[MIPS] Reimplement clear_page/copy_page
Fold the SB-1 specific implementation of clear_page/copy_page in the
generic version, and rewrite that one in tlbex style. The immediate
benefits:
- It converts the compile-time workaround for SB-1 pass 1 prefetches
to a more efficient run-time check.
- It allows adjustment of loop unfolling, which helps to reduce the
number of redundant cdex cache ops.
- It fixes some esoteric cornercases (the cache line length calculations
can go wrong, and support for 64k pages without prefetch instructions
will overflow the addiu immediate).
- Somewhat better guesses of "good" prefetch values.
Signed-off-by: Thiemo Seufer <ths@networkno.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mm/page.c b/arch/mips/mm/page.c
new file mode 100644
index 0000000..d827d61
--- /dev/null
+++ b/arch/mips/mm/page.c
@@ -0,0 +1,684 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2003, 04, 05 Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (C) 2007 Maciej W. Rozycki
+ * Copyright (C) 2008 Thiemo Seufer
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+
+#include <asm/bugs.h>
+#include <asm/cacheops.h>
+#include <asm/inst.h>
+#include <asm/io.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/prefetch.h>
+#include <asm/system.h>
+#include <asm/bootinfo.h>
+#include <asm/mipsregs.h>
+#include <asm/mmu_context.h>
+#include <asm/cpu.h>
+#include <asm/war.h>
+
+#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
+#include <asm/sibyte/sb1250.h>
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/sb1250_dma.h>
+#endif
+
+#include "uasm.h"
+
+/* Registers used in the assembled routines. */
+#define ZERO 0
+#define AT 2
+#define A0 4
+#define A1 5
+#define A2 6
+#define T0 8
+#define T1 9
+#define T2 10
+#define T3 11
+#define T9 25
+#define RA 31
+
+/* Handle labels (which must be positive integers). */
+enum label_id {
+ label_clear_nopref = 1,
+ label_clear_pref,
+ label_copy_nopref,
+ label_copy_pref_both,
+ label_copy_pref_store,
+};
+
+UASM_L_LA(_clear_nopref)
+UASM_L_LA(_clear_pref)
+UASM_L_LA(_copy_nopref)
+UASM_L_LA(_copy_pref_both)
+UASM_L_LA(_copy_pref_store)
+
+/* We need one branch and therefore one relocation per target label. */
+static struct uasm_label __cpuinitdata labels[5];
+static struct uasm_reloc __cpuinitdata relocs[5];
+
+#define cpu_is_r4600_v1_x() ((read_c0_prid() & 0xfffffff0) == 0x00002010)
+#define cpu_is_r4600_v2_x() ((read_c0_prid() & 0xfffffff0) == 0x00002020)
+
+/*
+ * Maximum sizes:
+ *
+ * R4000 128 bytes S-cache: 0x058 bytes
+ * R4600 v1.7: 0x05c bytes
+ * R4600 v2.0: 0x060 bytes
+ * With prefetching, 16 word strides 0x120 bytes
+ */
+
+static u32 clear_page_array[0x120 / 4];
+
+#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
+void clear_page_cpu(void *page) __attribute__((alias("clear_page_array")));
+#else
+void clear_page(void *page) __attribute__((alias("clear_page_array")));
+#endif
+
+EXPORT_SYMBOL(clear_page);
+
+/*
+ * Maximum sizes:
+ *
+ * R4000 128 bytes S-cache: 0x11c bytes
+ * R4600 v1.7: 0x080 bytes
+ * R4600 v2.0: 0x07c bytes
+ * With prefetching, 16 word strides 0x540 bytes
+ */
+static u32 copy_page_array[0x540 / 4];
+
+#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
+void
+copy_page_cpu(void *to, void *from) __attribute__((alias("copy_page_array")));
+#else
+void copy_page(void *to, void *from) __attribute__((alias("copy_page_array")));
+#endif
+
+EXPORT_SYMBOL(copy_page);
+
+
+static int pref_bias_clear_store __cpuinitdata;
