diff options
Diffstat (limited to 'plat/marvell/armada/a3k/common/a3700_ea.c')
| -rw-r--r-- | plat/marvell/armada/a3k/common/a3700_ea.c | 78 |
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); +} |