Re: [PATCH 4/9] mvebu: ddr: Rename CONFIG_DDR_FIXED_SIZE to CONFIG_SYS_SDRAM_SIZE

[Tom Rini <trini@konsulko.com>]

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On Wed, Sep 01, 2021 at 07:27:54AM +0200, Stefan Roese wrote:
> Hi Tom,
> 
> On 31.08.21 14:43, Tom Rini wrote:
> > On Tue, Aug 31, 2021 at 07:51:29AM +0200, Stefan Roese wrote:
> > > Hi Tom,
> > > 
> > > On 21.08.21 19:50, Tom Rini wrote:
> > > > We have a number of CONFIG symbols to express the fixed size of system
> > > > memory.  For now, rename CONFIG_DDR_FIXED_SIZE to CONFIG_SYS_SDRAM_SIZE
> > > > and adjust usage to match that CONFIG_SYS_SDRAM_SIZE expects the entire
> > > > size rather than MiB.
> > > > 
> > > > Cc: Marek Behún <marek.behun@nic.cz>
> > > > Cc: Stefan Roese <sr@denx.de>
> > > > Signed-off-by: Tom Rini <trini@konsulko.com>
> > > > ---
> > > >    drivers/ddr/marvell/axp/ddr3_axp.h | 4 ++--
> > > >    include/configs/maxbcm.h           | 4 +++-
> > > >    include/configs/theadorable.h      | 4 +++-
> > > >    3 files changed, 8 insertions(+), 4 deletions(-)
> > > > 
> > > > diff --git a/drivers/ddr/marvell/axp/ddr3_axp.h b/drivers/ddr/marvell/axp/ddr3_axp.h
> > > > index 270691e9bcd3..970651f87029 100644
> > > > --- a/drivers/ddr/marvell/axp/ddr3_axp.h
> > > > +++ b/drivers/ddr/marvell/axp/ddr3_axp.h
> > > > @@ -19,10 +19,10 @@
> > > >    #define FAR_END_DIMM_ADDR		0x50
> > > >    #define MAX_DIMM_ADDR			0x60
> > > > -#ifndef CONFIG_DDR_FIXED_SIZE
> > > > +#ifndef CONFIG_SYS_SDRAM_SIZE
> > > >    #define SDRAM_CS_SIZE			0xFFFFFFF
> > > >    #else
> > > > -#define SDRAM_CS_SIZE			(CONFIG_DDR_FIXED_SIZE - 1)
> > > > +#define SDRAM_CS_SIZE			((CONFIG_SYS_SDRAM_SIZE >> 10) - 1)
> > > 
> > > Why are you using ">> 10" (dividing by 1024) here?
> > > 
> > > Thanks,
> > > Stefan
> > > 
> > > >    #endif
> > > >    #define SDRAM_CS_BASE			0x0
> > > >    #define SDRAM_DIMM_SIZE			0x80000000
> > > > diff --git a/include/configs/maxbcm.h b/include/configs/maxbcm.h
> > > > index fc2393204bec..5098f12f5425 100644
> > > > --- a/include/configs/maxbcm.h
> > > > +++ b/include/configs/maxbcm.h
> > > > @@ -6,6 +6,8 @@
> > > >    #ifndef _CONFIG_DB_MV7846MP_GP_H
> > > >    #define _CONFIG_DB_MV7846MP_GP_H
> > > > +#include <linux/sizes.h>
> > > > +
> > > >    /*
> > > >     * High Level Configuration Options (easy to change)
> > > >     */
> > > > @@ -65,7 +67,7 @@
> > > >    /* SPL related SPI defines */
> > > >    /* Enable DDR support in SPL (DDR3 training from Marvell bin_hdr) */
> > > > -#define CONFIG_DDR_FIXED_SIZE		(1 << 20)	/* 1GiB */
> > > > +#define CONFIG_SYS_SDRAM_SIZE		SZ_1G
> > 
> > OK, so before my change, SDRAM_CS_SIZE = 0xfffff.  After my change,
> > SDRAM_CS_SIZE = 0xfffff, still.
> > 
> > > >    #define CONFIG_BOARD_ECC_SUPPORT	/* this board supports ECC */
> > > >    #endif /* _CONFIG_DB_MV7846MP_GP_H */
> > > > diff --git a/include/configs/theadorable.h b/include/configs/theadorable.h
> > > > index 760713d3ef87..abc48ff44ca5 100644
> > > > --- a/include/configs/theadorable.h
> > > > +++ b/include/configs/theadorable.h
> > > > @@ -6,6 +6,8 @@
> > > >    #ifndef _CONFIG_THEADORABLE_H
> > > >    #define _CONFIG_THEADORABLE_H
> > > > +#include <linux/sizes.h>
> > > > +
> > > >    /*
> > > >     * High Level Configuration Options (easy to change)
> > > >     */
> > > > @@ -93,6 +95,6 @@
> > > >    #define CONFIG_SPL_BOOTROM_SAVE		(CONFIG_SPL_STACK + 4)
> > > >    /* Enable DDR support in SPL (DDR3 training from Marvell bin_hdr) */
> > > > -#define CONFIG_DDR_FIXED_SIZE		(2 << 20)	/* 2GiB */
> > > > +#define CONFIG_SYS_SDRAM_SIZE		SZ_2G
> > 
> > Here, before SDRAM_CS_SIZE = 0x1fffff and then after SDRAM_CS_SIZE =
> > 0x1fffff.
> > 
> > This is because CONFIG_DDR_FIXED_SIZE is kilobytes and
> > CONFIG_SYS_SDRAM_SIZE is bytes, yes?  Thanks.
> 
> Only if CONFIG_DDR_FIXED_SIZE / CONFIG_SYS_SDRAM_SIZE is undefined.
> 
> Please see e.g. theadorable.h above. Here we have:
> 
> #define CONFIG_DDR_FIXED_SIZE		(2 << 20)	/* 2GiB */
> 
> With this, the following will happen in ddr3_axp.h:
> 
> #ifndef CONFIG_DDR_FIXED_SIZE
> #define SDRAM_CS_SIZE			0xFFFFFFF
> #else
> #define SDRAM_CS_SIZE			(CONFIG_DDR_FIXED_SIZE - 1)
> #endif
> 
> So SDRAM_CS_SIZE will be set to "(2 << 20) - 1".
> 
> AFAICT, on Armada XP CONFIG_DDR_FIXED_SIZE is bytes and not
> kilobytes.

I'm not follow, sorry.  There's exactly two defines of
CONFIG_DDR_FIXED_SIZE before this patch, neither platform also set
CONFIG_SYS_SDRAM_SIZE, and they're converted to CONFIG_SYS_SDRAM_SIZE
now.  I did the evaluations to confirm the code is unchanged.

As an aside, I do need to get merging of Pali's series to finish
reproducible builds as I could then do a before/after world build where
I verify things by objdump before/after.

-- 
Tom

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