MIPS: PowerTV: Use O(1) algorthm for phys_to_dma/dma_to_phys
Replace phys_to_dma()/dma_to_phys() looping algorithm with an O(1) algorithm
The approach taken is inspired by the sparse memory implementation: take a
certain number of high-order bits off the address them, use this as an
index into a table containing an offset to the desired address and add
it to the original value. There is a table for mapping physical addresses
to DMA addresses and another one for the reverse mapping. The table sizes
depend on how fine-grained the mappings need to be; Coarser granularity
less to smaller tables. On a processor with 32-bit physical and DMA
addresses, with 4 MIB granularity, memory usage is two 2048-byte arrays.
Each 32-byte cache line thus covers 64 MiB of address space.
Also, renames phys_to_bus() to phys_to_dma() and bus_to_phys() to
dma_to_phys() to align with kernel usage.
[Ralf: Fixed silly build breakage due to stackoverflow warning caused by
huge array on stack.]
Signed-off-by: David VomLehn <dvomlehn@cisco.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1257/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/powertv/memory.c b/arch/mips/powertv/memory.c
index f49eb3d..73880ad 100644
--- a/arch/mips/powertv/memory.c
+++ b/arch/mips/powertv/memory.c
@@ -30,28 +30,141 @@
#include <asm/sections.h>
#include <asm/mips-boards/prom.h>
+#include <asm/mach-powertv/asic.h>
+#include <asm/mach-powertv/ioremap.h>
#include "init.h"
/* Memory constants */
#define KIBIBYTE(n) ((n) * 1024) /* Number of kibibytes */
#define MEBIBYTE(n) ((n) * KIBIBYTE(1024)) /* Number of mebibytes */
-#define DEFAULT_MEMSIZE MEBIBYTE(256) /* If no memsize provided */
-#define LOW_MEM_MAX MEBIBYTE(252) /* Max usable low mem */
-#define RES_BOOTLDR_MEMSIZE MEBIBYTE(1) /* Memory reserved for bldr */
-#define BOOT_MEM_SIZE KIBIBYTE(256) /* Memory reserved for bldr */
-#define PHYS_MEM_START 0x10000000 /* Start of physical memory */
+#define DEFAULT_MEMSIZE MEBIBYTE(128) /* If no memsize provided */
-char __initdata cmdline[COMMAND_LINE_SIZE];
+#define BLDR_SIZE KIBIBYTE(256) /* Memory reserved for bldr */
+#define RV_SIZE MEBIBYTE(4) /* Size of reset vector */
-void __init prom_meminit(void)
+#define LOW_MEM_END 0x20000000 /* Highest low memory address */
+#define BLDR_ALIAS 0x10000000 /* Bootloader address */
+#define RV_PHYS 0x1fc00000 /* Reset vector address */
+#define LOW_RAM_END RV_PHYS /* End of real RAM in low mem */
+
+/*
+ * Very low-level conversion from processor physical address to device
+ * DMA address for the first bank of memory.
+ */
+#define PHYS_TO_DMA(paddr) ((paddr) + (CONFIG_LOW_RAM_DMA - LOW_RAM_ALIAS))
+
+unsigned long ptv_memsize;
+
+/*
+ * struct low_mem_reserved - Items in low memmory that are reserved
+ * @start: Physical address of item
+ * @size: Size, in bytes, of this item
+ * @is_aliased: True if this is RAM aliased from another location. If false,
+ * it is something other than aliased RAM and the RAM in the
+ * unaliased address is still visible outside of low memory.
+ */
+struct low_mem_reserved {
+ phys_addr_t start;
+ phys_addr_t size;
+ bool is_aliased;
+};
+
+/*
+ * Must be in ascending address order
+ */
+struct low_mem_reserved low_mem_reserved[] = {
+ {BLDR_ALIAS, BLDR_SIZE, true}, /* Bootloader RAM */
+ {RV_PHYS, RV_SIZE, false}, /* Reset vector */
+};
+
+/*
+ * struct mem_layout - layout of a piece of the system RAM
+ * @phys: Physical address of the start of this piece of RAM. This is the
+ * address at which both the processor and I/O devices see the
+ * RAM.
