removing addr_needs_map in struct dma_mapping_ops

FUJITA Tomonori fujita.tomonori at lab.ntt.co.jp
Tue Jul 14 10:49:55 EST 2009


On Mon, 13 Jul 2009 16:50:43 -0500
Becky Bruce <beckyb at kernel.crashing.org> wrote:

> > talked about defining something like struct dma_data. Then we could
> >
> > struct dev_archdata {
> >      ...
> >
> >      struct dma_data *ddata;
> > };
> >
> > or
> >
> > struct dev_archdata {
> >      ...
> >
> >      struct dma_data ddata;
> > };
> >
> >
> > struct dma_data needs dma_direct_offset, iommu_table, dma_base, and
> > dma_window_size, anything else?
> 
> IIRC, what we had talked about was simpler - we talked about changing  
> the current dev_archdata from this:
> 
> struct dev_archdata {
>         struct device_node      *of_node;
>         struct dma_mapping_ops  *dma_ops;
>         void                    *dma_data;
> };
> 
> to this:
> 
> struct dev_archdata {
> 	struct device_node *of_node;
> 	struct dma_mapping_ops *dma_ops;
> 	unsigned long long dma_data;
> #ifdef CONFIG_SWIOTLB
> 	dma_addr_t max_direct_dma_addr;
> #endif
> };
> 
> Where max_direct_dma_addr is the address beyond which a specific  
> device must use swiotlb, and dma_data is the offset like it is now  
> (but wider on 32-bit systems than void *). I believe Ben had mentioned  
> wanting to make the max_direct_dma_addr part conditional so we don't  
> bloat archdata on platforms that don't ever bounce.

Only maximum address is enough? The minimum (dma_window_base_cur in
swiotlb_pci_addr_needs_map) is not necessary?


> The change to the type of dma_data is actually in preparation for an  
> optimization I have planned for 64-bit PCI devices (and which probably  
> requires more discussion), so that doesn't need to happen now -  just  
> leave it as a void *, and I can post a followup patch.
> 
> Let me know if I can help or do any testing - I've been meaning to  
> look into switching to dma_map_ops for a while now but it hasn't  
> managed to pop off my todo stack.

Ok, how about this? I'm not familiar with POWERPC so I might
misunderstand something.


diff --git a/arch/powerpc/include/asm/device.h b/arch/powerpc/include/asm/device.h
index 7d2277c..0086f8d 100644
--- a/arch/powerpc/include/asm/device.h
+++ b/arch/powerpc/include/asm/device.h
@@ -16,6 +16,9 @@ struct dev_archdata {
 	/* DMA operations on that device */
 	struct dma_mapping_ops	*dma_ops;
 	void			*dma_data;
+#ifdef CONFIG_SWIOTLB
+	dma_addr_t		max_direct_dma_addr;
+#endif
 };
 
 static inline void dev_archdata_set_node(struct dev_archdata *ad,
diff --git a/arch/powerpc/include/asm/swiotlb.h b/arch/powerpc/include/asm/swiotlb.h
index 30891d6..b23a4f1 100644
--- a/arch/powerpc/include/asm/swiotlb.h
+++ b/arch/powerpc/include/asm/swiotlb.h
@@ -24,4 +24,6 @@ static inline void dma_mark_clean(void *addr, size_t size) {}
 extern unsigned int ppc_swiotlb_enable;
 int __init swiotlb_setup_bus_notifier(void);
 
+extern void pci_dma_dev_setup_swiotlb(struct pci_dev *pdev);
+
 #endif /* __ASM_SWIOTLB_H */
diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c
index 68ccf11..e21359e 100644
--- a/arch/powerpc/kernel/dma-swiotlb.c
+++ b/arch/powerpc/kernel/dma-swiotlb.c
@@ -56,39 +56,16 @@ swiotlb_arch_address_needs_mapping(struct device *hwdev, dma_addr_t addr,
 				   size_t size)
 {
 	struct dma_mapping_ops *dma_ops = get_dma_ops(hwdev);
+	struct dev_archdata *sd = &hwdev->archdata;
 
 	BUG_ON(!dma_ops);
-	return dma_ops->addr_needs_map(hwdev, addr, size);
-}
 
-/*
- * Determine if an address is reachable by a pci device, or if we must bounce.
- */
-static int
-swiotlb_pci_addr_needs_map(struct device *hwdev, dma_addr_t addr, size_t size)
-{
-	u64 mask = dma_get_mask(hwdev);
-	dma_addr_t max;
-	struct pci_controller *hose;
-	struct pci_dev *pdev = to_pci_dev(hwdev);
-
-	hose = pci_bus_to_host(pdev->bus);
-	max = hose->dma_window_base_cur + hose->dma_window_size;
-
-	/* check that we're within mapped pci window space */
-	if ((addr + size > max) | (addr < hose->dma_window_base_cur))
+	if (sd->max_direct_dma_addr && addr + size > sd->max_direct_dma_addr)
 		return 1;
 
-	return !is_buffer_dma_capable(mask, addr, size);
-}
-
-static int
-swiotlb_addr_needs_map(struct device *hwdev, dma_addr_t addr, size_t size)
-{
 	return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
 }
 
