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* next take at setting up a dma mask by default for platform devices v2
@ 2019-08-16  6:24 Christoph Hellwig
  2019-08-16  6:24 ` [PATCH 1/6] usb: don't create dma pools for HCDs with a localmem_pool Christoph Hellwig
                   ` (6 more replies)
  0 siblings, 7 replies; 15+ messages in thread
From: Christoph Hellwig @ 2019-08-16  6:24 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Maxime Chevallier
  Cc: Gavin Li, Laurentiu Tudor, Minas Harutyunyan, Alan Stern,
	Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Mathias Nyman, Bin Liu, linux-arm-kernel, linux-usb,
	linuxppc-dev, linux-m68k, iommu, linux-arch, linux-kernel

Hi all,

this is another attempt to make sure the dma_mask pointer is always
initialized for platform devices.  Not doing so lead to lots of
boilerplate code, and makes platform devices different from all our
major busses like PCI where we always set up a dma_mask.  In the long
run this should also help to eventually make dma_mask a scalar value
instead of a pointer and remove even more cruft.

The bigger blocker for this last time was the fact that the usb
subsystem uses the presence or lack of a dma_mask to check if the core
should do dma mapping for the driver, which is highly unusual.  So we
fix this first.  Note that this has some overlap with the pending
desire to use the proper dma_mmap_coherent helper for mapping usb
buffers.  The first two patches have already been queued up by Greg
and are only included for completeness.

Changes since v1:
 - fix a compile error in the ppc of ohci driver
 - revamp the last patch to get rid of the archdata callout entirely.

^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 1/6] usb: don't create dma pools for HCDs with a localmem_pool
  2019-08-16  6:24 next take at setting up a dma mask by default for platform devices v2 Christoph Hellwig
@ 2019-08-16  6:24 ` Christoph Hellwig
  2019-08-16  6:24 ` [PATCH 2/6] usb: add a hcd_uses_dma helper Christoph Hellwig
                   ` (5 subsequent siblings)
  6 siblings, 0 replies; 15+ messages in thread
From: Christoph Hellwig @ 2019-08-16  6:24 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Maxime Chevallier
  Cc: Gavin Li, Laurentiu Tudor, Minas Harutyunyan, Alan Stern,
	Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Mathias Nyman, Bin Liu, linux-arm-kernel, linux-usb,
	linuxppc-dev, linux-m68k, iommu, linux-arch, linux-kernel

If the HCD provides a localmem pool we will never use the DMA pools, so
don't create them.

Fixes: b0310c2f09bb ("USB: use genalloc for USB HCs with local memory")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/usb/core/buffer.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index 1359b78a624e..1a5b3dcae930 100644
--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -66,9 +66,9 @@ int hcd_buffer_create(struct usb_hcd *hcd)
 	char		name[16];
 	int		i, size;
 
-	if (!IS_ENABLED(CONFIG_HAS_DMA) ||
-	    (!is_device_dma_capable(hcd->self.sysdev) &&
-	     !hcd->localmem_pool))
+	if (hcd->localmem_pool ||
+	    !IS_ENABLED(CONFIG_HAS_DMA) ||
+	    !is_device_dma_capable(hcd->self.sysdev))
 		return 0;
 
 	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
-- 
2.20.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 2/6] usb: add a hcd_uses_dma helper
  2019-08-16  6:24 next take at setting up a dma mask by default for platform devices v2 Christoph Hellwig
  2019-08-16  6:24 ` [PATCH 1/6] usb: don't create dma pools for HCDs with a localmem_pool Christoph Hellwig
@ 2019-08-16  6:24 ` Christoph Hellwig
  2019-08-16  6:24 ` [PATCH 3/6] usb: add a HCD_DMA flag instead of guestimating DMA capabilities Christoph Hellwig
                   ` (4 subsequent siblings)
  6 siblings, 0 replies; 15+ messages in thread
From: Christoph Hellwig @ 2019-08-16  6:24 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Maxime Chevallier
  Cc: Gavin Li, Laurentiu Tudor, Minas Harutyunyan, Alan Stern,
	Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Mathias Nyman, Bin Liu, linux-arm-kernel, linux-usb,
	linuxppc-dev, linux-m68k, iommu, linux-arch, linux-kernel

The USB buffer allocation code is the only place in the usb core (and in
fact the whole kernel) that uses is_device_dma_capable, while the URB
mapping code uses the uses_dma flag in struct usb_bus.  Switch the buffer
allocation to use the uses_dma flag used by the rest of the USB code,
and create a helper in hcd.h that checks this flag as well as the
CONFIG_HAS_DMA to simplify the caller a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/usb/core/buffer.c | 10 +++-------
 drivers/usb/core/hcd.c    |  4 ++--
 drivers/usb/dwc2/hcd.c    |  2 +-
 include/linux/usb.h       |  2 +-
 include/linux/usb/hcd.h   |  3 +++
 5 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index 1a5b3dcae930..6cf22c27f2d2 100644
--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -66,9 +66,7 @@ int hcd_buffer_create(struct usb_hcd *hcd)
 	char		name[16];
 	int		i, size;
 
-	if (hcd->localmem_pool ||
-	    !IS_ENABLED(CONFIG_HAS_DMA) ||
-	    !is_device_dma_capable(hcd->self.sysdev))
+	if (hcd->localmem_pool || !hcd_uses_dma(hcd))
 		return 0;
 
 	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
@@ -129,8 +127,7 @@ void *hcd_buffer_alloc(
 		return gen_pool_dma_alloc(hcd->localmem_pool, size, dma);
 
 	/* some USB hosts just use PIO */
-	if (!IS_ENABLED(CONFIG_HAS_DMA) ||
-	    !is_device_dma_capable(bus->sysdev)) {
+	if (!hcd_uses_dma(hcd)) {
 		*dma = ~(dma_addr_t) 0;
 		return kmalloc(size, mem_flags);
 	}
@@ -160,8 +157,7 @@ void hcd_buffer_free(
 		return;
 	}
 
-	if (!IS_ENABLED(CONFIG_HAS_DMA) ||
-	    !is_device_dma_capable(bus->sysdev)) {
+	if (!hcd_uses_dma(hcd)) {
 		kfree(addr);
 		return;
 	}
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 2ccbc2f83570..8592c0344fe8 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1412,7 +1412,7 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 	if (usb_endpoint_xfer_control(&urb->ep->desc)) {
 		if (hcd->self.uses_pio_for_control)
 			return ret;
-		if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) {
+		if (hcd_uses_dma(hcd)) {
 			if (is_vmalloc_addr(urb->setup_packet)) {
 				WARN_ONCE(1, "setup packet is not dma capable\n");
 				return -EAGAIN;
@@ -1446,7 +1446,7 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 	if (urb->transfer_buffer_length != 0
 	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
-		if (IS_ENABLED(CONFIG_HAS_DMA) && hcd->self.uses_dma) {
+		if (hcd_uses_dma(hcd)) {
 			if (urb->num_sgs) {
 				int n;
 
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index ee144ff8af5b..111787a137ee 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -4608,7 +4608,7 @@ static int _dwc2_hcd_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 
 	buf = urb->transfer_buffer;
 
-	if (hcd->self.uses_dma) {
+	if (hcd_uses_dma(hcd)) {
 		if (!buf && (urb->transfer_dma & 3)) {
 			dev_err(hsotg->dev,
 				"%s: unaligned transfer with no transfer_buffer",
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 83d35d993e8c..e87826e23d59 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1457,7 +1457,7 @@ typedef void (*usb_complete_t)(struct urb *);
  * field rather than determining a dma address themselves.
  *
  * Note that transfer_buffer must still be set if the controller
- * does not support DMA (as indicated by bus.uses_dma) and when talking
+ * does not support DMA (as indicated by hcd_uses_dma()) and when talking
  * to root hub. If you have to trasfer between highmem zone and the device
  * on such controller, create a bounce buffer or bail out with an error.
  * If transfer_buffer cannot be set (is in highmem) and the controller is DMA
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index bab27ccc8ff5..a20e7815d814 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -422,6 +422,9 @@ static inline bool hcd_periodic_completion_in_progress(struct usb_hcd *hcd,
 	return hcd->high_prio_bh.completing_ep == ep;
 }
 
+#define hcd_uses_dma(hcd) \
+	(IS_ENABLED(CONFIG_HAS_DMA) && (hcd)->self.uses_dma)
+
 extern int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb);
 extern int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
 		int status);
-- 
2.20.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 3/6] usb: add a HCD_DMA flag instead of guestimating DMA capabilities
  2019-08-16  6:24 next take at setting up a dma mask by default for platform devices v2 Christoph Hellwig
  2019-08-16  6:24 ` [PATCH 1/6] usb: don't create dma pools for HCDs with a localmem_pool Christoph Hellwig
  2019-08-16  6:24 ` [PATCH 2/6] usb: add a hcd_uses_dma helper Christoph Hellwig
@ 2019-08-16  6:24 ` Christoph Hellwig
  2019-08-16  6:24 ` [PATCH 4/6] usb/max3421: remove the dummy {un,}map_urb_for_dma methods Christoph Hellwig
                   ` (3 subsequent siblings)
  6 siblings, 0 replies; 15+ messages in thread
From: Christoph Hellwig @ 2019-08-16  6:24 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Maxime Chevallier
  Cc: Gavin Li, Laurentiu Tudor, Minas Harutyunyan, Alan Stern,
	Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Mathias Nyman, Bin Liu, linux-arm-kernel, linux-usb,
	linuxppc-dev, linux-m68k, iommu, linux-arch, linux-kernel

The usb core is the only major place in the kernel that checks for
a non-NULL device dma_mask to see if a device is DMA capable.  This
is generally a bad idea, as all major busses always set up a DMA mask,
even if the device is not DMA capable - in fact bus layers like PCI
can't even know if a device is DMA capable at enumeration time.  This
leads to lots of workaround in HCD drivers, and also prevented us from
setting up a DMA mask for platform devices by default last time we
tried.

Replace this guess with an explicit HCD_DMA that is set by drivers that
appear to have DMA support.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/staging/octeon-usb/octeon-hcd.c | 2 +-
 drivers/usb/core/hcd.c                  | 1 -
 drivers/usb/dwc2/hcd.c                  | 6 +++---
 drivers/usb/host/ehci-grlib.c           | 2 +-
 drivers/usb/host/ehci-hcd.c             | 2 +-
 drivers/usb/host/ehci-pmcmsp.c          | 2 +-
 drivers/usb/host/ehci-ppc-of.c          | 2 +-
 drivers/usb/host/ehci-ps3.c             | 2 +-
 drivers/usb/host/ehci-sh.c              | 2 +-
 drivers/usb/host/ehci-xilinx-of.c       | 2 +-
 drivers/usb/host/fhci-hcd.c             | 2 +-
 drivers/usb/host/fotg210-hcd.c          | 2 +-
 drivers/usb/host/imx21-hcd.c            | 2 +-
 drivers/usb/host/isp116x-hcd.c          | 6 ------
 drivers/usb/host/isp1362-hcd.c          | 5 -----
 drivers/usb/host/ohci-hcd.c             | 2 +-
 drivers/usb/host/ohci-ppc-of.c          | 2 +-
 drivers/usb/host/ohci-ps3.c             | 2 +-
 drivers/usb/host/ohci-sa1111.c          | 2 +-
 drivers/usb/host/ohci-sm501.c           | 2 +-
 drivers/usb/host/ohci-tmio.c            | 2 +-
 drivers/usb/host/oxu210hp-hcd.c         | 3 ---
 drivers/usb/host/r8a66597-hcd.c         | 6 ------
 drivers/usb/host/sl811-hcd.c            | 6 ------
 drivers/usb/host/u132-hcd.c             | 2 --
 drivers/usb/host/uhci-grlib.c           | 2 +-
 drivers/usb/host/uhci-pci.c             | 2 +-
 drivers/usb/host/uhci-platform.c        | 2 +-
 drivers/usb/host/xhci.c                 | 2 +-
 drivers/usb/isp1760/isp1760-core.c      | 3 ---
 drivers/usb/isp1760/isp1760-if.c        | 1 -
 drivers/usb/musb/musb_host.c            | 2 +-
 drivers/usb/renesas_usbhs/mod_host.c    | 2 +-
 include/linux/usb.h                     | 1 -
 include/linux/usb/hcd.h                 | 7 +++++--
 35 files changed, 31 insertions(+), 62 deletions(-)

diff --git a/drivers/staging/octeon-usb/octeon-hcd.c b/drivers/staging/octeon-usb/octeon-hcd.c
index cd2b777073c4..a5321cc692c5 100644
--- a/drivers/staging/octeon-usb/octeon-hcd.c
+++ b/drivers/staging/octeon-usb/octeon-hcd.c
@@ -3512,7 +3512,7 @@ static const struct hc_driver octeon_hc_driver = {
 	.product_desc		= "Octeon Host Controller",
 	.hcd_priv_size		= sizeof(struct octeon_hcd),
 	.irq			= octeon_usb_irq,
-	.flags			= HCD_MEMORY | HCD_USB2,
+	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB2,
 	.start			= octeon_usb_start,
 	.stop			= octeon_usb_stop,
 	.urb_enqueue		= octeon_usb_urb_enqueue,
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 8592c0344fe8..add2af4af766 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2454,7 +2454,6 @@ struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver,
 	hcd->self.controller = dev;
 	hcd->self.sysdev = sysdev;
 	hcd->self.bus_name = bus_name;
-	hcd->self.uses_dma = (sysdev->dma_mask != NULL);
 
 	timer_setup(&hcd->rh_timer, rh_timer_func, 0);
 #ifdef CONFIG_PM
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 111787a137ee..81afe553aa66 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -5062,13 +5062,13 @@ int dwc2_hcd_init(struct dwc2_hsotg *hsotg)
 		dwc2_hc_driver.reset_device = dwc2_reset_device;
 	}
 
+	if (hsotg->params.host_dma)
+		dwc2_hc_driver.flags |= HCD_DMA;
+
 	hcd = usb_create_hcd(&dwc2_hc_driver, hsotg->dev, dev_name(hsotg->dev));
 	if (!hcd)
 		goto error1;
 
-	if (!hsotg->params.host_dma)
-		hcd->self.uses_dma = 0;
-
 	hcd->has_tt = 1;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
diff --git a/drivers/usb/host/ehci-grlib.c b/drivers/usb/host/ehci-grlib.c
index 656b8c08efc8..a2c3b4ec8a8b 100644
--- a/drivers/usb/host/ehci-grlib.c
+++ b/drivers/usb/host/ehci-grlib.c
@@ -30,7 +30,7 @@ static const struct hc_driver ehci_grlib_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq			= ehci_irq,
-	.flags			= HCD_MEMORY | HCD_USB2 | HCD_BH,
+	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 9da7e22848c9..cf2b7ae93b7e 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -1193,7 +1193,7 @@ static const struct hc_driver ehci_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq =			ehci_irq,
-	.flags =		HCD_MEMORY | HCD_USB2 | HCD_BH,
+	.flags =		HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/host/ehci-pmcmsp.c b/drivers/usb/host/ehci-pmcmsp.c
index 46e160370d6e..a2b610dbedfc 100644
--- a/drivers/usb/host/ehci-pmcmsp.c
+++ b/drivers/usb/host/ehci-pmcmsp.c
@@ -250,7 +250,7 @@ static const struct hc_driver ehci_msp_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq =			ehci_irq,
-	.flags =		HCD_MEMORY | HCD_USB2 | HCD_BH,
+	.flags =		HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/host/ehci-ppc-of.c b/drivers/usb/host/ehci-ppc-of.c
index 576f7d79ad4e..6bbaee74f7e7 100644
--- a/drivers/usb/host/ehci-ppc-of.c
+++ b/drivers/usb/host/ehci-ppc-of.c
@@ -31,7 +31,7 @@ static const struct hc_driver ehci_ppc_of_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq			= ehci_irq,
-	.flags			= HCD_MEMORY | HCD_USB2 | HCD_BH,
+	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/host/ehci-ps3.c b/drivers/usb/host/ehci-ps3.c
index 454d8c624a3f..fb52133c3557 100644
--- a/drivers/usb/host/ehci-ps3.c
+++ b/drivers/usb/host/ehci-ps3.c
@@ -59,7 +59,7 @@ static const struct hc_driver ps3_ehci_hc_driver = {
 	.product_desc		= "PS3 EHCI Host Controller",
 	.hcd_priv_size		= sizeof(struct ehci_hcd),
 	.irq			= ehci_irq,
-	.flags			= HCD_MEMORY | HCD_USB2 | HCD_BH,
+	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH,
 	.reset			= ps3_ehci_hc_reset,
 	.start			= ehci_run,
 	.stop			= ehci_stop,
diff --git a/drivers/usb/host/ehci-sh.c b/drivers/usb/host/ehci-sh.c
index a9ee767952c1..6a28fb93b9f1 100644
--- a/drivers/usb/host/ehci-sh.c
+++ b/drivers/usb/host/ehci-sh.c
@@ -33,7 +33,7 @@ static const struct hc_driver ehci_sh_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq				= ehci_irq,
-	.flags				= HCD_USB2 | HCD_MEMORY | HCD_BH,
+	.flags				= HCD_USB2 | HCD_DMA | HCD_MEMORY | HCD_BH,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/host/ehci-xilinx-of.c b/drivers/usb/host/ehci-xilinx-of.c
index d2a27578e440..67a6ee8cb5d8 100644
--- a/drivers/usb/host/ehci-xilinx-of.c
+++ b/drivers/usb/host/ehci-xilinx-of.c
@@ -66,7 +66,7 @@ static const struct hc_driver ehci_xilinx_of_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq			= ehci_irq,
-	.flags			= HCD_MEMORY | HCD_USB2 | HCD_BH,
+	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/host/fhci-hcd.c b/drivers/usb/host/fhci-hcd.c
index 48fe9e6c2465..04733876c9c6 100644
--- a/drivers/usb/host/fhci-hcd.c
+++ b/drivers/usb/host/fhci-hcd.c
@@ -538,7 +538,7 @@ static const struct hc_driver fhci_driver = {
 
 	/* generic hardware linkage */
 	.irq = fhci_irq,
-	.flags = HCD_USB11 | HCD_MEMORY,
+	.flags = HCD_DMA | HCD_USB11 | HCD_MEMORY,
 
 	/* basic lifecycle operation */
 	.start = fhci_start,
diff --git a/drivers/usb/host/fotg210-hcd.c b/drivers/usb/host/fotg210-hcd.c
index 77cc36efae95..8d7ccd032d47 100644
--- a/drivers/usb/host/fotg210-hcd.c
+++ b/drivers/usb/host/fotg210-hcd.c
@@ -5504,7 +5504,7 @@ static const struct hc_driver fotg210_fotg210_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq			= fotg210_irq,
-	.flags			= HCD_MEMORY | HCD_USB2,
+	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB2,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/host/imx21-hcd.c b/drivers/usb/host/imx21-hcd.c
index 6e3dad19d369..bd5fcc935e09 100644
--- a/drivers/usb/host/imx21-hcd.c
+++ b/drivers/usb/host/imx21-hcd.c
@@ -1771,7 +1771,7 @@ static const struct hc_driver imx21_hc_driver = {
 	.product_desc = "IMX21 USB Host Controller",
 	.hcd_priv_size = sizeof(struct imx21),
 
-	.flags = HCD_USB11,
+	.flags = HCD_DMA | HCD_USB11,
 	.irq = imx21_irq,
 
 	.reset = imx21_hc_reset,
diff --git a/drivers/usb/host/isp116x-hcd.c b/drivers/usb/host/isp116x-hcd.c
index 74da136d322a..a87c0b26279e 100644
--- a/drivers/usb/host/isp116x-hcd.c
+++ b/drivers/usb/host/isp116x-hcd.c
@@ -1581,12 +1581,6 @@ static int isp116x_probe(struct platform_device *pdev)
 	irq = ires->start;
 	irqflags = ires->flags & IRQF_TRIGGER_MASK;
 
-	if (pdev->dev.dma_mask) {
-		DBG("DMA not supported\n");
-		ret = -EINVAL;
-		goto err1;
-	}
-
 	if (!request_mem_region(addr->start, 2, hcd_name)) {
 		ret = -EBUSY;
 		goto err1;
diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
index 28bf8bfb091e..96f8daa11f25 100644
--- a/drivers/usb/host/isp1362-hcd.c
+++ b/drivers/usb/host/isp1362-hcd.c
@@ -2645,11 +2645,6 @@ static int isp1362_probe(struct platform_device *pdev)
 	if (pdev->num_resources < 3)
 		return -ENODEV;
 
-	if (pdev->dev.dma_mask) {
-		DBG(1, "won't do DMA");
-		return -ENODEV;
-	}
-
 	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	if (!irq_res)
 		return -ENODEV;
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index b457fdaff297..1eb8d17e19db 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -1178,7 +1178,7 @@ static const struct hc_driver ohci_hc_driver = {
 	 * generic hardware linkage
 	*/
 	.irq =                  ohci_irq,
-	.flags =                HCD_MEMORY | HCD_USB11,
+	.flags =                HCD_MEMORY | HCD_DMA | HCD_USB11,
 
 	/*
 	* basic lifecycle operations
diff --git a/drivers/usb/host/ohci-ppc-of.c b/drivers/usb/host/ohci-ppc-of.c
index 76a9b40b08f1..45f7cceb6df3 100644
--- a/drivers/usb/host/ohci-ppc-of.c
+++ b/drivers/usb/host/ohci-ppc-of.c
@@ -50,7 +50,7 @@ static const struct hc_driver ohci_ppc_of_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq =			ohci_irq,
-	.flags =		HCD_USB11 | HCD_MEMORY,
+	.flags =		HCD_USB11 | HCD_DMA | HCD_MEMORY,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/host/ohci-ps3.c b/drivers/usb/host/ohci-ps3.c
index 395f9d3bc849..f77cd6af0ccf 100644
--- a/drivers/usb/host/ohci-ps3.c
+++ b/drivers/usb/host/ohci-ps3.c
@@ -46,7 +46,7 @@ static const struct hc_driver ps3_ohci_hc_driver = {
 	.product_desc		= "PS3 OHCI Host Controller",
 	.hcd_priv_size		= sizeof(struct ohci_hcd),
 	.irq			= ohci_irq,
-	.flags			= HCD_MEMORY | HCD_USB11,
+	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB11,
 	.reset			= ps3_ohci_hc_reset,
 	.start			= ps3_ohci_hc_start,
 	.stop			= ohci_stop,
diff --git a/drivers/usb/host/ohci-sa1111.c b/drivers/usb/host/ohci-sa1111.c
index ebec9a7699e3..8e19a5eb5b62 100644
--- a/drivers/usb/host/ohci-sa1111.c
+++ b/drivers/usb/host/ohci-sa1111.c
@@ -84,7 +84,7 @@ static const struct hc_driver ohci_sa1111_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq =			ohci_irq,
-	.flags =		HCD_USB11 | HCD_MEMORY,
+	.flags =		HCD_USB11 | HCD_DMA | HCD_MEMORY,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/host/ohci-sm501.c b/drivers/usb/host/ohci-sm501.c
index c158cda9e4b9..0b2aea6e28d4 100644
--- a/drivers/usb/host/ohci-sm501.c
+++ b/drivers/usb/host/ohci-sm501.c
@@ -49,7 +49,7 @@ static const struct hc_driver ohci_sm501_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq =			ohci_irq,
-	.flags =		HCD_USB11 | HCD_MEMORY,
+	.flags =		HCD_USB11 | HCD_DMA | HCD_MEMORY,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/host/ohci-tmio.c b/drivers/usb/host/ohci-tmio.c
index d5a293a707b6..8edbacd3eb17 100644
--- a/drivers/usb/host/ohci-tmio.c
+++ b/drivers/usb/host/ohci-tmio.c
@@ -153,7 +153,7 @@ static const struct hc_driver ohci_tmio_hc_driver = {
 
 	/* generic hardware linkage */
 	.irq =			ohci_irq,
-	.flags =		HCD_USB11 | HCD_MEMORY,
+	.flags =		HCD_USB11 | HCD_DMA | HCD_MEMORY,
 
 	/* basic lifecycle operations */
 	.start =		ohci_tmio_start,
diff --git a/drivers/usb/host/oxu210hp-hcd.c b/drivers/usb/host/oxu210hp-hcd.c
index 47c5515a9ce4..29a49cc8a1ed 100644
--- a/drivers/usb/host/oxu210hp-hcd.c
+++ b/drivers/usb/host/oxu210hp-hcd.c
@@ -2649,9 +2649,6 @@ static int oxu_reset(struct usb_hcd *hcd)
 	INIT_LIST_HEAD(&oxu->urb_list);
 	oxu->urb_len = 0;
 
-	/* FIMXE */
-	hcd->self.controller->dma_mask = NULL;
-
 	if (oxu->is_otg) {
 		oxu->caps = hcd->regs + OXU_OTG_CAP_OFFSET;
 		oxu->regs = hcd->regs + OXU_OTG_CAP_OFFSET + \
diff --git a/drivers/usb/host/r8a66597-hcd.c b/drivers/usb/host/r8a66597-hcd.c
index 42668aeca57c..0c03ac6b0213 100644
--- a/drivers/usb/host/r8a66597-hcd.c
+++ b/drivers/usb/host/r8a66597-hcd.c
@@ -2411,12 +2411,6 @@ static int r8a66597_probe(struct platform_device *pdev)
 	if (usb_disabled())
 		return -ENODEV;
 
-	if (pdev->dev.dma_mask) {
-		ret = -EINVAL;
-		dev_err(&pdev->dev, "dma not supported\n");
-		goto clean_up;
-	}
-
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		ret = -ENODEV;
diff --git a/drivers/usb/host/sl811-hcd.c b/drivers/usb/host/sl811-hcd.c
index 5b061e599948..72a34a1eb618 100644
--- a/drivers/usb/host/sl811-hcd.c
+++ b/drivers/usb/host/sl811-hcd.c
@@ -1632,12 +1632,6 @@ sl811h_probe(struct platform_device *dev)
 	irq = ires->start;
 	irqflags = ires->flags & IRQF_TRIGGER_MASK;
 
