[ARM] 3052/1: add ixp2000 microcode loader
Patch from Lennert Buytenhek
This patch adds a microcode loader for the ixp2000 architecture.
The ixp2000 is an xscale-based CPU with a number of additional small
CPUs ('microengines') on die that can be programmed to do various
things. Depending on the ixp2000 model, there are between 2 and 16
microengines.
This code provides an API that allows configuring the microengines,
loading code into them, and starting and stopping them and reading
out a number of status registers, and is used by the microengine
network driver that was recently announced to netdev.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-ixp2000/Makefile b/arch/arm/mach-ixp2000/Makefile
index 1e6139d..9621aeb 100644
--- a/arch/arm/mach-ixp2000/Makefile
+++ b/arch/arm/mach-ixp2000/Makefile
@@ -1,7 +1,7 @@
#
# Makefile for the linux kernel.
#
-obj-y := core.o pci.o
+obj-y := core.o pci.o uengine.o
obj-m :=
obj-n :=
obj- :=
diff --git a/arch/arm/mach-ixp2000/uengine.c b/arch/arm/mach-ixp2000/uengine.c
new file mode 100644
index 0000000..43e2343
--- /dev/null
+++ b/arch/arm/mach-ixp2000/uengine.c
@@ -0,0 +1,474 @@
+/*
+ * Generic library functions for the microengines found on the Intel
+ * IXP2000 series of network processors.
+ *
+ * Copyright (C) 2004, 2005 Lennert Buytenhek <buytenh@wantstofly.org>
+ * Dedicated to Marija Kulikova.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of the
+ * License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <asm/hardware.h>
+#include <asm/arch/ixp2000-regs.h>
+#include <asm/arch/uengine.h>
+#include <asm/io.h>
+
+#define USTORE_ADDRESS 0x000
+#define USTORE_DATA_LOWER 0x004
+#define USTORE_DATA_UPPER 0x008
+#define CTX_ENABLES 0x018
+#define CC_ENABLE 0x01c
+#define CSR_CTX_POINTER 0x020
+#define INDIRECT_CTX_STS 0x040
+#define ACTIVE_CTX_STS 0x044
+#define INDIRECT_CTX_SIG_EVENTS 0x048
+#define INDIRECT_CTX_WAKEUP_EVENTS 0x050
+#define NN_PUT 0x080
+#define NN_GET 0x084
+#define TIMESTAMP_LOW 0x0c0
+#define TIMESTAMP_HIGH 0x0c4
+#define T_INDEX_BYTE_INDEX 0x0f4
+#define LOCAL_CSR_STATUS 0x180
+
+u32 ixp2000_uengine_mask;
+
+static void *ixp2000_uengine_csr_area(int uengine)
+{
+ return ((void *)IXP2000_UENGINE_CSR_VIRT_BASE) + (uengine << 10);
+}
+
+/*
+ * LOCAL_CSR_STATUS=1 after a read or write to a microengine's CSR
+ * space means that the microengine we tried to access was also trying
+ * to access its own CSR space on the same clock cycle as we did. When
+ * this happens, we lose the arbitration process by default, and the
+ * read or write we tried to do was not actually performed, so we try
+ * again until it succeeds.
+ */
+u32 ixp2000_uengine_csr_read(int uengine, int offset)
+{
+ void *uebase;
+ u32 *local_csr_status;
+ u32 *reg;
+ u32 value;
+
+ uebase = ixp2000_uengine_csr_area(uengine);
+
+ local_csr_status = (u32 *)(uebase + LOCAL_CSR_STATUS);
+ reg = (u32 *)(uebase + offset);
+ do {
+ value = ixp2000_reg_read(reg);
+ } while (ixp2000_reg_read(local_csr_status) & 1);
+
+ return value;
+}
+EXPORT_SYMBOL(ixp2000_uengine_csr_read);
+
+void ixp2000_uengine_csr_write(int uengine, int offset, u32 value)
+{
+ void *uebase;
+ u32 *local_csr_status;
+ u32 *reg;
+
+ uebase = ixp2000_uengine_csr_area(uengine);
+
+ local_csr_status = (u32 *)(uebase + LOCAL_CSR_STATUS);
+ reg = (u32 *)(uebase + offset);
+ do {
+ ixp2000_reg_write(reg, value);
+ } while (ixp2000_reg_read(local_csr_status) & 1);
+}
+EXPORT_SYMBOL(ixp2000_uengine_csr_write);
+
+void ixp2000_uengine_reset(u32 uengine_mask)
+{
+ ixp2000_reg_write(IXP2000_RESET1, uengine_mask & ixp2000_uengine_mask);
+ ixp2000_reg_write(IXP2000_RESET1, 0);
+}
+EXPORT_SYMBOL(ixp2000_uengine_reset);
+
+void ixp2000_uengine_set_mode(int uengine, u32 mode)
+{
+ /*
+ * CTL_STR_PAR_EN: unconditionally enable parity checking on
+ * control store.
