[PATCH 2/5] ARM: mvebu: Simplify memory init order

Wed Sep 17 00:29:52 PDT 2014

On Wed, Sep 17, 2014 at 09:19:33AM +0200, Sebastian Hesselbarth wrote:
> On 09/17/2014 08:45 AM, Sascha Hauer wrote:
> >On Tue, Sep 16, 2014 at 10:05:44PM +0200, Sebastian Hesselbarth wrote:
> >>On 09/15/2014 09:41 AM, Sascha Hauer wrote:
> >>>The initialisation of the memory nodes on mvebu is a bit
> >>>compilcated:
> >>>
> >>>pure_initcall(mvebu_memory_fixup_register)
> >>>	of_register_fixup(mvebu_memory_of_fixup, NULL)
> >>>core_initcall(kirkwood_init_soc)
> >>>	mvebu_set_memory()
> >>>core_initcall(of_arm_init)
> >>>	of_fix_tree()
> >>>		mvebu_memory_of_fixup()
> >>>
> >>>First a mvebu common of_fixup function is registered, then the SoC
> >>>calls mvebu_set_memory which stores the memory base and size in global
> >>>variables. Afterwards the of_fixup is executed which fixes the memory
> >>>nodes according to the global variables.
> >>>
> >>>Instead register a SoC specific fixup which directly calls mvebu_set_memory
> >>>with the memory base and size as arguments:
> >>>
> >>>pure_initcall(kirkwood_register_soc_fixup);
> >>>	of_register_fixup(kirkwood_init_soc, NULL);
> >>>core_initcall(of_arm_init)
> >>>	of_fix_tree()
> >>>		kirkwood_init_soc()
> >>>			mvebu_set_memory(phys_base, phys_size);
> >>>
> >>>Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> >>
> >>Hmm, this breaks Armada 370 and most likely also Armada XP. Actually,
> >>it breaks any SoC that has a DTB with internal regs set to 0xd0000000.
> >>
> >>>---
> >>>  arch/arm/mach-mvebu/armada-370-xp.c       |  9 ++++++--
> >>>  arch/arm/mach-mvebu/common.c              | 34 ++++++++++---------------------
> >>>  arch/arm/mach-mvebu/dove.c                |  9 ++++++--
> >>>  arch/arm/mach-mvebu/include/mach/common.h |  2 +-
> >>>  arch/arm/mach-mvebu/kirkwood.c            |  9 ++++++--
> >>>  5 files changed, 33 insertions(+), 30 deletions(-)
> >>>
> >>>diff --git a/arch/arm/mach-mvebu/armada-370-xp.c b/arch/arm/mach-mvebu/armada-370-xp.c
> >>>index 6251100..5c8499b 100644
> >>>--- a/arch/arm/mach-mvebu/armada-370-xp.c
> >>>+++ b/arch/arm/mach-mvebu/armada-370-xp.c
> >>>@@ -52,7 +52,7 @@ static void __noreturn armada_370_xp_reset_cpu(unsigned long addr)
> >>>  		;
> >>>  }
> >>>
> >>>-static int armada_370_xp_init_soc(void)
> >>>+static int armada_370_xp_init_soc(struct device_node *root, void *context)
> >>>  {
> >>>  	unsigned long phys_base, phys_size;
> >>>  	u32 reg;
> >>>@@ -74,4 +74,9 @@ static int armada_370_xp_init_soc(void)
> >>
> >>Because armada_370_xp_init_soc() does
> >>
> >>	mvebu_mbus_add_range(0xf0, 0x01, MVEBU_REMAP_INT_REG_BASE);
> >>
> >>right above, which will add the range(s) required for internal register
> >>of_fixup. Since this patch moved armada_370_xp_init_soc to the
> >>of_fixups, we don't fix this up for the initial DT tree.
> >>
> >>>
> >>>  	return 0;
> >>>  }
> >>>-core_initcall(armada_370_xp_init_soc);
> >>>+
> >>>+static int armada_370_register_soc_fixup(void)
> >>>+{
> >>
> >>I guess moving mvebu_mbus_add_range() in here does not work, because
> >>it will add the armada_370_xp range also for dove and kirkwood.
> >
> >Do we need a separate of_fixup registered for fixing up the mbus? Can't
> >we just call mvebu_mbus_of_fixup() directly from mvebu_mbus_add_range()?
> >
> >This won't be very efficient for dove which calls mvebu_mbus_add_range()
> >twice so it has to iterate over the device tree twice, but it should
> >work, right?
> 
> It is not the number of iterations I am concerned about. In a Multi-SoC
> environment, we add ranges for MBUS_ID(0xf0, 0x01) three times anyway
> plus Dove's MBUS_ID(0xf0, 0x02).
> 
> Currently, we are lucky that MBUS_ID(0xf0, 0x01) is the same for all
> SoCs and MBUS_ID(0xf0, 0x02) is exclusive for Dove. If we cross our
> fingers and hope it will never change, we can just do:
> 
> static int dove_register_soc_fixup(void)
> {
> 	mvebu_mbus_add_range(0xf0, 0x01, MVEBU_REMAP_INT_REG_BASE);
> 	mvebu_mbus_add_range(0xf0, 0x02, DOVE_REMAP_MC_REGS);
> 	return of_register_fixup(dove_init_soc, NULL);
> }
> pure_initcall(dove_register_soc_fixup);
> 
> and
> 
> static int armada_370_xp_register_soc_fixup(void)
> {
> 	mvebu_mbus_add_range(0xf0, 0x01, MVEBU_REMAP_INT_REG_BASE);
> 	return of_register_fixup(armada_370_xp_init_soc, NULL);
> }
> pure_initcall(armada_370_xp_register_soc_fixup);
> 
> and the same for Kirkwood.
> 
> If we want to make it safe for any future SoC that might break the
> MBUS_ID() assumptions above, we can add the machine_id compatible
> to mvebu_mbus_add_range(), i.e.
> 
> static int armada_370_xp_register_soc_fixup(void)
> {
> 	mvebu_mbus_add_range("marvell,armada-370-xp", 0xf0, 0x01,
> MVEBU_REMAP_INT_REG_BASE);
> 	return of_register_fixup(armada_370_xp_init_soc, NULL);
> }
> pure_initcall(armada_370_xp_register_soc_fixup);
> 
> If you put your current series into some branch I can pull, I can
> add the required patches later today.

I pushed it to the work/mvebu-multisoc branch in the master repository.
It should have your previous comments integrated.

Sascha

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