hash_utils_64.c

linux-2.6.15.6

/*
 * PowerPC64 port by Mike Corrigan and Dave Engebretsen
 *   {mikejc|engebret}@us.ibm.com
 *
 *    Copyright (c) 2000 Mike Corrigan <[e-mail]>
 *
 * SMP scalability work:
 *    Copyright (C) 2001 Anton Blanchard <[e-mail]>, IBM
 * 
 *    Module name: htab.c
 *
 *    Description:
 *      PowerPC Hashed Page Table functions
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#undef DEBUG
#undef DEBUG_LOW

#include <linux/config.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/sysctl.h>
#include <linux/ctype.h>
#include <linux/cache.h>
#include <linux/init.h>
#include <linux/signal.h>

#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/page.h>
#include <asm/types.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/machdep.h>
#include <asm/lmb.h>
#include <asm/abs_addr.h>
#include <asm/tlbflush.h>
#include <asm/io.h>
#include <asm/eeh.h>
#include <asm/tlb.h>
#include <asm/cacheflush.h>
#include <asm/cputable.h>
#include <asm/abs_addr.h>
#include <asm/sections.h>

#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif

#ifdef DEBUG_LOW
#define DBG_LOW(fmt...) udbg_printf(fmt)
#else
#define DBG_LOW(fmt...)
#endif

#define KB (1024)
#define MB (1024*KB)

/*
 * Note:  pte   --> Linux PTE
 *        HPTE  --> PowerPC Hashed Page Table Entry
 *
 * Execution context:
 *   htab_initialize is called with the MMU off (of course), but
 *   the kernel has been copied down to zero so it can directly
 *   reference global data.  At this point it is very difficult
 *   to print debug info.
 *
 */

#ifdef CONFIG_U3_DART
extern unsigned long dart_tablebase;
#endif /* CONFIG_U3_DART */

static unsigned long _SDR1;
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];

hpte_t *htab_address;
unsigned long htab_hash_mask;
int mmu_linear_psize = MMU_PAGE_4K;
int mmu_virtual_psize = MMU_PAGE_4K;
#ifdef CONFIG_HUGETLB_PAGE
int mmu_huge_psize = MMU_PAGE_16M;
unsigned int HPAGE_SHIFT;
#endif

/* There are definitions of page sizes arrays to be used when none
 * is provided by the firmware.
 */

/* Pre-POWER4 CPUs (4k pages only)
 */
struct mmu_psize_def mmu_psize_defaults_old[] = {
	[MMU_PAGE_4K] = {
		.shift	= 12,
		.sllp	= 0,
		.penc	= 0,
		.avpnm	= 0,
		.tlbiel = 0,
	},
};

/* POWER4, GPUL, POWER5
 *
 * Support for 16Mb large pages
 */
struct mmu_psize_def mmu_psize_defaults_gp[] = {
	[MMU_PAGE_4K] = {
		.shift	= 12,
		.sllp	= 0,
		.penc	= 0,
		.avpnm	= 0,
		.tlbiel = 1,
	},
	[MMU_PAGE_16M] = {
		.shift	= 24,
		.sllp	= SLB_VSID_L,
		.penc	= 0,
		.avpnm	= 0x1UL,
		.tlbiel = 0,
	},
};


int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
		      unsigned long pstart, unsigned long mode, int psize)
{
	unsigned long vaddr, paddr;
	unsigned int step, shift;
	unsigned long tmp_mode;
	int ret = 0;

	shift = mmu_psize_defs[psize].shift;
	step = 1 << shift;

	for (vaddr = vstart, paddr = pstart; vaddr < vend;
	     vaddr += step, paddr += step) {
		unsigned long vpn, hash, hpteg;
		unsigned long vsid = get_kernel_vsid(vaddr);
		unsigned long va = (vsid << 28) | (vaddr & 0x0fffffff);

		vpn = va >> shift;
		tmp_mode = mode;
		
