[PATCH v5 9/9] vpci: don't pass command value to modify_bars()

[Stewart Hildebrand <stewart.hildebrand@xxxxxxx>]

Now that writing the command register is no longer deferred, there's no
need to pass the cmd value to modify_bars(). Replace it with a bool to
indicate map/unmap.

Signed-off-by: Stewart Hildebrand <stewart.hildebrand@xxxxxxx>
---
v4->v5:
* adapted from: ("vpci: allow BAR map/unmap without affecting memory
  decoding bit")
* significant rework

v3->v4:
* rebase on dynamically allocated map queue

v2->v3:
* use bool
* switch to task->map in more places

v1->v2:
* new patch
---
 xen/drivers/vpci/header.c | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
index 99ce67053068..187de3a12abb 100644
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -324,7 +324,7 @@ static void defer_map(struct map_task *task)
     raise_softirq(SCHEDULE_SOFTIRQ);
 }
 
-static int modify_bars(const struct pci_dev *pdev, uint16_t cmd, bool rom_only)
+static int modify_bars(const struct pci_dev *pdev, bool map, bool rom_only)
 {
     struct vpci_header *header = &pdev->vpci->header;
     struct pci_dev *tmp;
@@ -337,7 +337,7 @@ static int modify_bars(const struct pci_dev *pdev, uint16_t 
cmd, bool rom_only)
 
     ASSERT(rw_is_write_locked(&pdev->domain->pci_lock));
 
-    task = alloc_map_task(pdev, cmd & PCI_COMMAND_MEMORY, rom_only);
+    task = alloc_map_task(pdev, map, rom_only);
     if ( !task )
         return -ENOMEM;
 
@@ -369,7 +369,7 @@ static int modify_bars(const struct pci_dev *pdev, uint16_t 
cmd, bool rom_only)
              (rom_only ? bar->type != VPCI_BAR_ROM
                        : (bar->type == VPCI_BAR_ROM && !header->rom_enabled)) 
||
              /* Skip BARs already in the requested state. */
-             bar->enabled == !!(cmd & PCI_COMMAND_MEMORY) )
+             bar->enabled == map )
             continue;
 
         if ( !pci_check_bar(pdev, _mfn(start), _mfn(end)) )
@@ -409,8 +409,7 @@ static int modify_bars(const struct pci_dev *pdev, uint16_t 
cmd, bool rom_only)
             goto fail;
         }
 
-        rc = xsm_iomem_mapping_vpci(XSM_HOOK, pdev->domain, start, end,
-                                    !!(cmd & PCI_COMMAND_MEMORY));
+        rc = xsm_iomem_mapping_vpci(XSM_HOOK, pdev->domain, start, end, map);
         if ( rc )
         {
             printk(XENLOG_G_WARNING
@@ -555,7 +554,7 @@ static int modify_bars(const struct pci_dev *pdev, uint16_t 
cmd, bool rom_only)
     for ( i = 0; i < ARRAY_SIZE(header->bars); i++ )
     {
         if ( bar_valid[i] )
-            header->bars[i].enabled = cmd & PCI_COMMAND_MEMORY;
+            header->bars[i].enabled = map;
     }
 
     if ( system_state < SYS_STATE_active )
@@ -568,7 +567,7 @@ static int modify_bars(const struct pci_dev *pdev, uint16_t 
cmd, bool rom_only)
          * be called iff the memory decoding bit is enabled, thus the operation
          * will always be to establish mappings and process all the BARs.
          */
-        ASSERT((cmd & PCI_COMMAND_MEMORY) && !rom_only);
+        ASSERT(map && !rom_only);
         rc = apply_map(task);
         destroy_map_task(task);
         return rc;
@@ -607,7 +606,7 @@ static void cf_check cmd_write(
      * handled above and by the rsvdp_mask.
      */
     if ( header->bars_mapped != new_enabled &&
-         modify_bars(pdev, cmd, false) )
+         modify_bars(pdev, new_enabled, false) )
         /*
          * Ignore the error. No memory has been added or removed from the p2m
          * (because the actual p2m changes are deferred in defer_map) and the
@@ -784,12 +783,8 @@ static void cf_check rom_write(
         rom->guest_addr = rom->addr;
     }
 
-    /*
-     * Pass PCI_COMMAND_MEMORY or 0 to signal a map/unmap request, note that
-     * this fabricated command is never going to be written to the register.
-     */
     if ( header->bars_mapped && rom->enabled != new_enabled &&
-         modify_bars(pdev, new_enabled ? PCI_COMMAND_MEMORY : 0, true) )
+         modify_bars(pdev, new_enabled, true) )
         /*
          * No memory has been added or removed from the p2m (because the actual
          * p2m changes are deferred in defer_map) and the ROM enable bit has
@@ -988,7 +983,7 @@ int vpci_init_header(struct pci_dev *pdev)
         pci_conf_write16(pdev->sbdf, PCI_COMMAND, cmd);
     }
 
-    return (cmd & PCI_COMMAND_MEMORY) ? modify_bars(pdev, cmd, false) : 0;
+    return (cmd & PCI_COMMAND_MEMORY) ? modify_bars(pdev, true, false) : 0;
 
  fail:
     pci_conf_write16(pdev->sbdf, PCI_COMMAND, cmd);
-- 
2.54.0