+static int pref_bias_copy_load __cpuinitdata;
+static int pref_bias_copy_store __cpuinitdata;
+
+static u32 pref_src_mode __cpuinitdata;
+static u32 pref_dst_mode __cpuinitdata;
+
+static int clear_word_size __cpuinitdata;
+static int copy_word_size __cpuinitdata;
+
+static int half_clear_loop_size __cpuinitdata;
+static int half_copy_loop_size __cpuinitdata;
+
+static int cache_line_size __cpuinitdata;
+#define cache_line_mask() (cache_line_size - 1)
+
+static inline void __cpuinit
+pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
+{
+ if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
+ if (off > 0x7fff) {
+ uasm_i_lui(buf, T9, uasm_rel_hi(off));
+ uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
+ } else
+ uasm_i_addiu(buf, T9, ZERO, off);
+ uasm_i_daddu(buf, reg1, reg2, T9);
+ } else {
+ if (off > 0x7fff) {
+ uasm_i_lui(buf, T9, uasm_rel_hi(off));
+ uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
+ UASM_i_ADDU(buf, reg1, reg2, T9);
+ } else
+ UASM_i_ADDIU(buf, reg1, reg2, off);
+ }
+}
+
+static void __cpuinit set_prefetch_parameters(void)
+{
+ if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
+ clear_word_size = 8;
+ else
+ clear_word_size = 4;
+
+ if (cpu_has_64bit_gp_regs)
+ copy_word_size = 8;
+ else
+ copy_word_size = 4;
+
+ /*
+ * The pref's used here are using "streaming" hints, which cause the
+ * copied data to be kicked out of the cache sooner. A page copy often
+ * ends up copying a lot more data than is commonly used, so this seems
+ * to make sense in terms of reducing cache pollution, but I've no real
+ * performance data to back this up.
+ */
+ if (cpu_has_prefetch) {
+ /*
+ * XXX: Most prefetch bias values in here are based on
+ * guesswork.
+ */
+ cache_line_size = cpu_dcache_line_size();
+ switch (current_cpu_type()) {
+ case CPU_TX49XX:
+ /* TX49 supports only Pref_Load */
+ pref_bias_copy_load = 256;
+ break;
+
+ case CPU_RM9000:
+ /*
+ * As a workaround for erratum G105 which make the
+ * PrepareForStore hint unusable we fall back to
+ * StoreRetained on the RM9000. Once it is known which
+ * versions of the RM9000 we'll be able to condition-
+ * alize this.
+ */
+
+ case CPU_R10000:
+ case CPU_R12000:
+ case CPU_R14000:
+ /*
+ * Those values have been experimentally tuned for an
+ * Origin 200.
+ */
+ pref_bias_clear_store = 512;
+ pref_bias_copy_load = 256;
+ pref_bias_copy_store = 256;
+ pref_src_mode = Pref_LoadStreamed;
+ pref_dst_mode = Pref_StoreStreamed;
+ break;
+
+ case CPU_SB1:
+ case CPU_SB1A:
+ pref_bias_clear_store = 128;
+ pref_bias_copy_load = 128;
+ pref_bias_copy_store = 128;
+ /*
+ * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
+ * hints are broken.
+ */
+ if (current_cpu_type() == CPU_SB1 &&
+ (current_cpu_data.processor_id & 0xff) < 0x02) {
+ pref_src_mode = Pref_Load;
+ pref_dst_mode = Pref_Store;
+ } else {
+ pref_src_mode = Pref_LoadStreamed;
+ pref_dst_mode = Pref_StoreStreamed;
+ }
+ break;
+
+ default:
+ pref_bias_clear_store = 128;
+ pref_bias_copy_load = 256;
+ pref_bias_copy_store = 128;
+ pref_src_mode = Pref_LoadStreamed;
+ pref_dst_mode = Pref_PrepareForStore;
+ break;
+ }
+ } else {
+ if (cpu_has_cache_cdex_s)
+ cache_line_size = cpu_scache_line_size();
+ else if (cpu_has_cache_cdex_p)
+ cache_line_size = cpu_dcache_line_size();
+ }
+ /*
+ * Too much unrolling will overflow the available space in
+ * clear_space_array / copy_page_array. 8 words sounds generous,
+ * but a R4000 with 128 byte L2 line length can exceed even that.
