lp))
+#define SMC_GET_CTL(lp) SMC_in16(ioaddr, CTL_REG(lp))

-#define SMC_SET_CTL(lp, x) SMC_outw(x, ioaddr, CTL_REG(lp))
+#define SMC_SET_CTL(lp, x) SMC_out16(x, ioaddr, CTL_REG(lp))

-#define SMC_GET_MII(lp) SMC_inw(ioaddr, MII_REG(lp))
+#define SMC_GET_MII(lp) SMC_in16(ioaddr, MII_REG(lp))

-#define SMC_GET_GP(lp) SMC_inw(ioaddr, GP_REG(lp))
+#define SMC_GET_GP(lp) SMC_in16(ioaddr, GP_REG(lp))

#define SMC_SET_GP(lp, x) \
do { \
if (SMC_MUST_ALIGN_WRITE(lp)) \
SMC_outl((x)<<16, ioaddr, SMC_REG(lp, 8, 1)); \
else \
- SMC_outw(x, ioaddr, GP_REG(lp)); \
+ SMC_out16(x, ioaddr, GP_REG(lp)); \
} while (0)

-#define SMC_SET_MII(lp, x) SMC_outw(x, ioaddr, MII_REG(lp))
+#define SMC_SET_MII(lp, x) SMC_out16(x, ioaddr, MII_REG(lp))

-#define SMC_GET_MIR(lp) SMC_inw(ioaddr, MIR_REG(lp))
+#define SMC_GET_MIR(lp) SMC_in16(ioaddr, MIR_REG(lp))

-#define SMC_SET_MIR(lp, x) SMC_outw(x, ioaddr, MIR_REG(lp))
+#define SMC_SET_MIR(lp, x) SMC_out16(x, ioaddr, MIR_REG(lp))

-#define SMC_GET_MMU_CMD(lp) SMC_inw(ioaddr, MMU_CMD_REG(lp))
+#define SMC_GET_MMU_CMD(lp) SMC_in16(ioaddr, MMU_CMD_REG(lp))

-#define SMC_SET_MMU_CMD(lp, x) SMC_outw(x, ioaddr, MMU_CMD_REG(lp))
+#define SMC_SET_MMU_CMD(lp, x) SMC_out16(x, ioaddr, MMU_CMD_REG(lp))

-#define SMC_GET_FIFO(lp) SMC_inw(ioaddr, FIFO_REG(lp))
+#define SMC_GET_FIFO(lp) SMC_in16(ioaddr, FIFO_REG(lp))

-#define SMC_GET_PTR(lp) SMC_inw(ioaddr, PTR_REG(lp))
+#define SMC_GET_PTR(lp) SMC_in16(ioaddr, PTR_REG(lp))

#define SMC_SET_PTR(lp, x) \
do { \
if (SMC_MUST_ALIGN_WRITE(lp)) \
SMC_outl((x)<<16, ioaddr, SMC_REG(lp, 4, 2)); \
else \
- SMC_outw(x, ioaddr, PTR_REG(lp)); \
+ SMC_out16(x, ioaddr, PTR_REG(lp)); \
} while (0)

-#define SMC_GET_EPH_STATUS(lp) SMC_inw(ioaddr, EPH_STATUS_REG(lp))
+#define SMC_GET_EPH_STATUS(lp) SMC_in16(ioaddr, EPH_STATUS_REG(lp))

-#define SMC_GET_RCR(lp) SMC_inw(ioaddr, RCR_REG(lp))
+#define SMC_GET_RCR(lp) SMC_in16(ioaddr, RCR_REG(lp))

-#define SMC_SET_RCR(lp, x) SMC_outw(x, ioaddr, RCR_REG(lp))
+#define SMC_SET_RCR(lp, x) SMC_out16(x, ioaddr, RCR_REG(lp))

-#define SMC_GET_REV(lp) SMC_inw(ioaddr, REV_REG(lp))
+#define SMC_GET_REV(lp) SMC_in16(ioaddr, REV_REG(lp))

-#define SMC_GET_RPC(lp) SMC_inw(ioaddr, RPC_REG(lp))
+#define SMC_GET_RPC(lp) SMC_in16(ioaddr, RPC_REG(lp))

