ARM: footbridge: remove custom DMA address handling
authorArnd Bergmann <arnd@arndb.de>
Thu, 25 Aug 2022 08:51:42 +0000 (10:51 +0200)
committerArnd Bergmann <arnd@arndb.de>
Thu, 15 Sep 2022 13:59:16 +0000 (15:59 +0200)
Footbridge is the last Arm platform that has its own
__virt_to_bus()/__bus_to_virt()/phys_to_dma()/dma_to_phys() abstraction,
but this is just a simple offset now.

For PCI devices, the offset that is programmed into the PCI bridge must
also be set in each device using dma_direct_set_offset().  As Arm does
not have a pcibios_bus_add_device() helper yet, just use a bus notifier
for this.

For the ISA DMA, drivers now pass a non-translated physical address into
set_dma_addr(), so they have to be converted back with the corresponding
isa_bus_to_virt() function and then into the correct bus address with
the offset using the isa_dma_dev.

Tested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
arch/arm/include/asm/dma-direct.h [deleted file]
arch/arm/include/asm/dma.h
arch/arm/include/asm/hardware/dec21285.h
arch/arm/include/asm/memory.h
arch/arm/mach-footbridge/Kconfig
arch/arm/mach-footbridge/common.c
arch/arm/mach-footbridge/dc21285.c
arch/arm/mach-footbridge/dma-isa.c
arch/arm/mach-footbridge/include/mach/dma-direct.h [deleted file]
arch/arm/mach-footbridge/include/mach/memory.h

diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
deleted file mode 100644 (file)
index 4f7bcde..0000000
+++ /dev/null
@@ -1 +0,0 @@
-#include <mach/dma-direct.h>
index 05f29a7..c6aded1 100644 (file)
@@ -106,7 +106,7 @@ extern void set_dma_sg(unsigned int chan, struct scatterlist *sg, int nr_sg);
  */
 extern void __set_dma_addr(unsigned int chan, void *addr);
 #define set_dma_addr(chan, addr)                               \
-       __set_dma_addr(chan, (void *)__bus_to_virt(addr))
+       __set_dma_addr(chan, (void *)isa_bus_to_virt(addr))
 
 /* Set the DMA byte count for this channel
  *
index eee390e..894f2a6 100644 (file)
 #define DC21285_IO(x)          (x)
 #endif
 
+/*
+ * The footbridge is programmed to expose the system RAM at 0xe0000000.
+ * The requirement is that the RAM isn't placed at bus address 0, which
+ * would clash with VGA cards.
+ */
+#define BUS_OFFSET 0xe0000000
+
 #define CSR_PCICMD             DC21285_IO(0x0004)
 #define CSR_CLASSREV           DC21285_IO(0x0008)
 #define CSR_PCICACHELINESIZE   DC21285_IO(0x000c)
index a55a903..d8eef4b 100644 (file)
@@ -369,17 +369,6 @@ static inline unsigned long __virt_to_idmap(unsigned long x)
 
 #define virt_to_idmap(x)       __virt_to_idmap((unsigned long)(x))
 
-/*
- * Virtual <-> DMA view memory address translations
- * Again, these are *only* valid on the kernel direct mapped RAM
- * memory.  Use of these is *deprecated* (and that doesn't mean
- * use the __ prefixed forms instead.)  See dma-mapping.h.
- */
-#ifndef __virt_to_bus
-#define __virt_to_bus  __virt_to_phys
-#define __bus_to_virt  __phys_to_virt
-#endif
-
 /*
  * Conversion between a struct page and a physical address.
  *
index 1a36761..b7a4e40 100644 (file)
@@ -46,7 +46,6 @@ endmenu
 # Footbridge support
 config FOOTBRIDGE
        def_bool y
-       select ARCH_HAS_PHYS_TO_DMA
        select ARCH_MIGHT_HAVE_PC_SERIO
        select ISA_DMA_API
 
