linux/drivers/video/omap2/vram.c
Tomi Valkeinen 4422c04bbb OMAP: DSS: VRAM: Align start & size of vram to 2M
Align the start address and size of VRAM area to 2M as per comments from
Russell King:

> > So, why SZ_2M?
>
> Firstly, that's the granularity which we allocate page tables - one
> Linux page table covers 2MB of memory.  We want to avoid creating page
> tables for the main memory mapping as that increases TLB pressure through
> the use of additional TLB entries, and more page table walks.
>
> Plus, we never used to allow the kernel's direct memory mapping to be
> mapped at anything less than section size - this restriction has since
> been lifted due to OMAP SRAM problems, but I'd rather we stuck with it
> to ensure that we have proper behaviour from all parts of the system.
>
> Secondly, we don't want to end up with lots of fragmentation at the end
> of the memory mapping as that'll reduce performance, not only by making
> the pfn_valid() search more expensive.
>
> Emsuring a minimum allocation size and alignment makes sure that the
> regions can be coalesced together into one block, and minimises run-time
> expenses.
>
> So please, 2MB, or if you object, at the _very_ _least_ 1MB.  But
> definitely not PAGE_SIZE.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2010-12-15 11:16:08 +02:00

659 lines
14 KiB
C

/*
* VRAM manager for OMAP
*
* Copyright (C) 2009 Nokia Corporation
* Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/*#define DEBUG*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/memblock.h>
#include <linux/completion.h>
#include <linux/debugfs.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <asm/setup.h>
#include <plat/sram.h>
#include <plat/vram.h>
#include <plat/dma.h>
#ifdef DEBUG
#define DBG(format, ...) pr_debug("VRAM: " format, ## __VA_ARGS__)
#else
#define DBG(format, ...)
#endif
#define OMAP2_SRAM_START 0x40200000
/* Maximum size, in reality this is smaller if SRAM is partially locked. */
#define OMAP2_SRAM_SIZE 0xa0000 /* 640k */
/* postponed regions are used to temporarily store region information at boot
* time when we cannot yet allocate the region list */
#define MAX_POSTPONED_REGIONS 10
static bool vram_initialized;
static int postponed_cnt;
static struct {
unsigned long paddr;
size_t size;
} postponed_regions[MAX_POSTPONED_REGIONS];
struct vram_alloc {
struct list_head list;
unsigned long paddr;
unsigned pages;
};
struct vram_region {
struct list_head list;
struct list_head alloc_list;
unsigned long paddr;
unsigned pages;
};
static DEFINE_MUTEX(region_mutex);
static LIST_HEAD(region_list);
static inline int region_mem_type(unsigned long paddr)
{
if (paddr >= OMAP2_SRAM_START &&
paddr < OMAP2_SRAM_START + OMAP2_SRAM_SIZE)
return OMAP_VRAM_MEMTYPE_SRAM;
else
return OMAP_VRAM_MEMTYPE_SDRAM;
}
static struct vram_region *omap_vram_create_region(unsigned long paddr,
unsigned pages)
{
struct vram_region *rm;
rm = kzalloc(sizeof(*rm), GFP_KERNEL);
if (rm) {
INIT_LIST_HEAD(&rm->alloc_list);
rm->paddr = paddr;
rm->pages = pages;
}
return rm;
}
#if 0
static void omap_vram_free_region(struct vram_region *vr)
{
list_del(&vr->list);
kfree(vr);
}
#endif
static struct vram_alloc *omap_vram_create_allocation(struct vram_region *vr,
unsigned long paddr, unsigned pages)
{
struct vram_alloc *va;
struct vram_alloc *new;
new = kzalloc(sizeof(*va), GFP_KERNEL);
if (!new)
return NULL;
new->paddr = paddr;
new->pages = pages;
list_for_each_entry(va, &vr->alloc_list, list) {
if (va->paddr > new->paddr)
break;
}
list_add_tail(&new->list, &va->list);
return new;
}
static void omap_vram_free_allocation(struct vram_alloc *va)
{
list_del(&va->list);
kfree(va);
}
int omap_vram_add_region(unsigned long paddr, size_t size)
{