+ * @alias: Alias of this piece of memory in order to make it appear in
+ * the low memory part of the processor's address space. I/O
+ * devices don't see anything here.
+ * @size: Size, in bytes, of this piece of RAM
+ */
+struct mem_layout {
+ phys_addr_t phys;
+ phys_addr_t alias;
+ phys_addr_t size;
+};
+
+/*
+ * struct mem_layout_list - list descriptor for layouts of system RAM pieces
+ * @family: Specifies the family being described
+ * @n: Number of &struct mem_layout elements
+ * @layout: Pointer to the list of &mem_layout structures
+ */
+struct mem_layout_list {
+ enum family_type family;
+ size_t n;
+ struct mem_layout *layout;
+};
+
+static struct mem_layout f1500_layout[] = {
+ {0x20000000, 0x10000000, MEBIBYTE(256)},
+};
+
+static struct mem_layout f4500_layout[] = {
+ {0x40000000, 0x10000000, MEBIBYTE(256)},
+ {0x20000000, 0x20000000, MEBIBYTE(32)},
+};
+
+static struct mem_layout f8500_layout[] = {
+ {0x40000000, 0x10000000, MEBIBYTE(256)},
+ {0x20000000, 0x20000000, MEBIBYTE(32)},
+ {0x30000000, 0x30000000, MEBIBYTE(32)},
+};
+
+static struct mem_layout fx600_layout[] = {
+ {0x20000000, 0x10000000, MEBIBYTE(256)},
+ {0x60000000, 0x60000000, MEBIBYTE(128)},
+};
+
+static struct mem_layout_list layout_list[] = {
+ {FAMILY_1500, ARRAY_SIZE(f1500_layout), f1500_layout},
+ {FAMILY_1500VZE, ARRAY_SIZE(f1500_layout), f1500_layout},
+ {FAMILY_1500VZF, ARRAY_SIZE(f1500_layout), f1500_layout},
+ {FAMILY_4500, ARRAY_SIZE(f4500_layout), f4500_layout},
+ {FAMILY_8500, ARRAY_SIZE(f8500_layout), f8500_layout},
+ {FAMILY_8500RNG, ARRAY_SIZE(f8500_layout), f8500_layout},
+ {FAMILY_4600, ARRAY_SIZE(fx600_layout), fx600_layout},
+ {FAMILY_4600VZA, ARRAY_SIZE(fx600_layout), fx600_layout},
+ {FAMILY_8600, ARRAY_SIZE(fx600_layout), fx600_layout},
+ {FAMILY_8600VZB, ARRAY_SIZE(fx600_layout), fx600_layout},
+};
+
+/* If we can't determine the layout, use this */
+static struct mem_layout default_layout[] = {
+ {0x20000000, 0x10000000, MEBIBYTE(128)},
+};
+
+/**
+ * register_non_ram - register low memory not available for RAM usage
+ */
+static __init void register_non_ram(void)
{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(low_mem_reserved); i++)
+ add_memory_region(low_mem_reserved[i].start,
+ low_mem_reserved[i].size, BOOT_MEM_RESERVED);
+}
+
+/**
+ * get_memsize - get the size of memory as a single bank
+ */
+static phys_addr_t get_memsize(void)
+{
+ static char cmdline[COMMAND_LINE_SIZE] __initdata;
+ phys_addr_t memsize = 0;
char *memsize_str;
- unsigned long memsize = 0;
- unsigned int physend;
char *ptr;
- int low_mem;
- int high_mem;
/* Check the command line first for a memsize directive */
strcpy(cmdline, arcs_cmdline);
@@ -73,98 +186,158 @@
if (memsize == 0) {
if (_prom_memsize != 0) {
memsize = _prom_memsize;
- pr_info("_prom_memsize = 0x%lx\n", memsize);
+ pr_info("_prom_memsize = 0x%x\n", memsize);
/* add in memory that the bootloader doesn't
* report */