-	/* refuse to confuse usbcore */
-	if (dev->dev.dma_mask) {
-		dev_dbg(&dev->dev, "no we won't dma\n");
-		return -EINVAL;
-	}
-
 	/* the chip may be wired for either kind of addressing */
 	addr = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	data = platform_get_resource(dev, IORESOURCE_MEM, 1);
diff --git a/drivers/usb/host/u132-hcd.c b/drivers/usb/host/u132-hcd.c
index 400c40bc43a6..4efee34f154f 100644
--- a/drivers/usb/host/u132-hcd.c
+++ b/drivers/usb/host/u132-hcd.c
@@ -3077,8 +3077,6 @@ static int u132_probe(struct platform_device *pdev)
 	retval = ftdi_read_pcimem(pdev, roothub.a, &rh_a);
 	if (retval)
 		return retval;
-	if (pdev->dev.dma_mask)
-		return -EINVAL;
 
 	hcd = usb_create_hcd(&u132_hc_driver, &pdev->dev, dev_name(&pdev->dev));
 	if (!hcd) {
diff --git a/drivers/usb/host/uhci-grlib.c b/drivers/usb/host/uhci-grlib.c
index 2103b1ed0f8f..0a201a73b196 100644
--- a/drivers/usb/host/uhci-grlib.c
+++ b/drivers/usb/host/uhci-grlib.c
@@ -63,7 +63,7 @@ static const struct hc_driver uhci_grlib_hc_driver = {
 
 	/* Generic hardware linkage */
 	.irq =			uhci_irq,
-	.flags =		HCD_MEMORY | HCD_USB11,
+	.flags =		HCD_MEMORY | HCD_DMA | HCD_USB11,
 
 	/* Basic lifecycle operations */
 	.reset =		uhci_grlib_init,
diff --git a/drivers/usb/host/uhci-pci.c b/drivers/usb/host/uhci-pci.c
index 0dd944277c99..0fa3d72bae26 100644
--- a/drivers/usb/host/uhci-pci.c
+++ b/drivers/usb/host/uhci-pci.c
@@ -261,7 +261,7 @@ static const struct hc_driver uhci_driver = {
 
 	/* Generic hardware linkage */
 	.irq =			uhci_irq,
-	.flags =		HCD_USB11,
+	.flags =		HCD_DMA | HCD_USB11,
 
 	/* Basic lifecycle operations */
 	.reset =		uhci_pci_init,
diff --git a/drivers/usb/host/uhci-platform.c b/drivers/usb/host/uhci-platform.c
index 89700e26fb29..70dbd95c3f06 100644
--- a/drivers/usb/host/uhci-platform.c
+++ b/drivers/usb/host/uhci-platform.c
@@ -41,7 +41,7 @@ static const struct hc_driver uhci_platform_hc_driver = {
 
 	/* Generic hardware linkage */
 	.irq =			uhci_irq,
-	.flags =		HCD_MEMORY | HCD_USB11,
+	.flags =		HCD_MEMORY | HCD_DMA | HCD_USB11,
 
 	/* Basic lifecycle operations */
 	.reset =		uhci_platform_init,
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 03d1e552769b..e315c0158e90 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -5217,7 +5217,7 @@ static const struct hc_driver xhci_hc_driver = {
 	 * generic hardware linkage
 	 */
 	.irq =			xhci_irq,
-	.flags =		HCD_MEMORY | HCD_USB3 | HCD_SHARED,
+	.flags =		HCD_MEMORY | HCD_DMA | HCD_USB3 | HCD_SHARED,
 
 	/*
 	 * basic lifecycle operations
diff --git a/drivers/usb/isp1760/isp1760-core.c b/drivers/usb/isp1760/isp1760-core.c
index 55b94fd10331..fdeb4cf97cc5 100644
--- a/drivers/usb/isp1760/isp1760-core.c
+++ b/drivers/usb/isp1760/isp1760-core.c
@@ -120,9 +120,6 @@ int isp1760_register(struct resource *mem, int irq, unsigned long irqflags,
 	    (!IS_ENABLED(CONFIG_USB_ISP1761_UDC) || udc_disabled))
 		return -ENODEV;
 
-	/* prevent usb-core allocating DMA pages */
-	dev->dma_mask = NULL;
-
 	isp = devm_kzalloc(dev, sizeof(*isp), GFP_KERNEL);
 	if (!isp)
 		return -ENOMEM;
diff --git a/drivers/usb/isp1760/isp1760-if.c b/drivers/usb/isp1760/isp1760-if.c
index 241a00d75027..07cc82ff327c 100644
--- a/drivers/usb/isp1760/isp1760-if.c
+++ b/drivers/usb/isp1760/isp1760-if.c
@@ -139,7 +139,6 @@ static int isp1761_pci_probe(struct pci_dev *dev,
 
 	pci_set_master(dev);
 
-	dev->dev.dma_mask = NULL;
 	ret = isp1760_register(&dev->resource[3], dev->irq, 0, &dev->dev,
 			       devflags);
 	if (ret < 0)
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index eb308ec35c66..5a44b70372d9 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -2689,7 +2689,7 @@ static const struct hc_driver musb_hc_driver = {
 	.description		= "musb-hcd",
 	.product_desc		= "MUSB HDRC host driver",
 	.hcd_priv_size		= sizeof(struct musb *),
-	.flags			= HCD_USB2 | HCD_MEMORY,
+	.flags			= HCD_USB2 | HCD_DMA | HCD_MEMORY,
 
 	/* not using irq handler or reset hooks from usbcore, since
 	 * those must be shared with peripheral code for OTG configs
diff --git a/drivers/usb/renesas_usbhs/mod_host.c b/drivers/usb/renesas_usbhs/mod_host.c
index ddd3be48f948..ae54221011c3 100644
--- a/drivers/usb/renesas_usbhs/mod_host.c
+++ b/drivers/usb/renesas_usbhs/mod_host.c
@@ -1283,7 +1283,7 @@ static const struct hc_driver usbhsh_driver = {
 	/*
 	 * generic hardware linkage
 	 */
-	.flags =		HCD_USB2,
+	.flags =		HCD_DMA | HCD_USB2,
 
 	.start =		usbhsh_host_start,
 	.stop =			usbhsh_host_stop,
diff --git a/include/linux/usb.h b/include/linux/usb.h
index e87826e23d59..85a8865f9e83 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -426,7 +426,6 @@ struct usb_bus {
 	struct device *sysdev;		/* as seen from firmware or bus */
 	int busnum;			/* Bus number (in order of reg) */
 	const char *bus_name;		/* stable id (PCI slot_name etc) */
-	u8 uses_dma;			/* Does the host controller use DMA? */
 	u8 uses_pio_for_control;	/*
 					 * Does the host controller use PIO
 					 * for control transfers?
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index a20e7815d814..8d3869c7de85 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -256,6 +256,7 @@ struct hc_driver {
 
 	int	flags;
 #define	HCD_MEMORY	0x0001		/* HC regs use memory (else I/O) */
+#define	HCD_DMA		0x0002		/* HC uses DMA */
 #define	HCD_SHARED	0x0004		/* Two (or more) usb_hcds share HW */
 #define	HCD_USB11	0x0010		/* USB 1.1 */
 #define	HCD_USB2	0x0020		/* USB 2.0 */
@@ -422,8 +423,10 @@ static inline bool hcd_periodic_completion_in_progress(struct usb_hcd *hcd,
 	return hcd->high_prio_bh.completing_ep == ep;
 }
 
-#define hcd_uses_dma(hcd) \
-	(IS_ENABLED(CONFIG_HAS_DMA) && (hcd)->self.uses_dma)
+static inline bool hcd_uses_dma(struct usb_hcd *hcd)
+{
+	return IS_ENABLED(CONFIG_HAS_DMA) && (hcd->driver->flags & HCD_DMA);
+}
 
 extern int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb);
 extern int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
-- 
2.20.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 4/6] usb/max3421: remove the dummy {un,}map_urb_for_dma methods
  2019-08-16  6:24 next take at setting up a dma mask by default for platform devices v2 Christoph Hellwig
                   ` (2 preceding siblings ...)
  2019-08-16  6:24 ` [PATCH 3/6] usb: add a HCD_DMA flag instead of guestimating DMA capabilities Christoph Hellwig
@ 2019-08-16  6:24 ` Christoph Hellwig
  2019-08-16  6:24 ` [PATCH 5/6] dma-mapping: remove is_device_dma_capable Christoph Hellwig
                   ` (2 subsequent siblings)
  6 siblings, 0 replies; 15+ messages in thread
From: Christoph Hellwig @ 2019-08-16  6:24 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Maxime Chevallier
  Cc: Gavin Li, Laurentiu Tudor, Minas Harutyunyan, Alan Stern,
	Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Mathias Nyman, Bin Liu, linux-arm-kernel, linux-usb,
	linuxppc-dev, linux-m68k, iommu, linux-arch, linux-kernel

Now that we have an explicit HCD_DMA flag, there is not need to override
these methods.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/usb/host/max3421-hcd.c | 17 -----------------
 1 file changed, 17 deletions(-)

diff --git a/drivers/usb/host/max3421-hcd.c b/drivers/usb/host/max3421-hcd.c
index afa321ab55fc..8819f502b6a6 100644
--- a/drivers/usb/host/max3421-hcd.c
+++ b/drivers/usb/host/max3421-hcd.c
@@ -1800,21 +1800,6 @@ max3421_bus_resume(struct usb_hcd *hcd)
 	return -1;
 }
 
