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[pci] Add ability to resize a VPD field
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Signed-off-by: Michael Brown <mcb30@ipxe.org>
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@mcb30
mcb30 committed Jan 19, 2011
1 parent 267ef31 commit e67c79b
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Showing 2 changed files with 166 additions and 0 deletions.
161 changes: 161 additions & 0 deletions src/drivers/bus/pcivpd.c
View file
Expand Up @@ -19,6 +19,7 @@
FILE_LICENCE ( GPL2_OR_LATER );

#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <byteswap.h>
Expand Down Expand Up @@ -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;
}
5 changes: 5 additions & 0 deletions src/include/ipxe/pcivpd.h
View file
Expand Up @@ -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
Expand Down Expand Up @@ -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 */

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