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authorDanilo Krummrich <dakr@kernel.org>2026-08-13 18:52:04 +0200
committerDanilo Krummrich <dakr@kernel.org>2026-08-17 01:41:36 +0200
commitf146c7bc85a51f95c05e0f8173d484eb301ece78 (patch)
tree07296ae54ed6551492b0c609dc0f5463f61f89ca /arch/powerpc/sysdev/dcr-low.S
downloadlinux-stable-f146c7bc85a51f95c05e0f8173d484eb301ece78.tar.gz
linux-stable-f146c7bc85a51f95c05e0f8173d484eb301ece78.zip
PCI: Add pci_irq_type() to query the allocated interrupt typegrafted
Add a helper that returns PCI_IRQ_MSIX, PCI_IRQ_MSI, or PCI_IRQ_INTX based on the interrupt type the PCI core selected after pci_alloc_irq_vectors(). Several drivers already open-code this check against pdev->msix_enabled and pdev->msi_enabled, or even open code this helper [1]. A common helper avoids the duplication and keeps drivers from accessing the bitfield directly (see also [2]). Acked-by: Bjorn Helgaas <bhelgaas@google.com> Tested-by: John Hubbard <jhubbard@nvidia.com> Link: https://elixir.bootlin.com/linux/v7.1/source/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c#L196 [1] Inspired-by: John Hubbard <jhubbard@nvidia.com> Link: https://lore.kernel.org/all/DKKG2QM3YJYB.Z2H2B2UXJ75N@kernel.org/ [2] Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260813165234.620555-5-dakr@kernel.org [ Add missing pci_irq_type() stub for CONFIG_PCI=n. ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Diffstat (limited to 'arch/powerpc/sysdev/dcr-low.S')
-rw-r--r--arch/powerpc/sysdev/dcr-low.S44
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/dcr-low.S b/arch/powerpc/sysdev/dcr-low.S
new file mode 100644
index 000000000..e8401b205
--- /dev/null
+++ b/arch/powerpc/sysdev/dcr-low.S
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * "Indirect" DCR access
+ *
+ * Copyright (c) 2004 Eugene Surovegin <ebs@ebshome.net>
+ */
+
+#include <linux/export.h>
+#include <asm/ppc_asm.h>
+#include <asm/processor.h>
+#include <asm/bug.h>
+
+#define DCR_ACCESS_PROLOG(table) \
+ cmplwi cr0,r3,1024; \
+ rlwinm r3,r3,4,18,27; \
+ lis r5,table@h; \
+ ori r5,r5,table@l; \
+ add r3,r3,r5; \
+ bge- 1f; \
+ mtctr r3; \
+ bctr; \
+1: trap; \
+ EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0; \
+ blr
+
+_GLOBAL(__mfdcr)
+ DCR_ACCESS_PROLOG(__mfdcr_table)
+EXPORT_SYMBOL(__mfdcr)
+
+_GLOBAL(__mtdcr)
+ DCR_ACCESS_PROLOG(__mtdcr_table)
+EXPORT_SYMBOL(__mtdcr)
+
+__mfdcr_table:
+ mfdcr r3,0; blr
+__mtdcr_table:
+ mtdcr 0,r4; blr
+
+dcr = 1
+ .rept 1023
+ mfdcr r3,dcr; blr
+ mtdcr dcr,r4; blr
+ dcr = dcr + 1
+ .endr