powerpc/swiotlb: Enable at early stage and disable if not necessary

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@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
Acked-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

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 */

arch/powerpc/kernel/dma-swiotlb.c

@@ -105,3 +105,23 @@ 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);

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;

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();
 }
 

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();
 

arch/powerpc/platforms/85xx/qemu_e500.c

@@ -42,6 +42,7 @@ 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();
 }
 

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