		/* Make non-kernel text non-executable */
		if (!in_kernel_text(vaddr))
			tmp_mode = mode | HPTE_R_N;

		hash = hpt_hash(va, shift);
		hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);

		/* The crap below can be cleaned once ppd_md.probe() can
		 * set up the hash callbacks, thus we can just used the
		 * normal insert callback here.
		 */
#ifdef CONFIG_PPC_ISERIES
		if (_machine == PLATFORM_ISERIES_LPAR)
			ret = iSeries_hpte_insert(hpteg, va,
						  virt_to_abs(paddr),
						  tmp_mode,
						  HPTE_V_BOLTED,
						  psize);
		else
#endif
#ifdef CONFIG_PPC_PSERIES
		if (_machine & PLATFORM_LPAR)
			ret = pSeries_lpar_hpte_insert(hpteg, va,
						       virt_to_abs(paddr),
						       tmp_mode,
						       HPTE_V_BOLTED,
						       psize);
		else
#endif
#ifdef CONFIG_PPC_MULTIPLATFORM
			ret = native_hpte_insert(hpteg, va,
						 virt_to_abs(paddr),
						 tmp_mode, HPTE_V_BOLTED,
						 psize);
#endif
		if (ret < 0)
			break;
	}
	return ret < 0 ? ret : 0;
}

static int __init htab_dt_scan_page_sizes(unsigned long node,
					  const char *uname, int depth,
					  void *data)
{
	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
	u32 *prop;
	unsigned long size = 0;

	/* We are scanning "cpu" nodes only */
	if (type == NULL || strcmp(type, "cpu") != 0)
		return 0;

	prop = (u32 *)of_get_flat_dt_prop(node,
					  "ibm,segment-page-sizes", &size);
	if (prop != NULL) {
		DBG("Page sizes from device-tree:\n");
		size /= 4;
		cur_cpu_spec->cpu_features &= ~(CPU_FTR_16M_PAGE);
		while(size > 0) {
			unsigned int shift = prop[0];
			unsigned int slbenc = prop[1];
			unsigned int lpnum = prop[2];
			unsigned int lpenc = 0;
			struct mmu_psize_def *def;
			int idx = -1;

			size -= 3; prop += 3;
			while(size > 0 && lpnum) {
				if (prop[0] == shift)
					lpenc = prop[1];
				prop += 2; size -= 2;
				lpnum--;
			}
			switch(shift) {
			case 0xc:
				idx = MMU_PAGE_4K;
				break;
			case 0x10:
				idx = MMU_PAGE_64K;
				break;
			case 0x14:
				idx = MMU_PAGE_1M;
				break;
			case 0x18:
				idx = MMU_PAGE_16M;
				cur_cpu_spec->cpu_features |= CPU_FTR_16M_PAGE;
				break;
			case 0x22:
				idx = MMU_PAGE_16G;
				break;
			}
			if (idx < 0)
				continue;
			def = &mmu_psize_defs[idx];
			def->shift = shift;
			if (shift <= 23)
				def->avpnm = 0;
			else
				def->avpnm = (1 << (shift - 23)) - 1;
			def->sllp = slbenc;
			def->penc = lpenc;
			/* We don't know for sure what's up with tlbiel, so
			 * for now we only set it for 4K and 64K pages
			 */
			if (idx == MMU_PAGE_4K || idx == MMU_PAGE_64K)
				def->tlbiel = 1;
			else
				def->tlbiel = 0;

			DBG(" %d: shift=%02x, sllp=%04x, avpnm=%08x, "
			    "tlbiel=%d, penc=%d\n",
			    idx, shift, def->sllp, def->avpnm, def->tlbiel,
			    def->penc);
		}
		return 1;
	}
	return 0;
}


static void __init htab_init_page_sizes(void)
{
	int rc;

	/* Default to 4K pages only */
	memcpy(mmu_psize_defs, mmu_psize_defaults_old,
	       sizeof(mmu_psize_defaults_old));

