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author | Haavard Skinnemoen <hskinnemoen@atmel.com> | 2007-03-21 16:16:50 +0100 |
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committer | Haavard Skinnemoen <hskinnemoen@atmel.com> | 2007-04-27 13:44:14 +0200 |
commit | f9692b9501c339ec90647d8cd6ee5c106f072f9f (patch) | |
tree | 3a11d55a0383d10cb712b31bc18e57585cdeed4c | |
parent | d8011768e6bdd0d9de5cc7bdbd3077b4b4fab8c7 (diff) | |
download | op-kernel-dev-f9692b9501c339ec90647d8cd6ee5c106f072f9f.zip op-kernel-dev-f9692b9501c339ec90647d8cd6ee5c106f072f9f.tar.gz |
[AVR32] Reserve framebuffer memory in early_parse_fbmem()
With the current strategy of using the bootmem allocator to allocate
or reserve framebuffer memory, there's a slight chance that the
requested area has been taken by the boot allocator bitmap before we
get around to reserving it.
By inserting the framebuffer region as a reserved region as early as
possible, we improve our chances for success and we make the region
visible as a reserved region in dmesg and /proc/iomem without any
extra work.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
-rw-r--r-- | arch/avr32/kernel/setup.c | 68 |
1 files changed, 61 insertions, 7 deletions
diff --git a/arch/avr32/kernel/setup.c b/arch/avr32/kernel/setup.c index d0a35a1..1682e2d 100644 --- a/arch/avr32/kernel/setup.c +++ b/arch/avr32/kernel/setup.c @@ -191,21 +191,45 @@ find_free_region(const struct resource *mem, resource_size_t size, return target; } +static int __init +alloc_reserved_region(resource_size_t *start, resource_size_t size, + resource_size_t align, const char *name) +{ + struct resource *mem; + resource_size_t target; + int ret; + + for (mem = system_ram; mem; mem = mem->sibling) { + target = find_free_region(mem, size, align); + if (target <= mem->end) { + ret = add_reserved_region(target, target + size - 1, + name); + if (!ret) + *start = target; + return ret; + } + } + + return -ENOMEM; +} + /* * Early framebuffer allocation. Works as follows: * - If fbmem_size is zero, nothing will be allocated or reserved. * - If fbmem_start is zero when setup_bootmem() is called, - * fbmem_size bytes will be allocated from the bootmem allocator. + * a block of fbmem_size bytes will be reserved before bootmem + * initialization. It will be aligned to the largest page size + * that fbmem_size is a multiple of. * - If fbmem_start is nonzero, an area of size fbmem_size will be - * reserved at the physical address fbmem_start if necessary. If - * the area isn't in a memory region known to the kernel, it will - * be left alone. + * reserved at the physical address fbmem_start if possible. If + * it collides with other reserved memory, a different block of + * same size will be allocated, just as if fbmem_start was zero. * * Board-specific code may use these variables to set up platform data * for the framebuffer driver if fbmem_size is nonzero. */ -static unsigned long __initdata fbmem_start; -static unsigned long __initdata fbmem_size; +static resource_size_t __initdata fbmem_start; +static resource_size_t __initdata fbmem_size; /* * "fbmem=xxx[kKmM]" allocates the specified amount of boot memory for @@ -219,9 +243,39 @@ static unsigned long __initdata fbmem_size; */ static int __init early_parse_fbmem(char *p) { + int ret; + unsigned long align; + fbmem_size = memparse(p, &p); - if (*p == '@') + if (*p == '@') { fbmem_start = memparse(p, &p); + ret = add_reserved_region(fbmem_start, + fbmem_start + fbmem_size - 1, + "Framebuffer"); + if (ret) { + printk(KERN_WARNING + "Failed to reserve framebuffer memory\n"); + fbmem_start = 0; + } + } + + if (!fbmem_start) { + if ((fbmem_size & 0x000fffffUL) == 0) + align = 0x100000; /* 1 MiB */ + else if ((fbmem_size & 0x0000ffffUL) == 0) + align = 0x10000; /* 64 KiB */ + else + align = 0x1000; /* 4 KiB */ + + ret = alloc_reserved_region(&fbmem_start, fbmem_size, + align, "Framebuffer"); + if (ret) { + printk(KERN_WARNING + "Failed to allocate framebuffer memory\n"); + fbmem_size = 0; + } + } + return 0; } early_param("fbmem", early_parse_fbmem); |