- memsize += BOOT_MEM_SIZE;
+ memsize += BLDR_SIZE;
} else {
memsize = DEFAULT_MEMSIZE;
pr_info("Memsize not passed by bootloader, "
- "defaulting to 0x%lx\n", memsize);
+ "defaulting to 0x%x\n", memsize);
}
}
}
- physend = PFN_ALIGN(&_end) - 0x80000000;
- if (memsize > LOW_MEM_MAX) {
- low_mem = LOW_MEM_MAX;
- high_mem = memsize - low_mem;
- } else {
- low_mem = memsize;
- high_mem = 0;
+ return memsize;
+}
+
+/**
+ * register_low_ram - register an aliased section of RAM
+ * @p: Alias address of memory
+ * @n: Number of bytes in this section of memory
+ *
+ * Returns the number of bytes registered
+ *
+ */
+static __init phys_addr_t register_low_ram(phys_addr_t p, phys_addr_t n)
+{
+ phys_addr_t s;
+ int i;
+ phys_addr_t orig_n;
+
+ orig_n = n;
+
+ BUG_ON(p + n > RV_PHYS);
+
+ for (i = 0; n != 0 && i < ARRAY_SIZE(low_mem_reserved); i++) {
+ phys_addr_t start;
+ phys_addr_t size;
+
+ start = low_mem_reserved[i].start;
+ size = low_mem_reserved[i].size;
+
+ /* Handle memory before this low memory section */
+ if (p < start) {
+ phys_addr_t s;
+ s = min(n, start - p);
+ add_memory_region(p, s, BOOT_MEM_RAM);
+ p += s;
+ n -= s;
+ }
+
+ /* Handle the low memory section itself. If it's aliased,
+ * we reduce the number of byes left, but if not, the RAM
+ * is available elsewhere and we don't reduce the number of
+ * bytes remaining. */
+ if (p == start) {
+ if (low_mem_reserved[i].is_aliased) {
+ s = min(n, size);
+ n -= s;
+ p += s;
+ } else
+ p += n;
+ }
}
+ return orig_n - n;
+}
+
/*
- * TODO: We will use the hard code for memory configuration until
- * the bootloader releases their device tree to us.
+ * register_ram - register real RAM
+ * @p: Address of memory as seen by devices
+ * @alias: If the memory is seen at an additional address by the processor,
+ * this will be the address, otherwise it is the same as @p.
+ * @n: Number of bytes in this section of memory
*/
+static __init void register_ram(phys_addr_t p, phys_addr_t alias,
+ phys_addr_t n)
+{
/*
- * Add the memory reserved for use by the bootloader to the
- * memory map.
+ * If some or all of this memory has an alias, break it into the
+ * aliased and non-aliased portion.
*/
- add_memory_region(PHYS_MEM_START, RES_BOOTLDR_MEMSIZE,
- BOOT_MEM_RESERVED);
-#ifdef CONFIG_HIGHMEM_256_128
- /*
- * Add memory in low for general use by the kernel and its friends
- * (like drivers, applications, etc).
- */
- add_memory_region(PHYS_MEM_START + RES_BOOTLDR_MEMSIZE,
- LOW_MEM_MAX - RES_BOOTLDR_MEMSIZE, BOOT_MEM_RAM);
- /*
- * Add the memory reserved for reset vector.
- */
- add_memory_region(0x1fc00000, MEBIBYTE(4), BOOT_MEM_RESERVED);
- /*
- * Add the memory reserved.
- */
- add_memory_region(0x20000000, MEBIBYTE(1024 + 75), BOOT_MEM_RESERVED);
- /*
- * Add memory in high for general use by the kernel and its friends
- * (like drivers, applications, etc).
- *
- * 75MB is reserved for devices which are using the memory in high.