-
 /*
  * At the moment, all platforms that use this code only require
  * swiotlb to be used if we're operating on HIGHMEM.  Since
@@ -104,7 +81,6 @@ struct dma_mapping_ops swiotlb_dma_ops = {
 	.dma_supported = swiotlb_dma_supported,
 	.map_page = swiotlb_map_page,
 	.unmap_page = swiotlb_unmap_page,
-	.addr_needs_map = swiotlb_addr_needs_map,
 	.sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
 	.sync_single_range_for_device = swiotlb_sync_single_range_for_device,
 	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
@@ -119,13 +95,23 @@ struct dma_mapping_ops swiotlb_pci_dma_ops = {
 	.dma_supported = swiotlb_dma_supported,
 	.map_page = swiotlb_map_page,
 	.unmap_page = swiotlb_unmap_page,
-	.addr_needs_map = swiotlb_pci_addr_needs_map,
 	.sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
 	.sync_single_range_for_device = swiotlb_sync_single_range_for_device,
 	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
 	.sync_sg_for_device = swiotlb_sync_sg_for_device
 };
 
+void pci_dma_dev_setup_swiotlb(struct pci_dev *pdev)
+{
+	struct pci_controller *hose;
+	struct dev_archdata *sd;
+
+	hose = pci_bus_to_host(pdev->bus);
+	sd = &pdev->dev.archdata;
+	sd->max_direct_dma_addr =
+		hose->dma_window_base_cur + hose->dma_window_size;
+}
+
 static int ppc_swiotlb_bus_notify(struct notifier_block *nb,
 				  unsigned long action, void *data)
 {
diff --git a/arch/powerpc/platforms/85xx/mpc8536_ds.c b/arch/powerpc/platforms/85xx/mpc8536_ds.c
index 055ff41..401751b 100644
--- a/arch/powerpc/platforms/85xx/mpc8536_ds.c
+++ b/arch/powerpc/platforms/85xx/mpc8536_ds.c
@@ -136,6 +136,7 @@ define_machine(mpc8536_ds) {
 	.init_IRQ		= mpc8536_ds_pic_init,
 #ifdef CONFIG_PCI
 	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
+	.pci_dma_dev_setup	= pci_dma_dev_setup_swiotlb,
 #endif
 	.get_irq		= mpic_get_irq,
 	.restart		= fsl_rstcr_restart,
diff --git a/arch/powerpc/platforms/85xx/mpc85xx_ds.c b/arch/powerpc/platforms/85xx/mpc85xx_ds.c
index 849c0ac..1ba8e38 100644
--- a/arch/powerpc/platforms/85xx/mpc85xx_ds.c
+++ b/arch/powerpc/platforms/85xx/mpc85xx_ds.c
@@ -277,6 +277,7 @@ define_machine(mpc8544_ds) {
 	.init_IRQ		= mpc85xx_ds_pic_init,
 #ifdef CONFIG_PCI
 	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
+	.pci_dma_dev_setup	= pci_dma_dev_setup_swiotlb,
 #endif
 	.get_irq		= mpic_get_irq,
 	.restart		= fsl_rstcr_restart,
@@ -291,6 +292,7 @@ define_machine(mpc8572_ds) {
 	.init_IRQ		= mpc85xx_ds_pic_init,
 #ifdef CONFIG_PCI
 	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
+	.pci_dma_dev_setup	= pci_dma_dev_setup_swiotlb,
 #endif
 	.get_irq		= mpic_get_irq,
 	.restart		= fsl_rstcr_restart,
@@ -305,6 +307,7 @@ define_machine(p2020_ds) {
 	.init_IRQ		= mpc85xx_ds_pic_init,
 #ifdef CONFIG_PCI
 	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
+	.pci_dma_dev_setup	= pci_dma_dev_setup_swiotlb,
 #endif
 	.get_irq		= mpic_get_irq,
 	.restart		= fsl_rstcr_restart,
diff --git a/arch/powerpc/platforms/85xx/mpc85xx_mds.c b/arch/powerpc/platforms/85xx/mpc85xx_mds.c
index 60ed9c0..165a2de 100644
--- a/arch/powerpc/platforms/85xx/mpc85xx_mds.c
+++ b/arch/powerpc/platforms/85xx/mpc85xx_mds.c
@@ -356,6 +356,7 @@ define_machine(mpc8568_mds) {
 	.progress	= udbg_progress,
 #ifdef CONFIG_PCI
 	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
+	.pci_dma_dev_setup	= pci_dma_dev_setup_swiotlb,
 #endif
 };
 
@@ -377,5 +378,6 @@ define_machine(mpc8569_mds) {
 	.progress	= udbg_progress,
 #ifdef CONFIG_PCI
 	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
+	.pci_dma_dev_setup	= pci_dma_dev_setup_swiotlb,
 #endif
 };
diff --git a/arch/powerpc/platforms/86xx/mpc86xx_hpcn.c b/arch/powerpc/platforms/86xx/mpc86xx_hpcn.c
index 6632702..d1878f3 100644
--- a/arch/powerpc/platforms/86xx/mpc86xx_hpcn.c
+++ b/arch/powerpc/platforms/86xx/mpc86xx_hpcn.c
@@ -187,5 +187,6 @@ define_machine(mpc86xx_hpcn) {
 	.progress		= udbg_progress,
 #ifdef CONFIG_PCI
 	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
+	.pci_dma_dev_setup	= pci_dma_dev_setup_swiotlb,
 #endif
 };


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