[Xen-devel] [PATCH v6 06/11] pci: add support to size ROM BARs to pci_size_mem_bar

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Cc: Jan Beulich <jbeulich@xxxxxxxx>
---
Changes since v5:
 - Use the flags field.
 - Introduce a mask local variable.
 - Simplify return.

Changes since v4:
 - New in this version.
---
 xen/drivers/passthrough/pci.c | 29 +++++++++++++++--------------
 xen/include/xen/pci.h         |  2 ++
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index ba58b4d0cc..92c1f9354a 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -610,11 +610,17 @@ int pci_size_mem_bar(pci_sbdf_t sbdf, unsigned int pos, 
bool last,
                                            sbdf.func, pos);
     uint64_t addr, size;
     bool vf = flags & PCI_BAR_VF;
-
-    ASSERT((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_MEMORY);
+    bool rom = flags & PCI_BAR_ROM;
+    bool is64bits = !rom && (bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
+                    PCI_BASE_ADDRESS_MEM_TYPE_64;
+    uint32_t mask = rom ? (uint32_t)PCI_ROM_ADDRESS_MASK
+                        : (uint32_t)PCI_BASE_ADDRESS_MEM_MASK;
+
+    ASSERT(!(rom && vf));
+    ASSERT(rom ||
+           (bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_MEMORY);
     pci_conf_write32(sbdf.seg, sbdf.bus, sbdf.dev, sbdf.func, pos, ~0);
-    if ( (bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
-         PCI_BASE_ADDRESS_MEM_TYPE_64 )
+    if ( is64bits )
     {
         if ( last )
         {
@@ -627,10 +633,9 @@ int pci_size_mem_bar(pci_sbdf_t sbdf, unsigned int pos, 
bool last,
         hi = pci_conf_read32(sbdf.seg, sbdf.bus, sbdf.dev, sbdf.func, pos + 4);
         pci_conf_write32(sbdf.seg, sbdf.bus, sbdf.dev, sbdf.func, pos + 4, ~0);
     }
-    size = pci_conf_read32(sbdf.seg, sbdf.bus, sbdf.dev, sbdf.func, pos) &
-           PCI_BASE_ADDRESS_MEM_MASK;
-    if ( (bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
-         PCI_BASE_ADDRESS_MEM_TYPE_64 )
+    size = pci_conf_read32(sbdf.seg, sbdf.bus, sbdf.dev, sbdf.func,
+                           pos) & mask;
+    if ( is64bits )
     {
         size |= (uint64_t)pci_conf_read32(sbdf.seg, sbdf.bus, sbdf.dev,
                                           sbdf.func, pos + 4) << 32;
@@ -640,17 +645,13 @@ int pci_size_mem_bar(pci_sbdf_t sbdf, unsigned int pos, 
bool last,
         size |= (uint64_t)~0 << 32;
     pci_conf_write32(sbdf.seg, sbdf.bus, sbdf.dev, sbdf.func, pos, bar);
     size = -size;
-    addr = (bar & PCI_BASE_ADDRESS_MEM_MASK) | ((uint64_t)hi << 32);
+    addr = (bar & mask) | ((uint64_t)hi << 32);
 
     if ( paddr )
         *paddr = addr;
     *psize = size;
 
-    if ( (bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
-         PCI_BASE_ADDRESS_MEM_TYPE_64 )
-        return 2;
-
-    return 1;
+    return is64bits ? 2 : 1;
 }
 
 int pci_add_device(u16 seg, u8 bus, u8 devfn,
diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h
index 2bee6a3247..4489edf9b5 100644
--- a/xen/include/xen/pci.h
+++ b/xen/include/xen/pci.h
@@ -191,6 +191,8 @@ const char *parse_pci_seg(const char *, unsigned int *seg, 
unsigned int *bus,
 
 #define _PCI_BAR_VF     0
 #define PCI_BAR_VF      (1u << _PCI_BAR_VF)
+#define _PCI_BAR_ROM    1
+#define PCI_BAR_ROM     (1u << _PCI_BAR_ROM)
 int pci_size_mem_bar(pci_sbdf_t sbdf, unsigned int pos, bool last,
                      uint64_t *addr, uint64_t *size, unsigned int flags);
 
-- 
2.11.0 (Apple Git-81)


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