[Qemu-devel] [kvm-unit-tests PATCH v8 10/14] pci: provide pci_enable_defaults()

[Peter Xu]

One helper function to set/clear specific bit in PCI_COMMAND register is
introduced. Then, provide a function to do most of the common PCI init
work.

Suggested-by: Andrew Jones <address@hidden>
Reviewed-by: Andrew Jones <address@hidden>
Signed-off-by: Peter Xu <address@hidden>
---
 lib/pci.c | 19 +++++++++++++++++++
 lib/pci.h |  2 ++
 2 files changed, 21 insertions(+)

diff --git a/lib/pci.c b/lib/pci.c
index d4521be..bf2a3df 100644
--- a/lib/pci.c
+++ b/lib/pci.c
@@ -7,6 +7,18 @@
 #include "pci.h"
 #include "asm/pci.h"
 
+void pci_cmd_set_clr(struct pci_dev *dev, uint16_t set, uint16_t clr)
+{
+       uint16_t val = pci_config_readw(dev->bdf, PCI_COMMAND);
+
+       /* No overlap is allowed */
+       assert((set & clr) == 0);
+       val |= set;
+       val &= ~clr;
+
+       pci_config_writew(dev->bdf, PCI_COMMAND, val);
+}
+
 bool pci_dev_exists(pcidevaddr_t dev)
 {
        return (pci_config_readw(dev, PCI_VENDOR_ID) != 0xffff &&
@@ -242,3 +254,10 @@ void pci_scan_bars(struct pci_dev *dev)
                }
        }
 }
+
+void pci_enable_defaults(struct pci_dev *dev)
+{
+       pci_scan_bars(dev);
+       /* Enable device DMA operations */
+       pci_cmd_set_clr(dev, PCI_COMMAND_MASTER, 0);
+}
diff --git a/lib/pci.h b/lib/pci.h
index 8215c9d..d3052ef 100644
--- a/lib/pci.h
+++ b/lib/pci.h
@@ -25,6 +25,8 @@ struct pci_dev {
 
 extern void pci_dev_init(struct pci_dev *dev, pcidevaddr_t bdf);
 extern void pci_scan_bars(struct pci_dev *dev);
+extern void pci_cmd_set_clr(struct pci_dev *dev, uint16_t set, uint16_t clr);
+extern void pci_enable_defaults(struct pci_dev *dev);
 
 extern bool pci_probe(void);
 extern void pci_print(void);
-- 
2.7.4