On Wed, Jun 10, 2009 at 21:32, Konrad Eisele<konrad@xxxxxxxxxxx> wrote:
>>
>> [snip]
>>
>>> +#ifndef __ASSEMBLY__
>>> +
>>> +/* do a virtual address read without cache */
>>> +static inline unsigned long leon_readnobuffer_reg(unsigned long paddr)
>>> +{
>>> + unsigned long retval;
>>> + __asm__ __volatile__("lda [%1] %2, %0\n\t" :
>>> + "=r"(retval) : "r"(paddr),
>>> "i"(ASI_LEON_NOCACHE));
>>> + return retval;
>>> +}
>>> +
>>> +/* do a physical address bypass write, i.e. for 0x80000000 */
>>> +static inline void leon_store_reg(unsigned long paddr, unsigned long
>>> value)
>>> +{
>>> + __asm__ __volatile__("sta %0, [%1] %2\n\t" : : "r"(value),
>>> "r"(paddr),
>>> + "i"(ASI_LEON_BYPASS) : "memory");
>>> +}
>>> +
>>> +/* do a physical address bypass load, i.e. for 0x80000000 */
>>> +static inline unsigned long leon_load_reg(unsigned long paddr)
>>> +{
>>> + unsigned long retval;
>>> + __asm__ __volatile__("lda [%1] %2, %0\n\t" :
>>> + "=r"(retval) : "r"(paddr),
>>> "i"(ASI_LEON_BYPASS));
>>> + return retval;
>>> +}
>>> +
>>> +extern inline void leon_srmmu_disabletlb(void)
>>> +{
>>> + unsigned int retval;
>>> + __asm__ __volatile__("lda [%%g0] %2, %0\n\t" : "=r"(retval) :
>>> "r"(0),
>>> + "i"(ASI_LEON_MMUREGS));
>>> + retval |= LEON_CNR_CTRL_TLBDIS;
>>> + __asm__ __volatile__("sta %0, [%%g0] %2\n\t" : : "r"(retval),
>>> "r"(0),
>>> + "i"(ASI_LEON_MMUREGS) : "memory");
>>> +}
>>> +
>>> +extern inline void leon_srmmu_enabletlb(void)
>>> +{
>>> + unsigned int retval;
>>> + __asm__ __volatile__("lda [%%g0] %2, %0\n\t" : "=r"(retval) :
>>> "r"(0),
>>> + "i"(ASI_LEON_MMUREGS));
>>> + retval = retval & ~LEON_CNR_CTRL_TLBDIS;
>>> + __asm__ __volatile__("sta %0, [%%g0] %2\n\t" : : "r"(retval),
>>> "r"(0),
>>> + "i"(ASI_LEON_MMUREGS) : "memory");
>>> +}
>
> leon_readnobuffer_reg() read from virtual address but force a cache miss
> leon_store_reg() leon_load_reg() read from physical address using MMU bypass
> leon_srmmu_disabletlb() and leon_srmmu_enabletlb() are 2 leon specific
> helper
> functions: the leon-srmmu's tlb can be enabled/disabled (like caches).
> Mostly
> used for debugging but useful anyway.
>
>>
>> [snip]
>>
>>> +extern inline unsigned long sparc_leon3_get_dcachecfg(void)
>>> +{
>>> + unsigned int retval;
>>> + __asm__ __volatile__("lda [%1] %2, %0\n\t" :
>>> + "=r"(retval) :
>>> + "r"(ASI_LEON3_SYSCTRL_DCFG),
>>> + "i"(ASI_LEON3_SYSCTRL));
>>> + return retval;
>>> +}
>>> +
>>> +/*enable snooping*/
>>> +extern inline void sparc_leon3_enable_snooping(void)
>>> +{
>>> + __asm__ __volatile__ ("lda [%%g0] 2, %%l1\n\t"
>>> + "set 0x800000, %%l2\n\t"
>>> + "or %%l2, %%l1, %%l2\n\t"
>>> + "sta %%l2, [%%g0] 2\n\t" : : : "l1", "l2");
>>> +};
>>> +
>>> +extern inline void sparc_leon3_disable_cache(void)
>>> +{
>>> + __asm__ __volatile__ ("lda [%%g0] 2, %%l1\n\t"
>>> + "set 0x00000f, %%l2\n\t"
>>> + "andn %%l2, %%l1, %%l2\n\t"
>>> + "sta %%l2, [%%g0] 2\n\t" : : : "l1", "l2");
>>> +};
>>
>> I don't understand what's going on with this code, but I don't think
>> it should live in a header file.
>
> Note that there is a
> #ifdef CONFIG_SPARC_LEON
> around the whole leon.h file.
>
> sparc_leon3_get_dcachecfg() gets the cache configuration information.
> That is cache size etc.
> sparc_leon3_enable_snooping() enables snooping on the amba bus for the
> caches.
> sparc_leon3_disable_cache() disable the caches.
>
> All of theses functions are useful to leon.h . How do you think one
> should proceed? Do you really think it is cleaner when creating a
> new .h file just for the inlines. Isnt it quite neat with just one leon.h
> file that includes all sparc-leon specific things?
My issue with these functions being in leon.h is that they are code in
a header file, despite being small inline functions.
If I were writing this code, I would have placed the functions in
files called leon_debug.c or leon_cache.c. However given that these
are very low-level functions, and are essentially being used as
macros, I can understand why you've put them in this file.
It's pretty much up to you. Now that I've had a better look at these,
I understand why you've done this the way you have.
Thanks,
--
Julian Calaby
Email: julian.calaby@xxxxxxxxx
.Plan: http://sites.google.com/site/juliancalaby/
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