linux-kernel - [PATCH 21/33] powerpc/dma: remove get_pci_dma

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Message-Id: <20181009132500.17643-22-hch@lst.de>
Date:   Tue,  9 Oct 2018 15:24:48 +0200
From:   Christoph Hellwig <hch@....de>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>
Cc:     linuxppc-dev@...ts.ozlabs.org, iommu@...ts.linux-foundation.org,
        linux-mm@...ck.org, linux-arch@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 21/33] powerpc/dma: remove get_pci_dma_ops

This function is only used by the Cell iommu code, which can keep track
if it is using the iommu internally just as good.

Signed-off-by: Christoph Hellwig <hch@....de>
---
 arch/powerpc/include/asm/pci.h      |  2 --
 arch/powerpc/kernel/pci-common.c    |  6 ------
 arch/powerpc/platforms/cell/iommu.c | 17 ++++++++---------
 3 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index a01d2e3d6ff9..4f7cf0a7f89d 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -52,10 +52,8 @@ static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
 
 #ifdef CONFIG_PCI
 extern void set_pci_dma_ops(const struct dma_map_ops *dma_ops);
-extern const struct dma_map_ops *get_pci_dma_ops(void);
 #else	/* CONFIG_PCI */
 #define set_pci_dma_ops(d)
-#define get_pci_dma_ops()	NULL
 #endif
 
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 88e4f69a09e5..a84707680525 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -69,12 +69,6 @@ void set_pci_dma_ops(const struct dma_map_ops *dma_ops)
 	pci_dma_ops = dma_ops;
 }
 
-const struct dma_map_ops *get_pci_dma_ops(void)
-{
-	return pci_dma_ops;
-}
-EXPORT_SYMBOL(get_pci_dma_ops);
-
 /*
  * This function should run under locking protection, specifically
  * hose_spinlock.
diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index fb51f78035ce..93c7e4aef571 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -544,6 +544,7 @@ static struct cbe_iommu *cell_iommu_for_node(int nid)
 static unsigned long cell_dma_nommu_offset;
 
 static unsigned long dma_iommu_fixed_base;
+static bool cell_iommu_enabled;
 
 /* iommu_fixed_is_weak is set if booted with iommu_fixed=weak */
 bool iommu_fixed_is_weak;
@@ -572,16 +573,14 @@ static u64 cell_iommu_get_fixed_address(struct device *dev);
 
 static void cell_dma_dev_setup(struct device *dev)
 {
-	if (get_pci_dma_ops() == &dma_iommu_ops) {
+	if (cell_iommu_enabled) {
 		u64 addr = cell_iommu_get_fixed_address(dev);
 
 		if (addr != OF_BAD_ADDR)
 			set_dma_offset(dev, addr + dma_iommu_fixed_base);
 		set_iommu_table_base(dev, cell_get_iommu_table(dev));
-	} else if (get_pci_dma_ops() == &dma_nommu_ops) {
-		set_dma_offset(dev, cell_dma_nommu_offset);
 	} else {
-		BUG();
+		set_dma_offset(dev, cell_dma_nommu_offset);
 	}
 }
 
@@ -599,11 +598,11 @@ static int cell_of_bus_notify(struct notifier_block *nb, unsigned long action,
 	if (action != BUS_NOTIFY_ADD_DEVICE)
 		return 0;
 
-	/* We use the PCI DMA ops */
-	dev->dma_ops = get_pci_dma_ops();
-
+	if (cell_iommu_enabled)
+		dev->dma_ops = &dma_iommu_ops;
+	else
+		dev->dma_ops = &dma_nommu_ops;
 	cell_dma_dev_setup(dev);
-
 	return 0;
 }
 
@@ -1091,7 +1090,7 @@ static int __init cell_iommu_init(void)
 				cell_pci_iommu_bypass_supported;
 	}
 	set_pci_dma_ops(&dma_iommu_ops);
-
+	cell_iommu_enabled = true;
  bail:
 	/* Register callbacks on OF platform device addition/removal
 	 * to handle linking them to the right DMA operations
-- 
2.19.0