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>

1 files changed, 1 insertions, 46 deletions

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 3bb4c26f2799..963a92943a6d 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1627,7 +1627,6 @@ static int default_bdl_pos_adj(struct azx *chip)
 /*
  * constructor
  */
-static const struct hdac_io_ops pci_hda_io_ops;
 static const struct hda_controller_ops pci_hda_ops;
 
 static int azx_create(struct snd_card *card, struct pci_dev *pci,
@@ -1687,7 +1686,7 @@ static int azx_create(struct snd_card *card, struct pci_dev *pci,
 	else
 		chip->bdl_pos_adj = bdl_pos_adj[dev];
 
-	err = azx_bus_init(chip, model[dev], &pci_hda_io_ops);
+	err = azx_bus_init(chip, model[dev]);
 	if (err < 0) {
 		kfree(hda);
 		pci_disable_device(pci);
@@ -1932,41 +1931,6 @@ static void azx_firmware_cb(const struct firmware *fw, void *context)
 }
 #endif
 
-/*
- * HDA controller ops.
- */
-
-/* PCI register access. */
-static void pci_azx_writel(u32 value, u32 __iomem *addr)
-{
-	writel(value, addr);
-}
-
-static u32 pci_azx_readl(u32 __iomem *addr)
-{
-	return readl(addr);
-}
-
-static void pci_azx_writew(u16 value, u16 __iomem *addr)
-{
-	writew(value, addr);
-}
-
-static u16 pci_azx_readw(u16 __iomem *addr)
-{
-	return readw(addr);
-}
-
-static void pci_azx_writeb(u8 value, u8 __iomem *addr)
-{
-	writeb(value, addr);
-}
-
-static u8 pci_azx_readb(u8 __iomem *addr)
-{
-	return readb(addr);
-}
-
 static int disable_msi_reset_irq(struct azx *chip)
 {
 	struct hdac_bus *bus = azx_bus(chip);
@@ -1994,15 +1958,6 @@ static void pcm_mmap_prepare(struct snd_pcm_substream *substream,
 #endif
 }
 
-static const struct hdac_io_ops pci_hda_io_ops = {
-	.reg_writel = pci_azx_writel,
-	.reg_readl = pci_azx_readl,
-	.reg_writew = pci_azx_writew,
-	.reg_readw = pci_azx_readw,
-	.reg_writeb = pci_azx_writeb,
-	.reg_readb = pci_azx_readb,
-};
-
 static const struct hda_controller_ops pci_hda_ops = {
 	.disable_msi_reset_irq = disable_msi_reset_irq,
 	.pcm_mmap_prepare = pcm_mmap_prepare,