driver core: initialize a default DMA mask for platform device

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>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20190816062435.881-7-hch@lst.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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;
-	}
-}

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");

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);

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 +

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);

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);

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 +

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);

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 *