struct vram_region *rm;
unsigned pages;
if (vram_initialized) {
DBG("adding region paddr %08lx size %d\n",
paddr, size);
size &= PAGE_MASK;
pages = size >> PAGE_SHIFT;
rm = omap_vram_create_region(paddr, pages);
if (rm == NULL)
return -ENOMEM;
list_add(&rm->list, &region_list);
} else {
if (postponed_cnt == MAX_POSTPONED_REGIONS)
return -ENOMEM;
postponed_regions[postponed_cnt].paddr = paddr;
postponed_regions[postponed_cnt].size = size;
++postponed_cnt;
}
return 0;
}
int omap_vram_free(unsigned long paddr, size_t size)
{
struct vram_region *rm;
struct vram_alloc *alloc;
unsigned start, end;
DBG("free mem paddr %08lx size %d\n", paddr, size);
size = PAGE_ALIGN(size);
mutex_lock(&region_mutex);
list_for_each_entry(rm, &region_list, list) {
list_for_each_entry(alloc, &rm->alloc_list, list) {
start = alloc->paddr;
end = alloc->paddr + (alloc->pages >> PAGE_SHIFT);
if (start >= paddr && end < paddr + size)
goto found;
}
}
mutex_unlock(&region_mutex);
return -EINVAL;
found:
omap_vram_free_allocation(alloc);
mutex_unlock(&region_mutex);
return 0;
}
EXPORT_SYMBOL(omap_vram_free);
static int _omap_vram_reserve(unsigned long paddr, unsigned pages)
{
struct vram_region *rm;
struct vram_alloc *alloc;
size_t size;
size = pages << PAGE_SHIFT;
list_for_each_entry(rm, &region_list, list) {
unsigned long start, end;
DBG("checking region %lx %d\n", rm->paddr, rm->pages);
if (region_mem_type(rm->paddr) != region_mem_type(paddr))
continue;
start = rm->paddr;
end = start + (rm->pages << PAGE_SHIFT) - 1;
if (start > paddr || end < paddr + size - 1)
continue;
DBG("block ok, checking allocs\n");
list_for_each_entry(alloc, &rm->alloc_list, list) {
end = alloc->paddr - 1;
if (start <= paddr && end >= paddr + size - 1)
goto found;
start = alloc->paddr + (alloc->pages << PAGE_SHIFT);
}
end = rm->paddr + (rm->pages << PAGE_SHIFT) - 1;
if (!(start <= paddr && end >= paddr + size - 1))
continue;
found:
DBG("found area start %lx, end %lx\n", start, end);
if (omap_vram_create_allocation(rm, paddr, pages) == NULL)
return -ENOMEM;
return 0;
}
return -ENOMEM;
}
int omap_vram_reserve(unsigned long paddr, size_t size)
{
unsigned pages;
int r;
DBG("reserve mem paddr %08lx size %d\n", paddr, size);
size = PAGE_ALIGN(size);
pages = size >> PAGE_SHIFT;
mutex_lock(&region_mutex);
r = _omap_vram_reserve(paddr, pages);
mutex_unlock(&region_mutex);
return r;
}
EXPORT_SYMBOL(omap_vram_reserve);
static void _omap_vram_dma_cb(int lch, u16 ch_status, void *data)
{
struct completion *compl = data;
complete(compl);
}
static int _omap_vram_clear(u32 paddr, unsigned pages)
{
struct completion compl;
unsigned elem_count;
unsigned frame_count;
int r;
int lch;
init_completion(&compl);
r = omap_request_dma(OMAP_DMA_NO_DEVICE, "VRAM DMA",
_omap_vram_dma_cb,
&compl, &lch);
if (r) {
pr_err("VRAM: request_dma failed for memory clear\n");
return -EBUSY;
}
elem_count = pages * PAGE_SIZE / 4;
frame_count = 1;
omap_set_dma_transfer_params(lch, OMAP_DMA_DATA_TYPE_S32,
elem_count, frame_count,
OMAP_DMA_SYNC_ELEMENT,
0, 0);
omap_set_dma_dest_params(lch, 0, OMAP_DMA_AMODE_POST_INC,
paddr, 0, 0);
omap_set_dma_color_mode(lch, OMAP_DMA_CONSTANT_FILL, 0x000000);
omap_start_dma(lch);
if (wait_for_completion_timeout(&compl, msecs_to_jiffies(1000)) == 0) {
omap_stop_dma(lch);
pr_err("VRAM: dma timeout while clearing memory\n");
r = -EIO;
goto err;
}
r = 0;
err:
omap_free_dma(lch);
return r;
}
static int _omap_vram_alloc(int mtype, unsigned pages, unsigned long *paddr)
{
struct vram_region *rm;
struct vram_alloc *alloc;
list_for_each_entry(rm, &region_list, list) {
unsigned long start, end;
DBG("checking region %lx %d\n", rm->paddr, rm->pages);
if (region_mem_type(rm->paddr) != mtype)
continue;
start = rm->paddr;
