Adding upstream version 2.8.0+dfsg.upstream/2.8.0+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/plat/marvell/armada/a3k/common/a3700_ea.c b/plat/marvell/armada/a3k/common/a3700_ea.c
new file mode 100644
index 0000000..5696b5c
--- /dev/null
+++ b/plat/marvell/armada/a3k/common/a3700_ea.c
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2019 Repk repk@triplefau.lt
+ *
+ * SPDX-License-Identifier:	BSD-3-Clause
+ * https://spdx.org/licenses
+ */
+
+#include <inttypes.h>
+#include <stdint.h>
+
+#include <common/bl_common.h>
+#include <common/debug.h>
+#include <arch_helpers.h>
+#include <plat/common/platform.h>
+#include <bl31/ea_handle.h>
+
+#define A53_SERR_INT_AXI_SLVERR_ON_EXTERNAL_ACCESS 0xbf000002
+
+/*
+ * This source file with custom plat_ea_handler function is compiled only when
+ * building TF-A with compile option HANDLE_EA_EL3_FIRST_NS=1
+ */
+void plat_ea_handler(unsigned int ea_reason, uint64_t syndrome, void *cookie,
+		void *handle, uint64_t flags)
+{
+	unsigned int level = (unsigned int)GET_EL(read_spsr_el3());
+
+	/*
+	 * Asynchronous External Abort with syndrome 0xbf000002 on Cortex A53
+	 * core means SError interrupt caused by AXI SLVERR on external access.
+	 *
+	 * In most cases this indicates a bug in U-Boot or Linux kernel driver
+	 * pci-aardvark.c which implements access to A3700 PCIe config space.
+	 * Driver does not wait for PCIe PIO transfer completion and try to
+	 * start a new PCIe PIO transfer while previous has not finished yet.
+	 * A3700 PCIe controller in this case sends SLVERR via AXI which results
+	 * in a fatal Asynchronous SError interrupt on Cortex A53 CPU.
+	 *
+	 * Following patches fix that bug in U-Boot and Linux kernel drivers:
+	 * https://source.denx.de/u-boot/u-boot/-/commit/eccbd4ad8e4e182638eafbfb87ac139c04f24a01
+	 * https://git.kernel.org/stable/c/f18139966d072dab8e4398c95ce955a9742e04f7
+	 *
+	 * As a hacky workaround for unpatched U-Boot and Linux kernel drivers
+	 * ignore all asynchronous aborts with that syndrome value received on
+	 * CPU from level lower than EL3.
+	 *
+	 * Because these aborts are delivered on CPU asynchronously, they are
+	 * imprecise and we cannot check the real reason of abort and neither
+	 * who and why sent this abort. We expect that on A3700 it is always
+	 * PCIe controller.
+	 *
+	 * Hence ignoring all aborts with this syndrome value is just a giant
+	 * hack that we need only because of bugs in old U-Boot and Linux kernel
+	 * versions and because it was decided that TF-A would implement this
+	 * hack for U-Boot and Linux kernel it in this way. New patched U-Boot
+	 * and kernel versions do not need it anymore.
+	 *
+	 * Links to discussion about this workaround:
+	 * https://lore.kernel.org/linux-pci/20190316161243.29517-1-repk@triplefau.lt/
+	 * https://lore.kernel.org/linux-pci/971be151d24312cc533989a64bd454b4@www.loen.fr/
+	 * https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/1541
+	 */
+	if (level < MODE_EL3 && ea_reason == ERROR_EA_ASYNC &&
+	    syndrome == A53_SERR_INT_AXI_SLVERR_ON_EXTERNAL_ACCESS) {
+		ERROR_NL();
+		ERROR("Ignoring Asynchronous External Abort with"
+		     " syndrome 0x%" PRIx64 " received on 0x%lx from %s\n",
+		     syndrome, read_mpidr_el1(), get_el_str(level));
+		ERROR("SError interrupt: AXI SLVERR on external access\n");
+		ERROR("This indicates a bug in pci-aardvark.c driver\n");
+		ERROR("Please update U-Boot/Linux to the latest version\n");
+		ERROR_NL();
+		console_flush();
+		return;
+	}
+
+	plat_default_ea_handler(ea_reason, syndrome, cookie, handle, flags);
+}