First cut at RM7000 support.

1 files changed, 578 insertions, 0 deletions

diff --git a/arch/mips/mm/rm7k.c b/arch/mips/mm/rm7k.c
new file mode 100644
index 000000000..85bb7e1c5
--- /dev/null
+++ b/arch/mips/mm/rm7k.c
@@ -0,0 +1,578 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * r4xx0.c: R4000 processor variant specific MMU/Cache routines.
+ *
+ * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
+ * Copyright (C) 1997, 1998 Ralf Baechle ralf@gnu.org
+ *
+ * To do:
+ *
+ *  - this code is a overbloated pig
+ *  - many of the bug workarounds are not efficient at all, but at
+ *    least they are functional ...
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+
+#include <asm/io.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/bootinfo.h>
+#include <asm/mmu_context.h>
+
+/* CP0 hazard avoidance. */
+#define BARRIER __asm__ __volatile__(".set noreorder\n\t" \
+				     "nop; nop; nop; nop; nop; nop;\n\t" \
+				     ".set reorder\n\t")
+
+/* Primary cache parameters. */
+static int icache_size, dcache_size; /* Size in bytes */
+
+#define ic_lsize	32		/* Fixed to 32 byte on RM7000  */
+#define dc_lsize	32		/* Fixed to 32 byte on RM7000  */
+#define sc_lsize	32		/* Fixed to 32 byte on RM7000  */
+
+/* Secondary cache parameters. */
+#define scache_size	(256*1024)	/* Fixed to 256kb on RM7000 */
+
+#include <asm/cacheops.h>
+#include <asm/r4kcache.h>
+
+/*
+ * Zero an entire page.  Note that while the RM7000 has a second level cache
+ * it doesn't have a Create_Dirty_Excl_SD operation.
+ */
+static void rm7k_clear_page(void * page)
+{
+	__asm__ __volatile__(
+		".set\tnoreorder\n\t"
+		".set\tnoat\n\t"
+		".set\tmips3\n\t"
+		"daddiu\t$1,%0,%2\n"
+		"1:\tcache\t%3,(%0)\n\t"
+		"sd\t$0,(%0)\n\t"
+		"sd\t$0,8(%0)\n\t"
+		"sd\t$0,16(%0)\n\t"
+		"sd\t$0,24(%0)\n\t"
+		"daddiu\t%0,64\n\t"
+		"cache\t%3,-32(%0)\n\t"
+		"sd\t$0,-32(%0)\n\t"
+		"sd\t$0,-24(%0)\n\t"
+		"sd\t$0,-16(%0)\n\t"
+		"bne\t$1,%0,1b\n\t"
+		"sd\t$0,-8(%0)\n\t"
+		".set\tmips0\n\t"
+		".set\tat\n\t"
+		".set\treorder"
+		:"=r" (page)
+		:"0" (page),
+		 "I" (PAGE_SIZE),
+		 "i" (Create_Dirty_Excl_D)
+		:"$1","memory");
+}
+
+
+/*
+ * Copy an entire page.  Note that while the RM7000 has a second level cache
+ * it doesn't have a Create_Dirty_Excl_SD operation.