index 9483ecc..629e467 100644 (file)
@@ -281,13 +281,3 @@ void footbridge_restart(enum reboot_mode mode, const char *cmd)
                *CSR_SA110_CNTL |= (1 << 13);
        }
 }
-
-dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-       return paddr + (BUS_OFFSET - PHYS_OFFSET);
-}
-
-phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
-{
-       return dev_addr - (BUS_OFFSET - PHYS_OFFSET);
-}
index 372600b..f8920d0 100644 (file)
@@ -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);
+
+       return NOTIFY_OK;
+}
+
+static struct notifier_block dc21285_pci_bus_nb = {
+       .notifier_call = dc21285_pci_bus_notifier,
+};
+
 int __init dc21285_setup(int nr, struct pci_sys_data *sys)
 {
        struct resource *res;
@@ -266,6 +283,8 @@ int __init dc21285_setup(int nr, struct pci_sys_data *sys)
        pci_add_resource_offset(&sys->resources, &res[0], sys->mem_offset);
        pci_add_resource_offset(&sys->resources, &res[1], sys->mem_offset);
 
+       bus_register_notifier(&pci_bus_type, &dc21285_pci_bus_nb);
+
        return 1;
 }
 
@@ -329,7 +348,7 @@ void __init dc21285_preinit(void)
         */
        *CSR_PCICSRBASE       = 0xf4000000;
        *CSR_PCICSRIOBASE     = 0;
-       *CSR_PCISDRAMBASE     = __virt_to_bus(PAGE_OFFSET);
+       *CSR_PCISDRAMBASE     = BUS_OFFSET;
        *CSR_PCIROMBASE       = 0;
        *CSR_PCICMD = PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
                      PCI_COMMAND_INVALIDATE | PCICMD_ERROR_BITS;
index 0fc0705..937f537 100644 (file)
@@ -11,6 +11,7 @@
  *   arch/arm/kernel/dma-ebsa285.c
  *   Copyright (C) 1998 Phil Blundell
  */
+#include <linux/dma-map-ops.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/dma-mapping.h>
@@ -18,6 +19,7 @@
 
 #include <asm/dma.h>
 #include <asm/mach/dma.h>
+#include <asm/hardware/dec21285.h>
 
 #define ISA_DMA_MASK           0
 #define ISA_DMA_MODE           1
@@ -221,6 +223,8 @@ static int __init isa_dma_init(void)
                request_dma(DMA_ISA_CASCADE, "cascade");
        }
 
+       dma_direct_set_offset(&isa_dma_dev, PHYS_OFFSET, BUS_OFFSET, SZ_256M);
+
        return 0;
 }
 core_initcall(isa_dma_init);
diff --git a/arch/arm/mach-footbridge/include/mach/dma-direct.h b/arch/arm/mach-footbridge/include/mach/dma-direct.h
deleted file mode 100644 (file)
index 01f9e83..0000000
+++ /dev/null
@@ -1,8 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef MACH_FOOTBRIDGE_DMA_DIRECT_H
-#define MACH_FOOTBRIDGE_DMA_DIRECT_H 1
-
-dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
-phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr);
-
-#endif /* MACH_FOOTBRIDGE_DMA_DIRECT_H */
index 8f0ca8e..9516877 100644 (file)
 #ifndef __ASM_ARCH_MEMORY_H
 #define __ASM_ARCH_MEMORY_H
 
-/*
- * The footbridge is programmed to expose the system RAM at 0xe0000000.
- * The requirement is that the RAM isn't placed at bus address 0, which
- * would clash with VGA cards.
- */
-#define BUS_OFFSET             0xe0000000
-#define __virt_to_bus(x)       ((x) + (BUS_OFFSET - PAGE_OFFSET))
-#define __bus_to_virt(x)       ((x) - (BUS_OFFSET - PAGE_OFFSET))
-
 /*
  * Cache flushing area.
  */