-/*
- * The SPI driver already takes care of DMA-mapping/unmapping, so no
- * reason to do it twice.
- */
-static int
-max3421_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
-{
-	return 0;
-}
-
-static void
-max3421_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
-{
-}
-
 static const struct hc_driver max3421_hcd_desc = {
 	.description =		"max3421",
 	.product_desc =		DRIVER_DESC,
@@ -1826,8 +1811,6 @@ static const struct hc_driver max3421_hcd_desc = {
 	.get_frame_number =	max3421_get_frame_number,
 	.urb_enqueue =		max3421_urb_enqueue,
 	.urb_dequeue =		max3421_urb_dequeue,
-	.map_urb_for_dma =	max3421_map_urb_for_dma,
-	.unmap_urb_for_dma =	max3421_unmap_urb_for_dma,
 	.endpoint_disable =	max3421_endpoint_disable,
 	.hub_status_data =	max3421_hub_status_data,
 	.hub_control =		max3421_hub_control,
-- 
2.20.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 5/6] dma-mapping: remove is_device_dma_capable
  2019-08-16  6:24 next take at setting up a dma mask by default for platform devices v2 Christoph Hellwig
                   ` (3 preceding siblings ...)
  2019-08-16  6:24 ` [PATCH 4/6] usb/max3421: remove the dummy {un,}map_urb_for_dma methods Christoph Hellwig
@ 2019-08-16  6:24 ` Christoph Hellwig
  2019-08-16  6:24 ` [PATCH 6/6] driver core: initialize a default DMA mask for platform device Christoph Hellwig
  2019-08-22 17:11 ` next take at setting up a dma mask by default for platform devices v2 Greg Kroah-Hartman
  6 siblings, 0 replies; 15+ messages in thread
From: Christoph Hellwig @ 2019-08-16  6:24 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Maxime Chevallier
  Cc: Gavin Li, Laurentiu Tudor, Minas Harutyunyan, Alan Stern,
	Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Mathias Nyman, Bin Liu, linux-arm-kernel, linux-usb,
	linuxppc-dev, linux-m68k, iommu, linux-arch, linux-kernel

No users left.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/dma-mapping.h | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index f7d1eea32c78..14702e2d6fa8 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -149,11 +149,6 @@ static inline int valid_dma_direction(int dma_direction)
 		(dma_direction == DMA_FROM_DEVICE));
 }
 
-static inline int is_device_dma_capable(struct device *dev)
-{
-	return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
-}
-
 #ifdef CONFIG_DMA_DECLARE_COHERENT
 /*
  * These three functions are only for dma allocator.
-- 
2.20.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 6/6] driver core: initialize a default DMA mask for platform device
  2019-08-16  6:24 next take at setting up a dma mask by default for platform devices v2 Christoph Hellwig
                   ` (4 preceding siblings ...)
  2019-08-16  6:24 ` [PATCH 5/6] dma-mapping: remove is_device_dma_capable Christoph Hellwig
@ 2019-08-16  6:24 ` Christoph Hellwig
  2019-08-16  7:39   ` Geert Uytterhoeven
  2019-08-22 17:11 ` next take at setting up a dma mask by default for platform devices v2 Greg Kroah-Hartman
  6 siblings, 1 reply; 15+ messages in thread
From: Christoph Hellwig @ 2019-08-16  6:24 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Maxime Chevallier
  Cc: Gavin Li, Laurentiu Tudor, Minas Harutyunyan, Alan Stern,
	Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Mathias Nyman, Bin Liu, linux-arm-kernel, linux-usb,
	linuxppc-dev, linux-m68k, iommu, linux-arch, linux-kernel

We still treat devices without a DMA mask as defaulting to 32-bits for
both mask, but a few releases ago we've started warning about such
cases, as they require special cases to work around this sloppyness.
Add a dma_mask field to struct platform_device so that we can initialize
the dma_mask pointer in struct device and initialize both masks to
32-bits by default, replacing similar functionality in m68k and
powerpc.  The arch_setup_pdev_archdata hooks is now unused and removed.

Note that the code looks a little odd with the various conditionals
because we have to support platform_device structures that are
statically allocated.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/m68k/kernel/dma.c               |  9 -------
 arch/powerpc/kernel/setup-common.c   |  6 -----
 arch/sh/boards/mach-ap325rxa/setup.c |  1 -
 arch/sh/boards/mach-ecovec24/setup.c |  2 --
 arch/sh/boards/mach-kfr2r09/setup.c  |  1 -
 arch/sh/boards/mach-migor/setup.c    |  1 -
 arch/sh/boards/mach-se/7724/setup.c  |  2 --
 drivers/base/platform.c              | 37 ++++++++++++----------------
 include/linux/platform_device.h      |  2 +-
 9 files changed, 17 insertions(+), 44 deletions(-)

diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c
index 30cd59caf037..447849d1d645 100644
--- a/arch/m68k/kernel/dma.c
+++ b/arch/m68k/kernel/dma.c
@@ -79,12 +79,3 @@ void arch_sync_dma_for_device(struct device *dev, phys_addr_t handle,
 		break;
 	}
 }
-
-void arch_setup_pdev_archdata(struct platform_device *pdev)
-{
-	if (pdev->dev.coherent_dma_mask == DMA_MASK_NONE &&
-	    pdev->dev.dma_mask == NULL) {
-		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
-		pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
-	}
-}
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 1f8db666468d..5e6543aba1b3 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -778,12 +778,6 @@ void ppc_printk_progress(char *s, unsigned short hex)
 	pr_info("%s\n", s);
 }
 
-void arch_setup_pdev_archdata(struct platform_device *pdev)
-{
-	pdev->archdata.dma_mask = DMA_BIT_MASK(32);
-	pdev->dev.dma_mask = &pdev->archdata.dma_mask;
-}
-
 static __init void print_system_info(void)
 {
 	pr_info("-----------------------------------------------------\n");
diff --git a/arch/sh/boards/mach-ap325rxa/setup.c b/arch/sh/boards/mach-ap325rxa/setup.c
index 8301a4378f50..665cad452798 100644
--- a/arch/sh/boards/mach-ap325rxa/setup.c
+++ b/arch/sh/boards/mach-ap325rxa/setup.c
@@ -527,7 +527,6 @@ static int __init ap325rxa_devices_setup(void)
 
 	/* Initialize CEU platform device separately to map memory first */
 	device_initialize(&ap325rxa_ceu_device.dev);
-	arch_setup_pdev_archdata(&ap325rxa_ceu_device);
 	dma_declare_coherent_memory(&ap325rxa_ceu_device.dev,
 			ceu_dma_membase, ceu_dma_membase,
 			ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1);
diff --git a/arch/sh/boards/mach-ecovec24/setup.c b/arch/sh/boards/mach-ecovec24/setup.c
index f402aa741bf3..acaa97459531 100644
--- a/arch/sh/boards/mach-ecovec24/setup.c
+++ b/arch/sh/boards/mach-ecovec24/setup.c
@@ -1440,7 +1440,6 @@ static int __init arch_setup(void)
 
 	/* Initialize CEU platform devices separately to map memory first */
 	device_initialize(&ecovec_ceu_devices[0]->dev);
-	arch_setup_pdev_archdata(ecovec_ceu_devices[0]);
 	dma_declare_coherent_memory(&ecovec_ceu_devices[0]->dev,
 				    ceu0_dma_membase, ceu0_dma_membase,
 				    ceu0_dma_membase +
@@ -1448,7 +1447,6 @@ static int __init arch_setup(void)
 	platform_device_add(ecovec_ceu_devices[0]);
 
 	device_initialize(&ecovec_ceu_devices[1]->dev);
-	arch_setup_pdev_archdata(ecovec_ceu_devices[1]);
 	dma_declare_coherent_memory(&ecovec_ceu_devices[1]->dev,
 				    ceu1_dma_membase, ceu1_dma_membase,
 				    ceu1_dma_membase +
diff --git a/arch/sh/boards/mach-kfr2r09/setup.c b/arch/sh/boards/mach-kfr2r09/setup.c
index 1cf9a47ac90e..96538ba3aa32 100644
--- a/arch/sh/boards/mach-kfr2r09/setup.c
+++ b/arch/sh/boards/mach-kfr2r09/setup.c
@@ -601,7 +601,6 @@ static int __init kfr2r09_devices_setup(void)
 
 	/* Initialize CEU platform device separately to map memory first */
 	device_initialize(&kfr2r09_ceu_device.dev);
-	arch_setup_pdev_archdata(&kfr2r09_ceu_device);
 	dma_declare_coherent_memory(&kfr2r09_ceu_device.dev,
 			ceu_dma_membase, ceu_dma_membase,
 			ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1);
diff --git a/arch/sh/boards/mach-migor/setup.c b/arch/sh/boards/mach-migor/setup.c
index 90702740f207..9ed369dad62d 100644
--- a/arch/sh/boards/mach-migor/setup.c
+++ b/arch/sh/boards/mach-migor/setup.c
@@ -602,7 +602,6 @@ static int __init migor_devices_setup(void)
 
