drivers: firewire: Let several sub-modules depend on HAS_DMA

Several sub-modules of 'firewire' need HAS_DMA, so let them depend on it. FIREWIRE_NET and FIREWIRE_OHCI use 'core-iso.c' which also needs HAS_DMA, so need 'ifdef' the related function by CONFIG_HAS_DMA in 'core-iso.c'.

The related error (with allmodconfig under score):

MODPOST 1365 modules
ERROR: "dma_mapping_error" [drivers/firewire/firewire-sbp2.ko] undefined!
ERROR: "dma_map_single" [drivers/firewire/firewire-sbp2.ko] undefined!
ERROR: "dma_unmap_single" [drivers/firewire/firewire-sbp2.ko] undefined!
ERROR: "scsi_dma_map" [drivers/firewire/firewire-sbp2.ko] undefined!
ERROR: "scsi_dma_unmap" [drivers/firewire/firewire-sbp2.ko] undefined!
ERROR: "dma_mapping_error" [drivers/firewire/firewire-core.ko] undefined!
ERROR: "dma_map_page" [drivers/firewire/firewire-core.ko] undefined!
ERROR: "dma_unmap_page" [drivers/firewire/firewire-core.ko] undefined!

Signed-off-by Chen Gang <[email protected]>

---
 drivers/firewire/Kconfig    |  6 +++---
 drivers/firewire/core-iso.c | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 3 deletions(-)

drivers/firewire/Kconfig +0 -0

index 4199849..fd75278 100644

drivers/firewire/core-iso.c +9 -0

index 38c0aa6..995f038 100644
@@ -64,6 +64,7 @@ int fw_iso_buffer_alloc(struct fw_iso_buffer *buffer, int page_count)
 	return 0;
 }
 
+#ifdef CONFIG_HAS_DMA
 int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card,
 			  enum dma_data_direction direction)
 {

@@ -86,6 +87,13 @@ int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card,
 
 	return 0;
 }
+#else
+int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card,
+			  enum dma_data_direction direction)
+{
+	return -ENXIO;
+}
+#endif
 
 int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
 		       int page_count, enum dma_data_direction direction)

@@ -122,6 +130,7 @@ int fw_iso_buffer_map_vma(struct fw_iso_buffer *buffer,
 	return 0;
 }
 
+#ifdef CONFIG_HAS_DMA
 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
 			   struct fw_card *card)
 {

@@ -141,6 +150,12 @@ void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
 	buffer->page_count = 0;
 	buffer->page_count_mapped = 0;

Review

Quoted 8 lines · On Jul 13 Chen Gang wrote:

config FIREWIRE_OHCI

(quoted diff) +1 -1

 	tristate "OHCI-1394 controllers"
-	depends on PCI && FIREWIRE && MMU
+	depends on PCI && FIREWIRE && MMU && HAS_DMA
 	help
 	  Enable this driver if you have a FireWire controller based
 	  on the OHCI specification.  For all practical purposes, this

As far as I understand, architecture configuration files shall already ensure that CONFIG_PCI is not enabled if !CONFIG_HAS_DMA. If so, this part can be omitted. Or am I mistaken?

Review config FIREWIRE_SBP2 · line 51

Quoted 9 lines

(quoted diff) +1 -1

@@ -45,7 +45,7 @@ config FIREWIRE_SBP2
 
 config FIREWIRE_NET
 	tristate "IP networking over 1394"
-	depends on FIREWIRE && INET
+	depends on FIREWIRE && INET && HAS_DMA
 	help
 	  This enables IPv4/IPv6 over IEEE 1394, providing IP connectivity
 	  with other implementations of RFC 2734/3146 as found on several

This is not completely necessary: firewire-net does not use DMA mapping APIs directly, it uses them only through firewire-core. Same with sound/firewire/* (a few audio device drivers) and with drivers/media/firewire/* (a DVB device driver) which you did not patch.

