[dropping Jason, whose email address has been bouncing for weeks now]
On 2020-11-07 10:42, Xu Qiang wrote:
On my platform, ITS_FLAGS_SAVE_SUSPEND_STATE is not set,thus do nothing
Which platform?
in its suspend and resuse function.On the other hand,firmware stores
GITS_CTRL,GITS_CBASER,GITS_CWRITER and GITS_BASER<n> in the suspend,
and restores these registers in the resume. As a result, the ITS
executes
the residual commands in the queue.
Which firmware are you using? I just had a look at the trusted firmware
source
code, and while it definitely does something that *looks* like what you
are
describing, it doesn't re-enable the ITS on resume.
So what are you running?
Memory corruption may occur in the following scenarios:
The kernel sends three commands in the following sequence:
1.mapd(deviceA, ITT_addr1, valid:1)
2.mapti(deviceA):ITS write ITT_addr1 memory;
3.mapd(deviceA, ITT_addr1, valid:0) and kfree(ITT_addr1);
The ITS doesn't 'kfree' stuff.
4.mapd(deviceA, ITT_addr2, valid:1);
5.mapti(deviceA):ITS write ITT_addr2 memory;
I don't think this example is relevant. The core of the problem is that
the ITS gets re-enabled by your firmware. What are the affected systems?
To solve this problem,dropping the checks for
ITS_FLAGS_SAVE_SUSPEND_STATE.
Signed-off-by: Xu Qiang <xuqian...@huawei.com>
---
drivers/irqchip/irq-gic-v3-its.c | 13 -------------
1 file changed, 13 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c
b/drivers/irqchip/irq-gic-v3-its.c
index 0fec31931e11..06f2c1c252b9 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -42,7 +42,6 @@
#define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1ULL << 0)
#define ITS_FLAGS_WORKAROUND_CAVIUM_22375 (1ULL << 1)
#define ITS_FLAGS_WORKAROUND_CAVIUM_23144 (1ULL << 2)
-#define ITS_FLAGS_SAVE_SUSPEND_STATE (1ULL << 3)
#define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0)
#define RDIST_FLAGS_RD_TABLES_PREALLOCATED (1 << 1)
@@ -4741,9 +4740,6 @@ static int its_save_disable(void)
list_for_each_entry(its, &its_nodes, entry) {
void __iomem *base;
- if (!(its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE))
- continue;
-
base = its->base;
its->ctlr_save = readl_relaxed(base + GITS_CTLR);
err = its_force_quiescent(base);
@@ -4762,9 +4758,6 @@ static int its_save_disable(void)
list_for_each_entry_continue_reverse(its, &its_nodes, entry) {
void __iomem *base;
- if (!(its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE))
- continue;
-
base = its->base;
writel_relaxed(its->ctlr_save, base + GITS_CTLR);
}
@@ -4784,9 +4777,6 @@ static void its_restore_enable(void)
void __iomem *base;
int i;
- if (!(its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE))
- continue;
-
base = its->base;
/*
@@ -5074,9 +5064,6 @@ static int __init its_probe_one(struct resource
*res,
ctlr |= GITS_CTLR_ImDe;
writel_relaxed(ctlr, its->base + GITS_CTLR);
- if (GITS_TYPER_HCC(typer))
- its->flags |= ITS_FLAGS_SAVE_SUSPEND_STATE;
-
err = its_init_domain(handle, its);
if (err)
goto out_free_tables;
I'm OK with the patch itself, but I don't want to paper over broken
firmware.
I'll get TF-A fixed one way or another, but I want to be sure yours is
too.
If firmware does its job correctly, we shouldn't have to do all of this.
M.
--
Jazz is not dead. It just smells funny...
