Re: [PATCH 09/14] cxl: Add preliminary workaround for CX4 interrupt limitation
From: Frederic Barrat <hidden>
Date: 2016-07-06 18:34:38
Le 04/07/2016 15:22, Ian Munsie a écrit :
From: Ian Munsie <redacted> The Mellanox CX4 has a hardware limitation where only 4 bits of the AFU interrupt number can be passed to the XSL when sending an interrupt, limiting it to only 15 interrupts per context (AFU interrupt number 0 is invalid). In order to overcome this, we will allocate additional contexts linked to the default context as extra address space for the extra interrupts - this will be implemented in the next patch. This patch adds the preliminary support to allow this, by way of adding a linked list in the context structure that we use to keep track of the contexts dedicated to interrupts, and an API to simultaneously iterate over the related context structures, AFU interrupt numbers and hardware interrupt numbers. The point of using a single API to iterate these is to hide some of the details of the iteration from external code, and to reduce the number of APIs that need to be exported via base.c to allow built in code to call.
Reviewed-by: Frederic Barrat <redacted> Just one typo below
quoted hunk ↗ jump to hunk
diff --git a/include/misc/cxl.h b/include/misc/cxl.h index fc07ed4..ed81a17 100644 --- a/include/misc/cxl.h +++ b/include/misc/cxl.h@@ -178,6 +178,15 @@ int cxl_set_max_irqs_per_process(struct pci_dev *dev, int irqs); int cxl_get_max_irqs_per_process(struct pci_dev *dev); /* + * Use to simultaneously iterate over hardware interrupt numbers, contexts and + * afu interrupt numbers allocated for the device via pci_enable_msix_range and + * is a useful convinience function when working with hardware that has
convenience