On Thu, 2010-01-14 at 14:45 -0800, Yinghai Lu wrote: > On 01/14/2010 02:23 PM, Myron Stowe wrote: > > Subject: [PATCH -v2] PCI: Exclude VTBAR range from Local MMIOL if necessary > To: jbarnes@xxxxxxxxxxxxxxxx > From: Myron Stowe <myron.stowe@xxxxxx> > Cc: linux-pci@xxxxxxxxxxxxxxx, yinghai@xxxxxxxxxx > > Intel's x58 chipset (IOH) includes a VTBAR (Base Address Register for > Intel VT-d Chipset Registers) that specifies an 8K aligned system memory > address for VT-d memory mapped registers. If BIOS has placed the VT-d > register window within the Local MMIOL range, it will not be available > for downstream PCI devices, so remove it from the host bridge's MMIOL > range. > > This patch determines if the VTBAR is enabled and modifies the IOH's > Local MMIOL range if it is programmed within such. > > > Reference: "Intel X58 Express Chipset Datasheet" > http://www.intel.com/Assets/PDF/datasheet/320838.pdf > > -v2: yinghai update it with more complete range comparing > and change 0x120 to 0x200 again > -v3: yinghai update it with add/subtract_range > > --- > > arch/x86/pci/intel_bus.c | 29 +++++++++++++++++++++++++++-- > 1 file changed, 27 insertions(+), 2 deletions(-) > > Index: linux-2.6/arch/x86/pci/intel_bus.c > =================================================================== > --- linux-2.6.orig/arch/x86/pci/intel_bus.c > +++ linux-2.6/arch/x86/pci/intel_bus.c > @@ -41,6 +41,11 @@ static inline void print_ioh_resources(s > #define IOH_LMMIOH_LIMITU 0x118 > #define IOH_LCFGBUS 0x11c > > +#define IOH_VTBAR 0x180 > +#define IOH_VTSIZE 0x2000 /* Fixed HW size (not programmable) */ > + > +#define RANGE_NUM 16 > + > static void __devinit pci_root_bus_res(struct pci_dev *dev) > { > u16 word; > @@ -50,9 +55,11 @@ static void __devinit pci_root_bus_res(s > u32 mmiol_base, mmiol_end; > u64 mmioh_base, mmioh_end; > int bus_base, bus_end; > + struct range range[RANGE_NUM]; > + int i; > > /* some sys doesn't get mmconf enabled */ > - if (dev->cfg_size < 0x120) > + if (dev->cfg_size < 0x200) > return; > > if (pci_root_num >= PCI_ROOT_NR) { > @@ -78,7 +85,25 @@ static void __devinit pci_root_bus_res(s > pci_read_config_dword(dev, IOH_LMMIOL, &dword); > mmiol_base = (dword & 0xff00) << (24 - 8); > mmiol_end = (dword & 0xff000000) | 0xffffff; > - update_res(info, mmiol_base, mmiol_end, IORESOURCE_MEM, 0); > + memset(range, 0, sizeof(range)); > + add_range(range, RANGE_NUM, 0, mmiol_base, (u64)mmiol_end + 1); > + pci_read_config_dword(dev, IOH_VTBAR, &dword); > + if (dword & 0x1) { > + u32 vt_base, vt_end; > + > + vt_base = dword & 0xfffffffe; > + vt_end = vt_base + IOH_VTSIZE - 1; > + > + subtract_range(range, RANGE_NUM, vt_base, vt_end + 1); > + } > + for (i = 0; i < RANGE_NUM; i++) { > + if (!range[i].end) > + continue; > + > + update_res(info, cap_resource(range[i].start), > + cap_resource(range[i].end - 1), > + IORESOURCE_MEM, 0); > + } > > pci_read_config_dword(dev, IOH_LMMIOH, &dword); > mmioh_base = ((u64)(dword & 0xfc00)) << (26 - 10); > You originally asked if I could create a 'vt_base' and a 'vt_end', is that all your stuck on? I find it a little interesting that your latest alternate suggestion creates 'vt_base' and 'vt_end' with no real purpose. If you have discovered a real hole/issue in the original patch then please let me know about such. I do think your usage of 'add_range()' and 'subtract_range()' may lead to a better long term solution. They effectively do the exact same thing as the patch content I added, albeit by separating out the range manipulation into a separate routine which will be better in the long term (so that others can leverage - much the same way you are trying to leverage the mtrr specific routines). I do have to ask however - what tree are you using? I noticed that 'add_range()' and 'subtract_range()' are static routines related to mtrr code. I rebased my git tree to tip and applied your latest patch and got: arch/x86/pci/intel_bus.c: In function ‘pci_root_bus_res’: arch/x86/pci/intel_bus.c:56: error: array type has incomplete element type arch/x86/pci/intel_bus.c:87: error: implicit declaration of function ‘add_range’ arch/x86/pci/intel_bus.c:95: error: implicit declaration of function ‘subtract_range’ arch/x86/pci/intel_bus.c:101: error: implicit declaration of function ‘cap_resource’ arch/x86/pci/intel_bus.c:56: warning: unused variable ‘range’ make[1]: *** [arch/x86/pci/intel_bus.o] Error 1 make: *** [arch/x86/pci] Error 2 Myron -- Myron Stowe HP Open Source Linux Lab (OSLL) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