+ */
+static void rm7k_copy_page(void * to, void * from)
+{
+	unsigned long dummy1, dummy2;
+	unsigned long reg1, reg2, reg3, reg4;
+
+	__asm__ __volatile__(
+		".set\tnoreorder\n\t"
+		".set\tnoat\n\t"
+		".set\tmips3\n\t"
+		"daddiu\t$1,%0,%8\n"
+		"1:\tcache\t%9,(%0)\n\t"
+		"lw\t%2,(%1)\n\t"
+		"lw\t%3,4(%1)\n\t"
+		"lw\t%4,8(%1)\n\t"
+		"lw\t%5,12(%1)\n\t"
+		"sw\t%2,(%0)\n\t"
+		"sw\t%3,4(%0)\n\t"
+		"sw\t%4,8(%0)\n\t"
+		"sw\t%5,12(%0)\n\t"
+		"lw\t%2,16(%1)\n\t"
+		"lw\t%3,20(%1)\n\t"
+		"lw\t%4,24(%1)\n\t"
+		"lw\t%5,28(%1)\n\t"
+		"sw\t%2,16(%0)\n\t"
+		"sw\t%3,20(%0)\n\t"
+		"sw\t%4,24(%0)\n\t"
+		"sw\t%5,28(%0)\n\t"
+		"cache\t%9,32(%0)\n\t"
+		"daddiu\t%0,64\n\t"
+		"daddiu\t%1,64\n\t"
+		"lw\t%2,-32(%1)\n\t"
+		"lw\t%3,-28(%1)\n\t"
+		"lw\t%4,-24(%1)\n\t"
+		"lw\t%5,-20(%1)\n\t"
+		"sw\t%2,-32(%0)\n\t"
+		"sw\t%3,-28(%0)\n\t"
+		"sw\t%4,-24(%0)\n\t"
+		"sw\t%5,-20(%0)\n\t"
+		"lw\t%2,-16(%1)\n\t"
+		"lw\t%3,-12(%1)\n\t"
+		"lw\t%4,-8(%1)\n\t"
+		"lw\t%5,-4(%1)\n\t"
+		"sw\t%2,-16(%0)\n\t"
+		"sw\t%3,-12(%0)\n\t"
+		"sw\t%4,-8(%0)\n\t"
+		"bne\t$1,%0,1b\n\t"
+		"sw\t%5,-4(%0)\n\t"
+		".set\tmips0\n\t"
+		".set\tat\n\t"
+		".set\treorder"
+		:"=r" (dummy1), "=r" (dummy2),
+		 "=&r" (reg1), "=&r" (reg2), "=&r" (reg3), "=&r" (reg4)
+		:"0" (to), "1" (from),
+		 "I" (PAGE_SIZE),
+		 "i" (Create_Dirty_Excl_D));
+}
+
+static void __flush_cache_all_d32i32(void)
+{
+	blast_dcache32();
+	blast_icache32();
+}
+
+static inline void rm7k_flush_cache_all_d32i32(void)
+{
+	/* Yes! Caches that don't suck ...  */
+}
+
+static void rm7k_flush_cache_range_d32i32(struct mm_struct *mm,
+					 unsigned long start,
+					 unsigned long end)
+{
+	/* RM7000 caches are sane ...  */
+}
+
+static void rm7k_flush_cache_mm_d32i32(struct mm_struct *mm)
+{
+	/* RM7000 caches are sane ...  */
+}
+
+static void rm7k_flush_cache_page_d32i32(struct vm_area_struct *vma,
+					unsigned long page)
+{
+	/* RM7000 caches are sane ...  */
+}
+
+static void rm7k_flush_page_to_ram_d32i32(struct page * page)
+{
+	/* Yes!  Caches that don't suck!  */
+}
+
+static void rm7k_flush_icache_range(unsigned long start, unsigned long end)
+{
+	/*
+	 * FIXME: This is overdoing things and harms performance.
+	 */
+	__flush_cache_all_d32i32();
+}
+
+static void rm7k_flush_icache_page(struct page *page, unsigned long addr)
+{
+	/*
+	 * FIXME: We should not flush the entire cache but establish some
+	 * temporary mapping and use hit_invalidate operation to flush out
+	 * the line from the cache.
+	 */
+	__flush_cache_all_d32i32();
+}
+
+
+/*
+ * Writeback and invalidate the primary cache dcache before DMA.
+ * (XXX These need to be fixed ...)
