V4L/DVB (9724): cx18: Streamline cx18-io[ch] wrappers and enforce MMIO retry strategy

cx18: Streamline cx18-io[ch] wrappers and enforce MMIO retry strategy so that
write retries always occur and read retries never occur (as they never help).
Remove MMIO statistics logging to speed up MMIO accesses.  Deprecate & ignore
retry_mmio and mmio_ndelay module parameters, to essentially force
retry_mmio=1 and mmio_ndelay=0.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 55 insertions, 265 deletions

diff --git a/drivers/media/video/cx18/cx18-io.h b/drivers/media/video/cx18/cx18-io.h
index fdc2bcc92fca..73321fb4cbf5 100644
--- a/drivers/media/video/cx18/cx18-io.h
+++ b/drivers/media/video/cx18/cx18-io.h
@@ -25,230 +25,118 @@
 
 #include "cx18-driver.h"
 
-static inline void cx18_io_delay(struct cx18 *cx)
-{
-        if (cx->options.mmio_ndelay)
-                ndelay(cx->options.mmio_ndelay);
-}
-
 /*
  * Readback and retry of MMIO access for reliability:
  * The concept was suggested by Steve Toth <stoth@linuxtv.org>.
  * The implmentation is the fault of Andy Walls <awalls@radix.net>.
+ *
+ * *write* functions are implied to retry the mmio unless suffixed with _noretry
+ * *read* functions never retry the mmio (it never helps to do so)
  */
 
 /* Statistics gathering */
-static inline
-void cx18_log_write_retries(struct cx18 *cx, int i, const void __iomem *addr)
-{
-        if (i > CX18_MAX_MMIO_WR_RETRIES)
-                i = CX18_MAX_MMIO_WR_RETRIES;
-        atomic_inc(&cx->mmio_stats.retried_write[i]);
-        return;
-}
-
-static inline
-void cx18_log_read_retries(struct cx18 *cx, int i, const void __iomem *addr)
-{
-        if (i > CX18_MAX_MMIO_RD_RETRIES)
-                i = CX18_MAX_MMIO_RD_RETRIES;
-        atomic_inc(&cx->mmio_stats.retried_read[i]);
-        return;
-}
 
 void cx18_log_statistics(struct cx18 *cx);
 
 /* Non byteswapping memory mapped IO */
+static inline u32 cx18_raw_readl(struct cx18 *cx, const void __iomem *addr)
+{
+        return __raw_readl(addr);
+}
+
 static inline
 void cx18_raw_writel_noretry(struct cx18 *cx, u32 val, void __iomem *addr)
 {
         __raw_writel(val, addr);
-        cx18_io_delay(cx);
 }
 
-void cx18_raw_writel_retry(struct cx18 *cx, u32 val, void __iomem *addr);
-
 static inline void cx18_raw_writel(struct cx18 *cx, u32 val, void __iomem *addr)
 {
-        if (cx18_retry_mmio)
-                cx18_raw_writel_retry(cx, val, addr);
-        else
+        int i;
+        for (i = 0; i < CX18_MAX_MMIO_WR_RETRIES; i++) {
                 cx18_raw_writel_noretry(cx, val, addr);
+                if (val == cx18_raw_readl(cx, addr))
+                        break;
+        }
 }
 
-
-static inline
-u32 cx18_raw_readl_noretry(struct cx18 *cx, const void __iomem *addr)
-{
-        u32 ret = __raw_readl(addr);
-        cx18_io_delay(cx);
-        return ret;
-}
-
-u32 cx18_raw_readl_retry(struct cx18 *cx, const void __iomem *addr);
-
-static inline u32 cx18_raw_readl(struct cx18 *cx, const void __iomem *addr)
+/* Normal memory mapped IO */
+static inline u32 cx18_readl(struct cx18 *cx, const void __iomem *addr)
 {
-        if (cx18_retry_mmio)
-                return cx18_raw_readl_retry(cx, addr);
-
-        return cx18_raw_readl_noretry(cx, addr);
+        return readl(addr);
 }
 
