--- /dev/null
+/* Copyright 2013-2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define STACK_TOP 0x4000
+
+/* Load an immediate 64-bit value into a register */
+#define LOAD_IMM64(r, e) \
+ lis r,(e)@highest; \
+ ori r,r,(e)@higher; \
+ rldicr r,r, 32, 31; \
+ oris r,r, (e)@h; \
+ ori r,r, (e)@l;
+
+ .section ".head","ax"
+
+ /* Microwatt currently enters in LE mode at 0x0 */
+ . = 0
+.global _start
+_start:
+ LOAD_IMM64(%r12, 0x000000000ffffff)
+ mtdec %r12
+ LOAD_IMM64(%r12, 0x9000000000008003)
+ mtmsrd %r12 // EE on
+ /* setup stack */
+ LOAD_IMM64(%r1, STACK_TOP - 0x100)
+ LOAD_IMM64(%r12, main)
+ mtctr %r12
+ bctrl
+ attn // terminate on exit
+ b .
+
+#define EXCEPTION(nr) \
+ .= nr ;\
+ b .
+
+ /* More exception stubs */
+ EXCEPTION(0x300)
+ EXCEPTION(0x380)
+ EXCEPTION(0x400)
+ EXCEPTION(0x480)
+ . = 0x500
+ b __isr
+
+ EXCEPTION(0x600)
+ EXCEPTION(0x700)
+ EXCEPTION(0x800)
+ EXCEPTION(0x900)
+ EXCEPTION(0x980)
+ EXCEPTION(0xa00)
+ EXCEPTION(0xb00)
+ EXCEPTION(0xc00)
+ EXCEPTION(0xd00)
+
+// ISR data
+
+#define REDZONE_SIZE (512)
+#define REG_SAVE_SIZE ((32 + 5)*8)
+#define STACK_FRAME_C_MINIMAL 64
+
+#define SAVE_NIA (32*8)
+#define SAVE_LR (33*8)
+#define SAVE_CTR (34*8)
+#define SAVE_CR (35*8)
+#define SAVE_SRR1 (36*8)
+
+__isr:
+/*
+ * Assume where we are coming from has a stack and can save there.
+ * We save the full register set. Since we are calling out to C, we
+ * could just save the ABI volatile registers
+ */
+ stdu %r1,-(REG_SAVE_SIZE+REDZONE_SIZE)(%r1)
+ std %r0, 1*8(%r1)
+// std %r1, 1*8(%r1)
+ std %r2, 2*8(%r1)
+ std %r3, 3*8(%r1)
+ std %r4, 4*8(%r1)
+ std %r5, 5*8(%r1)
+ std %r6, 6*8(%r1)
+ std %r7, 7*8(%r1)
+ std %r8, 8*8(%r1)
+ std %r9, 9*8(%r1)
+ std %r10, 10*8(%r1)
+ std %r11, 11*8(%r1)
+ std %r12, 12*8(%r1)
+ std %r13, 13*8(%r1)
+ std %r14, 14*8(%r1)
+ std %r15, 15*8(%r1)
+ std %r16, 16*8(%r1)
+ std %r17, 17*8(%r1)
+ std %r18, 18*8(%r1)
+ std %r19, 19*8(%r1)
+ std %r20, 20*8(%r1)
+ std %r21, 21*8(%r1)
+ std %r22, 22*8(%r1)
+ std %r23, 23*8(%r1)
+ std %r24, 24*8(%r1)
+ std %r25, 25*8(%r1)
+ std %r26, 26*8(%r1)
+ std %r27, 27*8(%r1)
+ std %r28, 28*8(%r1)
+ std %r29, 29*8(%r1)
+ std %r30, 30*8(%r1)
+ std %r31, 31*8(%r1)
+ mfsrr0 %r0
+ std %r0, SAVE_NIA*8(%r1)
+ mflr %r0
+ std %r0, SAVE_LR*8(%r1)
+ mfctr %r0
+ std %r0, SAVE_CTR*8(%r1)
+ mfcr %r0
+ std %r0, SAVE_CR*8(%r1)
+ mfsrr1 %r0
+ std %r0, SAVE_SRR1*8(%r1)
+
+ stdu %r1,-STACK_FRAME_C_MINIMAL(%r1)
+ LOAD_IMM64(%r3, isr)
+ mtctr %r3,
+ bctrl
+ nop
+ ld %r1, 0(%r1)
+
+ ld %r0, 1*8(%r1)
+// ld %r1, 1*8(%r1) // do this at rfid
+ ld %r2, 2*8(%r1)
+// ld %r3, 3*8(%r1) // do this at rfid
+ ld %r4, 4*8(%r1)
