Re: [Qemu-ppc] [PATCH v2 3/6] PPC 85xx: Add qemu-ppce500 machine

[Scott Wood]

On Fri, 2014-01-31 at 12:16 +0100, Alexander Graf wrote:
> +void pci_init_board(void)
> +{
> +     struct fsl_pci_info pci_info;
> +     const void *fdt = get_fdt();
> +     int pci_node;
> +
> +     puts("\n");
> +
> +     pci_node = fdt_path_offset(fdt, "/pci");
> +     if (pci_node < 0) {
> +             printf("PCI: disabled\n\n");
> +             return;
> +     }
> +
> +     SET_STD_PCI_INFO(pci_info, 1);
> +
> +     fsl_setup_hose(&pci1_hose, pci_info.regs);
> +     printf("PCI: 32 bit, 66 MHz, async, host, base address %lx\n",
> +             pci_info.regs);

Why hardcode these things in a message?  Just don't print anything if
you don't have the info.

Is QEMU's PCI emulation 32-bit-only?

> +void init_tlbs_dynamic(void)
> +{
> +     unsigned long fdt_tlb = (unsigned long)get_fdt() & ~0xffffful;
> +     u32 mas0, mas1, mas2, mas3, mas7;
> +     phys_size_t ram_size;
> +
> +     /*
> +      * Create a temporary AS=1 map for the fdt
> +      *
> +      * We use ESEL=0 here to overwrite the previous AS=0 map for ourselves
> +      * which was only 4k big. This way we don't have to clear any other 
> maps.
> +      */
> +     mas0 = MAS0_TLBSEL(1) | MAS0_ESEL(0);
> +     mas1 = MAS1_VALID | MAS1_TID(0) | MAS1_TS | MAS1_TSIZE(BOOKE_PAGESZ_1M);
> +     mas2 = FSL_BOOKE_MAS2(fdt_tlb, 0);
> +     mas3 = FSL_BOOKE_MAS3(fdt_tlb, 0, MAS3_SW|MAS3_SR|MAS3_SX);
> +     mas7 = FSL_BOOKE_MAS7(fdt_tlb);
> +
> +     write_tlb(mas0, mas1, mas2, mas3, mas7);

How do you know you're not creating an overlapping TLB entry?  You
should map this to a fixed virtual address that you know is safe.

> +     /* Create a dynamic AS=0 CCSRBAR mapping */
> +     mas0 = MAS0_TLBSEL(1) | MAS0_ESEL(13);
> +     mas1 = MAS1_VALID | MAS1_TID(0) | MAS1_TSIZE(BOOKE_PAGESZ_1M);
> +     mas2 = FSL_BOOKE_MAS2(CONFIG_SYS_CCSRBAR, MAS2_I|MAS2_G);
> +     mas3 = FSL_BOOKE_MAS3(CONFIG_SYS_CCSRBAR_PHYS, 0, MAS3_SW|MAS3_SR);
> +     mas7 = FSL_BOOKE_MAS7(CONFIG_SYS_CCSRBAR_PHYS);

CCSRBAR may be 1M or 16M (assuming qemu-ppce500 sticks with a CCSR-ish
layout at all).  Really we should be creating explicit maps for
everything we find in the device tree that we care about.

> +#define CONFIG_SYS_CCSRBAR           0xe0000000
> +#define CONFIG_SYS_CCSRBAR_PHYS_LOW  CONFIG_SYS_CCSRBAR

Set CONFIG_SYS_CCSR_DO_NOT_RELOCATE instead of
CONFIG_SYS_CCSRBAR_PHYS_LOW.

> +/* Get RAM size from device tree */
> +#define CONFIG_DDR_SPD

That's not what CONFIG_DDR_SPD means.

-Scott