-
 static inline
-u16 cx18_raw_readw_noretry(struct cx18 *cx, const void __iomem *addr)
+void cx18_writel_noretry(struct cx18 *cx, u32 val, void __iomem *addr)
 {
-        u16 ret = __raw_readw(addr);
-        cx18_io_delay(cx);
-        return ret;
+        writel(val, addr);
 }
 
-u16 cx18_raw_readw_retry(struct cx18 *cx, const void __iomem *addr);
-
-static inline u16 cx18_raw_readw(struct cx18 *cx, const void __iomem *addr)
+static inline void cx18_writel(struct cx18 *cx, u32 val, void __iomem *addr)
 {
-        if (cx18_retry_mmio)
-                return cx18_raw_readw_retry(cx, addr);
-
-        return cx18_raw_readw_noretry(cx, addr);
+        int i;
+        for (i = 0; i < CX18_MAX_MMIO_WR_RETRIES; i++) {
+                cx18_writel_noretry(cx, val, addr);
+                if (val == cx18_readl(cx, addr))
+                        break;
+        }
 }
 
-
-/* Normal memory mapped IO */
 static inline
-void cx18_writel_noretry(struct cx18 *cx, u32 val, void __iomem *addr)
+void cx18_writel_expect(struct cx18 *cx, u32 val, void __iomem *addr,
+                        u32 eval, u32 mask)
 {
-        writel(val, addr);
-        cx18_io_delay(cx);
+        int i;
+        eval &= mask;
+        for (i = 0; i < CX18_MAX_MMIO_WR_RETRIES; i++) {
+                cx18_writel_noretry(cx, val, addr);
+                if (eval == (cx18_readl(cx, addr) & mask))
+                        break;
+        }
 }
 
-void cx18_writel_retry(struct cx18 *cx, u32 val, void __iomem *addr);
-
-static inline void cx18_writel(struct cx18 *cx, u32 val, void __iomem *addr)
+static inline u16 cx18_readw(struct cx18 *cx, const void __iomem *addr)
 {
-        if (cx18_retry_mmio)
-                cx18_writel_retry(cx, val, addr);
-        else
-                cx18_writel_noretry(cx, val, addr);
+        return readw(addr);
 }
 
-void _cx18_writel_expect(struct cx18 *cx, u32 val, void __iomem *addr,
-                         u32 eval, u32 mask);
-
 static inline
 void cx18_writew_noretry(struct cx18 *cx, u16 val, void __iomem *addr)
 {
         writew(val, addr);
-        cx18_io_delay(cx);
 }
 
-void cx18_writew_retry(struct cx18 *cx, u16 val, void __iomem *addr);
-
 static inline void cx18_writew(struct cx18 *cx, u16 val, void __iomem *addr)
 {
-        if (cx18_retry_mmio)
-                cx18_writew_retry(cx, val, addr);
-        else
+        int i;
+        for (i = 0; i < CX18_MAX_MMIO_WR_RETRIES; i++) {
                 cx18_writew_noretry(cx, val, addr);
+                if (val == cx18_readw(cx, addr))
+                        break;
+        }
 }
 
+static inline u8 cx18_readb(struct cx18 *cx, const void __iomem *addr)
+{
+        return readb(addr);
+}
 
 static inline
 void cx18_writeb_noretry(struct cx18 *cx, u8 val, void __iomem *addr)
 {
         writeb(val, addr);
-        cx18_io_delay(cx);
 }
 
-void cx18_writeb_retry(struct cx18 *cx, u8 val, void __iomem *addr);
-
 static inline void cx18_writeb(struct cx18 *cx, u8 val, void __iomem *addr)
 {
-        if (cx18_retry_mmio)
-                cx18_writeb_retry(cx, val, addr);
-        else
+        int i;
+        for (i = 0; i < CX18_MAX_MMIO_WR_RETRIES; i++) {
                 cx18_writeb_noretry(cx, val, addr);
+                if (val == cx18_readb(cx, addr))
+                        break;
+        }
 }
 
