[pci] Add ability to resize a VPD field

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

diff --git a/src/drivers/bus/pcivpd.c b/src/drivers/bus/pcivpd.c
index 1ee6c6415aee7e24d5506d4a884c0e6562915060..15cf905985b2d857661e50c9454c4c9621aebf0c 100644 (file)
--- a/src/drivers/bus/pcivpd.c
+++ b/src/drivers/bus/pcivpd.c
@@ -19,6 +19,7 @@
 FILE_LICENCE ( GPL2_OR_LATER );
 
 #include <stdint.h>
+#include <stdlib.h>
 #include <unistd.h>
 #include <errno.h>
 #include <byteswap.h>
@@ -392,3 +393,163 @@ int pci_vpd_find ( struct pci_vpd *vpd, unsigned int field,
               PCI_ARGS ( vpd->pci ), PCI_VPD_FIELD_ARGS ( field ) );
        return -ENOENT;
 }
+
+/**
+ * Resize VPD field
+ *
+ * @v vpd              PCI VPD
+ * @v field            VPD field descriptor
+ * @v len              New length of field body
+ * @ret address                Address of field body
+ * @ret rc             Return status code
+ */
+int pci_vpd_resize ( struct pci_vpd *vpd, unsigned int field, size_t len,
+                    unsigned int *address ) {
+       struct pci_vpd_field rw_field;
+       struct pci_vpd_field old_field;
+       struct pci_vpd_field new_field;
+       unsigned int rw_address;
+       unsigned int old_address;
+       unsigned int copy_address;
+       unsigned int dst_address;
+       unsigned int dump_address;
+       size_t rw_len;
+       size_t old_len;
+       size_t available_len;
+       size_t copy_len;
+       size_t dump_len;
+       void *copy;
+       int rc;
+
+       /* Sanity checks */
+       assert ( PCI_VPD_TAG ( field ) == PCI_VPD_TAG_RW );
+       assert ( PCI_VPD_KEYWORD ( field ) != 0 );
+       assert ( field != PCI_VPD_FIELD_RW );
+
+       /* Locate 'RW' field */
+       if ( ( rc = pci_vpd_find ( vpd, PCI_VPD_FIELD_RW, &rw_address,
+                                  &rw_len ) ) != 0 )
+               goto err_no_rw;
+
+       /* Locate old field, if any */
+       if ( ( rc = pci_vpd_find ( vpd, field, &old_address,
+                                  &old_len ) ) == 0 ) {
+
+               /* Field already exists */
+               if ( old_address > rw_address ) {
+                       DBGC ( vpd, PCI_FMT " VPD field " PCI_VPD_FIELD_FMT
+                              " at [%04x,%04zx) is after field "
+                              PCI_VPD_FIELD_FMT " at [%04x,%04zx)\n",
+                              PCI_ARGS ( vpd->pci ),
+                              PCI_VPD_FIELD_ARGS ( field ),
+                              old_address, ( old_address + old_len ),
+                              PCI_VPD_FIELD_ARGS ( PCI_VPD_FIELD_RW ),
+                              rw_address, ( rw_address + rw_len ) );
+                       rc = -ENXIO;
+                       goto err_after_rw;
+               }
+               dst_address = ( old_address - sizeof ( old_field ) );
+               copy_address = ( old_address + old_len );
+               copy_len = ( rw_address - sizeof ( rw_field ) - copy_address );
+
+               /* Calculate available length */
+               available_len = ( rw_len + old_len );
+
+       } else {
+
+               /* Field does not yet exist */
+               dst_address = ( rw_address - sizeof ( rw_field ) );
+               copy_address = dst_address;
+               copy_len = 0;
+
+               /* Calculate available length */
+               available_len = ( ( rw_len > sizeof ( new_field ) ) ?
+                                 ( rw_len - sizeof ( new_field ) ) : 0 );
+       }
+
+       /* Dump region before changes */
+       dump_address = dst_address;
+       dump_len = ( rw_address + rw_len - dump_address );
+       DBGC ( vpd, PCI_FMT " VPD before resizing field " PCI_VPD_FIELD_FMT
+              " to %zd bytes:\n", PCI_ARGS ( vpd->pci ),
+              PCI_VPD_FIELD_ARGS ( field ), len );
+       pci_vpd_dump ( vpd, dump_address, dump_len );
+
+       /* Check available length */
+       if ( available_len > PCI_VPD_MAX_LEN )
