powerpc/mm/32s: rework mmu_mapin_ram() (e4d6654e) · Commits · 戴 / test

arch/powerpc/mm/ppc_mmu_32.c

+41 −22

Original line number	Diff line number	Diff line
		@@ -73,39 +73,58 @@ unsigned long p_block_mapped(phys_addr_t pa)
		return 0;
		}

		static int find_free_bat(void)
		{
		int b;

		if (cpu_has_feature(CPU_FTR_601)) {
		for (b = 0; b < 4; b++) {
		struct ppc_bat *bat = BATS[b];

		if (!(bat[0].batl & 0x40))
		return b;
		}
		} else {
		int n = mmu_has_feature(MMU_FTR_USE_HIGH_BATS) ? 8 : 4;

		for (b = 0; b < n; b++) {
		struct ppc_bat *bat = BATS[b];

		if (!(bat[1].batu & 3))
		return b;
		}
		}
		return -1;
		}

		static unsigned int block_size(unsigned long base, unsigned long top)
		{
		unsigned int max_size = (cpu_has_feature(CPU_FTR_601) ? 8 : 256) << 20;
		unsigned int base_shift = (fls(base) - 1) & 31;
		unsigned int block_shift = (fls(top - base) - 1) & 31;

		return min3(max_size, 1U << base_shift, 1U << block_shift);
		}

		unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
		{
		unsigned long tot, bl, done;
		unsigned long max_size = (256<<20);
		int idx;

		if (__map_without_bats) {
		printk(KERN_DEBUG "RAM mapped without BATs\n");
		return 0;
		return base;
		}

		/* Set up BAT2 and if necessary BAT3 to cover RAM. */

		/* Make sure we don't map a block larger than the
		smallest alignment of the physical address. */
		tot = top;
		for (bl = 128<<10; bl < max_size; bl <<= 1) {
		if (bl * 2 > tot)
		break;
		}
		while ((idx = find_free_bat()) != -1 && base != top) {
		unsigned int size = block_size(base, top);

		setbat(2, PAGE_OFFSET, 0, bl, PAGE_KERNEL_X);
		done = (unsigned long)bat_addrs[2].limit - PAGE_OFFSET + 1;
		if ((done < tot) && !bat_addrs[3].limit) {
		/* use BAT3 to cover a bit more */
		tot -= done;
		for (bl = 128<<10; bl < max_size; bl <<= 1)
		if (bl * 2 > tot)
		if (size < 128 << 10)
		break;
		setbat(3, PAGE_OFFSET+done, done, bl, PAGE_KERNEL_X);
		done = (unsigned long)bat_addrs[3].limit - PAGE_OFFSET + 1;
		setbat(idx, PAGE_OFFSET + base, base, size, PAGE_KERNEL_X);
		base += size;
		}

		return done;
		return base;
		}

		/*

Admin message