ALSA: hda: Direct MMIO accesses

HD-audio drivers access to the mmio registers indirectly via the
corresponding bus->io_ops callbacks.  This is because some platform
(notably Tegra SoC) requires the word-aligned access.  But it's rather
a rare case, and other platforms suffer from the penalties by indirect
calls unnecessarily.

This patch is an attempt to optimize and cleanup for this situation.
Now the special aligned access is used only when a new kconfig
CONFIG_SND_HDA_ALIGNED_MMIO is set.  And the HD-audio core itself
provides the aligned MMIO access helpers instead of the driver side.
If Kconfig isn't set (as default), the standard helpers like readl()
or writel() are used directly.

A couple of places in ASoC Intel drivers have the access via io_ops
reg_writel(), and they are replaced with the direct writel() calls.

And now with this patch, the whole bus->io_ops becomes empty, so it's
dropped completely.  The bus initialization functions are changed
accordingly as well to drop the whole bus->io_ops.

Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 1 insertions, 41 deletions

diff --git a/sound/soc/sof/intel/hda-bus.c b/sound/soc/sof/intel/hda-bus.c
index 0bc93fa06b5b..438121c70f99 100644
--- a/sound/soc/sof/intel/hda-bus.c
+++ b/sound/soc/sof/intel/hda-bus.c
@@ -21,45 +21,6 @@ static const struct hdac_bus_ops bus_ops = {
 
 #endif
 
-static void sof_hda_writel(u32 value, u32 __iomem *addr)
-{
-        writel(value, addr);
-}
-
-static u32 sof_hda_readl(u32 __iomem *addr)
-{
-        return readl(addr);
-}
-
-static void sof_hda_writew(u16 value, u16 __iomem *addr)
-{
-        writew(value, addr);
-}
-
-static u16 sof_hda_readw(u16 __iomem *addr)
-{
-        return readw(addr);
-}
-
-static void sof_hda_writeb(u8 value, u8 __iomem *addr)
-{
-        writeb(value, addr);
-}
-
-static u8 sof_hda_readb(u8 __iomem *addr)
-{
-        return readb(addr);
-}
-
-static const struct hdac_io_ops io_ops = {
-        .reg_writel = sof_hda_writel,
-        .reg_readl = sof_hda_readl,
-        .reg_writew = sof_hda_writew,
-        .reg_readw = sof_hda_readw,
-        .reg_writeb = sof_hda_writeb,
-        .reg_readb = sof_hda_readb,
-};
-
 /*
  * This can be used for both with/without hda link support.
  */
@@ -69,7 +30,6 @@ void sof_hda_bus_init(struct hdac_bus *bus, struct device *dev,
         memset(bus, 0, sizeof(*bus));
         bus->dev = dev;
 
-        bus->io_ops = &io_ops;
         INIT_LIST_HEAD(&bus->stream_list);
 
         bus->irq = -1;
diff --git a/sound/soc/sof/intel/hda-dsp.c b/sound/soc/sof/intel/hda-dsp.c
index 91de4785b6a3..8d4ce5b4febd 100644
--- a/sound/soc/sof/intel/hda-dsp.c
+++ b/sound/soc/sof/intel/hda-dsp.c
@@ -356,7 +356,7 @@ static int hda_resume(struct snd_sof_dev *sdev)
 
         /* Reset stream-to-link mapping */
         list_for_each_entry(hlink, &bus->hlink_list, list)
-                bus->io_ops->reg_writel(0, hlink->ml_addr + AZX_REG_ML_LOSIDV);
+                writel(0, hlink->ml_addr + AZX_REG_ML_LOSIDV);
 
         hda_dsp_ctrl_misc_clock_gating(sdev, true);
 #else