kernel-ark/arch/arm/plat-orion/addr-map.c
Thomas Petazzoni 217bef3d37 arm: plat-orion: fix address decoding when > 4GB is used
During the system initialization, the orion_setup_cpu_mbus_target()
function reads the SDRAM address decoding registers to find out how
many chip-selects of SDRAM have been enabled, and builds a small array
with one entry per chip-select. This array is then used by device
drivers (XOR, Ethernet, etc.) to configure their own address decoding
windows to the SDRAM.

However, devices can only access the first 32 bits of the physical
memory. Even though LPAE is not supported for now, some Marvell boards
are now showing up with 8 GB of RAM, configured using two SDRAM
address decoding windows: the first covering the first 4 GB, the
second covering the last 4 GB. The array built by
orion_setup_cpu_mbus_target() has therefore two entries, and device
drivers try to set up two address decoding windows to the
SDRAM. However, in the device registers for the address decoding, the
base address is only 32 bits, so those two windows overlap each other,
and the devices do not work at all.

This patch makes sure that the array built by
orion_setup_cpu_mbus_target() only contains the SDRAM decoding windows
that correspond to the first 4 GB of the memory. To do that, it
ignores the SDRAM decoding windows for which the 4 low-order bits are
not zero (the 4 low-order bits of the base register are used to store
bits 32:35 of the base address, so they actually indicate whether the
base address is above 4 GB).

This patch allows the newly introduced armada-xp-gp board to properly
operate when it is mounted with more than 4 GB of RAM. Without that,
all devices doing DMA (for example XOR and Ethernet) do not work at
all.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2013-03-08 22:07:19 +00:00

179 lines
4.2 KiB
C

/*
* arch/arm/plat-orion/addr-map.c
*
* Address map functions for Marvell Orion based SoCs
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mbus.h>
#include <linux/io.h>
#include <plat/addr-map.h>
struct mbus_dram_target_info orion_mbus_dram_info;
const struct mbus_dram_target_info *mv_mbus_dram_info(void)
{
return &orion_mbus_dram_info;
}
EXPORT_SYMBOL_GPL(mv_mbus_dram_info);
/*
* DDR target is the same on all Orion platforms.
*/
#define TARGET_DDR 0
/*
* Helpers to get DDR bank info
*/
#define DDR_BASE_CS_OFF(n) (0x0000 + ((n) << 3))
#define DDR_SIZE_CS_OFF(n) (0x0004 + ((n) << 3))
/*
* CPU Address Decode Windows registers
*/
#define WIN_CTRL_OFF 0x0000
#define WIN_BASE_OFF 0x0004
#define WIN_REMAP_LO_OFF 0x0008
#define WIN_REMAP_HI_OFF 0x000c
#define ATTR_HW_COHERENCY (0x1 << 4)
/*
* Default implementation
*/
static void __init __iomem *
orion_win_cfg_base(const struct orion_addr_map_cfg *cfg, int win)
{
return cfg->bridge_virt_base + (win << 4);
}
/*
* Default implementation
*/
static int __init orion_cpu_win_can_remap(const struct orion_addr_map_cfg *cfg,
const int win)
{
if (win < cfg->remappable_wins)
return 1;
return 0;
}
void __init orion_setup_cpu_win(const struct orion_addr_map_cfg *cfg,
const int win, const u32 base,
const u32 size, const u8 target,
const u8 attr, const int remap)
{
void __iomem *addr = cfg->win_cfg_base(cfg, win);
u32 ctrl, base_high, remap_addr;
if (win >= cfg->num_wins) {
printk(KERN_ERR "setup_cpu_win: trying to allocate window "
"%d when only %d allowed\n", win, cfg->num_wins);
}
base_high = base & 0xffff0000;
ctrl = ((size - 1) & 0xffff0000) | (attr << 8) | (target << 4) | 1;
writel(base_high, addr + WIN_BASE_OFF);
writel(ctrl, addr + WIN_CTRL_OFF);
if (cfg->cpu_win_can_remap(cfg, win)) {
if (remap < 0)
remap_addr = base;
else
remap_addr = remap;
writel(remap_addr & 0xffff0000, addr + WIN_REMAP_LO_OFF);
writel(0, addr + WIN_REMAP_HI_OFF);
}
}
/*
* Configure a number of windows.
*/
static void __init orion_setup_cpu_wins(const struct orion_addr_map_cfg * cfg,
const struct orion_addr_map_info *info)
{
while (info->win != -1) {
orion_setup_cpu_win(cfg, info->win, info->base, info->size,
info->target, info->attr, info->remap);
info++;
}
}
static void __init orion_disable_wins(const struct orion_addr_map_cfg * cfg)
{
void __iomem *addr;
int i;
for (i = 0; i < cfg->num_wins; i++) {
addr = cfg->win_cfg_base(cfg, i);
writel(0, addr + WIN_BASE_OFF);
writel(0, addr + WIN_CTRL_OFF);
if (cfg->cpu_win_can_remap(cfg, i)) {
writel(0, addr + WIN_REMAP_LO_OFF);
writel(0, addr + WIN_REMAP_HI_OFF);
}
}
}
/*
* Disable, clear and configure windows.
*/
void __init orion_config_wins(struct orion_addr_map_cfg * cfg,
const struct orion_addr_map_info *info)
{
if (!cfg->cpu_win_can_remap)
cfg->cpu_win_can_remap = orion_cpu_win_can_remap;
if (!cfg->win_cfg_base)
cfg->win_cfg_base = orion_win_cfg_base;
orion_disable_wins(cfg);
if (info)
orion_setup_cpu_wins(cfg, info);
}
/*
* Setup MBUS dram target info.
*/
void __init orion_setup_cpu_mbus_target(const struct orion_addr_map_cfg *cfg,
const void __iomem *ddr_window_cpu_base)
{
int i;
int cs;
orion_mbus_dram_info.mbus_dram_target_id = TARGET_DDR;
for (i = 0, cs = 0; i < 4; i++) {
u32 base = readl(ddr_window_cpu_base + DDR_BASE_CS_OFF(i));
u32 size = readl(ddr_window_cpu_base + DDR_SIZE_CS_OFF(i));
/*
* We only take care of entries for which the chip
* select is enabled, and that don't have high base
* address bits set (devices can only access the first
* 32 bits of the memory).
*/
if ((size & 1) && !(base & 0xF)) {
struct mbus_dram_window *w;
w = &orion_mbus_dram_info.cs[cs++];
w->cs_index = i;
w->mbus_attr = 0xf & ~(1 << i);
if (cfg->hw_io_coherency)
w->mbus_attr |= ATTR_HW_COHERENCY;
w->base = base & 0xffff0000;
w->size = (size | 0x0000ffff) + 1;
}
}
orion_mbus_dram_info.num_cs = cs;
}