efi_loader: correctly aligned transmit buffer

Calling net_send_packet() requires that the buffer is aligned to a multiple
of PKTALIGN (= ARCH_DMA_MINALIGN). The UEFI spec does not require
efi_net_transmit() to be called with a buffer with any special alignment.
So we have to copy to an aligned buffer. The current coding copies to an
aligned buffer only if CONFIG_EFI_LOADER_BOUNCE_BUFFER=y. Many boards
like the Odroid C2 do not use a bounce buffer.

With the patch we copy to a correctly aligned buffer in all cases.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

diff --git a/lib/efi_loader/efi_net.c b/lib/efi_loader/efi_net.c
index a64c603ed3e0d39e5039e129f8ab51d1720ec3b8..68ed9e9520c97494c2d08ddf685fdf871a2e974f 100644 (file)
--- a/lib/efi_loader/efi_net.c
+++ b/lib/efi_loader/efi_net.c
@@ -14,6 +14,8 @@ static const efi_guid_t efi_pxe_guid = EFI_PXE_GUID;
 static struct efi_pxe_packet *dhcp_ack;
 static bool new_rx_packet;
 static void *new_tx_packet;
+static void *transmit_buffer;
+
 /*
  * The notification function of this event is called in every timer cycle
  * to check if a new network packet has been received.
@@ -198,13 +200,11 @@ static efi_status_t EFIAPI efi_net_transmit(struct efi_simple_network *this,
                return EFI_EXIT(EFI_INVALID_PARAMETER);
        }
 
-#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
-       /* Ethernet packets always fit, just bounce */
-       memcpy(efi_bounce_buffer, buffer, buffer_size);
-       net_send_packet(efi_bounce_buffer, buffer_size);
-#else
-       net_send_packet(buffer, buffer_size);
-#endif
+       /* Ensure that the packet fits into the buffer */
+       if (buffer_size > PKTSIZE_ALIGN)
+               return EFI_EXIT(EFI_INVALID_PARAMETER);
+       memcpy(transmit_buffer, buffer, buffer_size);
+       net_send_packet(transmit_buffer, buffer_size);
 
        new_tx_packet = buffer;
 
@@ -325,10 +325,14 @@ efi_status_t efi_net_register(void)
 
        /* We only expose the "active" network device, so one is enough */
        netobj = calloc(1, sizeof(*netobj));
-       if (!netobj) {
-               printf("ERROR: Out of memory\n");
-               return EFI_OUT_OF_RESOURCES;
-       }
+       if (!netobj)
+               goto out_of_resources;
+
+       /* Allocate an aligned transmit buffer */
+       transmit_buffer = calloc(1, PKTSIZE_ALIGN + PKTALIGN);
+       if (!transmit_buffer)
+               goto out_of_resources;
+       transmit_buffer = (void *)ALIGN((uintptr_t)transmit_buffer, PKTALIGN);
 
        /* Hook net up to the device list */
        efi_add_handle(&netobj->header);
@@ -408,4 +412,9 @@ efi_status_t efi_net_register(void)
 failure_to_add_protocol:
        printf("ERROR: Failure to add protocol\n");
        return r;
+out_of_resources:
+       free(netobj);
+       /* free(transmit_buffer) not needed yet */
+       printf("ERROR: Out of memory\n");
+       return EFI_OUT_OF_RESOURCES;
 }