From: Shanker Donthineni <shankerd@codeaurora.org>
Date: Thu, 22 Jun 2017 18:19:14 -0500
Subject: irqchip/gic-v3-its: Don't assume GICv3 hardware supports 16bit INTID
Patch-mainline: v4.13-rc1
Git-commit: 6c31e123dc4c59eeaae6ac1cd08b929e8b6f7651
References: FATE#323954
The current ITS driver is assuming every ITS hardware implementation
supports minimum of 16bit INTID. But this is not true, as per GICv3
specification, INTID field is IMPLEMENTATION DEFINED in the range of
14-24 bits. We might see an unpredictable system behavior on systems
where hardware support less than 16bits and software tries to use
64K LPI interrupts.
On Qualcomm Datacenter Technologies QDF2400 platform, boot log shows
confusing information about number of LPI chunks as shown below. The
QDF2400 ITS hardware supports 24bit INTID.
This patch allocates the memory resources for PEND/PROP tables based
on discoverable value which is specified in GITS_TYPER.IDbits. Also
it fixes the log message that reflects the correct number of LPI
chunks were allocated.
ITS@0xff7efe0000: allocated 524288 Devices @3c0400000 (indirect, esz 8, psz 64K, shr 1)
ITS@0xff7efe0000: allocated 8192 Interrupt Collections @3c0130000 (flat, esz 8, psz 64K, shr 1)
ITS@0xff7efe0000: allocated 8192 Virtual CPUs @3c0140000 (flat, esz 8, psz 64K, shr 1)
ITS: Allocated 524032 chunks for LPIs
PCI/MSI: ITS@0xff7efe0000 domain created
Platform MSI: ITS@0xff7efe0000 domain created
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Alexander Graf <agraf@suse.de>
---
drivers/irqchip/irq-gic-v3-its.c | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -691,9 +691,11 @@
*/
#define IRQS_PER_CHUNK_SHIFT 5
#define IRQS_PER_CHUNK (1 << IRQS_PER_CHUNK_SHIFT)
+#define ITS_MAX_LPI_NRBITS 16 /* 64K LPIs */
static unsigned long *lpi_bitmap;
static u32 lpi_chunks;
+static u32 lpi_id_bits;
static DEFINE_SPINLOCK(lpi_lock);
static int its_lpi_to_chunk(int lpi)
@@ -789,17 +791,13 @@
}
/*
- * We allocate 64kB for PROPBASE. That gives us at most 64K LPIs to
+ * We allocate memory for PROPBASE to cover 2 ^ lpi_id_bits LPIs to
* deal with (one configuration byte per interrupt). PENDBASE has to
* be 64kB aligned (one bit per LPI, plus 8192 bits for SPI/PPI/SGI).
*/
-#define LPI_PROPBASE_SZ SZ_64K
-#define LPI_PENDBASE_SZ (LPI_PROPBASE_SZ / 8 + SZ_1K)
-
-/*
- * This is how many bits of ID we need, including the useless ones.
- */
-#define LPI_NRBITS ilog2(LPI_PROPBASE_SZ + SZ_8K)
+#define LPI_NRBITS lpi_id_bits
+#define LPI_PROPBASE_SZ ALIGN(BIT(LPI_NRBITS), SZ_64K)
+#define LPI_PENDBASE_SZ ALIGN(BIT(LPI_NRBITS) / 8, SZ_64K)
#define LPI_PROP_DEFAULT_PRIO 0xa0
@@ -807,6 +805,7 @@
{
phys_addr_t paddr;
+ lpi_id_bits = min_t(u32, gic_rdists->id_bits, ITS_MAX_LPI_NRBITS);
gic_rdists->prop_page = alloc_pages(GFP_NOWAIT,
get_order(LPI_PROPBASE_SZ));
if (!gic_rdists->prop_page) {
@@ -825,7 +824,7 @@
/* Make sure the GIC will observe the written configuration */
gic_flush_dcache_to_poc(page_address(gic_rdists->prop_page), LPI_PROPBASE_SZ);
- return 0;
+ return its_lpi_init(lpi_id_bits);
}
static const char *its_base_type_string[] = {
@@ -1100,7 +1099,7 @@
* hence the 'max(LPI_PENDBASE_SZ, SZ_64K)' below.
*/
pend_page = alloc_pages(GFP_NOWAIT | __GFP_ZERO,
- get_order(max(LPI_PENDBASE_SZ, SZ_64K)));
+ get_order(max_t(u32, LPI_PENDBASE_SZ, SZ_64K)));
if (!pend_page) {
pr_err("Failed to allocate PENDBASE for CPU%d\n",
smp_processor_id());
@@ -1975,8 +1974,5 @@
}
gic_rdists = rdists;
- its_alloc_lpi_tables();
- its_lpi_init(rdists->id_bits);
-
- return 0;
+ return its_alloc_lpi_tables();
}