Message ID | 1397136581-10500-2-git-send-email-marcel.a@redhat.com |
---|---|
State | New |
Headers | show |
On Thu, Apr 10, 2014 at 04:29:40PM +0300, Marcel Apfelbaum wrote: > If a pci-2-pci bridge supports hot-plug functionality but there are no devices > connected to it, reserve IO/mem in order to be able to attach devices > later. Do not waste space, use minimum allowed. > > Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> Looks good to me Reviewed-by: Michael S. Tsirkin <mst@redhat.com> but let's apply with patch 2 (after it's fixed): otherwise there's no way for hypervisors to avoid wasting resources unnecessaily on bridges. > --- > src/fw/pciinit.c | 3 +++ > src/hw/pci.c | 19 +++++++++++++++++++ > src/hw/pci.h | 1 + > 3 files changed, 23 insertions(+) > > diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c > index 64f1d41..9b5d7ad 100644 > --- a/src/fw/pciinit.c > +++ b/src/fw/pciinit.c > @@ -677,12 +677,15 @@ static int pci_bios_check_devices(struct pci_bus *busses) > continue; > struct pci_bus *parent = &busses[pci_bdf_to_bus(s->bus_dev->bdf)]; > int type; > + u8 shpc_cap = pci_find_capability(s->bus_dev, PCI_CAP_ID_SHPC); > for (type = 0; type < PCI_REGION_TYPE_COUNT; type++) { > u64 align = (type == PCI_REGION_TYPE_IO) ? > PCI_BRIDGE_IO_MIN : PCI_BRIDGE_MEM_MIN; > if (pci_region_align(&s->r[type]) > align) > align = pci_region_align(&s->r[type]); > u64 sum = pci_region_sum(&s->r[type]); > + if (!sum && shpc_cap) > + sum = align; /* reserve min size for hot-plug */ > u64 size = ALIGN(sum, align); > int is64 = pci_bios_bridge_region_is64(&s->r[type], > s->bus_dev, type); > diff --git a/src/hw/pci.c b/src/hw/pci.c > index caf9265..055353d 100644 > --- a/src/hw/pci.c > +++ b/src/hw/pci.c > @@ -225,6 +225,25 @@ pci_find_init_device(const struct pci_device_id *ids, void *arg) > return NULL; > } > > +u8 pci_find_capability(struct pci_device *pci, u8 cap_id) > +{ > + int i; > + u8 cap; > + u16 status = pci_config_readw(pci->bdf, PCI_STATUS); > + > + if (!(status & PCI_STATUS_CAP_LIST)) > + return 0; > + > + for (i = 0, cap = pci_config_readb(pci->bdf, PCI_CAPABILITY_LIST); > + (i <= 0xff) && cap; > + i++, cap = pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_NEXT)) > + if (pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_ID) == cap_id) > + return cap; > + > + return 0; > +} > + > + > void > pci_reboot(void) > { > diff --git a/src/hw/pci.h b/src/hw/pci.h > index 167a027..e828225 100644 > --- a/src/hw/pci.h > +++ b/src/hw/pci.h > @@ -116,6 +116,7 @@ int pci_init_device(const struct pci_device_id *ids > , struct pci_device *pci, void *arg); > struct pci_device *pci_find_init_device(const struct pci_device_id *ids > , void *arg); > +u8 pci_find_capability(struct pci_device *pci, u8 cap_id); > void pci_reboot(void); > > #endif > -- > 1.8.3.1
On Thu, Apr 10, 2014 at 04:29:40PM +0300, Marcel Apfelbaum wrote: [...] > + for (i = 0, cap = pci_config_readb(pci->bdf, PCI_CAPABILITY_LIST); > + (i <= 0xff) && cap; > + i++, cap = pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_NEXT)) > + if (pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_ID) == cap_id) > + return cap; I hate to nitpick, but I find that for-loop hard to read. What about something like: int i; u8 cap = pci_config_readb(pci->bdf, PCI_CAPABILITY_LIST); for (i = 0, cap && i <= 0xff; i++) { if (pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_ID) == cap_id) return cap; cap = pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_NEXT)) } Otherwise, your patches look fine to me. -Kevin
