[Qemu-devel] Re: [PATCH 12/25] pci: 64bit bar support.

[Michael S. Tsirkin]

On Sat, Oct 03, 2009 at 05:16:04AM +0900, Isaku Yamahata wrote:
> implemented pci 64bit bar support.
> 
> Signed-off-by: Isaku Yamahata <address@hidden>
> ---
>  hw/pci.c |   41 ++++++++++++++++++++++++++++++++++++-----
>  hw/pci.h |    9 +++++++++
>  2 files changed, 45 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/pci.c b/hw/pci.c
> index 510fad2..75af2cd 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -427,8 +427,13 @@ void pci_register_bar(PCIDevice *pci_dev, int region_num,
>          addr = 0x10 + region_num * 4;
>      }
>      pci_set_long(pci_dev->config + addr, type);
> -    pci_set_long(pci_dev->wmask + addr, wmask & 0xffffffff);
> -    pci_set_long(pci_dev->cmask + addr, 0xffffffff);
> +    if (pci_bar_is_64bit(r)) {
> +        pci_set_quad(pci_dev->wmask + addr, wmask);
> +        pci_set_quad(pci_dev->cmask + addr, ~0ULL);
> +    } else {
> +        pci_set_long(pci_dev->wmask + addr, wmask & 0xffffffff);
> +        pci_set_long(pci_dev->cmask + addr, 0xffffffff);
> +    }
>  }
>  
>  static void pci_update_mappings(PCIDevice *d)
> @@ -462,7 +467,11 @@ static void pci_update_mappings(PCIDevice *d)
>                  }
>              } else {
>                  if (cmd & PCI_COMMAND_MEMORY) {
> -                    new_addr = pci_get_long(d->config + config_ofs);
> +                    if (pci_bar_is_64bit(r)) {
> +                        new_addr = pci_get_quad(d->config + config_ofs);
> +                    } else {
> +                        new_addr = pci_get_long(d->config + config_ofs);
> +                    }
>                      /* the ROM slot has a specific enable bit */
>                      if (i == PCI_ROM_SLOT && !(new_addr & 1))
>                          goto no_mem_map;
> @@ -477,7 +486,7 @@ static void pci_update_mappings(PCIDevice *d)
>  
>                          /* keep old behaviour
>                           * without this, PC ide doesn't work well. */
> -                        last_addr >= UINT32_MAX) {
> +                        (!pci_bar_is_64bit(r) && last_addr >= UINT32_MAX)) {
>                          new_addr = PCI_BAR_UNMAPPED;

I don't really understand what is this doing

>                      }
>                  } else {
> @@ -736,7 +745,29 @@ static void pci_info_device(PCIDevice *d)
>                  monitor_printf(mon, "I/O at 0x%04"FMT_pcibus" 
> [0x%04"FMT_pcibus"].\n",
>                                 r->addr, r->addr + r->size - 1);
>              } else {
> -                monitor_printf(mon, "32 bit memory at 0x%08"FMT_pcibus" 
> [0x%08"FMT_pcibus"].\n",
> +                const char *type;
> +                const char* prefetch;
> +
> +                switch (r->type & PCI_ADDRESS_SPACE_MEM_TYPE_MASK) {
> +                case PCI_ADDRESS_SPACE_MEM:
> +                    type = "32 bit";
> +                    break;
> +                case PCI_ADDRESS_SPACE_MEM_64:
> +                    type = "64 bit";
> +                    break;
> +                default:
> +                    type = "unknown";
> +                    break;

this default is just dead code?
How about type = is_64bit() ? "64" : "32"

> +                }
> +
> +                prefetch = "";
> +                if (r->type & PCI_ADDRESS_SPACE_MEM_PREFETCH) {
> +                    prefetch = " prefetchable";
> +                }
> +
> +                monitor_printf(mon, "%s%s memory at "
> +                               "0x%08"FMT_pcibus" [0x%08"FMT_pcibus"].\n",
> +                               type, prefetch,
>                                 r->addr, r->addr + r->size - 1);
>              }
>          }
> diff --git a/hw/pci.h b/hw/pci.h
> index c209f34..0455b30 100644
> --- a/hw/pci.h
> +++ b/hw/pci.h
> @@ -84,6 +84,8 @@ typedef int PCIUnregisterFunc(PCIDevice *pci_dev);
>  
>  #define PCI_ADDRESS_SPACE_MEM                0x00
>  #define PCI_ADDRESS_SPACE_IO         0x01
> +#define PCI_ADDRESS_SPACE_MEM_64        0x04    /* 64 bit address */

PCI_ADDRESS_MEM_TYPE_64 is a better name: it's a type of memory,
not a separate address space.

Actually, we should probably just reuse macros from pci_regs.h
and put them with rest of macros imported from there.
The list of relevant macros (prefixes with // these that we don't use
and probably shouldn't put in header):

        #define  PCI_BASE_ADDRESS_SPACE         0x01    /* 0 = memory, 1 = I/O 
*/
        #define  PCI_BASE_ADDRESS_SPACE_IO      0x01
        #define  PCI_BASE_ADDRESS_SPACE_MEMORY  0x00
        //#define  PCI_BASE_ADDRESS_MEM_TYPE_MASK       0x06
        //#define  PCI_BASE_ADDRESS_MEM_TYPE_32 0x00    /* 32 bit address */
        //#define  PCI_BASE_ADDRESS_MEM_TYPE_1M 0x02    /* Below 1M [obsolete] 
*/
        #define  PCI_BASE_ADDRESS_MEM_TYPE_64   0x04    /* 64 bit address */
        #define  PCI_BASE_ADDRESS_MEM_PREFETCH  0x08    /* prefetchable? */


> +#define PCI_ADDRESS_SPACE_MEM_TYPE_MASK 0x06

This one is used in pci_regs.h to include 64 bit an 1M.
what do you use it for?
It seems unnecessary.

>  #define PCI_ADDRESS_SPACE_MEM_PREFETCH       0x08
>  
>  typedef struct PCIIORegion {
> @@ -94,6 +96,13 @@ typedef struct PCIIORegion {
>      PCIMapIORegionFunc *map_func;
>  } PCIIORegion;
>  
> +static inline int pci_bar_is_64bit(const PCIIORegion *r)

Is it used outside pci.c? If no, do not put in pci.h

> +{
> +    return !(r->type & PCI_ADDRESS_SPACE_IO) &&
> +        ((r->type & PCI_ADDRESS_SPACE_MEM_TYPE_MASK) ==
> +         PCI_ADDRESS_SPACE_MEM_64);

This is probably wrong: we should only care about the MEM_64 bit.

Why don't we just return (r->type & PCI_BASE_ADDRESS_MEM_TYPE_64)?
And this function is simple enough to be open-coded then.

Nit: we don't need () around the == comparison.

> +}
> +
>  #define PCI_ROM_SLOT 6
>  #define PCI_NUM_REGIONS 7
>  
> -- 
> 1.6.0.2
> 
>