+ */
+ half_clear_loop_size = min(8 * clear_word_size,
+ max(cache_line_size >> 1,
+ 4 * clear_word_size));
+ half_copy_loop_size = min(8 * copy_word_size,
+ max(cache_line_size >> 1,
+ 4 * copy_word_size));
+}
+
+static void __cpuinit build_clear_store(u32 **buf, int off)
+{
+ if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
+ uasm_i_sd(buf, ZERO, off, A0);
+ } else {
+ uasm_i_sw(buf, ZERO, off, A0);
+ }
+}
+
+static inline void __cpuinit build_clear_pref(u32 **buf, int off)
+{
+ if (off & cache_line_mask())
+ return;
+
+ if (pref_bias_clear_store) {
+ uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
+ A0);
+ } else if (cpu_has_cache_cdex_s) {
+ uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
+ } else if (cpu_has_cache_cdex_p) {
+ if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
+ uasm_i_nop(buf);
+ uasm_i_nop(buf);
+ uasm_i_nop(buf);
+ uasm_i_nop(buf);
+ }
+
+ if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
+ uasm_i_lw(buf, ZERO, ZERO, AT);
+
+ uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
+ }
+}
+
+void __cpuinit build_clear_page(void)
+{
+ int off;
+ u32 *buf = (u32 *)&clear_page_array;
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+ int i;
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ set_prefetch_parameters();
+
+ /*
+ * This algorithm makes the following assumptions:
+ * - The prefetch bias is a multiple of 2 words.
+ * - The prefetch bias is less than one page.
+ */
+ BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
+ BUG_ON(PAGE_SIZE < pref_bias_clear_store);
+
+ off = PAGE_SIZE - pref_bias_clear_store;
+ if (off > 0xffff || !pref_bias_clear_store)
+ pg_addiu(&buf, A2, A0, off);
+ else
+ uasm_i_ori(&buf, A2, A0, off);
+
+ if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
+ uasm_i_lui(&buf, AT, 0xa000);
+
+ off = min(8, pref_bias_clear_store / cache_line_size) *
+ cache_line_size;
+ while (off) {
+ build_clear_pref(&buf, -off);
+ off -= cache_line_size;
+ }
+ uasm_l_clear_pref(&l, buf);
+ do {
+ build_clear_pref(&buf, off);
+ build_clear_store(&buf, off);
+ off += clear_word_size;
+ } while (off < half_clear_loop_size);
+ pg_addiu(&buf, A0, A0, 2 * off);
+ off = -off;
+ do {
+ build_clear_pref(&buf, off);
+ if (off == -clear_word_size)
+ uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
+ build_clear_store(&buf, off);
+ off += clear_word_size;
+ } while (off < 0);
+
+ if (pref_bias_clear_store) {
+ pg_addiu(&buf, A2, A0, pref_bias_clear_store);
+ uasm_l_clear_nopref(&l, buf);
+ off = 0;
+ do {
+ build_clear_store(&buf, off);
+ off += clear_word_size;
+ } while (off < half_clear_loop_size);
+ pg_addiu(&buf, A0, A0, 2 * off);
+ off = -off;
+ do {
+ if (off == -clear_word_size)
+ uasm_il_bne(&buf, &r, A0, A2,
+ label_clear_nopref);
+ build_clear_store(&buf, off);
+ off += clear_word_size;
+ } while (off < 0);
+ }
+
+ uasm_i_jr(&buf, RA);
+ uasm_i_nop(&buf);
+
+ BUG_ON(buf > clear_page_array + ARRAY_SIZE(clear_page_array));
+
+ uasm_resolve_relocs(relocs, labels);
+
+ pr_debug("Synthesized clear page handler (%u instructions).\n",
+ (u32)(buf - clear_page_array));
+
+ pr_debug("\t.set push\n");
+ pr_debug("\t.set noreorder\n");
+ for (i = 0; i < (buf - clear_page_array); i++)
+ pr_debug("\t.word 0x%08x\n", clear_page_array[i]);
+ pr_debug("\t.set pop\n");
+}
+
+static void __cpuinit build_copy_load(u32 **buf, int reg, int off)
