[PATCH libpciaccess 1/2] Add map_legacy interface

[Adam Jackson]

This allows platforms to hand back mmaps of the low 1M (ISA) address
space on a per-domain basis.

Signed-off-by: Adam Jackson <ajax at redhat.com>
---
 include/pciaccess.h     |    8 ++++++++
 src/common_interface.c  |   43 +++++++++++++++++++++++++++++++++++++++++++
 src/pciaccess_private.h |    3 +++
 3 files changed, 54 insertions(+), 0 deletions(-)

diff --git a/include/pciaccess.h b/include/pciaccess.h
index 88515e2..b7795b9 100644
--- a/include/pciaccess.h
+++ b/include/pciaccess.h
@@ -526,4 +526,12 @@ void pci_io_write32(struct pci_io_handle *handle, uint32_t reg, uint32_t data);
 void pci_io_write16(struct pci_io_handle *handle, uint32_t reg, uint16_t data);
 void pci_io_write8(struct pci_io_handle *handle, uint32_t reg, uint8_t data);
 
+/*
+ * Legacy memory access
+ */
+
+int pci_device_map_legacy(struct pci_device *dev, pciaddr_t base,
+			  pciaddr_t size, int write_enable, void **addr);
+int pci_device_unmap_legacy(struct pci_device *dev, void *addr, pciaddr_t size);
+
 #endif /* PCIACCESS_H */
diff --git a/src/common_interface.c b/src/common_interface.c
index 4af772a..fe3c1af 100644
--- a/src/common_interface.c
+++ b/src/common_interface.c
@@ -32,6 +32,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <sys/mman.h>
 
 #include "pciaccess.h"
 #include "pciaccess_private.h"
@@ -654,3 +655,45 @@ pci_device_enable(struct pci_device *dev)
     if (pci_sys->methods->enable)
 	pci_sys->methods->enable(dev);
 }
+
+/**
+ * Map the legacy memory space for the PCI domain containing \c dev.
+ *
+ * \param dev          Device whose memory region is to be mapped.
+ * \param base         Base address of the range to be mapped.
+ * \param size         Size of the range to be mapped.
+ * \param write_enable Map for writing (non-zero).
+ * \param addr         Location to store the mapped address.
+ *
+ * \returns
+ * Zero on success or an \c errno value on failure.
+ */
+int
+pci_device_map_legacy(struct pci_device *dev, pciaddr_t base, pciaddr_t size,
+		      int write_enable, void **addr)
+{
+    if (base > 1048576 || base + size > 1048576)
+	return EINVAL;
+
+    if (!pci_sys->methods->map_legacy)
+	return ENOSYS;
+
+    return pci_sys->methods->map_legacy(dev, base, size, write_enable, addr);
+}
+
+/**
+ * Unmap the legacy memory space for the PCI domain containing \c dev.
+ *
+ * \param dev          Device whose memory region is to be unmapped.
+ * \param addr         Location of the mapped address.
+ * \param size         Size of the range to be unmapped.
+ *
+ * \returns
+ * Zero on success or an \c errno value on failure.
+ */
+int
+pci_device_unmap_legacy(struct pci_device *dev, void *addr, pciaddr_t size)
+{
+    /* Maybe vtable this?  Meh. */
+    return munmap(addr, size);
+}
diff --git a/src/pciaccess_private.h b/src/pciaccess_private.h
index 1111ef0..7870395 100644
--- a/src/pciaccess_private.h
+++ b/src/pciaccess_private.h
@@ -77,6 +77,9 @@ struct pci_system_methods {
     void (*write16)( struct pci_io_handle *handle, uint32_t reg,
 		     uint16_t data );
     void (*write8)( struct pci_io_handle *handle, uint32_t reg, uint8_t data );
+
+    int (*map_legacy)(struct pci_device *dev, pciaddr_t base, pciaddr_t size,
+		      int write_enable, void **addr);
 };
 
 struct pci_device_mapping {
-- 
1.7.5