Your last step I have coded up but not tested yet. I will get that done today.
Thanks, Tom -----Original Message----- From: Wim Van Sebroeck [mailto:[email protected]] Sent: Friday, January 27, 2012 10:50 AM To: Mingarelli, Thomas; Linus Torvalds Cc: Maxim Uvarov; [email protected]; [email protected]; [email protected] Subject: Re: [PATCH] hpwdt: clean up set_memory_x call for 32 bit Hi Tom, > So I don't know who is supposed to be handling this (Wim?), but the > patch itself looks suspicious. > > On Sun, Jan 15, 2012 at 8:02 PM, Maxim Uvarov <[email protected]> wrote: > > - set_memory_x((unsigned long)bios32_entrypoint, (2 * PAGE_SIZE)); > > + set_memory_x((unsigned long)bios32_entrypoint & PAGE_MASK, 2); > > If it wasn't page-aligned to begin with, then maybe it needs three pages now? I have been looking at the code again and basically we have for 32 bit the following sequence: 1) scan/search from 0x0f0000 through 0x0fffff, inclusive (in steps of 16 bytes) until we find the 32-bit BIOS Service Directory with signature == PCI_BIOS32_SD_VALUE (=0x5F32335F ="_32_"). 2) If we find this area then we first do a checksum check to see if it's a valid area. 3) if it's a valid area then we will check this area for a $CRU record. the code for this is as follows: /* * According to the spec, we're looking for the * first 4KB-aligned address below the entrypoint * listed in the header. The Service Directory code * is guaranteed to occupy no more than 2 4KB pages. */ map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1); map_offset = bios_32_ptr->entry_point - map_entry; bios32_map = ioremap(map_entry, (2 * PAGE_SIZE)); if (bios32_map == NULL) return -ENODEV; bios32_entrypoint = bios32_map + map_offset; cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE; set_memory_x((unsigned long)bios32_entrypoint, (2 * PAGE_SIZE)); asminline_call(&cmn_regs, bios32_entrypoint); => So if I understand it correctly then map_entry is page aligned. And thus bios32_map is also page aligned. Wouldn't it then not make more sense to do a: set_memory_x((unsigned long)bios32_map, 2); > > - set_memory_x((unsigned long)cru_rom_addr, > > cru_length); > > + set_memory_x((unsigned long)cru_rom_addr & > > PAGE_MASK, cru_length >> PAGE_SHIFT); > > Same here. If we align the start address down, we should fix up the > length. And should we not align the number of pages up? > > In general, a "start/length" conversion to a "page/nr" model needs to be > roughly > > len += start & ~PAGE_MASK; > start &= PAGE_MASK; > nr_pages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; > > to do things right. But I don't know where those magic numbers come > from. Maybe the "2" is already due to the code possibly traversing a > page boundary, and has already been fixed up. Somebody who knows the > driver and the requirements should take a look at this. 4) if we then found the $CRU record then we do: physical_bios_base = cmn_regs.u2.rebx; physical_bios_offset = cmn_regs.u4.redx; cru_length = cmn_regs.u3.recx; cru_physical_address = physical_bios_base + physical_bios_offset; /* If the values look OK, then map it in. */ if (cru_physical_address) { cru_rom_addr = ioremap(cru_physical_address, cru_length); if (cru_rom_addr) { set_memory_x((unsigned long)cru_rom_addr, cru_length); retval = 0; } } => Which means that cru_physical_address and cru_rom_addr are not page-aligned. So if we follow the conversion model that Linus described we get: set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK, (cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT); Can you check this? Kind regards, Wim. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