So they could be *compiled* on architectures without HAS_DMA, they could just not be *used* (because firewire-core's isochronous DMA mapping functions would return errors, but more so because there are no IEEE 1394 host bus adapters on these platforms in the first place. Actually Texas Instruments used to make a 1394 HBA chip with some sort of GPIO host interface instead of PCI interface, but Linux only has a driver for PCI HBAs.)

But see below.

All in all, I like the following approach better:

Date: Wed, 9 Jul 2014 21:04:00 +0200
From: Geert Uytterhoeven <[email protected]>
To: Stefan Richter <[email protected]>
Cc: Jean Delvare <[email protected]>, [email protected], [email protected], Geert Uytterhoeven <[email protected]>
Subject: [PATCH] firewire: IEEE 1394 (FireWire) support should depend on HAS_DMA

Commit b3d681a4fc108f9653bbb44e4f4e72db2b8a5734 ("firewire: Use COMPILE_TEST for build testing") added COMPILE_TEST as an alternative dependency for the purpose of build testing the firewire core. However, this bypasses all other implicit dependencies assumed by PCI, like HAS_DMA.

If NO_DMA=y:

    drivers/built-in.o: In function `fw_iso_buffer_destroy':
    (.text+0x36a096): undefined reference to `dma_unmap_page'
    drivers/built-in.o: In function `fw_iso_buffer_map_dma':
    (.text+0x36a164): undefined reference to `dma_map_page'
    drivers/built-in.o: In function `fw_iso_buffer_map_dma':
    (.text+0x36a172): undefined reference to `dma_mapping_error'
    drivers/built-in.o: In function `sbp2_send_management_orb':
    sbp2.c:(.text+0x36c6b4): undefined reference to `dma_map_single'
    sbp2.c:(.text+0x36c6c8): undefined reference to `dma_mapping_error'
    sbp2.c:(.text+0x36c772): undefined reference to `dma_map_single'
    sbp2.c:(.text+0x36c786): undefined reference to `dma_mapping_error'
    sbp2.c:(.text+0x36c854): undefined reference to `dma_unmap_single'
    sbp2.c:(.text+0x36c872): undefined reference to `dma_unmap_single'
    drivers/built-in.o: In function `sbp2_map_scatterlist':
    sbp2.c:(.text+0x36ccbc): undefined reference to `scsi_dma_map'
    sbp2.c:(.text+0x36cd36): undefined reference to `dma_map_single'
    sbp2.c:(.text+0x36cd4e): undefined reference to `dma_mapping_error'
    sbp2.c:(.text+0x36cd84): undefined reference to `scsi_dma_unmap'
    drivers/built-in.o: In function `sbp2_unmap_scatterlist':
    sbp2.c:(.text+0x36cda6): undefined reference to `scsi_dma_unmap'
    sbp2.c:(.text+0x36cdc6): undefined reference to `dma_unmap_single'
    drivers/built-in.o: In function `complete_command_orb':
    sbp2.c:(.text+0x36d6ac): undefined reference to `dma_unmap_single'
    drivers/built-in.o: In function `sbp2_scsi_queuecommand':
    sbp2.c:(.text+0x36d8e0): undefined reference to `dma_map_single'
    sbp2.c:(.text+0x36d8f6): undefined reference to `dma_mapping_error'

Add an explicit dependency on HAS_DMA to fix this.

Signed-off-by Geert Uytterhoeven <[email protected]>

Reviewed-by Jean Delvare <[email protected]>

---
 drivers/firewire/Kconfig | 1 +
 1 file changed, 1 insertion(+)

drivers/firewire/Kconfig +1 -0

index 4199849e3758..145974f9662b 100644
@@ -1,4 +1,5 @@
 menu "IEEE 1394 (FireWire) support"
+	depends on HAS_DMA
 	depends on PCI || COMPILE_TEST
 	# firewire-core does not depend on PCI but is
 	# not useful without PCI controller driver

As a downside, this removes the ability to test-build the sound and DVB high-level 1394 drivers (and firewire-net) on !HAS_DMA architectures. But on the positive side, it is simpler. If there are no objections, I am going to commit Geert's fix.