list_for_each_entry(alloc, &rm->alloc_list, list) {
end = alloc->paddr;
if (end - start >= pages << PAGE_SHIFT)
goto found;
start = alloc->paddr + (alloc->pages << PAGE_SHIFT);
}
end = rm->paddr + (rm->pages << PAGE_SHIFT);
found:
if (end - start < pages << PAGE_SHIFT)
continue;
DBG("found %lx, end %lx\n", start, end);
alloc = omap_vram_create_allocation(rm, start, pages);
if (alloc == NULL)
return -ENOMEM;
*paddr = start;
_omap_vram_clear(start, pages);
return 0;
}
return -ENOMEM;
}
int omap_vram_alloc(int mtype, size_t size, unsigned long *paddr)
{
unsigned pages;
int r;
BUG_ON(mtype > OMAP_VRAM_MEMTYPE_MAX || !size);
DBG("alloc mem type %d size %d\n", mtype, size);
size = PAGE_ALIGN(size);
pages = size >> PAGE_SHIFT;
mutex_lock(&region_mutex);
r = _omap_vram_alloc(mtype, pages, paddr);
mutex_unlock(&region_mutex);
return r;
}
EXPORT_SYMBOL(omap_vram_alloc);
void omap_vram_get_info(unsigned long *vram,
unsigned long *free_vram,
unsigned long *largest_free_block)
{
struct vram_region *vr;
struct vram_alloc *va;
*vram = 0;
*free_vram = 0;
*largest_free_block = 0;
mutex_lock(&region_mutex);
list_for_each_entry(vr, &region_list, list) {
unsigned free;
unsigned long pa;
pa = vr->paddr;
*vram += vr->pages << PAGE_SHIFT;
list_for_each_entry(va, &vr->alloc_list, list) {
free = va->paddr - pa;
*free_vram += free;
if (free > *largest_free_block)
*largest_free_block = free;
pa = va->paddr + (va->pages << PAGE_SHIFT);
}
free = vr->paddr + (vr->pages << PAGE_SHIFT) - pa;
*free_vram += free;
if (free > *largest_free_block)
*largest_free_block = free;
}
mutex_unlock(&region_mutex);
}
EXPORT_SYMBOL(omap_vram_get_info);
#if defined(CONFIG_DEBUG_FS)
static int vram_debug_show(struct seq_file *s, void *unused)
{
struct vram_region *vr;
struct vram_alloc *va;
unsigned size;
mutex_lock(&region_mutex);
list_for_each_entry(vr, &region_list, list) {
size = vr->pages << PAGE_SHIFT;
seq_printf(s, "%08lx-%08lx (%d bytes)\n",
vr->paddr, vr->paddr + size - 1,
size);
list_for_each_entry(va, &vr->alloc_list, list) {
size = va->pages << PAGE_SHIFT;
seq_printf(s, " %08lx-%08lx (%d bytes)\n",
va->paddr, va->paddr + size - 1,
size);
}
}
mutex_unlock(&region_mutex);
return 0;
}
static int vram_debug_open(struct inode *inode, struct file *file)
{
return single_open(file, vram_debug_show, inode->i_private);
}
static const struct file_operations vram_debug_fops = {
.open = vram_debug_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init omap_vram_create_debugfs(void)
{
struct dentry *d;
d = debugfs_create_file("vram", S_IRUGO, NULL,
NULL, &vram_debug_fops);
if (IS_ERR(d))
return PTR_ERR(d);
return 0;
}
#endif
static __init int omap_vram_init(void)
{
int i;
vram_initialized = 1;
for (i = 0; i < postponed_cnt; i++)
omap_vram_add_region(postponed_regions[i].paddr,
postponed_regions[i].size);
#ifdef CONFIG_DEBUG_FS
if (omap_vram_create_debugfs())
pr_err("VRAM: Failed to create debugfs file\n");
#endif
return 0;
}
arch_initcall(omap_vram_init);
/* boottime vram alloc stuff */
/* set from board file */
static u32 omap_vram_sram_start __initdata;
static u32 omap_vram_sram_size __initdata;
/* set from board file */
static u32 omap_vram_sdram_start __initdata;
static u32 omap_vram_sdram_size __initdata;
/* set from kernel cmdline */
static u32 omap_vram_def_sdram_size __initdata;
static u32 omap_vram_def_sdram_start __initdata;
static int __init omap_vram_early_vram(char *p)
{
omap_vram_def_sdram_size = memparse(p, &p);
if (*p == ',')
omap_vram_def_sdram_start = simple_strtoul(p + 1, &p, 16);
return 0;
}
early_param("vram", omap_vram_early_vram);
/*
* Called from map_io. We need to call to this early enough so that we
* can reserve the fixed SDRAM regions before VM could get hold of them.
