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-rw-r--r--arch/mips/powertv/ioremap.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/arch/mips/powertv/ioremap.c b/arch/mips/powertv/ioremap.c
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+/*
+ * ioremap.c
+ *
+ * Support for mapping between dma_addr_t values a phys_addr_t values.
+ *
+ * Copyright (C) 2005-2009 Scientific-Atlanta, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Author: David VomLehn <dvomlehn@cisco.com>
+ *
+ * Description: Defines the platform resources for the SA settop.
+ *
+ * NOTE: The bootloader allocates persistent memory at an address which is
+ * 16 MiB below the end of the highest address in KSEG0. All fixed
+ * address memory reservations must avoid this region.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <asm/mach-powertv/ioremap.h>
+
+/*
+ * Define the sizes of and masks for grains in physical and DMA space. The
+ * values are the same but the types are not.
+ */
+#define IOR_PHYS_GRAIN ((phys_addr_t) 1 << IOR_LSBITS)
+#define IOR_PHYS_GRAIN_MASK (IOR_PHYS_GRAIN - 1)
+
+#define IOR_DMA_GRAIN ((dma_addr_t) 1 << IOR_LSBITS)
+#define IOR_DMA_GRAIN_MASK (IOR_DMA_GRAIN - 1)
+
+/*
+ * Values that, when accessed by an index derived from a phys_addr_t and
+ * added to phys_addr_t value, yield a DMA address
+ */
+struct ior_phys_to_dma _ior_phys_to_dma[IOR_NUM_PHYS_TO_DMA];
+EXPORT_SYMBOL(_ior_phys_to_dma);
+
+/*
+ * Values that, when accessed by an index derived from a dma_addr_t and
+ * added to that dma_addr_t value, yield a physical address
+ */
+struct ior_dma_to_phys _ior_dma_to_phys[IOR_NUM_DMA_TO_PHYS];
+EXPORT_SYMBOL(_ior_dma_to_phys);
+
+/**
+ * setup_dma_to_phys - set up conversion from DMA to physical addresses
+ * @dma_idx: Top IOR_LSBITS bits of the DMA address, i.e. an index
+ * into the array _dma_to_phys.
+ * @delta: Value that, when added to the DMA address, will yield the
+ * physical address
+ * @s: Number of bytes in the section of memory with the given delta
+ * between DMA and physical addresses.
+ */
+static void setup_dma_to_phys(dma_addr_t dma, phys_addr_t delta, dma_addr_t s)
+{
+ int dma_idx, first_idx, last_idx;
+ phys_addr_t first, last;
+
+ /*
+ * Calculate the first and last indices, rounding the first up and
+ * the second down.
+ */
+ first = dma & ~IOR_DMA_GRAIN_MASK;
+ last = (dma + s - 1) & ~IOR_DMA_GRAIN_MASK;
+ first_idx = first >> IOR_LSBITS; /* Convert to indices */
+ last_idx = last >> IOR_LSBITS;
+
+ for (dma_idx = first_idx; dma_idx <= last_idx; dma_idx++)
+ _ior_dma_to_phys[dma_idx].offset = delta >> IOR_DMA_SHIFT;
+}
+
+/**
+ * setup_phys_to_dma - set up conversion from DMA to physical addresses
+ * @phys_idx: Top IOR_LSBITS bits of the DMA address, i.e. an index
+ * into the array _phys_to_dma.
+ * @delta: Value that, when added to the DMA address, will yield the
+ * physical address
+ * @s: Number of bytes in the section of memory with the given delta
+ * between DMA and physical addresses.
+ */
+static void setup_phys_to_dma(phys_addr_t phys, dma_addr_t delta, phys_addr_t s)
+{
+ int phys_idx, first_idx, last_idx;
+ phys_addr_t first, last;
+
+ /*
+ * Calculate the first and last indices, rounding the first up and
+ * the second down.
+ */
+ first = phys & ~IOR_PHYS_GRAIN_MASK;
+ last = (phys + s - 1) & ~IOR_PHYS_GRAIN_MASK;
+ first_idx = first >> IOR_LSBITS; /* Convert to indices */
+ last_idx = last >> IOR_LSBITS;
+
+ for (phys_idx = first_idx; phys_idx <= last_idx; phys_idx++)
+ _ior_phys_to_dma[phys_idx].offset = delta >> IOR_PHYS_SHIFT;
+}
+
+/**
+ * ioremap_add_map - add to the physical and DMA address conversion arrays
+ * @phys: Process's view of the address of the start of the memory chunk
+ * @dma: DMA address of the start of the memory chunk
+ * @size: Size, in bytes, of the chunk of memory
+ *
+ * NOTE: It might be obvious, but the assumption is that all @size bytes have
+ * the same offset between the physical address and the DMA address.
+ */
+void ioremap_add_map(phys_addr_t phys, phys_addr_t dma, phys_addr_t size)
+{
+ if (size == 0)
+ return;
+
+ if ((dma & IOR_DMA_GRAIN_MASK) != 0 ||
+ (phys & IOR_PHYS_GRAIN_MASK) != 0 ||
+ (size & IOR_PHYS_GRAIN_MASK) != 0)
+ pr_crit("Memory allocation must be in chunks of 0x%x bytes\n",
+ IOR_PHYS_GRAIN);
+
+ setup_dma_to_phys(dma, phys - dma, size);
+ setup_phys_to_dma(phys, dma - phys, size);
+}