Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20180319' into staging

target-arm queue:
 * fsl-imx6: Fix incorrect Ethernet interrupt defines
 * dump: Update correct kdump phys_base field for AArch64
 * char: i.MX: Add support for "TX complete" interrupt
 * bcm2836/raspi: Fix various bugs resulting in panics trying
   to boot a Debian Linux kernel on raspi3

# gpg: Signature made Mon 19 Mar 2018 18:30:33 GMT
# gpg:                using RSA key 3C2525ED14360CDE
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>"
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>"
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>"
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20180319:
  hw/arm/raspi: Provide spin-loop code for AArch64 CPUs
  hw/arm/bcm2836: Hardcode correct CPU type
  hw/arm/bcm2836: Use correct affinity values for BCM2837
  hw/arm/bcm2836: Create proper bcm2837 device
  hw/arm/bcm2836: Rename bcm2836 type/struct to bcm283x
  hw/arm/bcm2386: Fix parent type of bcm2386
  hw/arm/boot: If booting a kernel in EL2, set SCR_EL3.HCE
  hw/arm/boot: assert that secure_boot and secure_board_setup are false for AArch64
  hw/arm/raspi: Don't do board-setup or secure-boot for raspi3
  char: i.MX: Add support for "TX complete" interrupt
  char: i.MX: Simplify imx_update()
  dump: Update correct kdump phys_base field for AArch64
  fsl-imx6: Swap Ethernet interrupt defines

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 27 insertions, 1 deletions

diff --git a/hw/net/imx_fec.c b/hw/net/imx_fec.c
index 9506f9b69f..6e297c5480 100644
--- a/hw/net/imx_fec.c
+++ b/hw/net/imx_fec.c
@@ -417,7 +417,33 @@ static void imx_enet_write_bd(IMXENETBufDesc *bd, dma_addr_t addr)
 
 static void imx_eth_update(IMXFECState *s)
 {
-    if (s->regs[ENET_EIR] & s->regs[ENET_EIMR] & ENET_INT_TS_TIMER) {
+    /*
+     * Previous versions of qemu had the ENET_INT_MAC and ENET_INT_TS_TIMER
+     * interrupts swapped. This worked with older versions of Linux (4.14
+     * and older) since Linux associated both interrupt lines with Ethernet
+     * MAC interrupts. Specifically,
+     * - Linux 4.15 and later have separate interrupt handlers for the MAC and
+     *   timer interrupts. Those versions of Linux fail with versions of QEMU
+     *   with swapped interrupt assignments.
+     * - In linux 4.14, both interrupt lines were registered with the Ethernet
+     *   MAC interrupt handler. As a result, all versions of qemu happen to
+     *   work, though that is accidental.
+     * - In Linux 4.9 and older, the timer interrupt was registered directly
+     *   with the Ethernet MAC interrupt handler. The MAC interrupt was
+     *   redirected to a GPIO interrupt to work around erratum ERR006687.
+     *   This was implemented using the SOC's IOMUX block. In qemu, this GPIO
+     *   interrupt never fired since IOMUX is currently not supported in qemu.
+     *   Linux instead received MAC interrupts on the timer interrupt.
+     *   As a result, qemu versions with the swapped interrupt assignment work,
+     *   albeit accidentally, but qemu versions with the correct interrupt
+     *   assignment fail.
+     *
+     * To ensure that all versions of Linux work, generate ENET_INT_MAC
+     * interrrupts on both interrupt lines. This should be changed if and when
+     * qemu supports IOMUX.
+     */
+    if (s->regs[ENET_EIR] & s->regs[ENET_EIMR] &
+        (ENET_INT_MAC | ENET_INT_TS_TIMER)) {
         qemu_set_irq(s->irq[1], 1);
     } else {
         qemu_set_irq(s->irq[1], 0);