*/
void __init omap_vram_reserve_sdram_memblock(void)
{
u32 paddr;
u32 size = 0;
/* cmdline arg overrides the board file definition */
if (omap_vram_def_sdram_size) {
size = omap_vram_def_sdram_size;
paddr = omap_vram_def_sdram_start;
}
if (!size) {
size = omap_vram_sdram_size;
paddr = omap_vram_sdram_start;
}
#ifdef CONFIG_OMAP2_VRAM_SIZE
if (!size) {
size = CONFIG_OMAP2_VRAM_SIZE * 1024 * 1024;
paddr = 0;
}
#endif
if (!size)
return;
size = ALIGN(size, SZ_2M);
if (paddr) {
if (paddr & ~PAGE_MASK) {
pr_err("VRAM start address 0x%08x not page aligned\n",
paddr);
return;
}
if (!memblock_is_region_memory(paddr, size)) {
pr_err("Illegal SDRAM region 0x%08x..0x%08x for VRAM\n",
paddr, paddr + size - 1);
return;
}
if (memblock_is_region_reserved(paddr, size)) {
pr_err("FB: failed to reserve VRAM - busy\n");
return;
}
if (memblock_reserve(paddr, size) < 0) {
pr_err("FB: failed to reserve VRAM - no memory\n");
return;
}
} else {
paddr = memblock_alloc(size, SZ_2M);
}
memblock_free(paddr, size);
memblock_remove(paddr, size);
omap_vram_add_region(paddr, size);
pr_info("Reserving %u bytes SDRAM for VRAM\n", size);
}
/*
* Called at sram init time, before anything is pushed to the SRAM stack.
* Because of the stack scheme, we will allocate everything from the
* start of the lowest address region to the end of SRAM. This will also
* include padding for page alignment and possible holes between regions.
*
* As opposed to the SDRAM case, we'll also do any dynamic allocations at
* this point, since the driver built as a module would have problem with
* freeing / reallocating the regions.
*/
unsigned long __init omap_vram_reserve_sram(unsigned long sram_pstart,
unsigned long sram_vstart,
unsigned long sram_size,
unsigned long pstart_avail,
unsigned long size_avail)
{
unsigned long pend_avail;
unsigned long reserved;
u32 paddr;
u32 size;
paddr = omap_vram_sram_start;
size = omap_vram_sram_size;
if (!size)
return 0;
reserved = 0;
pend_avail = pstart_avail + size_avail;
if (!paddr) {
/* Dynamic allocation */
if ((size_avail & PAGE_MASK) < size) {
pr_err("Not enough SRAM for VRAM\n");
return 0;
}
size_avail = (size_avail - size) & PAGE_MASK;
paddr = pstart_avail + size_avail;
}
if (paddr < sram_pstart ||
paddr + size > sram_pstart + sram_size) {
pr_err("Illegal SRAM region for VRAM\n");
return 0;
}
/* Reserve everything above the start of the region. */
if (pend_avail - paddr > reserved)
reserved = pend_avail - paddr;
size_avail = pend_avail - reserved - pstart_avail;
omap_vram_add_region(paddr, size);
if (reserved)
pr_info("Reserving %lu bytes SRAM for VRAM\n", reserved);
return reserved;
}
void __init omap_vram_set_sdram_vram(u32 size, u32 start)
{
omap_vram_sdram_start = start;
omap_vram_sdram_size = size;
}
void __init omap_vram_set_sram_vram(u32 size, u32 start)
{
omap_vram_sram_start = start;
omap_vram_sram_size = size;
}