Hi Eric,
On 2019/12/16 22:02, Eric Auger wrote:
Allocate the command queue and initialize related registers:
CBASER, CREADR, CWRITER.
The command queue is 64kB. This aims at not bothing with fullness.
Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
---
lib/arm/asm/gic-v3-its.h | 7 +++++++
lib/arm/gic-v3-its.c | 37 +++++++++++++++++++++++++++++++++++++
2 files changed, 44 insertions(+)
diff --git a/lib/arm/asm/gic-v3-its.h b/lib/arm/asm/gic-v3-its.h
index 0d11aed..ed42707 100644
--- a/lib/arm/asm/gic-v3-its.h
+++ b/lib/arm/asm/gic-v3-its.h
@@ -113,10 +113,17 @@ struct its_baser {
int esz;
};
+struct its_cmd_block {
+ u64 raw_cmd[4];
+};
+
struct its_data {
void *base;
struct its_typer typer;
struct its_baser baser[GITS_BASER_NR_REGS];
+ struct its_cmd_block *cmd_base;
+ struct its_cmd_block *cmd_write;
+ struct its_cmd_block *cmd_readr;
I think we can just get rid of the 'cmd_readr'. As GITS_CREADR is
generally manipulated by the ITS, and ...
};
extern struct its_data its_data;
diff --git a/lib/arm/gic-v3-its.c b/lib/arm/gic-v3-its.c
index 0b5a700..8b6a095 100644
--- a/lib/arm/gic-v3-its.c
+++ b/lib/arm/gic-v3-its.c
@@ -188,3 +188,40 @@ void set_pending_table_bit(int rdist, int n, bool set)
byte &= ~mask;
*ptr = byte;
}
+
+/**
+ * init_cmd_queue: Allocate the command queue and initialize
+ * CBASER, CREADR, CWRITER
+ */
+void init_cmd_queue(void);
+void init_cmd_queue(void)
+{
+ unsigned long n = SZ_64K >> PAGE_SHIFT;
+ unsigned long order = fls(n);
+ u64 cbaser, tmp;
+
+ its_data.cmd_base = (void *)virt_to_phys(alloc_pages(order));
+
+ cbaser = ((u64)its_data.cmd_base |
+ GITS_CBASER_WaWb |
+ GITS_CBASER_InnerShareable |
+ (SZ_64K / SZ_4K - 1) |
+ GITS_CBASER_VALID);
+
+ writeq(cbaser, its_data.base + GITS_CBASER);
..."(CREADR) is cleared to 0 when a value is written to GITS_CBASER."
-- from IHI0069E 9.19.3
+ tmp = readq(its_data.base + GITS_CBASER);
+
+ if ((tmp ^ cbaser) & GITS_CBASER_SHAREABILITY_MASK) {
+ if (!(tmp & GITS_CBASER_SHAREABILITY_MASK)) {
+ cbaser &= ~(GITS_CBASER_SHAREABILITY_MASK |
+ GITS_CBASER_CACHEABILITY_MASK);
+ cbaser |= GITS_CBASER_nC;
+ writeq(cbaser, its_data.base + GITS_CBASER);
+ }
+ }
+
+ its_data.cmd_write = its_data.cmd_base;
+ its_data.cmd_readr = its_data.cmd_base;
+ writeq(0, its_data.base + GITS_CWRITER);
+ writeq(0, its_data.base + GITS_CREADR);
So this writeq() is also not needed.
Or I've just missed the point that this is done by intention to test
"whether the GITS_CREADR implemented by KVM is Write Ignored"?
If so, please ignore all of the comments above :)
Thanks,
Zenghui
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