[Qemu-devel] Re: [PATCH 4/8] pci: Replace used bitmap with capability byte map

[Alex Williamson]

On Fri, 2010-11-12 at 07:40 +0200, Michael S. Tsirkin wrote:
> On Thu, Nov 11, 2010 at 07:55:43PM -0700, Alex Williamson wrote:
> > Capabilities are allocated in bytes, so we can track both whether
> > a byte is used and by what capability in the same structure.
> > 
> > Remove pci_reserve_capability() as there are no users.
> > 
> > Signed-off-by: Alex Williamson <address@hidden>
> 
> I actually wanted to remove the used array completely and ask
> all users to add offsets directly.
> Will this be needed then?

Can you give an example, I don't understand what you mean by asking
users to add offsets directly.  I think some kind of tracking what's
where in config space needs to be done somewhere and the common PCI code
seems like it'd be the place.  Thanks,

Alex

> > ---
> > 
> >  hw/pci.c |   16 +++++-----------
> >  hw/pci.h |    6 ++----
> >  2 files changed, 7 insertions(+), 15 deletions(-)
> > 
> > diff --git a/hw/pci.c b/hw/pci.c
> > index 6b2b320..e1e8a77 100644
> > --- a/hw/pci.c
> > +++ b/hw/pci.c
> > @@ -730,7 +730,7 @@ static void pci_config_alloc(PCIDevice *pci_dev)
> >      pci_dev->config = qemu_mallocz(config_size);
> >      pci_dev->cmask = qemu_mallocz(config_size);
> >      pci_dev->wmask = qemu_mallocz(config_size);
> > -    pci_dev->used = qemu_mallocz(config_size);
> > +    pci_dev->cap_map = qemu_mallocz(config_size);
> >  }
> >  
> >  static void pci_config_free(PCIDevice *pci_dev)
> > @@ -738,7 +738,7 @@ static void pci_config_free(PCIDevice *pci_dev)
> >      qemu_free(pci_dev->config);
> >      qemu_free(pci_dev->cmask);
> >      qemu_free(pci_dev->wmask);
> > -    qemu_free(pci_dev->used);
> > +    qemu_free(pci_dev->cap_map);
> >  }
> >  
> >  /* -1 for devfn means auto assign */
> > @@ -1928,7 +1928,7 @@ static int pci_find_space(PCIDevice *pdev, uint8_t 
> > size)
> >      int offset = PCI_CONFIG_HEADER_SIZE;
> >      int i;
> >      for (i = PCI_CONFIG_HEADER_SIZE; i < config_size; ++i)
> > -        if (pdev->used[i])
> > +        if (pdev->cap_map[i])
> >              offset = i + 1;
> >          else if (i - offset + 1 == size)
> >              return offset;
> > @@ -2033,7 +2033,7 @@ int pci_add_capability_at_offset(PCIDevice *pdev, 
> > uint8_t cap_id,
> >      config[PCI_CAP_LIST_ID] = cap_id;
> >      config[PCI_CAP_LIST_NEXT] = pdev->config[PCI_CAPABILITY_LIST];
> >      pdev->config[PCI_CAPABILITY_LIST] = offset;
> > -    memset(pdev->used + offset, 0xFF, size);
> > +    memset(pdev->cap_map + offset, cap_id, size);
> >      /* Make capability read-only by default */
> >      memset(pdev->wmask + offset, 0, size);
> >      /* Check capability by default */
> > @@ -2068,7 +2068,7 @@ void pci_del_capability(PCIDevice *pdev, uint8_t 
> > cap_id, uint8_t size)
> >      memset(pdev->wmask + offset, 0xff, size);
> >      /* Clear cmask as device-specific registers can't be checked */
> >      memset(pdev->cmask + offset, 0, size);
> > -    memset(pdev->used + offset, 0, size);
> > +    memset(pdev->cap_map + offset, 0, size);
> >  
> >      if (!pdev->config[PCI_CAPABILITY_LIST]) {
> >          pdev->config[PCI_STATUS] &= ~PCI_STATUS_CAP_LIST;
> > @@ -2076,12 +2076,6 @@ void pci_del_capability(PCIDevice *pdev, uint8_t 
> > cap_id, uint8_t size)
> >      }
> >  }
> >  
> > -/* Reserve space for capability at a known offset (to call after load). */
> > -void pci_reserve_capability(PCIDevice *pdev, uint8_t offset, uint8_t size)
> > -{
> > -    memset(pdev->used + offset, 0xff, size);
> > -}
> > -
> >  uint8_t pci_find_capability(PCIDevice *pdev, uint8_t cap_id)
> >  {
> >      return pci_find_capability_list(pdev, cap_id, NULL);
> > diff --git a/hw/pci.h b/hw/pci.h
> > index 0712e55..2265c70 100644
> > --- a/hw/pci.h
> > +++ b/hw/pci.h
> > @@ -151,8 +151,8 @@ struct PCIDevice {
> >      /* Used to implement R/W bytes */
> >      uint8_t *wmask;
> >  
> > -    /* Used to allocate config space for capabilities. */
> > -    uint8_t *used;
> > +    /* Used to allocate config space and track capabilities. */
> > +    uint8_t *cap_map;
> >  
> >      /* the following fields are read only */
> >      PCIBus *bus;
> > @@ -239,8 +239,6 @@ int pci_add_capability_at_offset(PCIDevice *pci_dev, 
> > uint8_t cap_id,
> >  
> >  void pci_del_capability(PCIDevice *pci_dev, uint8_t cap_id, uint8_t 
> > cap_size);
> >  
> > -void pci_reserve_capability(PCIDevice *pci_dev, uint8_t offset, uint8_t 
> > size);
> > -
> >  uint8_t pci_find_capability(PCIDevice *pci_dev, uint8_t cap_id);
> >  
> >  uint32_t pci_default_read_config(PCIDevice *d,