ALSA: emu10k1: add optional debug printouts with DMA addresses

When we get a IOMMU page fault for a emu10k1 device it is very hard to
discover which of chip many DMA allocations triggered it (since on a IOMMU
system the DMA address space is often very different from the CPU one).
Let's add optional debug printouts providing this information.

These debug printouts are only enabled on an explicit request via the
kernel dynamic debug mechanism.

Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
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 11e868f569d62ff0e385f15a38815e6c84038d07..8decd2a7a4041d16c7f218c8c6f2e43b20c85213 100644 (file)
--- a/sound/pci/emu10k1/emu10k1_main.c
+++ b/sound/pci/emu10k1/emu10k1_main.c
@@ -1898,6 +1898,9 @@ int snd_emu10k1_create(struct snd_card *card,
                err = -ENOMEM;
                goto error;
        }
+       dev_dbg(card->dev, "page table address range is %.8lx:%.8lx\n",
+               (unsigned long)emu->ptb_pages.addr,
+               (unsigned long)(emu->ptb_pages.addr + emu->ptb_pages.bytes));
 
        emu->page_ptr_table = vmalloc(emu->max_cache_pages * sizeof(void *));
        emu->page_addr_table = vmalloc(emu->max_cache_pages *
@@ -1912,6 +1915,11 @@ int snd_emu10k1_create(struct snd_card *card,
                err = -ENOMEM;
                goto error;
        }
+       dev_dbg(card->dev, "silent page range is %.8lx:%.8lx\n",
+               (unsigned long)emu->silent_page.addr,
+               (unsigned long)(emu->silent_page.addr +
+                               emu->silent_page.bytes));
+
        emu->memhdr = snd_util_memhdr_new(emu->max_cache_pages * PAGE_SIZE);
        if (emu->memhdr == NULL) {
                err = -ENOMEM;

diff --git a/sound/pci/emu10k1/memory.c b/sound/pci/emu10k1/memory.c
index eaa61024ac7ff471ed9bdbf79e1f149fd598877a..fcb04cbbc9ab16cb88ac1ffb909b77a5dbfc0665 100644 (file)
--- a/sound/pci/emu10k1/memory.c
+++ b/sound/pci/emu10k1/memory.c
@@ -34,7 +34,10 @@
  * aligned pages in others
  */
 #define __set_ptb_entry(emu,page,addr) \
-       (((u32 *)(emu)->ptb_pages.area)[page] = cpu_to_le32(((addr) << (emu->address_mode)) | (page)))
+       (((__le32 *)(emu)->ptb_pages.area)[page] = \
+        cpu_to_le32(((addr) << (emu->address_mode)) | (page)))
+#define __get_ptb_entry(emu, page) \
+       (le32_to_cpu(((__le32 *)(emu)->ptb_pages.area)[page]))
 
 #define UNIT_PAGES             (PAGE_SIZE / EMUPAGESIZE)
 #define MAX_ALIGN_PAGES0               (MAXPAGES0 / UNIT_PAGES)
@@ -44,8 +47,7 @@
 /* get offset address from aligned page */
 #define aligned_page_offset(page)      ((page) << PAGE_SHIFT)
 
-#if PAGE_SIZE == 4096
-/* page size == EMUPAGESIZE */
+#if PAGE_SIZE == EMUPAGESIZE && !IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
 /* fill PTB entrie(s) corresponding to page with addr */
 #define set_ptb_entry(emu,page,addr)   __set_ptb_entry(emu,page,addr)
 /* fill PTB entrie(s) corresponding to page with silence pointer */
@@ -58,6 +60,8 @@ static inline void set_ptb_entry(struct snd_emu10k1 *emu, int page, dma_addr_t a
        page *= UNIT_PAGES;
        for (i = 0; i < UNIT_PAGES; i++, page++) {
                __set_ptb_entry(emu, page, addr);
+               dev_dbg(emu->card->dev, "mapped page %d to entry %.8x\n", page,
+                       (unsigned int)__get_ptb_entry(emu, page));
                addr += EMUPAGESIZE;
        }
 }
@@ -65,9 +69,12 @@ static inline void set_silent_ptb(struct snd_emu10k1 *emu, int page)
 {
        int i;
        page *= UNIT_PAGES;
-       for (i = 0; i < UNIT_PAGES; i++, page++)
+       for (i = 0; i < UNIT_PAGES; i++, page++) {
                /* do not increment ptr */
                __set_ptb_entry(emu, page, emu->silent_page.addr);
+               dev_dbg(emu->card->dev, "mapped silent page %d to entry %.8x\n",
+                       page, (unsigned int)__get_ptb_entry(emu, page));
+       }
 }
 #endif /* PAGE_SIZE */