[legacy] Allocate legacy driver .bss-like segments at probe time

Some legacy drivers use large static allocations for transmit and
receive buffers.  To avoid bloating the .bss segment, we currently
implement these as a single common symbol named "_shared_bss" (which
is permissible since only one legacy driver may be active at any one
time).

Switch to dynamic allocation of these .bss-like segments, to avoid the
requirement for using common symbols.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

2 files changed, 20 insertions, 29 deletions

diff --git a/src/include/compiler.h b/src/include/compiler.h
index ec03f6f96..f8e948829 100644
--- a/src/include/compiler.h
+++ b/src/include/compiler.h
@@ -623,28 +623,6 @@ char __debug_disable(OBJECT) = ( DBGLVL_MAX & ~DBGLVL_DFLT );
  */
 #define inline inline __attribute__ (( no_instrument_function ))
 
-/**
- * Shared data.
- *
- * To save space in the binary when multiple-driver images are
- * compiled, uninitialised data areas can be shared between drivers.
- * This will typically be used to share statically-allocated receive
- * and transmit buffers between drivers.
- *
- * Use as e.g.
- *
- * @code
- *
- *   struct {
- *	char	rx_buf[NUM_RX_BUF][RX_BUF_SIZE];
- *	char	tx_buf[TX_BUF_SIZE];
- *   } my_static_data __shared;
- *
- * @endcode
- *
- */
-#define __shared __asm__ ( "_shared_bss" ) __aligned
-
 #endif /* ASSEMBLY */
 /** @} */
 
diff --git a/src/include/nic.h b/src/include/nic.h
index 678e23075..779d1d394 100644
--- a/src/include/nic.h
+++ b/src/include/nic.h
@@ -57,8 +57,14 @@ struct nic {
 	unsigned int		mbps;
 	duplex_t		duplex;
 	void			*priv_data;	/* driver private data */
+	void			*fake_bss;
+	size_t			fake_bss_len;
 };
 
+#define NIC_FAKE_BSS_PTR( type ) ( ( type * ) legacy_nic.fake_bss )
+#define NIC_FAKE_BSS( type ) ( * NIC_FAKE_BSS_PTR ( type ) )
+extern struct {} no_fake_bss;
+
 struct nic_operations {
 	int ( *connect ) ( struct nic * );
 	int ( *poll ) ( struct nic *, int retrieve );
@@ -90,7 +96,8 @@ extern int legacy_probe ( void *hwdev,
 			  void ( * set_drvdata ) ( void *hwdev, void *priv ),
 			  struct device *dev,
 			  int ( * probe ) ( struct nic *nic, void *hwdev ),
-			  void ( * disable ) ( struct nic *nic, void *hwdev ));
+			  void ( * disable ) ( struct nic *nic, void *hwdev ),
+			  size_t fake_bss_len );
 void legacy_remove ( void *hwdev,
 		     void * ( * get_drvdata ) ( void *hwdev ),
 		     void ( * disable ) ( struct nic *nic, void *hwdev ) );
@@ -210,7 +217,8 @@ static inline void * legacy_isa_get_drvdata ( void *hwdev ) {
 }
 
 #undef DRIVER
-#define DRIVER(_name_text,_unused2,_unused3,_name,_probe,_disable)	  \
+#define DRIVER( _name_text, _unused2, _unused3, _name, _probe, _disable,  \
+		_fake_bss )						  \
 	static __attribute__ (( unused )) const char			  \
 	_name ## _text[] = _name_text;					  \
 	static inline int						  \
@@ -225,7 +233,8 @@ static inline void * legacy_isa_get_drvdata ( void *hwdev ) {
 	_name ## _pci_legacy_probe ( struct pci_device *pci ) {		  \
 		return legacy_probe ( pci, legacy_pci_set_drvdata,	  \
 				      &pci->dev, _name ## _probe,	  \
-				      _name ## _disable );		  \
+				      _name ## _disable,		  \
+				      sizeof ( _fake_bss ) );		  \
 	}								  \
 	static inline void						  \
 	_name ## _pci_legacy_remove ( struct pci_device *pci ) {	  \
@@ -237,7 +246,8 @@ static inline void * legacy_isa_get_drvdata ( void *hwdev ) {
 			 const struct isapnp_device_id *id __unused ) {	  \
 		return legacy_probe ( isapnp, legacy_isapnp_set_drvdata,  \
 				      &isapnp->dev, _name ## _probe,	  \
-				      _name ## _disable );		  \
+				      _name ## _disable,		  \
+				      sizeof ( _fake_bss ) );		  \
 	}								  \
 	static inline void						  \
 	_name ## _isapnp_legacy_remove ( struct isapnp_device *isapnp ) { \
@@ -249,7 +259,8 @@ static inline void * legacy_isa_get_drvdata ( void *hwdev ) {
 			     const struct eisa_device_id *id __unused ) { \
 		return legacy_probe ( eisa, legacy_eisa_set_drvdata,	  \
 				      &eisa->dev, _name ## _probe,	  \
-				      _name ## _disable );		  \
+				      _name ## _disable,		  \
+				      sizeof ( _fake_bss ) );		  \
 	}								  \
 	static inline void						  \
 	_name ## _eisa_legacy_remove ( struct eisa_device *eisa ) {	  \
@@ -261,7 +272,8 @@ static inline void * legacy_isa_get_drvdata ( void *hwdev ) {
 			      const struct mca_device_id *id __unused ) { \
 		return legacy_probe ( mca, legacy_mca_set_drvdata,	  \
 				      &mca->dev, _name ## _probe,	  \
-				      _name ## _disable );		  \
+				      _name ## _disable,		  \
+				      sizeof ( _fake_bss ) );		  \
 	}								  \
 	static inline void						  \
 	_name ## _mca_legacy_remove ( struct mca_device *mca ) {	  \
@@ -272,7 +284,8 @@ static inline void * legacy_isa_get_drvdata ( void *hwdev ) {
 	_name ## _isa_legacy_probe ( struct isa_device *isa ) {		  \
 		return legacy_probe ( isa, legacy_isa_set_drvdata,	  \
 				      &isa->dev, _name ## _probe,	  \
-				      _name ## _disable );		  \
+				      _name ## _disable,		  \
+				      sizeof ( _fake_bss ) );		  \
 	}								  \
 	static inline void						  \
 	_name ## _isa_legacy_remove ( struct isa_device *isa ) {	  \