On 03.09.25 17:30, Leonid Komarianskyi wrote:
Hello Leonid
Introduced appropriate register definitions, helper macros,
and initialization of required GICv3.1 distributor registers
to support eSPI. This type of interrupt is handled in the
same way as regular SPI interrupts, with the following
differences:
1) eSPIs can have up to 1024 interrupts, starting from the
beginning of the range, whereas regular SPIs use INTIDs from
32 to 1019, totaling 988 interrupts;
2) eSPIs start at INTID 4096, necessitating additional interrupt
index conversion during register operations.
In case if appropriate config is disabled, or GIC HW doesn't
support eSPI, the existing functionality will remain the same.
Signed-off-by: Leonid Komarianskyi <leonid_komarians...@epam.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshche...@epam.com>
---
Changes in V6:
- removed unnecessary parentheses in gic_is_valid_espi()
- updated gic_is_valid_line(): it now verifies the condition irq <
gic_number_lines() first, as it is more likely that the irq number
will be from the non-eSPI range
- minor change: changed the macros ESPI_INTID2IDX and ESPI_IDX2INTID
into appropriate inline functions introduced in the previous patch
- added reviewed-by from Oleksandr Tyshchenko
Changes in V5:
- fixed minor nits, no functional changes: changed u32 to uint32_t and
added a comment noting that the configuration for eSPIs is the same as
for regular SPIs
- removed ifdefs for eSPI-specific offsets to reduce the number of
ifdefs and code duplication in further changes
- removed reviewed-by as moving offset from ifdefs requires additional
confirmation from reviewers
Changes in V4:
- added offsets for GICD_IGRPMODRnE and GICD_NSACRnE that are required
for vGIC emulation
- added a log banner with eSPI information, similar to the one for
regular SPI
- added newline after ifdef and before gic_is_valid_line
- added reviewed-by from Volodymyr Babchuk
Changes in V3:
- add __init attribute to gicv3_dist_espi_common_init
- change open-codded eSPI register initialization to the appropriate
gen-mask macro
- fixed formatting for lines with more than 80 symbols
- introduced gicv3_dist_espi_init_aff to be able to use stubs in case of
CONFIG_GICV3_ESPI disabled
- renamed parameter in the GICD_TYPER_ESPI_RANGE macro to espi_range
(name was taken from GIC specification) to avoid confusion
- changed type for i variable to unsigned int since it cannot be
negative
Changes in V2:
- move gic_number_espis function from
[PATCH 08/10] xen/arm: vgic: add resource management for extended SPIs
to use it in the newly introduced gic_is_valid_espi
- add gic_is_valid_espi which checks if IRQ number is in supported
by HW eSPI range
- update gic_is_valid_irq conditions to allow operations with eSPIs
---
xen/arch/arm/gic-v3.c | 83 ++++++++++++++++++++++++++
xen/arch/arm/include/asm/gic.h | 21 ++++++-
xen/arch/arm/include/asm/gic_v3_defs.h | 38 ++++++++++++
3 files changed, 141 insertions(+), 1 deletion(-)
diff --git a/xen/arch/arm/gic-v3.c b/xen/arch/arm/gic-v3.c
index a1e302fea2..a69263e461 100644
--- a/xen/arch/arm/gic-v3.c
+++ b/xen/arch/arm/gic-v3.c
@@ -485,6 +485,36 @@ static void __iomem *get_addr_by_offset(struct irq_desc
*irqd, uint32_t offset)
default:
break;
}
+#ifdef CONFIG_GICV3_ESPI
+ case ESPI_BASE_INTID ... ESPI_MAX_INTID:
+ {
+ uint32_t irq_index = espi_intid_to_idx(irqd->irq);
+
+ switch ( offset )
+ {
+ case GICD_ISENABLER:
+ return (GICD + GICD_ISENABLERnE + (irq_index / 32) * 4);
+ case GICD_ICENABLER:
+ return (GICD + GICD_ICENABLERnE + (irq_index / 32) * 4);
+ case GICD_ISPENDR:
+ return (GICD + GICD_ISPENDRnE + (irq_index / 32) * 4);
+ case GICD_ICPENDR:
+ return (GICD + GICD_ICPENDRnE + (irq_index / 32) * 4);
+ case GICD_ISACTIVER:
+ return (GICD + GICD_ISACTIVERnE + (irq_index / 32) * 4);
+ case GICD_ICACTIVER:
+ return (GICD + GICD_ICACTIVERnE + (irq_index / 32) * 4);
+ case GICD_ICFGR:
+ return (GICD + GICD_ICFGRnE + (irq_index / 16) * 4);
+ case GICD_IROUTER:
+ return (GICD + GICD_IROUTERnE + irq_index * 8);
+ case GICD_IPRIORITYR:
+ return (GICD + GICD_IPRIORITYRnE + irq_index);
+ default:
+ break;
+ }
+ }
+#endif
default:
break;
}
@@ -655,6 +685,55 @@ static void gicv3_set_irq_priority(struct irq_desc *desc,
spin_unlock(&gicv3.lock);
}
+#ifdef CONFIG_GICV3_ESPI
+unsigned int gic_number_espis(void)
+{
+ return gic_hw_ops->info->nr_espi;
+}
+
+static void __init gicv3_dist_espi_common_init(uint32_t type)
+{
+ unsigned int espi_nr, i;
+
+ espi_nr = min(1024U, GICD_TYPER_ESPIS_NUM(type));
+ gicv3_info.nr_espi = espi_nr;
Sorry, I have just noticed one thing, and gicv3_cpu_init() probably
would be a more correct place to write about it, but since you don't
modify that function (it is not visible in the context), so writing here:
From "Arm IHI 0069H.b (ID041224)"
10.1.2 GICv3.1 extended INTID range support
Note
Arm recommends that Armv8-R AArch64 PEs report ICC_CTLR_EL1.ExtRange==1,
indicating that the GICv3.1 extended SPI and PPI ranges are supported.
Linux driver has an extra check for that:
WARN((gic_data.ppi_nr > 16 || GIC_ESPI_NR != 0) &&
!(gic_read_ctlr() & ICC_CTLR_EL1_ExtRange),
"Distributor has extended ranges, but CPU%d doesn't\n",
smp_processor_id());
added by the following commit:
irqchip/gic-v3: Warn about inconsistent implementations of extended ranges
https://github.com/torvalds/linux/commit/ad5a78d3da81836c88d1f2d53310484462660997
What is your opinion, is it worth having a similar check in Xen?
+ /* The GIC HW doesn't support eSPI, so we can leave from here */
+ if ( gicv3_info.nr_espi == 0 )
+ return;
+
+ printk("GICv3: %d eSPI lines\n", gicv3_info.nr_espi);
+
[snip]