+ */
+ mode |= 0x10000000;
+ ixp2000_uengine_csr_write(uengine, CTX_ENABLES, mode);
+
+ /*
+ * Enable updating of condition codes.
+ */
+ ixp2000_uengine_csr_write(uengine, CC_ENABLE, 0x00002000);
+
+ /*
+ * Initialise other per-microengine registers.
+ */
+ ixp2000_uengine_csr_write(uengine, NN_PUT, 0x00);
+ ixp2000_uengine_csr_write(uengine, NN_GET, 0x00);
+ ixp2000_uengine_csr_write(uengine, T_INDEX_BYTE_INDEX, 0);
+}
+EXPORT_SYMBOL(ixp2000_uengine_set_mode);
+
+static int make_even_parity(u32 x)
+{
+ return hweight32(x) & 1;
+}
+
+static void ustore_write(int uengine, u64 insn)
+{
+ /*
+ * Generate even parity for top and bottom 20 bits.
+ */
+ insn |= (u64)make_even_parity((insn >> 20) & 0x000fffff) << 41;
+ insn |= (u64)make_even_parity(insn & 0x000fffff) << 40;
+
+ /*
+ * Write to microstore. The second write auto-increments
+ * the USTORE_ADDRESS index register.
+ */
+ ixp2000_uengine_csr_write(uengine, USTORE_DATA_LOWER, (u32)insn);
+ ixp2000_uengine_csr_write(uengine, USTORE_DATA_UPPER, (u32)(insn >> 32));
+}
+
+void ixp2000_uengine_load_microcode(int uengine, u8 *ucode, int insns)
+{
+ int i;
+
+ /*
+ * Start writing to microstore at address 0.
+ */
+ ixp2000_uengine_csr_write(uengine, USTORE_ADDRESS, 0x80000000);
+ for (i = 0; i < insns; i++) {
+ u64 insn;
+
+ insn = (((u64)ucode[0]) << 32) |
+ (((u64)ucode[1]) << 24) |
+ (((u64)ucode[2]) << 16) |
+ (((u64)ucode[3]) << 8) |
+ ((u64)ucode[4]);
+ ucode += 5;
+
+ ustore_write(uengine, insn);
+ }
+
+ /*
+ * Pad with a few NOPs at the end (to avoid the microengine
+ * aborting as it prefetches beyond the last instruction), unless
+ * we run off the end of the instruction store first, at which
+ * point the address register will wrap back to zero.
+ */
+ for (i = 0; i < 4; i++) {
+ u32 addr;
+
+ addr = ixp2000_uengine_csr_read(uengine, USTORE_ADDRESS);
+ if (addr == 0x80000000)
+ break;
+ ustore_write(uengine, 0xf0000c0300ULL);
+ }
+
+ /*
+ * End programming.
+ */
+ ixp2000_uengine_csr_write(uengine, USTORE_ADDRESS, 0x00000000);
+}
+EXPORT_SYMBOL(ixp2000_uengine_load_microcode);
+
+void ixp2000_uengine_init_context(int uengine, int context, int pc)
+{
+ /*
+ * Select the right context for indirect access.
+ */
+ ixp2000_uengine_csr_write(uengine, CSR_CTX_POINTER, context);
+
+ /*
+ * Initialise signal masks to immediately go to Ready state.
+ */
+ ixp2000_uengine_csr_write(uengine, INDIRECT_CTX_SIG_EVENTS, 1);
+ ixp2000_uengine_csr_write(uengine, INDIRECT_CTX_WAKEUP_EVENTS, 1);
+
+ /*
+ * Set program counter.
+ */
+ ixp2000_uengine_csr_write(uengine, INDIRECT_CTX_STS, pc);
+}
+EXPORT_SYMBOL(ixp2000_uengine_init_context);
+
+void ixp2000_uengine_start_contexts(int uengine, u8 ctx_mask)
+{
+ u32 mask;
+
+ /*
+ * Enable the specified context to go to Executing state.
+ */
+ mask = ixp2000_uengine_csr_read(uengine, CTX_ENABLES);
+ mask |= ctx_mask << 8;
+ ixp2000_uengine_csr_write(uengine, CTX_ENABLES, mask);
+}
+EXPORT_SYMBOL(ixp2000_uengine_start_contexts);
+
+void ixp2000_uengine_stop_contexts(int uengine, u8 ctx_mask)
+{
+ u32 mask;
+
+ /*
+ * Disable the Ready->Executing transition. Note that this
+ * does not stop the context until it voluntarily yields.