	/*
	 * Try to find the available page sizes in the device-tree
	 */
	rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
	if (rc != 0)  /* Found */
		goto found;

	/*
	 * Not in the device-tree, let's fallback on known size
	 * list for 16M capable GP & GR
	 */
	if ((_machine != PLATFORM_ISERIES_LPAR) &&
	    cpu_has_feature(CPU_FTR_16M_PAGE))
		memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
		       sizeof(mmu_psize_defaults_gp));
 found:
	/*
	 * Pick a size for the linear mapping. Currently, we only support
	 * 16M, 1M and 4K which is the default
	 */
	if (mmu_psize_defs[MMU_PAGE_16M].shift)
		mmu_linear_psize = MMU_PAGE_16M;
	else if (mmu_psize_defs[MMU_PAGE_1M].shift)
		mmu_linear_psize = MMU_PAGE_1M;

	/*
	 * Pick a size for the ordinary pages. Default is 4K, we support
	 * 64K if cache inhibited large pages are supported by the
	 * processor
	 */
#ifdef CONFIG_PPC_64K_PAGES
	if (mmu_psize_defs[MMU_PAGE_64K].shift &&
	    cpu_has_feature(CPU_FTR_CI_LARGE_PAGE))
		mmu_virtual_psize = MMU_PAGE_64K;
#endif

	printk(KERN_INFO "Page orders: linear mapping = %d, others = %d\n",
	       mmu_psize_defs[mmu_linear_psize].shift,
	       mmu_psize_defs[mmu_virtual_psize].shift);

#ifdef CONFIG_HUGETLB_PAGE
	/* Init large page size. Currently, we pick 16M or 1M depending
	 * on what is available
	 */
	if (mmu_psize_defs[MMU_PAGE_16M].shift)
		mmu_huge_psize = MMU_PAGE_16M;
	/* With 4k/4level pagetables, we can't (for now) cope with a
	 * huge page size < PMD_SIZE */
	else if (mmu_psize_defs[MMU_PAGE_1M].shift)
		mmu_huge_psize = MMU_PAGE_1M;

	/* Calculate HPAGE_SHIFT and sanity check it */
	if (mmu_psize_defs[mmu_huge_psize].shift > MIN_HUGEPTE_SHIFT &&
	    mmu_psize_defs[mmu_huge_psize].shift < SID_SHIFT)
		HPAGE_SHIFT = mmu_psize_defs[mmu_huge_psize].shift;
	else
		HPAGE_SHIFT = 0; /* No huge pages dude ! */
#endif /* CONFIG_HUGETLB_PAGE */
}

static int __init htab_dt_scan_pftsize(unsigned long node,
				       const char *uname, int depth,
				       void *data)
{
	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
	u32 *prop;

	/* We are scanning "cpu" nodes only */
	if (type == NULL || strcmp(type, "cpu") != 0)
		return 0;

	prop = (u32 *)of_get_flat_dt_prop(node, "ibm,pft-size", NULL);
	if (prop != NULL) {
		/* pft_size[0] is the NUMA CEC cookie */
		ppc64_pft_size = prop[1];
		return 1;
	}
	return 0;
}

static unsigned long __init htab_get_table_size(void)
{
	unsigned long mem_size, rnd_mem_size, pteg_count;

	/* If hash size isn't already provided by the platform, we try to
	 * retreive it from the device-tree. If it's not there neither, we
	 * calculate it now based on the total RAM size
	 */
	if (ppc64_pft_size == 0)
		of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
	if (ppc64_pft_size)
		return 1UL << ppc64_pft_size;

	/* round mem_size up to next power of 2 */
	mem_size = lmb_phys_mem_size();
	rnd_mem_size = 1UL << __ilog2(mem_size);
	if (rnd_mem_size < mem_size)
		rnd_mem_size <<= 1;

	/* # pages / 2 */
	pteg_count = max(rnd_mem_size >> (12 + 1), 1UL << 11);

	return pteg_count << 7;