 	/* Initialize CEU platform device separately to map memory first */
 	device_initialize(&migor_ceu_device.dev);
-	arch_setup_pdev_archdata(&migor_ceu_device);
 	dma_declare_coherent_memory(&migor_ceu_device.dev,
 			ceu_dma_membase, ceu_dma_membase,
 			ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1);
diff --git a/arch/sh/boards/mach-se/7724/setup.c b/arch/sh/boards/mach-se/7724/setup.c
index 3674064816c7..32f5dd944889 100644
--- a/arch/sh/boards/mach-se/7724/setup.c
+++ b/arch/sh/boards/mach-se/7724/setup.c
@@ -937,7 +937,6 @@ static int __init devices_setup(void)
 
 	/* Initialize CEU platform devices separately to map memory first */
 	device_initialize(&ms7724se_ceu_devices[0]->dev);
-	arch_setup_pdev_archdata(ms7724se_ceu_devices[0]);
 	dma_declare_coherent_memory(&ms7724se_ceu_devices[0]->dev,
 				    ceu0_dma_membase, ceu0_dma_membase,
 				    ceu0_dma_membase +
@@ -945,7 +944,6 @@ static int __init devices_setup(void)
 	platform_device_add(ms7724se_ceu_devices[0]);
 
 	device_initialize(&ms7724se_ceu_devices[1]->dev);
-	arch_setup_pdev_archdata(ms7724se_ceu_devices[1]);
 	dma_declare_coherent_memory(&ms7724se_ceu_devices[1]->dev,
 				    ceu1_dma_membase, ceu1_dma_membase,
 				    ceu1_dma_membase +
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index ec974ba9c0c4..600913aea73b 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -39,25 +39,6 @@ struct device platform_bus = {
 };
 EXPORT_SYMBOL_GPL(platform_bus);
 
-/**
- * arch_setup_pdev_archdata - Allow manipulation of archdata before its used
- * @pdev: platform device
- *
- * This is called before platform_device_add() such that any pdev_archdata may
- * be setup before the platform_notifier is called.  So if a user needs to
- * manipulate any relevant information in the pdev_archdata they can do:
- *
- *	platform_device_alloc()
- *	... manipulate ...
- *	platform_device_add()
- *
- * And if they don't care they can just call platform_device_register() and
- * everything will just work out.
- */
-void __weak arch_setup_pdev_archdata(struct platform_device *pdev)
-{
-}
-
 /**
  * platform_get_resource - get a resource for a device
  * @dev: platform device
@@ -264,6 +245,20 @@ struct platform_object {
 	char name[];
 };
 
+/*
+ * Set up default DMA mask for platform devices if the they weren't
+ * previously set by the architecture / DT.
+ */
+static void setup_pdev_dma_masks(struct platform_device *pdev)
+{
+	if (!pdev->dev.coherent_dma_mask)
+		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	if (!pdev->dma_mask)
+		pdev->dma_mask = DMA_BIT_MASK(32);
+	if (!pdev->dev.dma_mask)
+		pdev->dev.dma_mask = &pdev->dma_mask;
+};
+
 /**
  * platform_device_put - destroy a platform device
  * @pdev: platform device to free
@@ -310,7 +305,7 @@ struct platform_device *platform_device_alloc(const char *name, int id)
 		pa->pdev.id = id;
 		device_initialize(&pa->pdev.dev);
 		pa->pdev.dev.release = platform_device_release;
-		arch_setup_pdev_archdata(&pa->pdev);
+		setup_pdev_dma_masks(&pa->pdev);
 	}
 
 	return pa ? &pa->pdev : NULL;
@@ -512,7 +507,7 @@ EXPORT_SYMBOL_GPL(platform_device_del);
 int platform_device_register(struct platform_device *pdev)
 {
 	device_initialize(&pdev->dev);
-	arch_setup_pdev_archdata(pdev);
+	setup_pdev_dma_masks(pdev);
 	return platform_device_add(pdev);
 }
 EXPORT_SYMBOL_GPL(platform_device_register);
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 9bc36b589827..34a3d8ed8ba7 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -24,6 +24,7 @@ struct platform_device {
 	int		id;
 	bool		id_auto;
 	struct device	dev;
+	u64		dma_mask;
 	u32		num_resources;
 	struct resource	*resource;
 
@@ -48,7 +49,6 @@ extern void platform_device_unregister(struct platform_device *);
 extern struct bus_type platform_bus_type;
 extern struct device platform_bus;
 
-extern void arch_setup_pdev_archdata(struct platform_device *);
 extern struct resource *platform_get_resource(struct platform_device *,
 					      unsigned int, unsigned int);
 extern void __iomem *
-- 
2.20.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 6/6] driver core: initialize a default DMA mask for platform device
  2019-08-16  6:24 ` [PATCH 6/6] driver core: initialize a default DMA mask for platform device Christoph Hellwig
@ 2019-08-16  7:39   ` Geert Uytterhoeven
  0 siblings, 0 replies; 15+ messages in thread
From: Geert Uytterhoeven @ 2019-08-16  7:39 UTC (permalink / raw)
  To: Christoph Hellwig
  Cc: Greg Kroah-Hartman, Maxime Chevallier, Gavin Li, Laurentiu Tudor,
	Minas Harutyunyan, Alan Stern, Geoff Levand, Michal Simek,
	Shawn Guo, Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam,
	NXP Linux Team, Mathias Nyman, Bin Liu, Linux ARM, USB list,
	linuxppc-dev, linux-m68k, Linux IOMMU, Linux-Arch,
	Linux Kernel Mailing List

Hi Christoph,

On Fri, Aug 16, 2019 at 8:30 AM Christoph Hellwig <hch@lst.de> wrote:
> We still treat devices without a DMA mask as defaulting to 32-bits for
> both mask, but a few releases ago we've started warning about such
> cases, as they require special cases to work around this sloppyness.
> Add a dma_mask field to struct platform_device so that we can initialize
> the dma_mask pointer in struct device and initialize both masks to
> 32-bits by default, replacing similar functionality in m68k and
> powerpc.  The arch_setup_pdev_archdata hooks is now unused and removed.
>
> Note that the code looks a little odd with the various conditionals
> because we have to support platform_device structures that are
> statically allocated.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/m68k/kernel/dma.c               |  9 -------

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

>  arch/sh/boards/mach-ecovec24/setup.c |  2 --
>  arch/sh/boards/mach-migor/setup.c    |  1 -

Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
given "[PATCH 0/2] Remove calls to empty arch_setup_pdev_archdata()"
https://lore.kernel.org/linux-renesas-soc/1526641611-2769-1-git-send-email-geert+renesas@glider.be/

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: next take at setting up a dma mask by default for platform devices v2
  2019-08-16  6:24 next take at setting up a dma mask by default for platform devices v2 Christoph Hellwig
                   ` (5 preceding siblings ...)
  2019-08-16  6:24 ` [PATCH 6/6] driver core: initialize a default DMA mask for platform device Christoph Hellwig
@ 2019-08-22 17:11 ` Greg Kroah-Hartman
  6 siblings, 0 replies; 15+ messages in thread
From: Greg Kroah-Hartman @ 2019-08-22 17:11 UTC (permalink / raw)
  To: Christoph Hellwig
  Cc: Maxime Chevallier, Gavin Li, Laurentiu Tudor, Minas Harutyunyan,
	Alan Stern, Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Mathias Nyman, Bin Liu, linux-arm-kernel, linux-usb,
	linuxppc-dev, linux-m68k, iommu, linux-arch, linux-kernel

On Fri, Aug 16, 2019 at 08:24:29AM +0200, Christoph Hellwig wrote:
> Hi all,
> 
> this is another attempt to make sure the dma_mask pointer is always
> initialized for platform devices.  Not doing so lead to lots of
> boilerplate code, and makes platform devices different from all our
> major busses like PCI where we always set up a dma_mask.  In the long
> run this should also help to eventually make dma_mask a scalar value
> instead of a pointer and remove even more cruft.
> 
> The bigger blocker for this last time was the fact that the usb
> subsystem uses the presence or lack of a dma_mask to check if the core
> should do dma mapping for the driver, which is highly unusual.  So we
> fix this first.  Note that this has some overlap with the pending
> desire to use the proper dma_mmap_coherent helper for mapping usb
> buffers.  The first two patches have already been queued up by Greg
> and are only included for completeness.

Note to everyone.  The first two patches in this series is already in
5.3-rc5.

I've applied the rest of the series to my usb-next branch (with the 6th
patch landing there later today.)  They are scheduled to be merge to
Linus in 5.4-rc1.