+ */
+static void
+rm7k_dma_cache_wback_inv(unsigned long addr, unsigned long size)
+{
+	unsigned long end, a;
+
+	if (size >= scache_size) {
+		blast_dcache32();
+		return;
+	}
+
+	a = addr & ~(sc_lsize - 1);
+	end = (addr + size) & ~(sc_lsize - 1);
+	while (1) {
+		flush_scache_line(a);	/* Hit_Writeback_Inv_SD */
+		if (a == end) break;
+		a += sc_lsize;
+	}
+}
+
+static void
+rm7k_dma_cache_inv(unsigned long addr, unsigned long size)
+{
+	unsigned long end, a;
+
+	if (size >= scache_size) {
+		blast_dcache32();
+		return;
+	}
+
+	a = addr & ~(sc_lsize - 1);
+	end = (addr + size) & ~(sc_lsize - 1);
+	while (1) {
+		flush_scache_line(a); /* Hit_Writeback_Inv_SD */
+		if (a == end) break;
+		a += sc_lsize;
+	}
+}
+
+static void
+rm7k_dma_cache_wback(unsigned long addr, unsigned long size)
+{
+	panic("rm7k_dma_cache_wback called - should not happen.\n");
+}
+
+/*
+ * While we're protected against bad userland addresses we don't care
+ * very much about what happens in that case.  Usually a segmentation
+ * fault will dump the process later on anyway ...
+ */
+static void rm7k_flush_cache_sigtramp(unsigned long addr)
+{
+	protected_writeback_dcache_line(addr & ~(dc_lsize - 1));
+	protected_flush_icache_line(addr & ~(ic_lsize - 1));
+}
+
+/*
+ * Undocumented RM7000:  Bit 29 in the info register of the RM7000 v2.0
+ * indicates if the TLB has 48 or 64 entries.
+ *
+ * 29      1 =>    64 entry JTLB
+ *         0 =>    48 entry JTLB
+ */
+static inline int __attribute__((const)) ntlb_entries(void)
+{
+	if (get_info() & (1 << 29))
+		return 64;
+
+	return 48;
+}
+
+void flush_tlb_all(void)
+{
+	unsigned long flags;
+	unsigned long old_ctx;
+	int entry;
+
+	__save_and_cli(flags);
+	/* Save old context and create impossible VPN2 value */
+	old_ctx = get_entryhi() & 0xff;
+	set_entryhi(KSEG0);
+	set_entrylo0(0);
+	set_entrylo1(0);
+	BARRIER;
+
+	entry = get_wired();
+
+	/* Blast 'em all away. */
+	while (entry < ntlb_entries()) {
+		set_index(entry);
+		BARRIER;
+		tlb_write_indexed();
+		BARRIER;
+		entry++;
+	}
+	BARRIER;
+	set_entryhi(old_ctx);
+	__restore_flags(flags);
+}
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+	if(mm->context != 0) {
+		unsigned long flags;
+
+		__save_and_cli(flags);
+		get_new_mmu_context(mm, asid_cache);
+		if (mm == current->mm)
+			set_entryhi(mm->context & 0xff);
+		__restore_flags(flags);
+	}
+}
+
+void flush_tlb_range(struct mm_struct *mm, unsigned long start,
+				unsigned long end)
+{
+	if(mm->context != 0) {
+		unsigned long flags;
+		int size;
+
+		__save_and_cli(flags);
+		size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+		size = (size + 1) >> 1;
+		if (size <= (ntlb_entries() / 2)) {
+			int oldpid = (get_entryhi() & 0xff);
+			int newpid = (mm->context & 0xff);
+
+			start &= (PAGE_MASK << 1);
+			end += ((PAGE_SIZE << 1) - 1);
+			end &= (PAGE_MASK << 1);
+			while(start < end) {
+				int idx;
+
+				set_entryhi(start | newpid);
+				start += (PAGE_SIZE << 1);
+				BARRIER;
+				tlb_probe();
+				BARRIER;
+				idx = get_index();
+				set_entrylo0(0);
+				set_entrylo1(0);
+				set_entryhi(KSEG0);
+				BARRIER;
+				if(idx < 0)
+					continue;
+				tlb_write_indexed();
+				BARRIER;
+			}
+			set_entryhi(oldpid);
+		} else {
