[PATCH V2 12/16] drm/radeon: Make radeon card usable for Loongson.

Huacai Chen chenhuacai at gmail.com
Tue Jun 19 23:12:56 PDT 2012


On Tue, Jun 19, 2012 at 3:19 PM, Lucas Stach <dev at lynxeye.de> wrote:
> Hello Huacai,
>
> Am Dienstag, den 19.06.2012, 14:50 +0800 schrieb Huacai Chen:
>> 1, Use 32-bit DMA as a workaround (Loongson has a hardware bug that it
>>    doesn't support DMA address above 4GB).
>
> This is a bug of your platform/CPU and should be fixed at a lower level,
> not in every driver. While radeon might be the only device using 40bit
> DMA right know, it is very well possible that other devices pop up in
> the future. So please fix your platform code to disallow >32bit DMA.

Hi, Lucas
I have fixed my platform code to  disallow >32bit DMA. This method fix
the DMA problems in SATA and sound card, but fails on radeon (display
is OK, but accerlaration is unusable), because need_dma32 not only
affect dma_mask/coherent_dma_mask, but also affect th gfp_flags of
ttm_get_pages(). Platform code fixes cannot solve the problem of
ttm_get_pages(), could you please give me some suggestions? Thank you.

>
>> 2, Read vga bios offered by system firmware.
>> 3, Handle io prot correctly for MIPS.
>
> This seems good to me, but you should really split this out in a
> separate TTM patch.
>
>> 4, Don't use swiotlb on Loongson machines (when use swiotlb, GPU reset
>>    occurs at resume from suspend).
>>
> While SWIOTLB might not be a common setup, simply ignoring it because it
> doesn't work on your platform is the wrong thing to do. Could you please
> try to root-cause the issue?
>
> Thanks,
> Lucas
>
>> Signed-off-by: Huacai Chen <chenhc at lemote.com>
>> Signed-off-by: Hongliang Tao <taohl at lemote.com>
>> Signed-off-by: Hua Yan <yanh at lemote.com>
>> Cc: dri-devel at lists.freedesktop.org
>> ---
>>  drivers/gpu/drm/drm_vm.c               |    2 +-
>>  drivers/gpu/drm/radeon/radeon_bios.c   |   32 ++++++++++++++++++++++++++++++++
>>  drivers/gpu/drm/radeon/radeon_device.c |    5 +++++
>>  drivers/gpu/drm/radeon/radeon_ttm.c    |    6 +++---
>>  drivers/gpu/drm/ttm/ttm_bo_util.c      |    2 +-
>>  include/drm/drm_sarea.h                |    2 ++
>>  6 files changed, 44 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
>> index 961ee08..3f06166 100644
>> --- a/drivers/gpu/drm/drm_vm.c
>> +++ b/drivers/gpu/drm/drm_vm.c
>> @@ -62,7 +62,7 @@ static pgprot_t drm_io_prot(uint32_t map_type, struct vm_area_struct *vma)
>>               tmp = pgprot_writecombine(tmp);
>>       else
>>               tmp = pgprot_noncached(tmp);
>> -#elif defined(__sparc__) || defined(__arm__)
>> +#elif defined(__sparc__) || defined(__arm__) || defined(__mips__)
>>       tmp = pgprot_noncached(tmp);
>>  #endif
>>       return tmp;
>> diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
>> index 501f488..2630e22 100644
>> --- a/drivers/gpu/drm/radeon/radeon_bios.c
>> +++ b/drivers/gpu/drm/radeon/radeon_bios.c
>> @@ -29,6 +29,7 @@
>>  #include "radeon_reg.h"
>>  #include "radeon.h"
>>  #include "atom.h"
>> +#include <asm/bootinfo.h>
>>
>>  #include <linux/vga_switcheroo.h>
>>  #include <linux/slab.h>
>> @@ -73,6 +74,32 @@ static bool igp_read_bios_from_vram(struct radeon_device *rdev)
>>       return true;
>>  }
>>
>> +#ifdef CONFIG_CPU_LOONGSON3
>> +extern u64 vgabios_addr;
>> +static bool loongson3_read_bios(struct radeon_device *rdev)
>> +{
>> +     u8 *bios;
>> +     resource_size_t size = 512 * 1024; /* ??? */
>> +
>> +     rdev->bios = NULL;
>> +
>> +     bios = (u8 *)vgabios_addr;
>> +     if (!bios) {
>> +             return false;
>> +     }
>> +
>> +     if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
>> +             return false;
>> +     }
>> +     rdev->bios = kmalloc(size, GFP_KERNEL);
