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authorRussell King <rmk+kernel@armlinux.org.uk>2016-08-27 19:33:03 +0300
committerDavid S. Miller <davem@davemloft.net>2016-08-29 06:44:55 +0300
commit2fb04fdf30192ff1e2b5834e9b7745889ea8bbcb (patch)
tree2a05f0268408c60503c31ecc41153ff1bec04290 /drivers/net/ethernet/smsc
parent7d13eca09ed5e477f6ecfd97a35058762228b5e4 (diff)
downloadlinux-2fb04fdf30192ff1e2b5834e9b7745889ea8bbcb.tar.xz
net: smc91x: fix SMC accesses
Commit b70661c70830 ("net: smc91x: use run-time configuration on all ARM machines") broke some ARM platforms through several mistakes. Firstly, the access size must correspond to the following rule: (a) at least one of 16-bit or 8-bit access size must be supported (b) 32-bit accesses are optional, and may be enabled in addition to the above. Secondly, it provides no emulation of 16-bit accesses, instead blindly making 16-bit accesses even when the platform specifies that only 8-bit is supported. Reorganise smc91x.h so we can make use of the existing 16-bit access emulation already provided - if 16-bit accesses are supported, use 16-bit accesses directly, otherwise if 8-bit accesses are supported, use the provided 16-bit access emulation. If neither, BUG(). This exactly reflects the driver behaviour prior to the commit being fixed. Since the conversion incorrectly cut down the available access sizes on several platforms, we also need to go through every platform and fix up the overly-restrictive access size: Arnd assumed that if a platform can perform 32-bit, 16-bit and 8-bit accesses, then only a 32-bit access size needed to be specified - not so, all available access sizes must be specified. This likely fixes some performance regressions in doing this: if a platform does not support 8-bit accesses, 8-bit accesses have been emulated by performing a 16-bit read-modify-write access. Tested on the Intel Assabet/Neponset platform, which supports only 8-bit accesses, which was broken by the original commit. Fixes: b70661c70830 ("net: smc91x: use run-time configuration on all ARM machines") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/smsc')
-rw-r--r--drivers/net/ethernet/smsc/smc91x.c7
-rw-r--r--drivers/net/ethernet/smsc/smc91x.h65
2 files changed, 52 insertions, 20 deletions
diff --git a/drivers/net/ethernet/smsc/smc91x.c b/drivers/net/ethernet/smsc/smc91x.c
index 726b80f45906..503a3b6dce91 100644
--- a/drivers/net/ethernet/smsc/smc91x.c
+++ b/drivers/net/ethernet/smsc/smc91x.c
@@ -2275,6 +2275,13 @@ static int smc_drv_probe(struct platform_device *pdev)
if (pd) {
memcpy(&lp->cfg, pd, sizeof(lp->cfg));
lp->io_shift = SMC91X_IO_SHIFT(lp->cfg.flags);
+
+ if (!SMC_8BIT(lp) && !SMC_16BIT(lp)) {
+ dev_err(&pdev->dev,
+ "at least one of 8-bit or 16-bit access support is required.\n");
+ ret = -ENXIO;
+ goto out_free_netdev;
+ }
}
#if IS_BUILTIN(CONFIG_OF)
diff --git a/drivers/net/ethernet/smsc/smc91x.h b/drivers/net/ethernet/smsc/smc91x.h
index 1a55c7976df0..e17671c9d1b0 100644
--- a/drivers/net/ethernet/smsc/smc91x.h
+++ b/drivers/net/ethernet/smsc/smc91x.h
@@ -37,6 +37,27 @@
#include <linux/smc91x.h>
/*
+ * 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.
+ */
+#define SMC_outw_b(x, a, r) \
+ do { \
+ unsigned int __val16 = (x); \
+ unsigned int __reg = (r); \
+ SMC_outb(__val16, a, __reg); \
+ SMC_outb(__val16 >> 8, a, __reg + (1 << SMC_IO_SHIFT)); \
+ } while (0)
+
+#define SMC_inw_b(a, r) \
+ ({ \
+ unsigned int __val16; \
+ unsigned int __reg = r; \
+ __val16 = SMC_inb(a, __reg); \
+ __val16 |= SMC_inb(a, __reg + (1 << SMC_IO_SHIFT)) << 8; \
+ __val16; \
+ })
+
+/*
* Define your architecture specific bus configuration parameters here.
*/
@@ -55,10 +76,30 @@
#define SMC_IO_SHIFT (lp->io_shift)
#define SMC_inb(a, r) readb((a) + (r))
-#define SMC_inw(a, r) readw((a) + (r))
+#define SMC_inw(a, r) \
+ ({ \
+ unsigned int __smc_r = r; \
+ SMC_16BIT(lp) ? readw((a) + __smc_r) : \
+ SMC_8BIT(lp) ? SMC_inw_b(a, __smc_r) : \
+ ({ BUG(); 0; }); \
+ })
+
#define SMC_inl(a, r) readl((a) + (r))
#define SMC_outb(v, a, r) writeb(v, (a) + (r))
+#define SMC_outw(v, a, r) \
+ do { \
+ unsigned int __v = v, __smc_r = r; \
+ if (SMC_16BIT(lp)) \
+ __SMC_outw(__v, a, __smc_r); \
+ else if (SMC_8BIT(lp)) \
+ SMC_outw_b(__v, a, __smc_r); \
+ else \
+ BUG(); \
+ } while (0)
+
#define SMC_outl(v, a, r) writel(v, (a) + (r))
+#define SMC_insb(a, r, p, l) readsb((a) + (r), p, l)
+#define SMC_outsb(a, r, p, l) writesb((a) + (r), p, l)
#define SMC_insw(a, r, p, l) readsw((a) + (r), p, l)
#define SMC_outsw(a, r, p, l) writesw((a) + (r), p, l)
#define SMC_insl(a, r, p, l) readsl((a) + (r), p, l)
@@ -66,7 +107,7 @@
#define SMC_IRQ_FLAGS (-1) /* from resource */
/* We actually can't write halfwords properly if not word aligned */
-static inline void SMC_outw(u16 val, void __iomem *ioaddr, int reg)
+static inline void __SMC_outw(u16 val, void __iomem *ioaddr, int reg)
{
if ((machine_is_mainstone() || machine_is_stargate2() ||
machine_is_pxa_idp()) && reg & 2) {
@@ -416,24 +457,8 @@ smc_pxa_dma_insw(void __iomem *ioaddr, struct smc_local *lp, int reg, int dma,
#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.
- */
-#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 ); \
- __val16 |= SMC_inb( ioaddr, reg + (1 << SMC_IO_SHIFT)) << 8; \
- __val16; \
- })
-
+#define SMC_outw(x, ioaddr, reg) SMC_outw_b(x, ioaddr, reg)
+#define SMC_inw(ioaddr, reg) SMC_inw_b(ioaddr, reg)
#define SMC_insw(a, r, p, l) BUG()
#define SMC_outsw(a, r, p, l) BUG()