+			get_new_mmu_context(mm, asid_cache);
+			if(mm == current->mm)
+				set_entryhi(mm->context & 0xff);
+		}
+		__restore_flags(flags);
+	}
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+	if(vma->vm_mm->context != 0) {
+		unsigned long flags;
+		int oldpid, newpid, idx;
+
+		newpid = (vma->vm_mm->context & 0xff);
+		page &= (PAGE_MASK << 1);
+		__save_and_cli(flags);
+		oldpid = (get_entryhi() & 0xff);
+		set_entryhi(page | newpid);
+		BARRIER;
+		tlb_probe();
+		BARRIER;
+		idx = get_index();
+		set_entrylo0(0);
+		set_entrylo1(0);
+		set_entryhi(KSEG0);
+		if(idx < 0)
+			goto finish;
+		BARRIER;
+		tlb_write_indexed();
+
+	finish:
+		BARRIER;
+		set_entryhi(oldpid);
+		__restore_flags(flags);
+	}
+}
+
+/* Load a new root pointer into the TLB. */
+void load_pgd(unsigned long pg_dir)
+{
+}
+
+void pgd_init(unsigned long page)
+{
+	unsigned long *p = (unsigned long *) page;
+	int i;
+
+	for (i = 0; i < USER_PTRS_PER_PGD; i+=8) {
+		p[i + 0] = (unsigned long) invalid_pte_table;
+		p[i + 1] = (unsigned long) invalid_pte_table;
+		p[i + 2] = (unsigned long) invalid_pte_table;
+		p[i + 3] = (unsigned long) invalid_pte_table;
+		p[i + 4] = (unsigned long) invalid_pte_table;
+		p[i + 5] = (unsigned long) invalid_pte_table;
+		p[i + 6] = (unsigned long) invalid_pte_table;
+		p[i + 7] = (unsigned long) invalid_pte_table;
+	}
+}
+
+/*
+ * We will need multiple versions of update_mmu_cache(), one that just
+ * updates the TLB with the new pte(s), and another which also checks
+ * for the R4k "end of page" hardware bug and does the needy.
+ */
+void update_mmu_cache(struct vm_area_struct * vma,
+				 unsigned long address, pte_t pte)
+{
+	unsigned long flags;
+	pgd_t *pgdp;
+	pmd_t *pmdp;
+	pte_t *ptep;
+	int idx, pid;
+
+	/*
+	 * Handle debugger faulting in for debugee.
+	 */
+	if (current->active_mm != vma->vm_mm)
+		return;
+
+	pid = get_entryhi() & 0xff;
+
+	__save_and_cli(flags);
+	address &= (PAGE_MASK << 1);
+	set_entryhi(address | (pid));
+	pgdp = pgd_offset(vma->vm_mm, address);
+	BARRIER;
+	tlb_probe();
+	BARRIER;
+	pmdp = pmd_offset(pgdp, address);
+	idx = get_index();
+	ptep = pte_offset(pmdp, address);
+	BARRIER;
+	set_entrylo0(pte_val(*ptep++) >> 6);
+	set_entrylo1(pte_val(*ptep) >> 6);
+	set_entryhi(address | (pid));
+	BARRIER;
+	if (idx < 0) {
+		tlb_write_random();
+	} else {
+		tlb_write_indexed();
+	}
+	BARRIER;
+	set_entryhi(pid);
+	BARRIER;
+	__restore_flags(flags);
+}
+
+void show_regs(struct pt_regs * regs)
+{
+	/* Saved main processor registers. */
+	printk("$0 : %08lx %08lx %08lx %08lx\n",
+	       0UL, regs->regs[1], regs->regs[2], regs->regs[3]);
+	printk("$4 : %08lx %08lx %08lx %08lx\n",
+               regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]);
+	printk("$8 : %08lx %08lx %08lx %08lx\n",
+	       regs->regs[8], regs->regs[9], regs->regs[10], regs->regs[11]);
+	printk("$12: %08lx %08lx %08lx %08lx\n",
+               regs->regs[12], regs->regs[13], regs->regs[14], regs->regs[15]);
+	printk("$16: %08lx %08lx %08lx %08lx\n",
+	       regs->regs[16], regs->regs[17], regs->regs[18], regs->regs[19]);
+	printk("$20: %08lx %08lx %08lx %08lx\n",
+               regs->regs[20], regs->regs[21], regs->regs[22], regs->regs[23]);