+               available_len = PCI_VPD_MAX_LEN;
+       if ( len > available_len ) {
+               DBGC ( vpd, PCI_FMT " VPD no space for field "
+                      PCI_VPD_FIELD_FMT " (need %02zx, have %02zx)\n",
+                      PCI_ARGS ( vpd->pci ), PCI_VPD_FIELD_ARGS ( field ),
+                      len, available_len );
+               rc = -ENOSPC;
+               goto err_no_space;
+       }
+
+       /* Preserve intermediate fields, if any */
+       copy = malloc ( copy_len );
+       if ( ! copy ) {
+               rc = -ENOMEM;
+               goto err_copy_alloc;
+       }
+       if ( ( rc = pci_vpd_read ( vpd, copy_address, copy, copy_len ) ) != 0 )
+               goto err_copy_read;
+
+       /* Create new field, if applicable */
+       if ( len ) {
+               new_field.keyword = PCI_VPD_KEYWORD ( field );
+               new_field.len = len;
+               if ( ( rc = pci_vpd_write ( vpd, dst_address, &new_field,
+                                           sizeof ( new_field ) ) ) != 0 )
+                       goto err_new_write;
+               dst_address += sizeof ( new_field );
+               *address = dst_address;
+               DBGC ( vpd, PCI_FMT " VPD field " PCI_VPD_FIELD_FMT " is now "
+                      "at [%04x,%04x)\n", PCI_ARGS ( vpd->pci ),
+                      PCI_VPD_FIELD_ARGS ( field ), dst_address,
+                      ( dst_address + new_field.len ) );
+               dst_address += len;
+       } else {
+               DBGC ( vpd, PCI_FMT " VPD field " PCI_VPD_FIELD_FMT
+                      " no longer exists\n", PCI_ARGS ( vpd->pci ),
+                      PCI_VPD_FIELD_ARGS ( field ) );
+       }
+
+       /* Restore intermediate fields, if any */
+       if ( ( rc = pci_vpd_write ( vpd, dst_address, copy, copy_len ) ) != 0 )
+               goto err_copy_write;
+       dst_address += copy_len;
+
+       /* Create 'RW' field */
+       rw_field.keyword = PCI_VPD_KEYWORD ( PCI_VPD_FIELD_RW );
+       rw_field.len = ( rw_len +
+                        ( rw_address - sizeof ( rw_field ) ) - dst_address );
+       if ( ( rc = pci_vpd_write ( vpd, dst_address, &rw_field,
+                                   sizeof ( rw_field ) ) ) != 0 )
+               goto err_rw_write;
+       dst_address += sizeof ( rw_field );
+       DBGC ( vpd, PCI_FMT " VPD field " PCI_VPD_FIELD_FMT " is now "
+              "at [%04x,%04x)\n", PCI_ARGS ( vpd->pci ),
+              PCI_VPD_FIELD_ARGS ( PCI_VPD_FIELD_RW ), dst_address,
+              ( dst_address + rw_field.len ) );
+
+       /* Dump region after changes */
+       DBGC ( vpd, PCI_FMT " VPD after resizing field " PCI_VPD_FIELD_FMT
+              " to %zd bytes:\n", PCI_ARGS ( vpd->pci ),
+              PCI_VPD_FIELD_ARGS ( field ), len );
+       pci_vpd_dump ( vpd, dump_address, dump_len );
+
+       rc = 0;
+
+ err_rw_write:
+ err_new_write:
+ err_copy_write:
+ err_copy_read:
+       free ( copy );
+ err_copy_alloc:
+ err_no_space:
+ err_after_rw:
+ err_no_rw:
+       return rc;
+}

diff --git a/src/include/ipxe/pcivpd.h b/src/include/ipxe/pcivpd.h
index 469ec29f884cdbd59c0f5b977567b46cb1e0c866..0abf8a95668c1f86ba837b6dff6d5f35b46c9e7b 100644 (file)
--- a/src/include/ipxe/pcivpd.h
+++ b/src/include/ipxe/pcivpd.h
@@ -32,6 +32,9 @@ struct pci_vpd_field {
        uint8_t len;
 } __attribute__ (( packed ));
 
+/** Maximum PCI VPD field length */
+#define PCI_VPD_MAX_LEN 0xff
+
 /** Construct PCI VPD field descriptor
  *
  * @v tag              ISAPnP tag
@@ -172,5 +175,7 @@ extern int pci_vpd_write ( struct pci_vpd *vpd, unsigned int address,
                           const void *buf, size_t len );
 extern int pci_vpd_find ( struct pci_vpd *vpd, unsigned int field,
                          unsigned int *address, size_t *len );
+extern int pci_vpd_resize ( struct pci_vpd *vpd, unsigned int field,
+                           size_t len, unsigned int *address );
 
 #endif /* _IPXE_PCIVPD_H */