+ */
+ mask = ixp2000_uengine_csr_read(uengine, CTX_ENABLES);
+ mask &= ~(ctx_mask << 8);
+ ixp2000_uengine_csr_write(uengine, CTX_ENABLES, mask);
+}
+EXPORT_SYMBOL(ixp2000_uengine_stop_contexts);
+
+static int check_ixp_type(struct ixp2000_uengine_code *c)
+{
+ u32 product_id;
+ u32 rev;
+
+ product_id = ixp2000_reg_read(IXP2000_PRODUCT_ID);
+ if (((product_id >> 16) & 0x1f) != 0)
+ return 0;
+
+ switch ((product_id >> 8) & 0xff) {
+ case 0: /* IXP2800 */
+ if (!(c->cpu_model_bitmask & 4))
+ return 0;
+ break;
+
+ case 1: /* IXP2850 */
+ if (!(c->cpu_model_bitmask & 8))
+ return 0;
+ break;
+
+ case 2: /* IXP2400 */
+ if (!(c->cpu_model_bitmask & 2))
+ return 0;
+ break;
+
+ default:
+ return 0;
+ }
+
+ rev = product_id & 0xff;
+ if (rev < c->cpu_min_revision || rev > c->cpu_max_revision)
+ return 0;
+
+ return 1;
+}
+
+static void generate_ucode(u8 *ucode, u32 *gpr_a, u32 *gpr_b)
+{
+ int offset;
+ int i;
+
+ offset = 0;
+
+ for (i = 0; i < 128; i++) {
+ u8 b3;
+ u8 b2;
+ u8 b1;
+ u8 b0;
+
+ b3 = (gpr_a[i] >> 24) & 0xff;
+ b2 = (gpr_a[i] >> 16) & 0xff;
+ b1 = (gpr_a[i] >> 8) & 0xff;
+ b0 = gpr_a[i] & 0xff;
+
+ // immed[@ai, (b1 << 8) | b0]
+ // 11110000 0000VVVV VVVV11VV VVVVVV00 1IIIIIII
+ ucode[offset++] = 0xf0;
+ ucode[offset++] = (b1 >> 4);
+ ucode[offset++] = (b1 << 4) | 0x0c | (b0 >> 6);
+ ucode[offset++] = (b0 << 2);
+ ucode[offset++] = 0x80 | i;
+
+ // immed_w1[@ai, (b3 << 8) | b2]
+ // 11110100 0100VVVV VVVV11VV VVVVVV00 1IIIIIII
+ ucode[offset++] = 0xf4;
+ ucode[offset++] = 0x40 | (b3 >> 4);
+ ucode[offset++] = (b3 << 4) | 0x0c | (b2 >> 6);
+ ucode[offset++] = (b2 << 2);
+ ucode[offset++] = 0x80 | i;
+ }
+
+ for (i = 0; i < 128; i++) {
+ u8 b3;
+ u8 b2;
+ u8 b1;
+ u8 b0;
+
+ b3 = (gpr_b[i] >> 24) & 0xff;
+ b2 = (gpr_b[i] >> 16) & 0xff;
+ b1 = (gpr_b[i] >> 8) & 0xff;
+ b0 = gpr_b[i] & 0xff;
+
+ // immed[@bi, (b1 << 8) | b0]
+ // 11110000 0000VVVV VVVV001I IIIIII11 VVVVVVVV
+ ucode[offset++] = 0xf0;
+ ucode[offset++] = (b1 >> 4);
+ ucode[offset++] = (b1 << 4) | 0x02 | (i >> 6);
+ ucode[offset++] = (i << 2) | 0x03;
+ ucode[offset++] = b0;
+
+ // immed_w1[@bi, (b3 << 8) | b2]
+ // 11110100 0100VVVV VVVV001I IIIIII11 VVVVVVVV
+ ucode[offset++] = 0xf4;
+ ucode[offset++] = 0x40 | (b3 >> 4);
+ ucode[offset++] = (b3 << 4) | 0x02 | (i >> 6);
+ ucode[offset++] = (i << 2) | 0x03;
+ ucode[offset++] = b2;
+ }
+
+ // ctx_arb[kill]
+ ucode[offset++] = 0xe0;
+ ucode[offset++] = 0x00;
+ ucode[offset++] = 0x01;
+ ucode[offset++] = 0x00;
+ ucode[offset++] = 0x00;
+}
+
+static int set_initial_registers(int uengine, struct ixp2000_uengine_code *c)
+{
+ int per_ctx_regs;
+ u32 *gpr_a;
+ u32 *gpr_b;
+ u8 *ucode;
+ int i;
+
+ gpr_a = kmalloc(128 * sizeof(u32), GFP_KERNEL);
+ gpr_b = kmalloc(128 * sizeof(u32), GFP_KERNEL);
+ ucode = kmalloc(513 * 5, GFP_KERNEL);
