[PATCH V4 2/3] powerpc/swiotlb: Enable at early stage and disable if not necessary

[Jia Hongtao]

Remove the dependency on PCI initialization for SWIOTLB initialization.
So that PCI can be initialized at proper time.

SWIOTLB is partly determined by PCI inbound/outbound map which is assigned
in PCI initialization. But swiotlb_init() should be done at the stage of
mem_init() which is much earlier than PCI initialization. So we reserve the
memory for SWIOTLB first and free it if not necessary.

All boards are converted to fit this change.

Signed-off-by: Jia Hongtao <B38951 at freescale.com>
Signed-off-by: Li Yang <leoli at freescale.com>
---
 arch/powerpc/include/asm/swiotlb.h       |    6 ++++++
 arch/powerpc/kernel/dma-swiotlb.c        |   20 ++++++++++++++++++++
 arch/powerpc/mm/mem.c                    |    3 +--
 arch/powerpc/platforms/44x/currituck.c   |   10 ++--------
 arch/powerpc/platforms/85xx/mpc85xx_ds.c |    1 +
 arch/powerpc/platforms/85xx/qemu_e500.c  |    2 +-
 arch/powerpc/sysdev/fsl_pci.c            |    5 +----
 7 files changed, 32 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/swiotlb.h b/arch/powerpc/include/asm/swiotlb.h
index 8979d4c..de99d6e 100644
--- a/arch/powerpc/include/asm/swiotlb.h
+++ b/arch/powerpc/include/asm/swiotlb.h
@@ -22,4 +22,10 @@ int __init swiotlb_setup_bus_notifier(void);
 
 extern void pci_dma_dev_setup_swiotlb(struct pci_dev *pdev);
 
+#ifdef CONFIG_SWIOTLB
+void swiotlb_detect_4g(void);
+#else
+static inline void swiotlb_detect_4g(void) {}
+#endif
+
 #endif /* __ASM_SWIOTLB_H */
diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c
index 4ab88da..aa85550 100644
--- a/arch/powerpc/kernel/dma-swiotlb.c
+++ b/arch/powerpc/kernel/dma-swiotlb.c
@@ -104,3 +104,23 @@ int __init swiotlb_setup_bus_notifier(void)
 			      &ppc_swiotlb_plat_bus_notifier);
 	return 0;
 }
+
+void swiotlb_detect_4g(void)
+{
+	if ((memblock_end_of_DRAM() - 1) > 0xffffffff)
+		ppc_swiotlb_enable = 1;
+}
+
+static int __init swiotlb_late_init(void)
+{
+	if (ppc_swiotlb_enable) {
+		swiotlb_print_info();
+		set_pci_dma_ops(&swiotlb_dma_ops);
+		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_swiotlb;
+	} else {
+		swiotlb_free();
+	}
+
+	return 0;
+}
+subsys_initcall(swiotlb_late_init);
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index baaafde..f23c4e0 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -300,8 +300,7 @@ void __init mem_init(void)
 	unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 
 #ifdef CONFIG_SWIOTLB
-	if (ppc_swiotlb_enable)
-		swiotlb_init(1);
+	swiotlb_init(0);
 #endif
 
 	num_physpages = memblock_phys_mem_size() >> PAGE_SHIFT;
diff --git a/arch/powerpc/platforms/44x/currituck.c b/arch/powerpc/platforms/44x/currituck.c
index 9f6c33d..6bd89a0 100644
--- a/arch/powerpc/platforms/44x/currituck.c
+++ b/arch/powerpc/platforms/44x/currituck.c
@@ -21,7 +21,6 @@
  */
 
 #include <linux/init.h>
-#include <linux/memblock.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/rtc.h>
@@ -159,13 +158,8 @@ static void __init ppc47x_setup_arch(void)
 
 	/* No need to check the DMA config as we /know/ our windows are all of
  	 * RAM.  Lets hope that doesn't change */
-#ifdef CONFIG_SWIOTLB
-	if ((memblock_end_of_DRAM() - 1) > 0xffffffff) {
-		ppc_swiotlb_enable = 1;
-		set_pci_dma_ops(&swiotlb_dma_ops);
-		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_swiotlb;
-	}
-#endif
+	swiotlb_detect_4g();
+
 	ppc47x_smp_init();
 }
 
diff --git a/arch/powerpc/platforms/85xx/mpc85xx_ds.c b/arch/powerpc/platforms/85xx/mpc85xx_ds.c
index 6d3265f..56f8c8f 100644
--- a/arch/powerpc/platforms/85xx/mpc85xx_ds.c
+++ b/arch/powerpc/platforms/85xx/mpc85xx_ds.c
@@ -159,6 +159,7 @@ static void __init mpc85xx_ds_setup_arch(void)
 	if (ppc_md.progress)
 		ppc_md.progress("mpc85xx_ds_setup_arch()", 0);
 
+	swiotlb_detect_4g();
 	mpc85xx_ds_pci_init();
 	mpc85xx_smp_init();
 
diff --git a/arch/powerpc/platforms/85xx/qemu_e500.c b/arch/powerpc/platforms/85xx/qemu_e500.c
index 95a2e53..04260cd 100644
--- a/arch/powerpc/platforms/85xx/qemu_e500.c
+++ b/arch/powerpc/platforms/85xx/qemu_e500.c
@@ -41,7 +41,7 @@ static void __init qemu_e500_setup_arch(void)
 {
 	ppc_md.progress("qemu_e500_setup_arch()", 0);
 
-	fsl_pci_init();
+	swiotlb_detect_4g();
 	mpc85xx_smp_init();
 }
 
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index 6938792..da7a3d7 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -872,11 +872,8 @@ void __devinit fsl_pci_init(void)
 	 * we need SWIOTLB to handle buffers located outside of
 	 * dma capable memory region
 	 */
-	if (memblock_end_of_DRAM() - 1 > max) {
+	if (memblock_end_of_DRAM() - 1 > max)
 		ppc_swiotlb_enable = 1;
-		set_pci_dma_ops(&swiotlb_dma_ops);
-		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_swiotlb;
-	}
 #endif
 }
 #endif
-- 
1.7.5.1