[PATCHv5 03/13] qemu: add routines to manage PCI capabilities

Michael S. Tsirkin
2009-06-18T13:16:21Z

Add routines to manage PCI capability list. First user will be MSI-X.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
hw/pci.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
hw/pci.h | 18 +++++++++++++-
2 files changed, 96 insertions(+), 1 deletions(-)

diff --git a/hw/pci.c b/hw/pci.c
index d42fcd9..e3f80d0 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -160,6 +160,12 @@ int pci_device_load(PCIDevice *s, QEMUFile *f)
if (version_id >= 2)
for (i = 0; i < 4; i ++)
s->irq_state[i] = qemu_get_be32(f);
+ /* Clear wmask and used bits for capabilities.
+ Must be restored separately, since capabilities can
+ be placed anywhere in config space. */
+ memset(s->used, 0, PCI_CONFIG_SPACE_SIZE);
+ for (i = PCI_CONFIG_HEADER_SIZE; i < PCI_CONFIG_SPACE_SIZE; ++i)
+ s->wmask[i] = 0xff;
return 0;
}

@@ -867,3 +873,76 @@ PCIDevice *pci_create_simple(PCIBus *bus, int devfn, const char *name)

return (PCIDevice *)dev;
}
+
+static int pci_find_space(PCIDevice *pdev, uint8_t size)
+{
+ int offset = PCI_CONFIG_HEADER_SIZE;
+ int i;
+ for (i = PCI_CONFIG_HEADER_SIZE; i < PCI_CONFIG_SPACE_SIZE; ++i)
+ if (pdev->used[i])
+ offset = i + 1;
+ else if (i - offset + 1 == size)
+ return offset;
+ return 0;
+}
+
+static uint8_t pci_find_capability_list(PCIDevice *pdev, uint8_t cap_id,
+ uint8_t *prev_p)
+{
+ uint8_t next, prev;
+
+ if (!(pdev->config[PCI_STATUS] & PCI_STATUS_CAP_LIST))
+ return 0;
+
+ for (prev = PCI_CAPABILITY_LIST; (next = pdev->config[prev]);
+ prev = next + PCI_CAP_LIST_NEXT)
+ if (pdev->config[next + PCI_CAP_LIST_ID] == cap_id)
+ break;
+
+ if (prev_p)
+ *prev_p = prev;
+ return next;
+}
+
+/* Reserve space and add capability to the linked list in pci config space */
+int pci_add_capability(PCIDevice *pdev, uint8_t cap_id, uint8_t size)
+{
+ uint8_t offset = pci_find_space(pdev, size);
+ uint8_t *config = pdev->config + offset;
+ if (!offset)
+ return -ENOSPC;
+ config[PCI_CAP_LIST_ID] = cap_id;
+ config[PCI_CAP_LIST_NEXT] = pdev->config[PCI_CAPABILITY_LIST];
+ pdev->config[PCI_CAPABILITY_LIST] = offset;
+ pdev->config[PCI_STATUS] |= PCI_STATUS_CAP_LIST;
+ memset(pdev->used + offset, 0xFF, size);
+ /* Make capability read-only by default */
+ memset(pdev->wmask + offset, 0, size);
+ return offset;
+}
+
+/* Unlink capability from the pci config space. */
+void pci_del_capability(PCIDevice *pdev, uint8_t cap_id, uint8_t size)
+{
+ uint8_t prev, offset = pci_find_capability_list(pdev, cap_id, &prev);
+ if (!offset)
+ return;
+ pdev->config[prev] = pdev->config[offset + PCI_CAP_LIST_NEXT];
+ /* Make capability writeable again */
+ memset(pdev->wmask + offset, 0xff, size);
+ memset(pdev->used + offset, 0, size);
+
+ if (!pdev->config[PCI_CAPABILITY_LIST])
+ pdev->config[PCI_STATUS] &= ~PCI_STATUS_CAP_LIST;
+}
+
+/* Reserve space for capability at a known offset (to call after load). */
+void pci_reserve_capability(PCIDevice *pdev, uint8_t offset, uint8_t size)
+{
+ memset(pdev->used + offset, 0xff, size);
+}
+
+uint8_t pci_find_capability(PCIDevice *pdev, uint8_t cap_id)
+{
+ return pci_find_capability_list(pdev, cap_id, NULL);
+}
diff --git a/hw/pci.h b/hw/pci.h
index 1226846..4f90fdc 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -121,6 +121,10 @@ typedef struct PCIIORegion {
#define PCI_MIN_GNT 0x3e /* 8 bits */
#define PCI_MAX_LAT 0x3f /* 8 bits */

+/* Capability lists */
+#define PCI_CAP_LIST_ID 0 /* Capability ID */
+#define PCI_CAP_LIST_NEXT 1 /* Next capability in the list */
+
#define PCI_REVISION 0x08 /* obsolete, use PCI_REVISION_ID */
#define PCI_SUBVENDOR_ID 0x2c /* obsolete, use PCI_SUBSYSTEM_VENDOR_ID */
#define PCI_SUBDEVICE_ID 0x2e /* obsolete, use PCI_SUBSYSTEM_ID */
@@ -128,7 +132,7 @@ typedef struct PCIIORegion {
/* Bits in the PCI Status Register (PCI 2.3 spec) */
#define PCI_STATUS_RESERVED1 0x007
#define PCI_STATUS_INT_STATUS 0x008
-#define PCI_STATUS_CAPABILITIES 0x010
+#define PCI_STATUS_CAP_LIST 0x010
#define PCI_STATUS_66MHZ 0x020
#define PCI_STATUS_RESERVED2 0x040
#define PCI_STATUS_FAST_BACK 0x080
@@ -158,6 +162,9 @@ struct PCIDevice {
/* Used to implement R/W bytes */
uint8_t wmask[PCI_CONFIG_SPACE_SIZE];

+ /* Used to allocate config space for capabilities. */
+ uint8_t used[PCI_CONFIG_SPACE_SIZE];
+
/* the following fields are read only */
PCIBus *bus;
int devfn;
@@ -190,6 +197,15 @@ void pci_register_bar(PCIDevice *pci_dev, int region_num,
uint32_t size, int type,
PCIMapIORegionFunc *map_func);

+int pci_add_capability(PCIDevice *pci_dev, uint8_t cap_id, uint8_t cap_size);
+
+void pci_del_capability(PCIDevice *pci_dev, uint8_t cap_id, uint8_t cap_size);
+
+void pci_reserve_capability(PCIDevice *pci_dev, uint8_t offset, uint8_t size);
+
+uint8_t pci_find_capability(PCIDevice *pci_dev, uint8_t cap_id);
+
+
uint32_t pci_default_read_config(PCIDevice *d,
uint32_t address, int len);
void pci_default_write_config(PCIDevice *d,
--
1.6.2.2