Re: [Xen-devel] [PATCH 2/2] ioemu: Enable guest OS to program D0-D3hot states of an assigned device

[Isaku Yamahata <yamahata@xxxxxxxxxxxxx>]

On Thu, Feb 05, 2009 at 07:23:11PM +0900, Yuji Shimada wrote:
> We can clean up the existing code in pass-through.c in the same
> manner. I will submit the patch to clean up the code.

Thank you for clean up.
There are another logic duplications with mask operations.
I suppose helper functions like the following will help
to reduce the code more.

thanks,

static void __pt_read_{byte, word, long}(uint{8, 16, 32}_t *value,
                                         uint{8, 16, 32}_t dev_value,
                                         uint{8, 16, 32}_t emu_mask,
                                         uint{8, 16, 32}_t valid_mask)
{
    uint{8, 16, 32}_t valid_emu_mask = emu_mask & valid_mask;
    *value = ((*value & ~valid_emu_mask) | (dev_data & valid_emu_mask));
}

static void __pt_write_cfg_{byte, word, long}(struct pt_reg_tbl *cfg_entry,
                                              uint{8, 16, 32}_t value
                                              uint{8, 16, 32}_t emu_mask,
                                              uint{8, 16, 32}_t ro_mask,
                                              uint{8, 16, 32}_t valid_mask)
{
    uint{8, 16, 32}_t writable_mask = emu_mask & ~ro_mask & valid_mask;
    cfg_entry->data = ((value & writable_mask) |
                       (cfg_entry->data & ~writable_mask));
}

static void __pt_write_{byte, word, long}(uint{8, 16, 32}_t *value,
                                          uint{8, 16, 32}_t dev_value,
                                          uint{8, 16, 32}_t emu_mask,
                                          uint{8, 16, 32}_t valid_mask)
{
    uint{8, 16, 32}_t throughable_mask = ~emu_mask & valid_mask;
    *value = ((*value & throughable_mask) | (dev_value & ~throughable_mask));
}


-- 
yamahata

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