#define SMC_SET_RPC(lp, x) \
do { \
if (SMC_MUST_ALIGN_WRITE(lp)) \
SMC_outl((x)<<16, ioaddr, SMC_REG(lp, 8, 0)); \
else \
- SMC_outw(x, ioaddr, RPC_REG(lp)); \
+ SMC_out16(x, ioaddr, RPC_REG(lp)); \
} while (0)

-#define SMC_GET_TCR(lp) SMC_inw(ioaddr, TCR_REG(lp))
+#define SMC_GET_TCR(lp) SMC_in16(ioaddr, TCR_REG(lp))

-#define SMC_SET_TCR(lp, x) SMC_outw(x, ioaddr, TCR_REG(lp))
+#define SMC_SET_TCR(lp, x) SMC_out16(x, ioaddr, TCR_REG(lp))

#ifndef SMC_GET_MAC_ADDR
#define SMC_GET_MAC_ADDR(lp, addr) \
do { \
unsigned int __v; \
- __v = SMC_inw(ioaddr, ADDR0_REG(lp)); \
+ __v = SMC_in16(ioaddr, ADDR0_REG(lp)); \
addr[0] = __v; addr[1] = __v >> 8; \
- __v = SMC_inw(ioaddr, ADDR1_REG(lp)); \
+ __v = SMC_in16(ioaddr, ADDR1_REG(lp)); \
addr[2] = __v; addr[3] = __v >> 8; \
- __v = SMC_inw(ioaddr, ADDR2_REG(lp)); \
+ __v = SMC_in16(ioaddr, ADDR2_REG(lp)); \
addr[4] = __v; addr[5] = __v >> 8; \
} while (0)
#endif

#define SMC_SET_MAC_ADDR(lp, addr) \
do { \
- SMC_outw(addr[0]|(addr[1] << 8), ioaddr, ADDR0_REG(lp)); \
- SMC_outw(addr[2]|(addr[3] << 8), ioaddr, ADDR1_REG(lp)); \
- SMC_outw(addr[4]|(addr[5] << 8), ioaddr, ADDR2_REG(lp)); \
+ SMC_out16(addr[0]|(addr[1] << 8), ioaddr, ADDR0_REG(lp)); \
+ SMC_out16(addr[2]|(addr[3] << 8), ioaddr, ADDR1_REG(lp)); \
+ SMC_out16(addr[4]|(addr[5] << 8), ioaddr, ADDR2_REG(lp)); \
} while (0)

#define SMC_SET_MCAST(lp, x) \
do { \
const unsigned char *mt = (x); \
- SMC_outw(mt[0] | (mt[1] << 8), ioaddr, MCAST_REG1(lp)); \
- SMC_outw(mt[2] | (mt[3] << 8), ioaddr, MCAST_REG2(lp)); \
- SMC_outw(mt[4] | (mt[5] << 8), ioaddr, MCAST_REG3(lp)); \
- SMC_outw(mt[6] | (mt[7] << 8), ioaddr, MCAST_REG4(lp)); \
+ SMC_out16(mt[0] | (mt[1] << 8), ioaddr, MCAST_REG1(lp)); \
+ SMC_out16(mt[2] | (mt[3] << 8), ioaddr, MCAST_REG2(lp)); \
+ SMC_out16(mt[4] | (mt[5] << 8), ioaddr, MCAST_REG3(lp)); \
+ SMC_out16(mt[6] | (mt[7] << 8), ioaddr, MCAST_REG4(lp)); \
} while (0)

#define SMC_PUT_PKT_HDR(lp, status, length) \
@@ -1042,8 +1044,8 @@ static const char * chip_ids[ 16 ] = {
SMC_outl((status) | (length)<<16, ioaddr, \
DATA_REG(lp)); \
else { \
- SMC_outw(status, ioaddr, DATA_REG(lp)); \
- SMC_outw(length, ioaddr, DATA_REG(lp)); \
+ SMC_out16(status, ioaddr, DATA_REG(lp)); \
+ SMC_out16(length, ioaddr, DATA_REG(lp)); \
} \
} while (0)

@@ -1054,8 +1056,8 @@ static const char * chip_ids[ 16 ] = {
(status) = __val & 0xffff; \
(length) = __val >> 16; \
} else { \
- (status) = SMC_inw(ioaddr, DATA_REG(lp)); \
- (length) = SMC_inw(ioaddr, DATA_REG(lp)); \
+ (status) = SMC_in16(ioaddr, DATA_REG(lp)); \
+ (length) = SMC_in16(ioaddr, DATA_REG(lp)); \
} \
} while (0)