Christoph, thanks so much for these cleanups.

greg k-h

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 6/6] driver core: initialize a default DMA mask for platform device
  2019-08-15 13:38     ` Christoph Hellwig
@ 2019-08-15 14:05       ` Greg Kroah-Hartman
  0 siblings, 0 replies; 15+ messages in thread
From: Greg Kroah-Hartman @ 2019-08-15 14:05 UTC (permalink / raw)
  To: Christoph Hellwig
  Cc: Maxime Chevallier, Gavin Li, Laurentiu Tudor, Minas Harutyunyan,
	Alan Stern, Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Olav Kongas, Tony Prisk, Mathias Nyman, Bin Liu,
	linux-arm-kernel, linux-usb, linuxppc-dev, iommu, linux-arch,
	linux-kernel

On Thu, Aug 15, 2019 at 03:38:12PM +0200, Christoph Hellwig wrote:
> On Thu, Aug 15, 2019 at 03:03:25PM +0200, Greg Kroah-Hartman wrote:
> > > --- a/include/linux/platform_device.h
> > > +++ b/include/linux/platform_device.h
> > > @@ -24,6 +24,7 @@ struct platform_device {
> > >  	int		id;
> > >  	bool		id_auto;
> > >  	struct device	dev;
> > > +	u64		dma_mask;
> > 
> > Why is the dma_mask in 'struct device' which is part of this structure,
> > not sufficient here?  Shouldn't the "platform" be setting that up
> > correctly already in the "archdata" type callback?
> 
> Becaus the dma_mask in struct device is a pointer that needs to point
> to something, and this is the best space we can allocate for 'something'.
> m68k and powerpc currently do something roughly equivalent at the moment,
> while everyone else just has horrible, horrible hacks.  As mentioned in
> the changelog the intent of this patch is that we treat platform devices
> like any other bus, where the bus allocates the space for the dma_mask.
> The long term plan is to eventually kill that weird pointer indirection
> that doesn't help anyone, but for that we need to sort out the basics
> first.

Ah, missed that, sorry.  Ok, no objection from me.  Might as well respin
this series and I can queue it up after 5.3-rc5 is out (which will have
your first 2 patches in it.)

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 6/6] driver core: initialize a default DMA mask for platform device
  2019-08-15 13:03   ` Greg Kroah-Hartman
@ 2019-08-15 13:38     ` Christoph Hellwig
  2019-08-15 14:05       ` Greg Kroah-Hartman
  0 siblings, 1 reply; 15+ messages in thread
From: Christoph Hellwig @ 2019-08-15 13:38 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: Christoph Hellwig, Maxime Chevallier, Gavin Li, Laurentiu Tudor,
	Minas Harutyunyan, Alan Stern, Geoff Levand, Michal Simek,
	Shawn Guo, Sascha Hauer, Pengutronix Kernel Team, Fabio Estevam,
	NXP Linux Team, Olav Kongas, Tony Prisk, Mathias Nyman, Bin Liu,
	linux-arm-kernel, linux-usb, linuxppc-dev, iommu, linux-arch,
	linux-kernel

On Thu, Aug 15, 2019 at 03:03:25PM +0200, Greg Kroah-Hartman wrote:
> > --- a/include/linux/platform_device.h
> > +++ b/include/linux/platform_device.h
> > @@ -24,6 +24,7 @@ struct platform_device {
> >  	int		id;
> >  	bool		id_auto;
> >  	struct device	dev;
> > +	u64		dma_mask;
> 
> Why is the dma_mask in 'struct device' which is part of this structure,
> not sufficient here?  Shouldn't the "platform" be setting that up
> correctly already in the "archdata" type callback?

Becaus the dma_mask in struct device is a pointer that needs to point
to something, and this is the best space we can allocate for 'something'.
m68k and powerpc currently do something roughly equivalent at the moment,
while everyone else just has horrible, horrible hacks.  As mentioned in
the changelog the intent of this patch is that we treat platform devices
like any other bus, where the bus allocates the space for the dma_mask.
The long term plan is to eventually kill that weird pointer indirection
that doesn't help anyone, but for that we need to sort out the basics
first.

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 6/6] driver core: initialize a default DMA mask for platform device
  2019-08-14 15:49   ` Robin Murphy
@ 2019-08-15 13:32     ` Christoph Hellwig
  0 siblings, 0 replies; 15+ messages in thread
From: Christoph Hellwig @ 2019-08-15 13:32 UTC (permalink / raw)
  To: Robin Murphy
  Cc: Christoph Hellwig, Greg Kroah-Hartman, Maxime Chevallier,
	linux-arch, Olav Kongas, Gavin Li, linuxppc-dev, Mathias Nyman,
	Geoff Levand, Fabio Estevam, Sascha Hauer, linux-usb,
	Michal Simek, linux-kernel, Tony Prisk, iommu, Alan Stern,
	NXP Linux Team, Pengutronix Kernel Team, Minas Harutyunyan,
	Shawn Guo, Bin Liu, linux-arm-kernel

On Wed, Aug 14, 2019 at 04:49:13PM +0100, Robin Murphy wrote:
>> because we have to support platform_device structures that are
>> statically allocated.
>
> This would be a good point to also get rid of the long-standing bodge in 
> platform_device_register_full().

platform_device_register_full looks odd to start with, especially
as the coumentation is rather lacking..

>>   +static void setup_pdev_archdata(struct platform_device *pdev)
>
> Bikeshed: painting the generic DMA API properties as "archdata" feels a bit 
> off-target :/
>
>> +{
>> +	if (!pdev->dev.coherent_dma_mask)
>> +		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
>> +	if (!pdev->dma_mask)
>> +		pdev->dma_mask = DMA_BIT_MASK(32);
>> +	if (!pdev->dev.dma_mask)
>> +		pdev->dev.dma_mask = &pdev->dma_mask;
>> +	arch_setup_pdev_archdata(pdev);
>
> AFAICS m68k's implementation of that arch hook becomes entirely redundant 
> after this change, so may as well go. That would just leave powerpc's 
> actual archdata, which at a glance looks like it could probably be cleaned 
> up with not *too* much trouble.

Actually I think we can just kill both off.  At the point archdata
is indeed entirely misnamed.

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 6/6] driver core: initialize a default DMA mask for platform device
  2019-08-11  8:05 ` [PATCH 6/6] driver core: initialize a default DMA mask for platform device Christoph Hellwig
  2019-08-14 15:49   ` Robin Murphy
@ 2019-08-15 13:03   ` Greg Kroah-Hartman
  2019-08-15 13:38     ` Christoph Hellwig
  1 sibling, 1 reply; 15+ messages in thread
From: Greg Kroah-Hartman @ 2019-08-15 13:03 UTC (permalink / raw)
  To: Christoph Hellwig
  Cc: Maxime Chevallier, Gavin Li, Laurentiu Tudor, Minas Harutyunyan,
	Alan Stern, Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Olav Kongas, Tony Prisk, Mathias Nyman, Bin Liu,
	linux-arm-kernel, linux-usb, linuxppc-dev, iommu, linux-arch,
	linux-kernel

On Sun, Aug 11, 2019 at 10:05:20AM +0200, Christoph Hellwig wrote:
> We still treat devices without a DMA mask as defaulting to 32-bits for
> both mask, but a few releases ago we've started warning about such
> cases, as they require special cases to work around this sloppyness.
> Add a dma_mask field to struct platform_object so that we can initialize
> the dma_mask pointer in struct device and initialize both masks to
> 32-bits by default.  Architectures can still override this in
> arch_setup_pdev_archdata if needed.
> 
> Note that the code looks a little odd with the various conditionals
> because we have to support platform_device structures that are
> statically allocated.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/base/platform.c         | 15 +++++++++++++--
>  include/linux/platform_device.h |  1 +
>  2 files changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index ec974ba9c0c4..b216fcb0a8af 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -264,6 +264,17 @@ struct platform_object {
>  	char name[];
>  };
>  
> +static void setup_pdev_archdata(struct platform_device *pdev)
> +{
> +	if (!pdev->dev.coherent_dma_mask)
> +		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
> +	if (!pdev->dma_mask)
> +		pdev->dma_mask = DMA_BIT_MASK(32);
> +	if (!pdev->dev.dma_mask)
> +		pdev->dev.dma_mask = &pdev->dma_mask;
> +	arch_setup_pdev_archdata(pdev);
> +};
> +
>  /**
>   * platform_device_put - destroy a platform device
>   * @pdev: platform device to free
> @@ -310,7 +321,7 @@ struct platform_device *platform_device_alloc(const char *name, int id)
>  		pa->pdev.id = id;
>  		device_initialize(&pa->pdev.dev);
>  		pa->pdev.dev.release = platform_device_release;
> -		arch_setup_pdev_archdata(&pa->pdev);
> +		setup_pdev_archdata(&pa->pdev);
>  	}
>  
>  	return pa ? &pa->pdev : NULL;
> @@ -512,7 +523,7 @@ EXPORT_SYMBOL_GPL(platform_device_del);
>  int platform_device_register(struct platform_device *pdev)
>  {
>  	device_initialize(&pdev->dev);
> -	arch_setup_pdev_archdata(pdev);
> +	setup_pdev_archdata(pdev);
>  	return platform_device_add(pdev);
>  }
>  EXPORT_SYMBOL_GPL(platform_device_register);
> diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
> index 9bc36b589827..a2abde2aef25 100644
> --- a/include/linux/platform_device.h
> +++ b/include/linux/platform_device.h
> @@ -24,6 +24,7 @@ struct platform_device {
>  	int		id;
>  	bool		id_auto;
>  	struct device	dev;
> +	u64		dma_mask;

Why is the dma_mask in 'struct device' which is part of this structure,
not sufficient here?  Shouldn't the "platform" be setting that up
correctly already in the "archdata" type callback?

