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

-----Original Message-----
From: Kumar Gala [mailto:galak@kernel.crashing.org]
Sent: Thursday, August 02, 2012 8:55 PM
To: Jia Hongtao-B38951
Cc: linuxppc-dev@lists.ozlabs.org; Wood Scott-B07421; Li Yang-R58472
Subject: Re: [PATCH V4 2/3] powerpc/swiotlb: Enable at early stage and
disable if not necessary
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On Aug 2, 2012, at 6:42 AM, Jia Hongtao wrote:
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quoted

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

quoted

in PCI initialization. But swiotlb_init() should be done at the stage

of

quoted

mem_init() which is much earlier than PCI initialization. So we reserve

the

quoted

memory for SWIOTLB first and free it if not necessary.

All boards are converted to fit this change.

Signed-off-by: Jia Hongtao <redacted>
Signed-off-by: Li Yang <redacted>
---

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This doesn't seem like it addresses our issue w/regards to not being able
to map all of memory from PCI.

PCI init will determine ppc_swiotlb_enable due to PCI map. swiotlb_late_ini=
t
will handle all swiotlb things depend on the result of pci init.

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quoted

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(-)

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Don't we also want to update all these:
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arch/powerpc/platforms/85xx/corenet_ds.c:
ppc_swiotlb_enable =3D 1;
arch/powerpc/platforms/85xx/ge_imp3a.c:         ppc_swiotlb_enable =3D 1;
arch/powerpc/platforms/85xx/mpc8536_ds.c:
ppc_swiotlb_enable =3D 1;
arch/powerpc/platforms/85xx/mpc85xx_mds.c:
ppc_swiotlb_enable =3D 1;
arch/powerpc/platforms/85xx/p1022_ds.c:         ppc_swiotlb_enable =3D 1;
arch/powerpc/platforms/86xx/mpc86xx_hpcn.c:
ppc_swiotlb_enable =3D 1;
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They are works fine at this point.

I will update all these boards after
[PATCH 3/3] Unify pci/pcie initialization code

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quoted

diff --git a/arch/powerpc/include/asm/swiotlb.h

b/arch/powerpc/include/asm/swiotlb.h

quoted

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

quoted

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 =3D 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 =3D 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 =3D 0, codesize, initsize, datasize,

bsssize;

quoted

#ifdef CONFIG_SWIOTLB
-	if (ppc_swiotlb_enable)
-		swiotlb_init(1);
+	swiotlb_init(0);
#endif

	num_physpages =3D memblock_phys_mem_size() >> PAGE_SHIFT;

diff --git a/arch/powerpc/platforms/44x/currituck.c

b/arch/powerpc/platforms/44x/currituck.c

quoted

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

quoted

 	 * RAM.  Lets hope that doesn't change */
-#ifdef CONFIG_SWIOTLB
-	if ((memblock_end_of_DRAM() - 1) > 0xffffffff) {
-		ppc_swiotlb_enable =3D 1;
-		set_pci_dma_ops(&swiotlb_dma_ops);
-		ppc_md.pci_dma_dev_setup =3D 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

quoted

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

quoted

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();

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removing fsl_pci_init() seems wrong.

You are right. I will fix this.
Thanks.

-Hongtao.

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quoted

	mpc85xx_smp_init();
}

diff --git a/arch/powerpc/sysdev/fsl_pci.c

b/arch/powerpc/sysdev/fsl_pci.c

quoted

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 =3D 1;
-		set_pci_dma_ops(&swiotlb_dma_ops);
-		ppc_md.pci_dma_dev_setup =3D pci_dma_dev_setup_swiotlb;
-	}
#endif
}
#endif
--
1.7.5.1

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