+ if (gpr_a == NULL || gpr_b == NULL || ucode == NULL) {
+ kfree(ucode);
+ kfree(gpr_b);
+ kfree(gpr_a);
+ return 1;
+ }
+
+ per_ctx_regs = 16;
+ if (c->uengine_parameters & IXP2000_UENGINE_4_CONTEXTS)
+ per_ctx_regs = 32;
+
+ memset(gpr_a, 0, sizeof(gpr_a));
+ memset(gpr_b, 0, sizeof(gpr_b));
+ for (i = 0; i < 256; i++) {
+ struct ixp2000_reg_value *r = c->initial_reg_values + i;
+ u32 *bank;
+ int inc;
+ int j;
+
+ if (r->reg == -1)
+ break;
+
+ bank = (r->reg & 0x400) ? gpr_b : gpr_a;
+ inc = (r->reg & 0x80) ? 128 : per_ctx_regs;
+
+ j = r->reg & 0x7f;
+ while (j < 128) {
+ bank[j] = r->value;
+ j += inc;
+ }
+ }
+
+ generate_ucode(ucode, gpr_a, gpr_b);
+ ixp2000_uengine_load_microcode(uengine, ucode, 513);
+ ixp2000_uengine_init_context(uengine, 0, 0);
+ ixp2000_uengine_start_contexts(uengine, 0x01);
+ for (i = 0; i < 100; i++) {
+ u32 status;
+
+ status = ixp2000_uengine_csr_read(uengine, ACTIVE_CTX_STS);
+ if (!(status & 0x80000000))
+ break;
+ }
+ ixp2000_uengine_stop_contexts(uengine, 0x01);
+
+ kfree(ucode);
+ kfree(gpr_b);
+ kfree(gpr_a);
+
+ return !!(i == 100);
+}
+
+int ixp2000_uengine_load(int uengine, struct ixp2000_uengine_code *c)
+{
+ int ctx;
+
+ if (!check_ixp_type(c))
+ return 1;
+
+ if (!(ixp2000_uengine_mask & (1 << uengine)))
+ return 1;
+
+ ixp2000_uengine_reset(1 << uengine);
+ ixp2000_uengine_set_mode(uengine, c->uengine_parameters);
+ if (set_initial_registers(uengine, c))
+ return 1;
+ ixp2000_uengine_load_microcode(uengine, c->insns, c->num_insns);
+
+ for (ctx = 0; ctx < 8; ctx++)
+ ixp2000_uengine_init_context(uengine, ctx, 0);
+
+ return 0;
+}
+EXPORT_SYMBOL(ixp2000_uengine_load);
+
+
+static int __init ixp2000_uengine_init(void)
+{
+ int uengine;
+ u32 value;
+
+ /*
+ * Determine number of microengines present.
+ */
+ switch ((ixp2000_reg_read(IXP2000_PRODUCT_ID) >> 8) & 0x1fff) {
+ case 0: /* IXP2800 */
+ case 1: /* IXP2850 */
+ ixp2000_uengine_mask = 0x00ff00ff;
+ break;
+
+ case 2: /* IXP2400 */
+ ixp2000_uengine_mask = 0x000f000f;
+ break;
+
+ default:
+ printk(KERN_INFO "Detected unknown IXP2000 model (%.8x)\n",
+ (unsigned int)ixp2000_reg_read(IXP2000_PRODUCT_ID));
+ ixp2000_uengine_mask = 0x00000000;
+ break;
+ }
+
+ /*
+ * Reset microengines.
+ */
+ ixp2000_reg_write(IXP2000_RESET1, ixp2000_uengine_mask);
+ ixp2000_reg_write(IXP2000_RESET1, 0);
+
+ /*
+ * Synchronise timestamp counters across all microengines.
+ */
+ value = ixp2000_reg_read(IXP2000_MISC_CONTROL);
+ ixp2000_reg_write(IXP2000_MISC_CONTROL, value & ~0x80);
+ for (uengine = 0; uengine < 32; uengine++) {
+ if (ixp2000_uengine_mask & (1 << uengine)) {
+ ixp2000_uengine_csr_write(uengine, TIMESTAMP_LOW, 0);
+ ixp2000_uengine_csr_write(uengine, TIMESTAMP_HIGH, 0);
+ }
+ }
+ ixp2000_reg_write(IXP2000_MISC_CONTROL, value | 0x80);
+
+ return 0;
+}
+
+subsys_initcall(ixp2000_uengine_init);