- */
- add_memory_region(0x60000000 + MEBIBYTE(75), MEBIBYTE(128 - 75),
- BOOT_MEM_RAM);
-#elif defined CONFIG_HIGHMEM_128_128
- /*
- * Add memory in low for general use by the kernel and its friends
- * (like drivers, applications, etc).
- */
- add_memory_region(PHYS_MEM_START + RES_BOOTLDR_MEMSIZE,
- MEBIBYTE(128) - RES_BOOTLDR_MEMSIZE, BOOT_MEM_RAM);
- /*
- * Add the memory reserved.
- */
- add_memory_region(PHYS_MEM_START + MEBIBYTE(128),
- MEBIBYTE(128 + 1024 + 75), BOOT_MEM_RESERVED);
- /*
- * Add memory in high for general use by the kernel and its friends
- * (like drivers, applications, etc).
- *
- * 75MB is reserved for devices which are using the memory in high.
- */
- add_memory_region(0x60000000 + MEBIBYTE(75), MEBIBYTE(128 - 75),
- BOOT_MEM_RAM);
-#else
- /* Add low memory regions for either:
- * - no-highmemory configuration case -OR-
- * - highmemory "HIGHMEM_LOWBANK_ONLY" case
- */
- /*
- * Add memory for general use by the kernel and its friends
- * (like drivers, applications, etc).
- */
- add_memory_region(PHYS_MEM_START + RES_BOOTLDR_MEMSIZE,
- low_mem - RES_BOOTLDR_MEMSIZE, BOOT_MEM_RAM);
- /*
- * Add the memory reserved for reset vector.
- */
- add_memory_region(0x1fc00000, MEBIBYTE(4), BOOT_MEM_RESERVED);
+ if (p != alias) {
+ phys_addr_t alias_size;
+ phys_addr_t registered;
+
+ alias_size = min(n, LOW_RAM_END - alias);
+ registered = register_low_ram(alias, alias_size);
+ ioremap_add_map(alias, p, n);
+ n -= registered;
+ p += registered;
+ }
+
+#ifdef CONFIG_HIGHMEM
+ if (n != 0) {
+ add_memory_region(p, n, BOOT_MEM_RAM);
+ ioremap_add_map(p, p, n);
+ }
#endif
}
+/**
+ * register_address_space - register things in the address space
+ * @memsize: Number of bytes of RAM installed
+ *
+ * Takes the given number of bytes of RAM and registers as many of the regions,
+ * or partial regions, as it can. So, the default configuration might have
+ * two regions with 256 MiB each. If the memsize passed in on the command line
+ * is 384 MiB, it will register the first region with 256 MiB and the second
+ * with 128 MiB.
+ */
+static __init void register_address_space(phys_addr_t memsize)
+{
+ int i;
+ phys_addr_t size;
+ size_t n;
+ struct mem_layout *layout;
+ enum family_type family;
+
+ /*
+ * Register all of the things that aren't available to the kernel as
+ * memory.
+ */
+ register_non_ram();
+
+ /* Find the appropriate memory description */
+ family = platform_get_family();
+
+ for (i = 0; i < ARRAY_SIZE(layout_list); i++) {
+ if (layout_list[i].family == family)
+ break;
+ }
+
+ if (i == ARRAY_SIZE(layout_list)) {
+ n = ARRAY_SIZE(default_layout);
+ layout = default_layout;
+ } else {
+ n = layout_list[i].n;
+ layout = layout_list[i].layout;
+ }
+
+ for (i = 0; memsize != 0 && i < n; i++) {
+ size = min(memsize, layout[i].size);
+ register_ram(layout[i].phys, layout[i].alias, size);
+ memsize -= size;
+ }
+}
+
+void __init prom_meminit(void)
+{
+ ptv_memsize = get_memsize();
+ register_address_space(ptv_memsize);
+}
+
void __init prom_free_prom_memory(void)
{
unsigned long addr;