On 05/02/2016 04:11 PM, Ladi Prosek wrote:
This commit adds two new functions. pci_enable_device gives drivers finer control over how the PCI device is initialized and pci_restore_device is the shutdown path counterpart.adjust_pci_device is now implemented in terms of pci_enable_device and its functionality hasn't changed, i.e. it still unconditionally enables both memory and I/O space access, and makes sure that the PCI latency timer is set to a minimum value of 32. Signed-off-by: Ladi Prosek <lpro...@redhat.com> Suggested-by: Michael S. Tsirkin <m...@redhat.com> --- src/drivers/bus/pci.c | 58 +++++++++++++++++++++++++++++++++++++++++--------- src/include/ipxe/pci.h | 3 +++ 2 files changed, 51 insertions(+), 10 deletions(-) diff --git a/src/drivers/bus/pci.c b/src/drivers/bus/pci.c index 6fbedd9..6ccbaf5 100644 --- a/src/drivers/bus/pci.c +++ b/src/drivers/bus/pci.c @@ -143,29 +143,67 @@ static void pci_read_bases ( struct pci_device *pci ) { * * @v pci PCI device * - * Set device to be a busmaster in case BIOS neglected to do so. Also - * adjust PCI latency timer to a reasonable value, 32. + * Set device to be a bus master in case BIOS neglected to do so. Enable + * both memory and I/O space access. Also adjust PCI latency timer to a + * reasonable value, 32. */ void adjust_pci_device ( struct pci_device *pci ) { + pci_enable_device ( pci, + PCI_COMMAND_MASTER | PCI_COMMAND_MEM | + PCI_COMMAND_IO, + 32 ); +} + +/** + * Enable PCI device + * + * @v pci PCI device + * @v flags PCI command flags to enable + * @v latency Minimum desired PCI latency timer or 0 to not adjust it + * @ret old_flags Original PCI command flags + * + * Enable device by setting bits in the command register in case BIOS neglected + * to do so. Also optionally adjust the PCI latency timer. + */ +unsigned pci_enable_device ( struct pci_device *pci, unsigned flags, + unsigned char latency ) { unsigned short new_command, pci_command; unsigned char pci_latency; pci_read_config_word ( pci, PCI_COMMAND, &pci_command ); - new_command = ( pci_command | PCI_COMMAND_MASTER | - PCI_COMMAND_MEM | PCI_COMMAND_IO ); + new_command = ( pci_command | flags ); if ( pci_command != new_command ) { - DBGC ( pci, PCI_FMT " device not enabled by BIOS! Updating " + DBGC ( pci, PCI_FMT " device not fully enabled by BIOS! Updating " "PCI command %04x->%04x\n", PCI_ARGS ( pci ), pci_command, new_command ); pci_write_config_word ( pci, PCI_COMMAND, new_command ); } - pci_read_config_byte ( pci, PCI_LATENCY_TIMER, &pci_latency); - if ( pci_latency < 32 ) { - DBGC ( pci, PCI_FMT " latency timer is unreasonably low at " - "%d. Setting to 32.\n", PCI_ARGS ( pci ), pci_latency ); - pci_write_config_byte ( pci, PCI_LATENCY_TIMER, 32); + if ( latency ) { + pci_read_config_byte ( pci, PCI_LATENCY_TIMER, &pci_latency ); + if ( pci_latency < latency ) { + DBGC ( pci, PCI_FMT " latency timer is unreasonably low at " + "%d. Setting to %d.\n", PCI_ARGS ( pci ), + pci_latency, latency ); + pci_write_config_byte ( pci, PCI_LATENCY_TIMER, latency ); + } } + return pci_command; +} + +/** + * Restore PCI device + * + * @v pci PCI device + * @v old_flags Flags to restore, returned from pci_enable_device + * + * Restore the command register of a PCI device to state it had before we + * changed it. + */ +void pci_restore_device ( struct pci_device *pci, unsigned old_flags ) { + DBGC ( pci, PCI_FMT " restoring PCI command to %04x\n", + PCI_ARGS ( pci ), old_flags ); + pci_write_config_word ( pci, PCI_COMMAND, old_flags ); } /** diff --git a/src/include/ipxe/pci.h b/src/include/ipxe/pci.h index 0c6bc7e..ced6128 100644 --- a/src/include/ipxe/pci.h +++ b/src/include/ipxe/pci.h @@ -278,6 +278,9 @@ struct pci_driver { PCI_FUNC ( (pci)->busdevfn ) extern void adjust_pci_device ( struct pci_device *pci ); +extern unsigned pci_enable_device ( struct pci_device *pci, unsigned flags, + unsigned char latency ); +extern void pci_restore_device ( struct pci_device *pci, unsigned old_flags ); extern unsigned long pci_bar_start ( struct pci_device *pci, unsigned int reg ); extern int pci_read_config ( struct pci_device *pci );
Looks good to me. Reviewed-by: Marcel Apfelbaum <mar...@redhat.com> Thanks, Marcel _______________________________________________ ipxe-devel mailing list ipxe-devel@lists.ipxe.org https://lists.ipxe.org/mailman/listinfo.cgi/ipxe-devel