On Thu, 2014-04-10 at 12:45 -0400, Kevin O'Connor wrote: > On Thu, Apr 10, 2014 at 04:29:40PM +0300, Marcel Apfelbaum wrote: > [...] > > + for (i = 0, cap = pci_config_readb(pci->bdf, PCI_CAPABILITY_LIST); > > + (i <= 0xff) && cap; > > + i++, cap = pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_NEXT)) > > + if (pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_ID) == cap_id) > > + return cap; > > I hate to nitpick, but I find that for-loop hard to read. What about > something like: > > int i; > u8 cap = pci_config_readb(pci->bdf, PCI_CAPABILITY_LIST); > for (i = 0, cap && i <= 0xff; i++) { > if (pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_ID) == cap_id) > return cap; > cap = pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_NEXT)) > } Sure! Thanks for the review, Marcel > > Otherwise, your patches look fine to me. > > -Kevin
diff --git a/src/fw/pciinit.c b/src/fw/pciinit.c index 64f1d41..9b5d7ad 100644 --- a/src/fw/pciinit.c +++ b/src/fw/pciinit.c @@ -677,12 +677,15 @@ static int pci_bios_check_devices(struct pci_bus *busses) continue; struct pci_bus *parent = &busses[pci_bdf_to_bus(s->bus_dev->bdf)]; int type; + u8 shpc_cap = pci_find_capability(s->bus_dev, PCI_CAP_ID_SHPC); for (type = 0; type < PCI_REGION_TYPE_COUNT; type++) { u64 align = (type == PCI_REGION_TYPE_IO) ? PCI_BRIDGE_IO_MIN : PCI_BRIDGE_MEM_MIN; if (pci_region_align(&s->r[type]) > align) align = pci_region_align(&s->r[type]); u64 sum = pci_region_sum(&s->r[type]); + if (!sum && shpc_cap) + sum = align; /* reserve min size for hot-plug */ u64 size = ALIGN(sum, align); int is64 = pci_bios_bridge_region_is64(&s->r[type], s->bus_dev, type); diff --git a/src/hw/pci.c b/src/hw/pci.c index caf9265..055353d 100644 --- a/src/hw/pci.c +++ b/src/hw/pci.c @@ -225,6 +225,25 @@ pci_find_init_device(const struct pci_device_id *ids, void *arg) return NULL; } +u8 pci_find_capability(struct pci_device *pci, u8 cap_id) +{ + int i; + u8 cap; + u16 status = pci_config_readw(pci->bdf, PCI_STATUS); + + if (!(status & PCI_STATUS_CAP_LIST)) + return 0; + + for (i = 0, cap = pci_config_readb(pci->bdf, PCI_CAPABILITY_LIST); + (i <= 0xff) && cap; + i++, cap = pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_NEXT)) + if (pci_config_readb(pci->bdf, cap + PCI_CAP_LIST_ID) == cap_id) + return cap; + + return 0; +} + + void pci_reboot(void) { diff --git a/src/hw/pci.h b/src/hw/pci.h index 167a027..e828225 100644 --- a/src/hw/pci.h +++ b/src/hw/pci.h @@ -116,6 +116,7 @@ int pci_init_device(const struct pci_device_id *ids , struct pci_device *pci, void *arg); struct pci_device *pci_find_init_device(const struct pci_device_id *ids , void *arg); +u8 pci_find_capability(struct pci_device *pci, u8 cap_id); void pci_reboot(void); #endif
If a pci-2-pci bridge supports hot-plug functionality but there are no devices connected to it, reserve IO/mem in order to be able to attach devices later. Do not waste space, use minimum allowed. Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com> --- src/fw/pciinit.c | 3 +++ src/hw/pci.c | 19 +++++++++++++++++++ src/hw/pci.h | 1 + 3 files changed, 23 insertions(+)