Re: [PATCH 1/2] m68k/atari - stram: alloc ST-RAM pool even if kernel not in ST-RAM

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Geert,
Instead of mucking around with ioremap (which appears to
rely on the physical area being mappped by mem_init), use

That's not true. E.g. I/O memory is never mapped by mem_init().

Why, then, does the ioremap() of ST-RAM fail? Because the physical address is lower than the lowest currently mapped physical address?

@@ -93,21 +92,54 @@ void __init atari_stram_init(void)
  */
 void __init atari_stram_reserve_pages(void *start_mem)
 {
-       /*
-        * always reserve first page of ST-RAM, the first 2 KiB are
-        * supervisor-only!
-        */
-       if (!kernel_in_stram)
-               reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT);
-
-       stram_pool.start = (resource_size_t)alloc_bootmem_low_pages(pool_size);
-       stram_pool.end = stram_pool.start + pool_size - 1;
-       request_resource(&iomem_resource, &stram_pool);
+       if (kernel_in_stram) {
+
+               stram_pool.start = (resource_size_t)alloc_bootmem_low_pages(pool_size);
+               stram_pool.end = stram_pool.start + pool_size - 1;
+               request_resource(&iomem_resource, &stram_pool);
+
+               printk("atari_stram pool: kernel in ST-RAM, using alloc_bootmem!\n");
+
+               printk("atari_stram pool: size = %lu bytes, resource = %pR\n",
+                        pool_size, &stram_pool);
+               printk("atari_stram pool: start = %p, end = %p\n",
+                         (void *) stram_pool.start, (void *) stram_pool.end);
+               printk("atari_stram pool: stram_virt_offset = %p\n",
+                         (void *) stram_virt_offset);
+       } else {
+               /*
+                * Skip page 0, as the fhe first 2 KiB are supervisor-only!
+                */
+
+               printk("atari_stram pool: kernel not in ST-RAM, using ioremap!\n");
+
+               stram_pool.start = PAGE_SIZE;
+               stram_pool.end = stram_pool.start + pool_size - 1;
+
+               request_resource(&iomem_resource, &stram_pool);
+
+               printk("atari_stram pool: size = %lu bytes, resource = %pR\n",
+                        pool_size, &stram_pool);
+               printk("atari_stram pool: start = %p, end = %p\n",
+                         (void *) stram_pool.start, (void *) stram_pool.end);
+
+               /* stram_virt_offset = ioremap(stram_pool.start, pool_size); */
+               stram_virt_offset = (unsigned long) 0xFF000000;
+
+               printk("atari_stram pool: stram_virt_offset = %p\n",
+                         (void *) stram_virt_offset);
+       }

If you reorder some lines, you can share more code between the "if" and
"else" cases.

+void *atari_stram_to_virt(unsigned long phys)
+{
+       return (void *)(phys + stram_virt_offset);
 }

+void *atari_stram_to_phys(unsigned long virt)

This should be "unsigned long atari_stram_to_phys(void *)",
allowing to remove a few casts in the callers...

Yep, that was a bit awkward to cast. This clearly needs a few more iterations.

Thanks for your feedback!

Cheers,

   Michael

--
To unsubscribe from this list: send the line "unsubscribe linux-m68k" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Video for Linux]     [Yosemite News]     [Linux S/390]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux