1 files changed, 97 insertions, 0 deletions

diff --git a/src/drivers/bus/pci.c b/src/drivers/bus/pci.c
index 92b389641..30163300a 100644
--- a/src/drivers/bus/pci.c
+++ b/src/drivers/bus/pci.c
@@ -25,6 +25,7 @@
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+FILE_SECBOOT ( PERMITTED );
 
 #include <stdint.h>
 #include <stdlib.h>
@@ -105,6 +106,92 @@ unsigned long pci_bar_start ( struct pci_device *pci, unsigned int reg ) {
 }
 
 /**
+ * Set the start of a PCI BAR
+ *
+ * @v pci		PCI device
+ * @v reg		PCI register number
+ * @v start		BAR start address
+ */
+void pci_bar_set ( struct pci_device *pci, unsigned int reg,
+		   unsigned long start ) {
+	unsigned int type;
+	uint32_t low;
+	uint32_t high;
+	uint16_t cmd;
+
+	/* Save the original command register and disable decoding */
+	pci_read_config_word ( pci, PCI_COMMAND, &cmd );
+	pci_write_config_word ( pci, PCI_COMMAND,
+				( cmd & ~( PCI_COMMAND_MEM |
+					   PCI_COMMAND_IO ) ) );
+
+	/* Check for a 64-bit BAR */
+	pci_read_config_dword ( pci, reg, &low );
+	type = ( low & ( PCI_BASE_ADDRESS_SPACE_IO |
+			 PCI_BASE_ADDRESS_MEM_TYPE_MASK ) );
+
+	/* Write low 32 bits */
+	low = start;
+	pci_write_config_dword ( pci, reg, low );
+
+	/* Write high 32 bits, if applicable */
+	if ( type == PCI_BASE_ADDRESS_MEM_TYPE_64 ) {
+		if ( sizeof ( unsigned long ) > sizeof ( uint32_t ) ) {
+			high = ( ( ( uint64_t ) start ) >> 32 );
+		} else {
+			high = 0;
+		}
+		pci_write_config_dword ( pci, reg + 4, high );
+	}
+
+	/* Restore the original command register */
+	pci_write_config_word ( pci, PCI_COMMAND, cmd );
+}
+
+/**
+ * Get the size of a PCI BAR
+ *
+ * @v pci		PCI device
+ * @v reg		PCI register number
+ * @ret size		BAR size
+ *
+ * Most drivers should not need to call this function.  It is not
+ * necessary to map the whole PCI BAR, only the portion that will be
+ * used for register access.  Since register offsets are almost always
+ * fixed by hardware design, the length of the mapped portion will
+ * almost always be a compile-time constant.
+ */
+unsigned long pci_bar_size ( struct pci_device *pci, unsigned int reg ) {
+	unsigned long start;
+	unsigned long size;
+	uint16_t cmd;
+
+	/* Save the original command register and disable decoding */
+	pci_read_config_word ( pci, PCI_COMMAND, &cmd );
+	pci_write_config_word ( pci, PCI_COMMAND,
+				( cmd & ~( PCI_COMMAND_MEM |
+					   PCI_COMMAND_IO ) ) );
+
+	/* Save the original start address */
+	start = pci_bar_start ( pci, reg );
+
+	/* Set all possible bits */
+	pci_bar_set ( pci, reg, -1UL );
+
+	/* Determine size by finding lowest set bit */
+	size = pci_bar_start ( pci, reg );
+	size &= ( -size );
+
+	/* Restore the original start address */
+	pci_bar_set ( pci, reg, start );
+
+	/* Restore the original command register */
+	pci_write_config_word ( pci, PCI_COMMAND, cmd );
+
+	return size;
+}
+
+/**
  * Read membase and ioaddr for a PCI device
  *
  * @v pci		PCI device
@@ -374,6 +461,10 @@ static int pcibus_probe ( struct root_device *rootdev ) {
 		if ( ( rc = pci_find_next ( pci, &busdevfn ) ) != 0 )
 			break;
 
+		/* Skip automatic probing if prohibited */
+		if ( ! pci_can_probe ( pci ) )
+			continue;
+
 		/* Look for a driver */
 		if ( ( rc = pci_find_driver ( pci ) ) != 0 ) {
 			DBGC ( pci, PCI_FMT " (%04x:%04x class %06x) has no "
@@ -434,3 +525,9 @@ struct root_device pci_root_device __root_device = {
 	.dev = { .name = "PCI" },
 	.driver = &pci_root_driver,
 };
+
+/* Drag in objects via pcibus_probe() */
+REQUIRING_SYMBOL ( pcibus_probe );
+
+/* Drag in PCI configuration */
+REQUIRE_OBJECT ( config_pci );