ALSA: emu10k1: Emu10k2 32 bit DMA mode

Looks like audigy emu10k2 (probably emu10k1 - sb live too) support two
modes for DMA. Second mode is useful for 64 bit os with more then 2 GB
of ram (fixes problems with big soundfont loading)

1) 32MB from 2 GB address space using 8192 pages (used now as default)
2) 16MB from 4 GB address space using 4096 pages

Mode is set using HCFG_EXPANDED_MEM flag in HCFG register.
Also format of emu10k2 page table is then different.

Signed-off-by: Peter Zubaj <pzubaj@marticonet.sk>
Tested-by: Takashi Iwai <tiwai@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/emu10k1/emu10k1_main.c b/sound/pci/emu10k1/emu10k1_main.c
index 4f8cf5e..a454814 100644
--- a/sound/pci/emu10k1/emu10k1_main.c
+++ b/sound/pci/emu10k1/emu10k1_main.c
@@ -282,7 +282,7 @@
 	snd_emu10k1_ptr_write(emu, TCB, 0, 0);	/* taken from original driver */
 	snd_emu10k1_ptr_write(emu, TCBS, 0, 4);	/* taken from original driver */
 
-	silent_page = (emu->silent_page.addr << 1) | MAP_PTI_MASK;
+	silent_page = (emu->silent_page.addr << emu->address_mode) | (emu->address_mode ? MAP_PTI_MASK1 : MAP_PTI_MASK0);
 	for (ch = 0; ch < NUM_G; ch++) {
 		snd_emu10k1_ptr_write(emu, MAPA, ch, silent_page);
 		snd_emu10k1_ptr_write(emu, MAPB, ch, silent_page);
@@ -348,6 +348,11 @@
 		outl(reg | A_IOCFG_GPOUT0, emu->port + A_IOCFG);
 	}
 
+	if (emu->address_mode == 0) {
+		/* use 16M in 4G */
+		outl(inl(emu->port + HCFG) | HCFG_EXPANDED_MEM, emu->port + HCFG);
+	}
+
 	return 0;
 }
 
@@ -1902,8 +1907,10 @@
 
 	is_audigy = emu->audigy = c->emu10k2_chip;
 
+	/* set addressing mode */
+	emu->address_mode = is_audigy ? 0 : 1;
 	/* set the DMA transfer mask */
-	emu->dma_mask = is_audigy ? AUDIGY_DMA_MASK : EMU10K1_DMA_MASK;
+	emu->dma_mask = emu->address_mode ? EMU10K1_DMA_MASK : AUDIGY_DMA_MASK;
 	if (pci_set_dma_mask(pci, emu->dma_mask) < 0 ||
 	    pci_set_consistent_dma_mask(pci, emu->dma_mask) < 0) {
 		dev_err(card->dev,
@@ -1928,7 +1935,7 @@
 
 	emu->max_cache_pages = max_cache_bytes >> PAGE_SHIFT;
 	if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(pci),
-				32 * 1024, &emu->ptb_pages) < 0) {
+				(emu->address_mode ? 32 : 16) * 1024, &emu->ptb_pages) < 0) {
 		err = -ENOMEM;
 		goto error;
 	}
@@ -2027,8 +2034,8 @@
 
 	/* Clear silent pages and set up pointers */
 	memset(emu->silent_page.area, 0, PAGE_SIZE);
-	silent_page = emu->silent_page.addr << 1;
-	for (idx = 0; idx < MAXPAGES; idx++)
+	silent_page = emu->silent_page.addr << emu->address_mode;
+	for (idx = 0; idx < (emu->address_mode ? MAXPAGES1 : MAXPAGES0); idx++)
 		((u32 *)emu->ptb_pages.area)[idx] = cpu_to_le32(silent_page | idx);
 
 	/* set up voice indices */