+{
+ if (cpu_has_64bit_gp_regs) {
+ uasm_i_ld(buf, reg, off, A1);
+ } else {
+ uasm_i_lw(buf, reg, off, A1);
+ }
+}
+
+static void __cpuinit build_copy_store(u32 **buf, int reg, int off)
+{
+ if (cpu_has_64bit_gp_regs) {
+ uasm_i_sd(buf, reg, off, A0);
+ } else {
+ uasm_i_sw(buf, reg, off, A0);
+ }
+}
+
+static inline void build_copy_load_pref(u32 **buf, int off)
+{
+ if (off & cache_line_mask())
+ return;
+
+ if (pref_bias_copy_load)
+ uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
+}
+
+static inline void build_copy_store_pref(u32 **buf, int off)
+{
+ if (off & cache_line_mask())
+ return;
+
+ if (pref_bias_copy_store) {
+ uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
+ A0);
+ } else if (cpu_has_cache_cdex_s) {
+ uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
+ } else if (cpu_has_cache_cdex_p) {
+ if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
+ uasm_i_nop(buf);
+ uasm_i_nop(buf);
+ uasm_i_nop(buf);
+ uasm_i_nop(buf);
+ }
+
+ if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
+ uasm_i_lw(buf, ZERO, ZERO, AT);
+
+ uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
+ }
+}
+
+void __cpuinit build_copy_page(void)
+{
+ int off;
+ u32 *buf = (u32 *)©_page_array;
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+ int i;
+
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ set_prefetch_parameters();
+
+ /*
+ * This algorithm makes the following assumptions:
+ * - All prefetch biases are multiples of 8 words.
+ * - The prefetch biases are less than one page.
+ * - The store prefetch bias isn't greater than the load
+ * prefetch bias.
+ */
+ BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
+ BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
+ BUG_ON(PAGE_SIZE < pref_bias_copy_load);
+ BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
+
+ off = PAGE_SIZE - pref_bias_copy_load;
+ if (off > 0xffff || !pref_bias_copy_load)
+ pg_addiu(&buf, A2, A0, off);
+ else
+ uasm_i_ori(&buf, A2, A0, off);
+
+ if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
+ uasm_i_lui(&buf, AT, 0xa000);
+
+ off = min(8, pref_bias_copy_load / cache_line_size) * cache_line_size;
+ while (off) {
+ build_copy_load_pref(&buf, -off);
+ off -= cache_line_size;
+ }
+ off = min(8, pref_bias_copy_store / cache_line_size) * cache_line_size;
+ while (off) {
+ build_copy_store_pref(&buf, -off);
+ off -= cache_line_size;
+ }
+ uasm_l_copy_pref_both(&l, buf);
+ do {
+ build_copy_load_pref(&buf, off);
+ build_copy_load(&buf, T0, off);
+ build_copy_load_pref(&buf, off + copy_word_size);
+ build_copy_load(&buf, T1, off + copy_word_size);
+ build_copy_load_pref(&buf, off + 2 * copy_word_size);
+ build_copy_load(&buf, T2, off + 2 * copy_word_size);
+ build_copy_load_pref(&buf, off + 3 * copy_word_size);
+ build_copy_load(&buf, T3, off + 3 * copy_word_size);
+ build_copy_store_pref(&buf, off);
+ build_copy_store(&buf, T0, off);
+ build_copy_store_pref(&buf, off + copy_word_size);
+ build_copy_store(&buf, T1, off + copy_word_size);
+ build_copy_store_pref(&buf, off + 2 * copy_word_size);
+ build_copy_store(&buf, T2, off + 2 * copy_word_size);
+ build_copy_store_pref(&buf, off + 3 * copy_word_size);
+ build_copy_store(&buf, T3, off + 3 * copy_word_size);
+ off += 4 * copy_word_size;
+ } while (off < half_copy_loop_size);
+ pg_addiu(&buf, A1, A1, 2 * off);