confused,

greg k-h

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH 6/6] driver core: initialize a default DMA mask for platform device
  2019-08-11  8:05 ` [PATCH 6/6] driver core: initialize a default DMA mask for platform device Christoph Hellwig
@ 2019-08-14 15:49   ` Robin Murphy
  2019-08-15 13:32     ` Christoph Hellwig
  2019-08-15 13:03   ` Greg Kroah-Hartman
  1 sibling, 1 reply; 15+ messages in thread
From: Robin Murphy @ 2019-08-14 15:49 UTC (permalink / raw)
  To: Christoph Hellwig, Greg Kroah-Hartman, Maxime Chevallier
  Cc: linux-arch, Olav Kongas, Gavin Li, linuxppc-dev, Mathias Nyman,
	Geoff Levand, Fabio Estevam, Sascha Hauer, linux-usb,
	Michal Simek, linux-kernel, Tony Prisk, iommu, Alan Stern,
	NXP Linux Team, Pengutronix Kernel Team, Minas Harutyunyan,
	Shawn Guo, Bin Liu, linux-arm-kernel

On 11/08/2019 09:05, Christoph Hellwig wrote:
> We still treat devices without a DMA mask as defaulting to 32-bits for
> both mask, but a few releases ago we've started warning about such
> cases, as they require special cases to work around this sloppyness.
> Add a dma_mask field to struct platform_object so that we can initialize

s/object/device/

> the dma_mask pointer in struct device and initialize both masks to
> 32-bits by default.  Architectures can still override this in
> arch_setup_pdev_archdata if needed.
> 
> Note that the code looks a little odd with the various conditionals
> because we have to support platform_device structures that are
> statically allocated.

This would be a good point to also get rid of the long-standing bodge in 
platform_device_register_full().

> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   drivers/base/platform.c         | 15 +++++++++++++--
>   include/linux/platform_device.h |  1 +
>   2 files changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index ec974ba9c0c4..b216fcb0a8af 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -264,6 +264,17 @@ struct platform_object {
>   	char name[];
>   };
>   
> +static void setup_pdev_archdata(struct platform_device *pdev)

Bikeshed: painting the generic DMA API properties as "archdata" feels a 
bit off-target :/

> +{
> +	if (!pdev->dev.coherent_dma_mask)
> +		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
> +	if (!pdev->dma_mask)
> +		pdev->dma_mask = DMA_BIT_MASK(32);
> +	if (!pdev->dev.dma_mask)
> +		pdev->dev.dma_mask = &pdev->dma_mask;
> +	arch_setup_pdev_archdata(pdev);

AFAICS m68k's implementation of that arch hook becomes entirely 
redundant after this change, so may as well go. That would just leave 
powerpc's actual archdata, which at a glance looks like it could 
probably be cleaned up with not *too* much trouble.

Robin.

> +};
> +
>   /**
>    * platform_device_put - destroy a platform device
>    * @pdev: platform device to free
> @@ -310,7 +321,7 @@ struct platform_device *platform_device_alloc(const char *name, int id)
>   		pa->pdev.id = id;
>   		device_initialize(&pa->pdev.dev);
>   		pa->pdev.dev.release = platform_device_release;
> -		arch_setup_pdev_archdata(&pa->pdev);
> +		setup_pdev_archdata(&pa->pdev);
>   	}
>   
>   	return pa ? &pa->pdev : NULL;
> @@ -512,7 +523,7 @@ EXPORT_SYMBOL_GPL(platform_device_del);
>   int platform_device_register(struct platform_device *pdev)
>   {
>   	device_initialize(&pdev->dev);
> -	arch_setup_pdev_archdata(pdev);
> +	setup_pdev_archdata(pdev);
>   	return platform_device_add(pdev);
>   }
>   EXPORT_SYMBOL_GPL(platform_device_register);
> diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
> index 9bc36b589827..a2abde2aef25 100644
> --- a/include/linux/platform_device.h
> +++ b/include/linux/platform_device.h
> @@ -24,6 +24,7 @@ struct platform_device {
>   	int		id;
>   	bool		id_auto;
>   	struct device	dev;
> +	u64		dma_mask;
>   	u32		num_resources;
>   	struct resource	*resource;
>   
> 

^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH 6/6] driver core: initialize a default DMA mask for platform device
  2019-08-11  8:05 next take at setting up a dma mask by default for platform devices Christoph Hellwig
@ 2019-08-11  8:05 ` Christoph Hellwig
  2019-08-14 15:49   ` Robin Murphy
  2019-08-15 13:03   ` Greg Kroah-Hartman
  0 siblings, 2 replies; 15+ messages in thread
From: Christoph Hellwig @ 2019-08-11  8:05 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Maxime Chevallier
  Cc: Gavin Li, Laurentiu Tudor, Minas Harutyunyan, Alan Stern,
	Geoff Levand, Michal Simek, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
	Olav Kongas, Tony Prisk, Mathias Nyman, Bin Liu,
	linux-arm-kernel, linux-usb, linuxppc-dev, iommu, linux-arch,
	linux-kernel

We still treat devices without a DMA mask as defaulting to 32-bits for
both mask, but a few releases ago we've started warning about such
cases, as they require special cases to work around this sloppyness.
Add a dma_mask field to struct platform_object so that we can initialize
the dma_mask pointer in struct device and initialize both masks to
32-bits by default.  Architectures can still override this in
arch_setup_pdev_archdata if needed.

Note that the code looks a little odd with the various conditionals
because we have to support platform_device structures that are
statically allocated.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/base/platform.c         | 15 +++++++++++++--
 include/linux/platform_device.h |  1 +
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index ec974ba9c0c4..b216fcb0a8af 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -264,6 +264,17 @@ struct platform_object {
 	char name[];
 };
 
+static void setup_pdev_archdata(struct platform_device *pdev)
+{
+	if (!pdev->dev.coherent_dma_mask)
+		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	if (!pdev->dma_mask)
+		pdev->dma_mask = DMA_BIT_MASK(32);
+	if (!pdev->dev.dma_mask)
+		pdev->dev.dma_mask = &pdev->dma_mask;
+	arch_setup_pdev_archdata(pdev);
+};
+
 /**
  * platform_device_put - destroy a platform device
  * @pdev: platform device to free
@@ -310,7 +321,7 @@ struct platform_device *platform_device_alloc(const char *name, int id)
 		pa->pdev.id = id;
 		device_initialize(&pa->pdev.dev);
 		pa->pdev.dev.release = platform_device_release;
-		arch_setup_pdev_archdata(&pa->pdev);
+		setup_pdev_archdata(&pa->pdev);
 	}
 
 	return pa ? &pa->pdev : NULL;
@@ -512,7 +523,7 @@ EXPORT_SYMBOL_GPL(platform_device_del);
 int platform_device_register(struct platform_device *pdev)
 {
 	device_initialize(&pdev->dev);
-	arch_setup_pdev_archdata(pdev);
+	setup_pdev_archdata(pdev);
 	return platform_device_add(pdev);
 }
 EXPORT_SYMBOL_GPL(platform_device_register);
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 9bc36b589827..a2abde2aef25 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -24,6 +24,7 @@ struct platform_device {
 	int		id;
 	bool		id_auto;
 	struct device	dev;
+	u64		dma_mask;
 	u32		num_resources;
 	struct resource	*resource;
 
-- 
2.20.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, back to index

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-08-16  6:24 next take at setting up a dma mask by default for platform devices v2 Christoph Hellwig
2019-08-16  6:24 ` [PATCH 1/6] usb: don't create dma pools for HCDs with a localmem_pool Christoph Hellwig
2019-08-16  6:24 ` [PATCH 2/6] usb: add a hcd_uses_dma helper Christoph Hellwig
2019-08-16  6:24 ` [PATCH 3/6] usb: add a HCD_DMA flag instead of guestimating DMA capabilities Christoph Hellwig
2019-08-16  6:24 ` [PATCH 4/6] usb/max3421: remove the dummy {un,}map_urb_for_dma methods Christoph Hellwig
2019-08-16  6:24 ` [PATCH 5/6] dma-mapping: remove is_device_dma_capable Christoph Hellwig
2019-08-16  6:24 ` [PATCH 6/6] driver core: initialize a default DMA mask for platform device Christoph Hellwig
2019-08-16  7:39   ` Geert Uytterhoeven
2019-08-22 17:11 ` next take at setting up a dma mask by default for platform devices v2 Greg Kroah-Hartman
  -- strict thread matches above, loose matches on Subject: below --
2019-08-11  8:05 next take at setting up a dma mask by default for platform devices Christoph Hellwig
2019-08-11  8:05 ` [PATCH 6/6] driver core: initialize a default DMA mask for platform device Christoph Hellwig
2019-08-14 15:49   ` Robin Murphy
2019-08-15 13:32     ` Christoph Hellwig
2019-08-15 13:03   ` Greg Kroah-Hartman
2019-08-15 13:38     ` Christoph Hellwig
2019-08-15 14:05       ` Greg Kroah-Hartman

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