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| author | Danilo Krummrich <dakr@kernel.org> | 2026-08-13 18:52:04 +0200 |
|---|---|---|
| committer | Danilo Krummrich <dakr@kernel.org> | 2026-08-17 01:41:36 +0200 |
| commit | f146c7bc85a51f95c05e0f8173d484eb301ece78 (patch) | |
| tree | 07296ae54ed6551492b0c609dc0f5463f61f89ca /arch/arm/lib/delay-loop.S | |
| download | linux-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/arm/lib/delay-loop.S')
| -rw-r--r-- | arch/arm/lib/delay-loop.S | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/arm/lib/delay-loop.S b/arch/arm/lib/delay-loop.S new file mode 100644 index 000000000..33b08ca1c --- /dev/null +++ b/arch/arm/lib/delay-loop.S @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/delay.S + * + * Copyright (C) 1995, 1996 Russell King + */ +#include <linux/linkage.h> +#include <linux/cfi_types.h> +#include <asm/assembler.h> +#include <asm/delay.h> + +#ifdef CONFIG_ARCH_RPC + .arch armv4 +#endif + + .text + +.LC0: .word loops_per_jiffy +.LC1: .word UDELAY_MULT + +/* + * loops = r0 * HZ * loops_per_jiffy / 1000000 + * + * r0 <= 2000 + * HZ <= 1000 + */ + +SYM_TYPED_FUNC_START(__loop_udelay) + ldr r2, .LC1 + mul r0, r2, r0 @ r0 = delay_us * UDELAY_MULT + b __loop_const_udelay +SYM_FUNC_END(__loop_udelay) + +SYM_TYPED_FUNC_START(__loop_const_udelay) @ 0 <= r0 <= 0xfffffaf0 + ldr r2, .LC0 + ldr r2, [r2] + umull r1, r0, r2, r0 @ r0-r1 = r0 * loops_per_jiffy + adds r1, r1, #0xffffffff @ rounding up ... + adcs r0, r0, r0 @ and right shift by 31 + reteq lr + b __loop_delay +SYM_FUNC_END(__loop_const_udelay) + + .align 3 + +@ Delay routine +SYM_TYPED_FUNC_START(__loop_delay) + subs r0, r0, #1 +#if 0 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 + retls lr + subs r0, r0, #1 +#endif + bhi __loop_delay + ret lr +SYM_FUNC_END(__loop_delay) |