+	printk("$24: %08lx %08lx\n",
+	       regs->regs[24], regs->regs[25]);
+	printk("$28: %08lx %08lx %08lx %08lx\n",
+	       regs->regs[28], regs->regs[29], regs->regs[30], regs->regs[31]);
+
+	/* Saved cp0 registers. */
+	printk("epc   : %08lx\nStatus: %08lx\nCause : %08lx\n",
+	       regs->cp0_epc, regs->cp0_status, regs->cp0_cause);
+}
+
+void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
+                     unsigned long entryhi, unsigned long pagemask)
+{
+        unsigned long flags;
+        unsigned long wired;
+        unsigned long old_pagemask;
+        unsigned long old_ctx;
+
+        __save_and_cli(flags);
+        /* Save old context and create impossible VPN2 value */
+        old_ctx = (get_entryhi() & 0xff);
+        old_pagemask = get_pagemask();
+        wired = get_wired();
+        set_wired (wired + 1);
+        set_index (wired);
+        BARRIER;    
+        set_pagemask (pagemask);
+        set_entryhi(entryhi);
+        set_entrylo0(entrylo0);
+        set_entrylo1(entrylo1);
+        BARRIER;    
+        tlb_write_indexed();
+        BARRIER;    
+    
+        set_entryhi(old_ctx);
+        BARRIER;    
+        set_pagemask (old_pagemask);
+        flush_tlb_all();    
+        __restore_flags(flags);
+}
+
+/* Detect and size the caches. */
+static inline void probe_icache(unsigned long config)
+{
+	icache_size = 1 << (12 + ((config >> 9) & 7));
+
+	printk("Primary instruction cache %dkb.\n", icache_size >> 10);
+}
+
+static inline void probe_dcache(unsigned long config)
+{
+	dcache_size = 1 << (12 + ((config >> 6) & 7));
+
+	printk("Primary data cache %dkb.\n", dcache_size >> 10);
+}
+
+static inline void probe_scache(unsigned long config)
+{
+	if ((config >> 31) & 1)
+		return;
+
+	printk("Secondary cache %dkb, linesize %d bytes.\n",
+	       (scache_size >> 10), sc_lsize);
+}
+
+void __init ld_mmu_rm7k(void)
+{
+	unsigned long config = read_32bit_cp0_register(CP0_CONFIG);
+
+	printk("CPU revision is: %08x\n", read_32bit_cp0_register(CP0_PRID));
+
+	set_cp0_config(CONF_CM_CMASK, CONF_CM_CACHABLE_NONCOHERENT);
+
+	probe_icache(config);
+	probe_dcache(config);
+	probe_scache(config);
+
+	printk("TLB has %d entries.\n", ntlb_entries());
+
+	_clear_page = rm7k_clear_page;
+	_copy_page = rm7k_copy_page;
+
+	_flush_cache_all = rm7k_flush_cache_all_d32i32;
+	_flush_cache_mm = rm7k_flush_cache_mm_d32i32;
+	_flush_cache_range = rm7k_flush_cache_range_d32i32;
+	_flush_cache_page = rm7k_flush_cache_page_d32i32;
+	_flush_page_to_ram = rm7k_flush_page_to_ram_d32i32;
+	_flush_cache_sigtramp = rm7k_flush_cache_sigtramp;
+	_flush_icache_range = rm7k_flush_icache_range;
+	_flush_icache_page = rm7k_flush_icache_page;
+
+	_dma_cache_wback_inv = rm7k_dma_cache_wback_inv;
+	_dma_cache_wback = rm7k_dma_cache_wback;
+	_dma_cache_inv = rm7k_dma_cache_inv;
+
+	__flush_cache_all_d32i32();
+	write_32bit_cp0_register(CP0_WIRED, 0);
+
+	/*
+	 * You should never change this register:
+	 *   - On R4600 1.7 the tlbp never hits for pages smaller than
+	 *     the value in the c0_pagemask register.
+	 *   - The entire mm handling assumes the c0_pagemask register to
+	 *     be set for 4kb pages.
+	 */
+	write_32bit_cp0_register(CP0_PAGEMASK, PM_4K);
+	flush_tlb_all();
+}