+ pg_addiu(&buf, A0, A0, 2 * off);
+ off = -off;
+ do {
+ build_copy_load_pref(&buf, off);
+ build_copy_load(&buf, T0, off);
+ build_copy_load_pref(&buf, off + copy_word_size);
+ build_copy_load(&buf, T1, off + copy_word_size);
+ build_copy_load_pref(&buf, off + 2 * copy_word_size);
+ build_copy_load(&buf, T2, off + 2 * copy_word_size);
+ build_copy_load_pref(&buf, off + 3 * copy_word_size);
+ build_copy_load(&buf, T3, off + 3 * copy_word_size);
+ build_copy_store_pref(&buf, off);
+ build_copy_store(&buf, T0, off);
+ build_copy_store_pref(&buf, off + copy_word_size);
+ build_copy_store(&buf, T1, off + copy_word_size);
+ build_copy_store_pref(&buf, off + 2 * copy_word_size);
+ build_copy_store(&buf, T2, off + 2 * copy_word_size);
+ build_copy_store_pref(&buf, off + 3 * copy_word_size);
+ if (off == -(4 * copy_word_size))
+ uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
+ build_copy_store(&buf, T3, off + 3 * copy_word_size);
+ off += 4 * copy_word_size;
+ } while (off < 0);
+
+ if (pref_bias_copy_load - pref_bias_copy_store) {
+ pg_addiu(&buf, A2, A0,
+ pref_bias_copy_load - pref_bias_copy_store);
+ uasm_l_copy_pref_store(&l, buf);
+ off = 0;
+ do {
+ build_copy_load(&buf, T0, off);
+ build_copy_load(&buf, T1, off + copy_word_size);
+ build_copy_load(&buf, T2, off + 2 * copy_word_size);
+ build_copy_load(&buf, T3, off + 3 * copy_word_size);
+ build_copy_store_pref(&buf, off);
+ build_copy_store(&buf, T0, off);
+ build_copy_store_pref(&buf, off + copy_word_size);
+ build_copy_store(&buf, T1, off + copy_word_size);
+ build_copy_store_pref(&buf, off + 2 * copy_word_size);
+ build_copy_store(&buf, T2, off + 2 * copy_word_size);
+ build_copy_store_pref(&buf, off + 3 * copy_word_size);
+ build_copy_store(&buf, T3, off + 3 * copy_word_size);
+ off += 4 * copy_word_size;
+ } while (off < half_copy_loop_size);
+ pg_addiu(&buf, A1, A1, 2 * off);
+ pg_addiu(&buf, A0, A0, 2 * off);
+ off = -off;
+ do {
+ build_copy_load(&buf, T0, off);
+ build_copy_load(&buf, T1, off + copy_word_size);
+ build_copy_load(&buf, T2, off + 2 * copy_word_size);
+ build_copy_load(&buf, T3, off + 3 * copy_word_size);
+ build_copy_store_pref(&buf, off);
+ build_copy_store(&buf, T0, off);
+ build_copy_store_pref(&buf, off + copy_word_size);
+ build_copy_store(&buf, T1, off + copy_word_size);
+ build_copy_store_pref(&buf, off + 2 * copy_word_size);
+ build_copy_store(&buf, T2, off + 2 * copy_word_size);
+ build_copy_store_pref(&buf, off + 3 * copy_word_size);
+ if (off == -(4 * copy_word_size))
+ uasm_il_bne(&buf, &r, A2, A0,
+ label_copy_pref_store);
+ build_copy_store(&buf, T3, off + 3 * copy_word_size);
+ off += 4 * copy_word_size;
+ } while (off < 0);
+ }
+
+ if (pref_bias_copy_store) {
+ pg_addiu(&buf, A2, A0, pref_bias_copy_store);
+ uasm_l_copy_nopref(&l, buf);
+ off = 0;
+ do {
+ build_copy_load(&buf, T0, off);
+ build_copy_load(&buf, T1, off + copy_word_size);
+ build_copy_load(&buf, T2, off + 2 * copy_word_size);
+ build_copy_load(&buf, T3, off + 3 * copy_word_size);
+ build_copy_store(&buf, T0, off);
+ build_copy_store(&buf, T1, off + copy_word_size);
+ build_copy_store(&buf, T2, off + 2 * copy_word_size);
+ build_copy_store(&buf, T3, off + 3 * copy_word_size);
+ off += 4 * copy_word_size;
+ } while (off < half_copy_loop_size);
+ pg_addiu(&buf, A1, A1, 2 * off);
+ pg_addiu(&buf, A0, A0, 2 * off);
+ off = -off;
+ do {
