PCI: check szhi when sz is 0 when 64 bit iomem bigger than 4G

For pci mem resource that size is bigger than 4G, the sz returned by
pc_size will be 0.
So that resource is skipped, and register contained hi address will be
treated as another 32bit resource. We need to use sz64 and pci_sz64 for
64 bit resource for clear logical.  Typical usages for this: Opteron
system with co-processor and the co-processor could take more than 4G
RAM as pre-fetchable mem resource.

Signed-off-by: Yinghai Lu <yinghai.lu@amd.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 0e0401d..9d77884 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -144,6 +144,32 @@ static u32 pci_size(u32 base, u32 maxbase, u32 mask)
        return size;
 }
 
+static u64 pci_size64(u64 base, u64 maxbase, u64 mask)
+{
+       u64 size = mask & maxbase;      /* Find the significant bits */
+       if (!size)
+               return 0;
+
+       /* Get the lowest of them to find the decode size, and
+          from that the extent.  */
+       size = (size & ~(size-1)) - 1;
+
+       /* base == maxbase can be valid only if the BAR has
+          already been programmed with all 1s.  */
+       if (base == maxbase && ((base | size) & mask) != mask)
+               return 0;
+
+       return size;
+}
+
+static inline int is_64bit_memory(u32 mask)
+{
+       if ((mask & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
+           (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64))
+               return 1;
+       return 0;
+}
+
 static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
 {
        unsigned int pos, reg, next;
@@ -151,6 +177,10 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
        struct resource *res;
 
        for(pos=0; pos<howmany; pos = next) {
+               u64 l64;
+               u64 sz64;
+               u32 raw_sz;
+
                next = pos+1;
                res = &dev->resource[pos];
                res->name = pci_name(dev);
@@ -163,9 +193,16 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
                        continue;
                if (l == 0xffffffff)
                        l = 0;
-               if ((l & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_MEMORY) {
+               raw_sz = sz;
+               if ((l & PCI_BASE_ADDRESS_SPACE) ==
+                               PCI_BASE_ADDRESS_SPACE_MEMORY) {
                        sz = pci_size(l, sz, (u32)PCI_BASE_ADDRESS_MEM_MASK);
-                       if (!sz)
+                       /*
+                        * For 64bit prefetchable memory sz could be 0, if the
+                        * real size is bigger than 4G, so we need to check
+                        * szhi for that.
+                        */
+                       if (!is_64bit_memory(l) && !sz)
                                continue;
                        res->start = l & PCI_BASE_ADDRESS_MEM_MASK;
                        res->flags |= l & ~PCI_BASE_ADDRESS_MEM_MASK;
@@ -178,30 +215,36 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
                }
                res->end = res->start + (unsigned long) sz;
                res->flags |= pci_calc_resource_flags(l);
-               if ((l & (PCI_BASE_ADDRESS_SPACE | PCI_BASE_ADDRESS_MEM_TYPE_MASK))
-                   == (PCI_BASE_ADDRESS_SPACE_MEMORY | PCI_BASE_ADDRESS_MEM_TYPE_64)) {
+               if (is_64bit_memory(l)) {
                        u32 szhi, lhi;
+
                        pci_read_config_dword(dev, reg+4, &lhi);
                        pci_write_config_dword(dev, reg+4, ~0);
                        pci_read_config_dword(dev, reg+4, &szhi);
                        pci_write_config_dword(dev, reg+4, lhi);
-                       szhi = pci_size(lhi, szhi, 0xffffffff);
+                       sz64 = ((u64)szhi << 32) | raw_sz;
+                       l64 = ((u64)lhi << 32) | l;
+                       sz64 = pci_size64(l64, sz64, PCI_BASE_ADDRESS_MEM_MASK);
                        next++;
 #if BITS_PER_LONG == 64
-                       res->start |= ((unsigned long) lhi) << 32;
-                       res->end = res->start + sz;
-                       if (szhi) {
-                               /* This BAR needs > 4GB?  Wow. */
-                               res->end |= (unsigned long)szhi<<32;
+                       if (!sz64) {
+                               res->start = 0;
+                               res->end = 0;
+                               res->flags = 0;
+                               continue;
                        }
+                       res->start = l64 & PCI_BASE_ADDRESS_MEM_MASK;
+                       res->end = res->start + sz64;
 #else
-                       if (szhi) {
-                               printk(KERN_ERR "PCI: Unable to handle 64-bit BAR for device %s\n", pci_name(dev));
+                       if (sz64 > 0x100000000ULL) {
+                               printk(KERN_ERR "PCI: Unable to handle 64-bit "
+                                       "BAR for device %s\n", pci_name(dev));
                                res->start = 0;
                                res->flags = 0;
                        } else if (lhi) {
                                /* 64-bit wide address, treat as disabled */
-                               pci_write_config_dword(dev, reg, l & ~(u32)PCI_BASE_ADDRESS_MEM_MASK);
+                               pci_write_config_dword(dev, reg,
+                                       l & ~(u32)PCI_BASE_ADDRESS_MEM_MASK);
                                pci_write_config_dword(dev, reg+4, 0);
                                res->start = 0;
                                res->end = sz;