1b5c850d4SMarcin Wojtas /* 2b5c850d4SMarcin Wojtas * Copyright (C) 2019 Repk repk@triplefau.lt 3b5c850d4SMarcin Wojtas * 4b5c850d4SMarcin Wojtas * SPDX-License-Identifier: BSD-3-Clause 5b5c850d4SMarcin Wojtas * https://spdx.org/licenses 6b5c850d4SMarcin Wojtas */ 7b5c850d4SMarcin Wojtas #include <common/bl_common.h> 8b5c850d4SMarcin Wojtas #include <common/debug.h> 9b5c850d4SMarcin Wojtas #include <arch_helpers.h> 1030e8fa7eSPali Rohár #include <plat/common/platform.h> 11*068fe919SPali Rohár #include <bl31/ea_handle.h> 12b5c850d4SMarcin Wojtas 13*068fe919SPali Rohár #define A53_SERR_INT_AXI_SLVERR_ON_EXTERNAL_ACCESS 0xbf000002 14*068fe919SPali Rohár 15*068fe919SPali Rohár #if !ENABLE_BACKTRACE 16*068fe919SPali Rohár static const char *get_el_str(unsigned int el) 17*068fe919SPali Rohár { 18*068fe919SPali Rohár if (el == MODE_EL3) { 19*068fe919SPali Rohár return "EL3"; 20*068fe919SPali Rohár } else if (el == MODE_EL2) { 21*068fe919SPali Rohár return "EL2"; 22*068fe919SPali Rohár } 23*068fe919SPali Rohár return "S-EL1"; 24*068fe919SPali Rohár } 25*068fe919SPali Rohár #endif /* !ENABLE_BACKTRACE */ 26b5c850d4SMarcin Wojtas 27b5c850d4SMarcin Wojtas void plat_ea_handler(unsigned int ea_reason, uint64_t syndrome, void *cookie, 28b5c850d4SMarcin Wojtas void *handle, uint64_t flags) 29b5c850d4SMarcin Wojtas { 30*068fe919SPali Rohár unsigned int level = (unsigned int)GET_EL(read_spsr_el3()); 31*068fe919SPali Rohár 32*068fe919SPali Rohár /* 33*068fe919SPali Rohár * Asynchronous External Abort with syndrome 0xbf000002 on Cortex A53 34*068fe919SPali Rohár * core means SError interrupt caused by AXI SLVERR on external access. 35*068fe919SPali Rohár * 36*068fe919SPali Rohár * In most cases this indicates a bug in U-Boot or Linux kernel driver 37*068fe919SPali Rohár * pci-aardvark.c which implements access to A3700 PCIe config space. 38*068fe919SPali Rohár * Driver does not wait for PCIe PIO transfer completion and try to 39*068fe919SPali Rohár * start a new PCIe PIO transfer while previous has not finished yet. 40*068fe919SPali Rohár * A3700 PCIe controller in this case sends SLVERR via AXI which results 41*068fe919SPali Rohár * in a fatal Asynchronous SError interrupt on Cortex A53 CPU. 42*068fe919SPali Rohár * 43*068fe919SPali Rohár * Following patches fix that bug in U-Boot and Linux kernel drivers: 44*068fe919SPali Rohár * https://source.denx.de/u-boot/u-boot/-/commit/eccbd4ad8e4e182638eafbfb87ac139c04f24a01 45*068fe919SPali Rohár * https://git.kernel.org/stable/c/f18139966d072dab8e4398c95ce955a9742e04f7 46*068fe919SPali Rohár * 47*068fe919SPali Rohár * As a hacky workaround for unpatched U-Boot and Linux kernel drivers 48*068fe919SPali Rohár * ignore all asynchronous aborts with that syndrome value received on 49*068fe919SPali Rohár * CPU from level lower than EL3. 50*068fe919SPali Rohár * 51*068fe919SPali Rohár * Because these aborts are delivered on CPU asynchronously, they are 52*068fe919SPali Rohár * imprecise and we cannot check the real reason of abort and neither 53*068fe919SPali Rohár * who and why sent this abort. We expect that on A3700 it is always 54*068fe919SPali Rohár * PCIe controller. 55*068fe919SPali Rohár * 56*068fe919SPali Rohár * Hence ignoring all aborts with this syndrome value is just a giant 57*068fe919SPali Rohár * hack that we need only because of bugs in old U-Boot and Linux kernel 58*068fe919SPali Rohár * versions and because it was decided that TF-A would implement this 59*068fe919SPali Rohár * hack for U-Boot and Linux kernel it in this way. New patched U-Boot 60*068fe919SPali Rohár * and kernel versions do not need it anymore. 61*068fe919SPali Rohár * 62*068fe919SPali Rohár * Links to discussion about this workaround: 63*068fe919SPali Rohár * https://lore.kernel.org/linux-pci/20190316161243.29517-1-repk@triplefau.lt/ 64*068fe919SPali Rohár * https://lore.kernel.org/linux-pci/971be151d24312cc533989a64bd454b4@www.loen.fr/ 65*068fe919SPali Rohár * https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/1541 66*068fe919SPali Rohár */ 67*068fe919SPali Rohár if (level < MODE_EL3 && ea_reason == ERROR_EA_ASYNC && 68*068fe919SPali Rohár syndrome == A53_SERR_INT_AXI_SLVERR_ON_EXTERNAL_ACCESS) { 69*068fe919SPali Rohár ERROR_NL(); 70*068fe919SPali Rohár ERROR("Ignoring Asynchronous External Abort with" 71*068fe919SPali Rohár " syndrome 0x%llx received on 0x%lx from %s\n", 72*068fe919SPali Rohár syndrome, read_mpidr_el1(), get_el_str(level)); 73*068fe919SPali Rohár ERROR("SError interrupt: AXI SLVERR on external access\n"); 74*068fe919SPali Rohár ERROR("This indicates a bug in pci-aardvark.c driver\n"); 75*068fe919SPali Rohár ERROR("Please update U-Boot/Linux to the latest version\n"); 76*068fe919SPali Rohár ERROR_NL(); 77*068fe919SPali Rohár console_flush(); 7830e8fa7eSPali Rohár return; 79*068fe919SPali Rohár } 8030e8fa7eSPali Rohár 8130e8fa7eSPali Rohár plat_default_ea_handler(ea_reason, syndrome, cookie, handle, flags); 82b5c850d4SMarcin Wojtas } 83