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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/powerpc/lib/div64.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/powerpc/lib/div64.S')
| -rw-r--r-- | arch/powerpc/lib/div64.S | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/arch/powerpc/lib/div64.S b/arch/powerpc/lib/div64.S new file mode 100644 index 000000000..3d5426e7d --- /dev/null +++ b/arch/powerpc/lib/div64.S @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Divide a 64-bit unsigned number by a 32-bit unsigned number. + * This routine assumes that the top 32 bits of the dividend are + * non-zero to start with. + * On entry, r3 points to the dividend, which get overwritten with + * the 64-bit quotient, and r4 contains the divisor. + * On exit, r3 contains the remainder. + * + * Copyright (C) 2002 Paul Mackerras, IBM Corp. + */ +#include <asm/ppc_asm.h> +#include <asm/processor.h> + +_GLOBAL(__div64_32) + lwz r5,0(r3) # get the dividend into r5/r6 + lwz r6,4(r3) + cmplw r5,r4 + li r7,0 + li r8,0 + blt 1f + divwu r7,r5,r4 # if dividend.hi >= divisor, + mullw r0,r7,r4 # quotient.hi = dividend.hi / divisor + subf. r5,r0,r5 # dividend.hi %= divisor + beq 3f +1: mr r11,r5 # here dividend.hi != 0 + andis. r0,r5,0xc000 + bne 2f + cntlzw r0,r5 # we are shifting the dividend right + li r10,-1 # to make it < 2^32, and shifting + srw r10,r10,r0 # the divisor right the same amount, + addc r9,r4,r10 # rounding up (so the estimate cannot + andc r11,r6,r10 # ever be too large, only too small) + andc r9,r9,r10 + addze r9,r9 + or r11,r5,r11 + rotlw r9,r9,r0 + rotlw r11,r11,r0 + divwu r11,r11,r9 # then we divide the shifted quantities +2: mullw r10,r11,r4 # to get an estimate of the quotient, + mulhwu r9,r11,r4 # multiply the estimate by the divisor, + subfc r6,r10,r6 # take the product from the divisor, + add r8,r8,r11 # and add the estimate to the accumulated + subfe. r5,r9,r5 # quotient + bne 1b +3: cmplw r6,r4 + blt 4f + divwu r0,r6,r4 # perform the remaining 32-bit division + mullw r10,r0,r4 # and get the remainder + add r8,r8,r0 + subf r6,r10,r6 +4: stw r7,0(r3) # return the quotient in *r3 + stw r8,4(r3) + mr r3,r6 # return the remainder in r3 + blr |