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authorRafał Miłecki <rafal@milecki.pl>2016-10-29 13:12:29 +0200
committerFlorian Fainelli <f.fainelli@gmail.com>2016-11-16 12:39:05 -0800
commit09f3510fb70a46c8921f2cf4a90dbcae460a6820 (patch)
tree3a7bf022267cbdb5a0d11f3ba2720a2f734d1d65 /arch/arm/mach-bcm/bcm_5301x.c
parent1001354ca34179f3db924eb66672442a173147dc (diff)
downloadlinux-stericsson-09f3510fb70a46c8921f2cf4a90dbcae460a6820.tar.gz
ARM: BCM5301X: Add back handler ignoring external imprecise aborts
Since early BCM5301X days we got abort handler that was removed by commit 937b12306ea79 ("ARM: BCM5301X: remove workaround imprecise abort fault handler"). It assumed we need to deal only with pending aborts left by the bootloader. Unfortunately this isn't true for BCM5301X. When probing PCI config space (device enumeration) it is expected to have master aborts on the PCI bus. Most bridges don't forward (or they allow disabling it) these errors onto the AXI/AMBA bus but not the Northstar (BCM5301X) one. iProc PCIe controller on Northstar seems to be some older one, without a control register for errors forwarding. It means we need to workaround this at platform level. All newer platforms are not affected by this issue. Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Diffstat (limited to 'arch/arm/mach-bcm/bcm_5301x.c')
-rw-r--r--arch/arm/mach-bcm/bcm_5301x.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/arm/mach-bcm/bcm_5301x.c b/arch/arm/mach-bcm/bcm_5301x.c
index c8830a2b0d60..fe067f6cebb6 100644
--- a/arch/arm/mach-bcm/bcm_5301x.c
+++ b/arch/arm/mach-bcm/bcm_5301x.c
@@ -9,14 +9,42 @@
#include <asm/hardware/cache-l2x0.h>
#include <asm/mach/arch.h>
+#include <asm/siginfo.h>
+#include <asm/signal.h>
+
+#define FSR_EXTERNAL (1 << 12)
+#define FSR_READ (0 << 10)
+#define FSR_IMPRECISE 0x0406
static const char *const bcm5301x_dt_compat[] __initconst = {
"brcm,bcm4708",
NULL,
};
+static int bcm5301x_abort_handler(unsigned long addr, unsigned int fsr,
+ struct pt_regs *regs)
+{
+ /*
+ * We want to ignore aborts forwarded from the PCIe bus that are
+ * expected and shouldn't really be passed by the PCIe controller.
+ * The biggest disadvantage is the same FSR code may be reported when
+ * reading non-existing APB register and we shouldn't ignore that.
+ */
+ if (fsr == (FSR_EXTERNAL | FSR_READ | FSR_IMPRECISE))
+ return 0;
+
+ return 1;
+}
+
+static void __init bcm5301x_init_early(void)
+{
+ hook_fault_code(16 + 6, bcm5301x_abort_handler, SIGBUS, BUS_OBJERR,
+ "imprecise external abort");
+}
+
DT_MACHINE_START(BCM5301X, "BCM5301X")
.l2c_aux_val = 0,
.l2c_aux_mask = ~0,
.dt_compat = bcm5301x_dt_compat,
+ .init_early = bcm5301x_init_early,
MACHINE_END