-
-static inline u32 cx18_readl_noretry(struct cx18 *cx, const void __iomem *addr)
-{
-        u32 ret = readl(addr);
-        cx18_io_delay(cx);
-        return ret;
-}
-
-u32 cx18_readl_retry(struct cx18 *cx, const void __iomem *addr);
-
-static inline u32 cx18_readl(struct cx18 *cx, const void __iomem *addr)
-{
-        if (cx18_retry_mmio)
-                return cx18_readl_retry(cx, addr);
-
-        return cx18_readl_noretry(cx, addr);
-}
-
-
-static inline u16 cx18_readw_noretry(struct cx18 *cx, const void __iomem *addr)
-{
-        u16 ret = readw(addr);
-        cx18_io_delay(cx);
-        return ret;
-}
-
-u16 cx18_readw_retry(struct cx18 *cx, const void __iomem *addr);
-
-static inline u16 cx18_readw(struct cx18 *cx, const void __iomem *addr)
-{
-        if (cx18_retry_mmio)
-                return cx18_readw_retry(cx, addr);
-
-        return cx18_readw_noretry(cx, addr);
-}
-
-
-static inline u8 cx18_readb_noretry(struct cx18 *cx, const void __iomem *addr)
-{
-        u8 ret = readb(addr);
-        cx18_io_delay(cx);
-        return ret;
-}
-
-u8 cx18_readb_retry(struct cx18 *cx, const void __iomem *addr);
-
-static inline u8 cx18_readb(struct cx18 *cx, const void __iomem *addr)
-{
-        if (cx18_retry_mmio)
-                return cx18_readb_retry(cx, addr);
-
-        return cx18_readb_noretry(cx, addr);
-}
-
-
-static inline
-u32 cx18_write_sync_noretry(struct cx18 *cx, u32 val, void __iomem *addr)
-{
-        cx18_writel_noretry(cx, val, addr);
-        return cx18_readl_noretry(cx, addr);
-}
-
-static inline
-u32 cx18_write_sync_retry(struct cx18 *cx, u32 val, void __iomem *addr)
-{
-        cx18_writel_retry(cx, val, addr);
-        return cx18_readl_retry(cx, addr);
-}
-
-static inline u32 cx18_write_sync(struct cx18 *cx, u32 val, void __iomem *addr)
-{
-        if (cx18_retry_mmio)
-                return cx18_write_sync_retry(cx, val, addr);
-
-        return cx18_write_sync_noretry(cx, val, addr);
-}
-
-
 static inline
 void cx18_memcpy_fromio(struct cx18 *cx, void *to,
                         const void __iomem *from, unsigned int len)
@@ -265,130 +153,32 @@ static inline void cx18_write_reg_noretry(struct cx18 *cx, u32 val, u32 reg)
         cx18_writel_noretry(cx, val, cx->reg_mem + reg);
 }
 
-static inline void cx18_write_reg_retry(struct cx18 *cx, u32 val, u32 reg)
-{
-        cx18_writel_retry(cx, val, cx->reg_mem + reg);
-}
-
 static inline void cx18_write_reg(struct cx18 *cx, u32 val, u32 reg)
 {
-        if (cx18_retry_mmio)
-                cx18_write_reg_retry(cx, val, reg);
-        else
-                cx18_write_reg_noretry(cx, val, reg);
-}
-
-static inline void _cx18_write_reg_expect(struct cx18 *cx, u32 val, u32 reg,
-                                          u32 eval, u32 mask)
-{
-        _cx18_writel_expect(cx, val, cx->reg_mem + reg, eval, mask);
+        cx18_writel(cx, val, cx->reg_mem + reg);
 }
 
