Re: [PATCH v2 5/4] ARM: footbridge: remove custom DMA address handling
From: Robin Murphy <robin.murphy@arm.com>
Date: 2022-08-30 12:22:11
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On 2022-08-25 21:15, Arnd Bergmann wrote: [...]
quoted hunk ↗ jump to hunk
diff --git a/arch/arm/mach-footbridge/dc21285.c b/arch/arm/mach-footbridge/dc21285.c index 372600bc15c8..f8920d0010de 100644 --- a/arch/arm/mach-footbridge/dc21285.c +++ b/arch/arm/mach-footbridge/dc21285.c@@ -5,6 +5,7 @@ * Copyright (C) 1998-2001 Russell King * Copyright (C) 1998-2000 Phil Blundell */ +#include <linux/dma-map-ops.h> #include <linux/kernel.h> #include <linux/pci.h> #include <linux/interrupt.h>@@ -241,6 +242,22 @@ static irqreturn_t dc21285_parity_irq(int irq, void *dev_id) return IRQ_HANDLED; } +static int dc21285_pci_bus_notifier(struct notifier_block *nb, + unsigned long action, + void *data) +{ + if (action != BUS_NOTIFY_ADD_DEVICE) + return NOTIFY_DONE; + + dma_direct_set_offset(data, PHYS_OFFSET, BUS_OFFSET, SZ_256M);
FWIW I've always had it in mind that for this kind of special case the platform could just statically allocate the dma_range_map and assign it to all devices. However in practice that needs some kfree_const() tweaks in the driver core, which I'm sure are out-of-scope for this series, so I'm mostly flagging this up to help myself remember that it might be worth doing a dma_direct_set_offset() cleanup sweep soon. As-is the patch at least makes things a lot clearer, and presumably there aren't likely to be enough PCI devices for the extra allocations to have noticeable impact in the meantime. Cheers, Robin. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel