Merge changes from topic "advk-serror" into integration
* changes:
fix(plat/marvell/a3k): disable HANDLE_EA_EL3_FIRST by default
fix(plat/marvell/a3k): update information about PCIe abort hack
diff --git a/docs/plat/marvell/armada/build.rst b/docs/plat/marvell/armada/build.rst
index 8af27b1..b125144 100644
--- a/docs/plat/marvell/armada/build.rst
+++ b/docs/plat/marvell/armada/build.rst
@@ -153,6 +153,29 @@
Armada37x0 specific build options:
+- HANDLE_EA_EL3_FIRST
+
+ When ``HANDLE_EA_EL3_FIRST=1``, External Aborts and SError Interrupts will be always trapped
+ in TF-A. TF-A in this case enables dirty hack / workaround for a bug found in U-Boot and
+ Linux kernel PCIe controller driver pci-aardvark.c, traps and then masks SError interrupt
+ caused by AXI SLVERR on external access (syndrome 0xbf000002).
+
+ Otherwise when ``HANDLE_EA_EL3_FIRST=0``, these exceptions will be trapped in the current
+ exception level (or in EL1 if the current exception level is EL0). So exceptions caused by
+ U-Boot will be trapped in U-Boot, exceptions caused by Linux kernel (or user applications)
+ will be trapped in Linux kernel.
+
+ Mentioned bug in pci-aardvark.c driver is fixed in U-Boot version v2021.07 and Linux kernel
+ version v5.13 (workarounded since Linux kernel version 5.9) and also backported in Linux
+ kernel stable releases since versions v5.12.13, v5.10.46, v5.4.128, v4.19.198, v4.14.240.
+
+ If target system has already patched version of U-Boot and Linux kernel then it is strongly
+ recommended to not enable this workaround as it disallows propagating of all External Aborts
+ to running Linux kernel and makes correctable errors as fatal aborts.
+
+ This option is now disabled by default. In past this option was enabled by default in
+ TF-A versions v2.2, v2.3, v2.4 and v2.5.
+
- CM3_SYSTEM_RESET
When ``CM3_SYSTEM_RESET=1``, the Cortex-M3 secure coprocessor will be used for system reset.
diff --git a/plat/marvell/armada/a3k/common/a3700_common.mk b/plat/marvell/armada/a3k/common/a3700_common.mk
index 0a89742..238587d 100644
--- a/plat/marvell/armada/a3k/common/a3700_common.mk
+++ b/plat/marvell/armada/a3k/common/a3700_common.mk
@@ -13,7 +13,6 @@
PLAT_COMMON_BASE := $(PLAT_FAMILY_BASE)/common
MARVELL_DRV_BASE := drivers/marvell
MARVELL_COMMON_BASE := $(MARVELL_PLAT_BASE)/common
-HANDLE_EA_EL3_FIRST := 1
include plat/marvell/marvell.mk
@@ -53,7 +52,6 @@
$(PLAT_COMMON_BASE)/dram_win.c \
$(PLAT_COMMON_BASE)/io_addr_dec.c \
$(PLAT_COMMON_BASE)/marvell_plat_config.c \
- $(PLAT_COMMON_BASE)/a3700_ea.c \
$(PLAT_FAMILY_BASE)/$(PLAT)/plat_bl31_setup.c \
$(MARVELL_COMMON_BASE)/marvell_cci.c \
$(MARVELL_COMMON_BASE)/marvell_ddr_info.c \
@@ -63,6 +61,10 @@
$(PLAT_COMMON_BASE)/a3700_sip_svc.c \
$(MARVELL_DRV)
+ifeq ($(HANDLE_EA_EL3_FIRST),1)
+BL31_SOURCES += $(PLAT_COMMON_BASE)/a3700_ea.c
+endif
+
ifeq ($(CM3_SYSTEM_RESET),1)
BL31_SOURCES += $(PLAT_COMMON_BASE)/cm3_system_reset.c
endif
diff --git a/plat/marvell/armada/a3k/common/a3700_ea.c b/plat/marvell/armada/a3k/common/a3700_ea.c
index 3a4f720..4a58fc6 100644
--- a/plat/marvell/armada/a3k/common/a3700_ea.c
+++ b/plat/marvell/armada/a3k/common/a3700_ea.c
@@ -8,14 +8,79 @@
#include <common/debug.h>
#include <arch_helpers.h>
#include <plat/common/platform.h>
+#include <bl31/ea_handle.h>
-#define ADVK_SERROR_SYNDROME 0xbf000002
+#define A53_SERR_INT_AXI_SLVERR_ON_EXTERNAL_ACCESS 0xbf000002
+#if !ENABLE_BACKTRACE
+static const char *get_el_str(unsigned int el)
+{
+ if (el == MODE_EL3) {
+ return "EL3";
+ } else if (el == MODE_EL2) {
+ return "EL2";
+ }
+ return "S-EL1";
+}
+#endif /* !ENABLE_BACKTRACE */
+
+/*
+ * This source file with custom plat_ea_handler function is compiled only when
+ * building TF-A with compile option HANDLE_EA_EL3_FIRST=1
+ */
void plat_ea_handler(unsigned int ea_reason, uint64_t syndrome, void *cookie,
void *handle, uint64_t flags)
{
- if (syndrome == ADVK_SERROR_SYNDROME)
+ 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%llx 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);
}