 static inline void cx18_write_reg_expect(struct cx18 *cx, u32 val, u32 reg,
                                          u32 eval, u32 mask)
 {
-        if (cx18_retry_mmio)
-                _cx18_write_reg_expect(cx, val, reg, eval, mask);
-        else
-                cx18_write_reg_noretry(cx, val, reg);
-}
-
-
-static inline u32 cx18_read_reg_noretry(struct cx18 *cx, u32 reg)
-{
-        return cx18_readl_noretry(cx, cx->reg_mem + reg);
-}
-
-static inline u32 cx18_read_reg_retry(struct cx18 *cx, u32 reg)
-{
-        return cx18_readl_retry(cx, cx->reg_mem + reg);
+        cx18_writel_expect(cx, val, cx->reg_mem + reg, eval, mask);
 }
 
 static inline u32 cx18_read_reg(struct cx18 *cx, u32 reg)
 {
-        if (cx18_retry_mmio)
-                return cx18_read_reg_retry(cx, reg);
-
-        return cx18_read_reg_noretry(cx, reg);
-}
-
-
-static inline u32 cx18_write_reg_sync_noretry(struct cx18 *cx, u32 val, u32 reg)
-{
-        return cx18_write_sync_noretry(cx, val, cx->reg_mem + reg);
-}
-
-static inline u32 cx18_write_reg_sync_retry(struct cx18 *cx, u32 val, u32 reg)
-{
-        return cx18_write_sync_retry(cx, val, cx->reg_mem + reg);
-}
-
-static inline u32 cx18_write_reg_sync(struct cx18 *cx, u32 val, u32 reg)
-{
-        if (cx18_retry_mmio)
-                return cx18_write_reg_sync_retry(cx, val, reg);
-
-        return cx18_write_reg_sync_noretry(cx, val, reg);
+        return cx18_readl(cx, cx->reg_mem + reg);
 }
 
 
 /* Access "encoder memory" region of CX23418 memory mapped I/O */
-static inline void cx18_write_enc_noretry(struct cx18 *cx, u32 val, u32 addr)
-{
-        cx18_writel_noretry(cx, val, cx->enc_mem + addr);
-}
-
-static inline void cx18_write_enc_retry(struct cx18 *cx, u32 val, u32 addr)
-{
-        cx18_writel_retry(cx, val, cx->enc_mem + addr);
-}
-
 static inline void cx18_write_enc(struct cx18 *cx, u32 val, u32 addr)
 {
-        if (cx18_retry_mmio)
-                cx18_write_enc_retry(cx, val, addr);
-        else
-                cx18_write_enc_noretry(cx, val, addr);
-}
-
-
-static inline u32 cx18_read_enc_noretry(struct cx18 *cx, u32 addr)
-{
-        return cx18_readl_noretry(cx, cx->enc_mem + addr);
-}
-
-static inline u32 cx18_read_enc_retry(struct cx18 *cx, u32 addr)
-{
-        return cx18_readl_retry(cx, cx->enc_mem + addr);
+        cx18_writel(cx, val, cx->enc_mem + addr);
 }
 
 static inline u32 cx18_read_enc(struct cx18 *cx, u32 addr)
 {
-        if (cx18_retry_mmio)
-                return cx18_read_enc_retry(cx, addr);
-
-        return cx18_read_enc_noretry(cx, addr);
-}
-
-static inline
-u32 cx18_write_enc_sync_noretry(struct cx18 *cx, u32 val, u32 addr)
-{
-        return cx18_write_sync_noretry(cx, val, cx->enc_mem + addr);
-}
-
-static inline
-u32 cx18_write_enc_sync_retry(struct cx18 *cx, u32 val, u32 addr)
-{
-        return cx18_write_sync_retry(cx, val, cx->enc_mem + addr);
-}
-
-static inline
-u32 cx18_write_enc_sync(struct cx18 *cx, u32 val, u32 addr)
-{
-        if (cx18_retry_mmio)
-                return cx18_write_enc_sync_retry(cx, val, addr);
-
-        return cx18_write_enc_sync_noretry(cx, val, addr);
+        return cx18_readl(cx, cx->enc_mem + addr);
 }
 
 void cx18_sw1_irq_enable(struct cx18 *cx, u32 val);