+ build_copy_load(&buf, T0, off);
+ build_copy_load(&buf, T1, off + copy_word_size);
+ build_copy_load(&buf, T2, off + 2 * copy_word_size);
+ build_copy_load(&buf, T3, off + 3 * copy_word_size);
+ build_copy_store(&buf, T0, off);
+ build_copy_store(&buf, T1, off + copy_word_size);
+ build_copy_store(&buf, T2, off + 2 * copy_word_size);
+ if (off == -(4 * copy_word_size))
+ uasm_il_bne(&buf, &r, A2, A0,
+ label_copy_nopref);
+ build_copy_store(&buf, T3, off + 3 * copy_word_size);
+ off += 4 * copy_word_size;
+ } while (off < 0);
+ }
+
+ uasm_i_jr(&buf, RA);
+ uasm_i_nop(&buf);
+
+ BUG_ON(buf > copy_page_array + ARRAY_SIZE(copy_page_array));
+
+ uasm_resolve_relocs(relocs, labels);
+
+ pr_debug("Synthesized copy page handler (%u instructions).\n",
+ (u32)(buf - copy_page_array));
+
+ pr_debug("\t.set push\n");
+ pr_debug("\t.set noreorder\n");
+ for (i = 0; i < (buf - copy_page_array); i++)
+ pr_debug("\t.word 0x%08x\n", copy_page_array[i]);
+ pr_debug("\t.set pop\n");
+}
+
+#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
+
+/*
+ * Pad descriptors to cacheline, since each is exclusively owned by a
+ * particular CPU.
+ */
+struct dmadscr {
+ u64 dscr_a;
+ u64 dscr_b;
+ u64 pad_a;
+ u64 pad_b;
+} ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
+
+void sb1_dma_init(void)
+{
+ int i;
+
+ for (i = 0; i < DM_NUM_CHANNELS; i++) {
+ const u64 base_val = CPHYSADDR((unsigned long)&page_descr[i]) |
+ V_DM_DSCR_BASE_RINGSZ(1);
+ void *base_reg = IOADDR(A_DM_REGISTER(i, R_DM_DSCR_BASE));
+
+ __raw_writeq(base_val, base_reg);
+ __raw_writeq(base_val | M_DM_DSCR_BASE_RESET, base_reg);
+ __raw_writeq(base_val | M_DM_DSCR_BASE_ENABL, base_reg);
+ }
+}
+
+void clear_page(void *page)
+{
+ u64 to_phys = CPHYSADDR((unsigned long)page);
+ unsigned int cpu = smp_processor_id();
+
+ /* if the page is not in KSEG0, use old way */
+ if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
+ return clear_page_cpu(page);
+
+ page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
+ M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
+ page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
+ __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
+
+ /*
+ * Don't really want to do it this way, but there's no
+ * reliable way to delay completion detection.
+ */
+ while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
+ & M_DM_DSCR_BASE_INTERRUPT))
+ ;
+ __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
+}
+
+void copy_page(void *to, void *from)
+{
+ u64 from_phys = CPHYSADDR((unsigned long)from);
+ u64 to_phys = CPHYSADDR((unsigned long)to);
+ unsigned int cpu = smp_processor_id();
+
+ /* if any page is not in KSEG0, use old way */
+ if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
+ || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
+ return copy_page_cpu(to, from);
+
+ page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
+ M_DM_DSCRA_INTERRUPT;
+ page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
+ __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
+
+ /*
+ * Don't really want to do it this way, but there's no
+ * reliable way to delay completion detection.
+ */
+ while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
+ & M_DM_DSCR_BASE_INTERRUPT))
+ ;
+ __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
+}
+
+#endif /* CONFIG_SIBYTE_DMA_PAGEOPS */