[PATCH 1/2] powerpc/44x: Fix PCI MSI support for APM821xx SoC and Bluestone board

[Josh Boyer]

On Wed, Feb 29, 2012 at 3:47 AM, Mai La <mla at apm.com> wrote:
> This patch consists of:
> - Enable PCI MSI as default for Bluestone board
> - Define number of MSI interrupt for Maui APM821xx

What is Maui?  Is that the same thing as Bluestone?

> - Fix returning ENODEV as finding MSI node
> - Fix MSI physical high and low address
> - Keep MSI data logically
>
> Signed-off-by: Mai La <mla at apm.com>

Wow.  So there are a lot of bugfixes here.  I'm surprised this ever worked at
all with some of the things you're fixing.  Nice to see.

> ---
>  arch/powerpc/platforms/44x/Kconfig |    2 ++
>  arch/powerpc/sysdev/ppc4xx_msi.c   |   28 ++++++++++++++++++----------
>  2 files changed, 20 insertions(+), 10 deletions(-)
>
> diff --git a/arch/powerpc/platforms/44x/Kconfig b/arch/powerpc/platforms/44x/Kconfig
> index fcf6bf2..9f04ce3 100644
> --- a/arch/powerpc/platforms/44x/Kconfig
> +++ b/arch/powerpc/platforms/44x/Kconfig
> @@ -23,6 +23,8 @@ config BLUESTONE
>        default n
>        select PPC44x_SIMPLE
>        select APM821xx
> +       select PCI_MSI
> +       select PPC4xx_MSI
>        select IBM_EMAC_RGMII
>        help
>          This option enables support for the APM APM821xx Evaluation board.
> diff --git a/arch/powerpc/sysdev/ppc4xx_msi.c b/arch/powerpc/sysdev/ppc4xx_msi.c
> index 1c2d7af..6103908 100644
> --- a/arch/powerpc/sysdev/ppc4xx_msi.c
> +++ b/arch/powerpc/sysdev/ppc4xx_msi.c
> @@ -31,7 +31,7 @@
>  #include <asm/prom.h>
>  #include <asm/hw_irq.h>
>  #include <asm/ppc-pci.h>
> -#include <boot/dcr.h>
> +#include <asm/dcr.h>
>  #include <asm/dcr-regs.h>
>  #include <asm/msi_bitmap.h>
>
> @@ -43,7 +43,12 @@
>  #define PEIH_FLUSH0    0x30
>  #define PEIH_FLUSH1    0x38
>  #define PEIH_CNTRST    0x48
> +
> +#ifdef CONFIG_APM821xx
> +#define NR_MSI_IRQS    8
> +#else
>  #define NR_MSI_IRQS    4
> +#endif

Hm.  Do you think this is going to change quite a bit depending on which SoC
is being used?  If so, it might be better to introduce a Kconfig variable
that just defines this instead.  Something like:

	config 4xx_MSI_IRQS
	   int "Number of MSI IRQs"
	   depends on 4xx
	   default "8" if APM821xx
	   default "4" if !APM821xx

If there aren't going to be a wide variety of numbers, then the simple ifdef
you have is probably sufficient.

>  struct ppc4xx_msi {
>        u32 msi_addr_lo;
> @@ -150,12 +155,11 @@ static int ppc4xx_setup_pcieh_hw(struct platform_device *dev,
>        if (!sdr_addr)
>                return -1;
>
> -       SDR0_WRITE(sdr_addr, (u64)res.start >> 32);      /*HIGH addr */
> -       SDR0_WRITE(sdr_addr + 1, res.start & 0xFFFFFFFF); /* Low addr */
> -
> +       mtdcri(SDR0, *sdr_addr, res.start >> 32);       /*HIGH addr */
> +       mtdcri(SDR0, *sdr_addr + 1, res.start & 0xFFFFFFFF);/* Low addr */

Don't you still want the (u64) cast on res.start?

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Is there a way you can drop this?  Others from APM seem to have figured out
how to do that, so hopefully it won't be a big problem.

josh