>> +     if (rdev->bios == NULL) {
>> +             return false;
>> +     }
>> +     memcpy(rdev->bios, bios, size);
>> +     return true;
>> +}
>> +#endif
>> +
>>  static bool radeon_read_bios(struct radeon_device *rdev)
>>  {
>>       uint8_t __iomem *bios;
>> @@ -490,6 +517,11 @@ bool radeon_get_bios(struct radeon_device *rdev)
>>       if (r == false) {
>>               r = radeon_read_disabled_bios(rdev);
>>       }
>> +#ifdef CONFIG_CPU_LOONGSON3
>> +     if (r == false) {
>> +             r = loongson3_read_bios(rdev);
>> +     }
>> +#endif
>>       if (r == false || rdev->bios == NULL) {
>>               DRM_ERROR("Unable to locate a BIOS ROM\n");
>>               rdev->bios = NULL;
>> diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
>> index 066c98b..8aac7ab 100644
>> --- a/drivers/gpu/drm/radeon/radeon_device.c
>> +++ b/drivers/gpu/drm/radeon/radeon_device.c
>> @@ -777,6 +777,11 @@ int radeon_device_init(struct radeon_device *rdev,
>>           (rdev->family < CHIP_RS400))
>>               rdev->need_dma32 = true;
>>
>> +#ifdef CONFIG_CPU_LOONGSON3
>> +     /* Workaround: Loongson 3 doesn't support 40-bits DMA */
>> +     rdev->need_dma32 = true;
>> +#endif
>> +
>>       dma_bits = rdev->need_dma32 ? 32 : 40;
>>       r = pci_set_dma_mask(rdev->pdev, DMA_BIT_MASK(dma_bits));
>>       if (r) {
>> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
>> index c94a225..f49bdd1 100644
>> --- a/drivers/gpu/drm/radeon/radeon_ttm.c
>> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
>> @@ -630,7 +630,7 @@ static int radeon_ttm_tt_populate(struct ttm_tt *ttm)
>>       }
>>  #endif
>>
>> -#ifdef CONFIG_SWIOTLB
>> +#if defined(CONFIG_SWIOTLB) && !defined(CONFIG_CPU_LOONGSON3)
>>       if (swiotlb_nr_tbl()) {
>>               return ttm_dma_populate(&gtt->ttm, rdev->dev);
>>       }
>> @@ -676,7 +676,7 @@ static void radeon_ttm_tt_unpopulate(struct ttm_tt *ttm)
>>       }
>>  #endif
>>
>> -#ifdef CONFIG_SWIOTLB
>> +#if defined(CONFIG_SWIOTLB) && !defined(CONFIG_CPU_LOONGSON3)
>>       if (swiotlb_nr_tbl()) {
>>               ttm_dma_unpopulate(&gtt->ttm, rdev->dev);
>>               return;
>> @@ -906,7 +906,7 @@ static int radeon_ttm_debugfs_init(struct radeon_device *rdev)
>>       radeon_mem_types_list[i].show = &ttm_page_alloc_debugfs;
>>       radeon_mem_types_list[i].driver_features = 0;
>>       radeon_mem_types_list[i++].data = NULL;
>> -#ifdef CONFIG_SWIOTLB
>> +#if defined(CONFIG_SWIOTLB) && !defined(CONFIG_CPU_LOONGSON3)
>>       if (swiotlb_nr_tbl()) {
>>               sprintf(radeon_mem_types_names[i], "ttm_dma_page_pool");
>>               radeon_mem_types_list[i].name = radeon_mem_types_names[i];
>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
>> index f8187ea..0df71ea 100644
>> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
>> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
>> @@ -472,7 +472,7 @@ pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp)
>>       else
>>               tmp = pgprot_noncached(tmp);
>>  #endif
>> -#if defined(__sparc__)
>> +#if defined(__sparc__) || defined(__mips__)
>>       if (!(caching_flags & TTM_PL_FLAG_CACHED))
>>               tmp = pgprot_noncached(tmp);
>>  #endif
>> diff --git a/include/drm/drm_sarea.h b/include/drm/drm_sarea.h
>> index ee5389d..1d1a858 100644
>> --- a/include/drm/drm_sarea.h
>> +++ b/include/drm/drm_sarea.h
>> @@ -37,6 +37,8 @@
>>  /* SAREA area needs to be at least a page */
>>  #if defined(__alpha__)
>>  #define SAREA_MAX                       0x2000U
>> +#elif defined(__mips__)
>> +#define SAREA_MAX                       0x4000U
>>  #elif defined(__ia64__)
>>  #define SAREA_MAX                       0x10000U     /* 64kB */
>>  #else
>
>


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