+ ld %r5, 5*8(%r1)
+ ld %r6, 6*8(%r1)
+ ld %r7, 7*8(%r1)
+ ld %r8, 8*8(%r1)
+ ld %r9, 9*8(%r1)
+ ld %r10, 10*8(%r1)
+ ld %r11, 11*8(%r1)
+ ld %r12, 12*8(%r1)
+ ld %r13, 13*8(%r1)
+ ld %r14, 14*8(%r1)
+ ld %r15, 15*8(%r1)
+ ld %r16, 16*8(%r1)
+ ld %r17, 17*8(%r1)
+ ld %r18, 18*8(%r1)
+ ld %r19, 19*8(%r1)
+ ld %r20, 20*8(%r1)
+ ld %r21, 21*8(%r1)
+ ld %r22, 22*8(%r1)
+ ld %r23, 23*8(%r1)
+ ld %r24, 24*8(%r1)
+ ld %r25, 25*8(%r1)
+ ld %r26, 26*8(%r1)
+ ld %r27, 27*8(%r1)
+ ld %r28, 28*8(%r1)
+ ld %r29, 29*8(%r1)
+ ld %r30, 30*8(%r1)
+ ld %r31, 31*8(%r1)
+
+ ld %r3, SAVE_LR*8(%r1)
+ mtlr %r3
+ ld %r3, SAVE_CTR*8(%r1)
+ mtctr %r3
+ ld %r3, SAVE_CR*8(%r1)
+ mtcr %r3
+ ld %r3, SAVE_SRR1*8(%r1)
+ mtsrr1 %r3
+ ld %r3, SAVE_NIA*8(%r1)
+ mtsrr0 %r3
+
+ /* restore %r3 */
+ ld %r3, 3*8(%r1)
+
+ /* do final fixup r1 */
+ ld %r1, 0*8(%r1)
+
+ rfid
--- /dev/null
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <limits.h>
+
+#include "console.h"
+#include "xics.h"
+
+#undef DEBUG
+//#define DEBUG 1
+
+void print_number(unsigned int i) // only for i = 0-999
+{
+ unsigned int j, k, m;
+ bool zeros = false;
+
+ k = 1000000000;
+
+ for (m = 0; m < 10 ; m++) {
+ j = i/k;
+ if (m == 9) zeros = true;
+ if (zeros || (j != 0)) {
+ putchar(48 + j);
+ zeros = true;
+ }
+ i = i % k;
+ k = k / 10;
+ }
+}
+
+#ifdef DEBUG
+#define DEBUG_STR "\r\nDEBUG: "
+void debug_print(int i)
+{
+ putstr(DEBUG_STR, strlen(DEBUG_STR));
+ print_number(i);
+ putstr("\r\n", 2);
+}
+
+#define debug_putstr(a, b) putstr(a,b)
+#else
+#define debug_putstr(a, b)
+#define debug_print(i)
+#endif
+
+#define ASSERT_FAIL "() ASSERT_FAILURE!\r\n "
+#define assert(cond) \
+ if (!(cond)) { \
+ putstr(__FILE__, strlen(__FILE__)); \
+ putstr(":", 1); \
+ print_number(__LINE__); \
+ putstr(":", 1); \
+ putstr(__FUNCTION__, strlen(__FUNCTION__));\
+ putstr(ASSERT_FAIL, strlen(ASSERT_FAIL)); \
+ __asm__ ("attn"); \
+ }
+
+
+volatile uint64_t isrs_run;
+
+#define ISR_IPI 0x0000000000000001
+#define ISR_UART 0x0000000000000002
+#define ISR_SPURIOUS 0x0000000000000004
+
+#define IPI "IPI\r\n"
+void ipi_isr(void) {
+ debug_putstr(IPI, strlen(IPI));
+
+ isrs_run |= ISR_IPI;
+}
+
+
+#define UART "UART\r\n"
+void uart_isr(void) {
+ debug_putstr(UART, strlen(UART));
+
+ potato_uart_irq_dis(); // disable interrupt to ack it
+
+ isrs_run |= ISR_UART;
+}
+
+// The hardware doesn't support this but it's part of XICS so add it.
+#define SPURIOUS "SPURIOUS\r\n"
+void spurious_isr(void) {
+ debug_putstr(SPURIOUS, strlen(SPURIOUS));
+
+ isrs_run |= ISR_SPURIOUS;
+}
+
+struct isr_op {
+ void (*func)(void);
+ int source_id;
+};
+
+struct isr_op isr_table[] = {
+ { .func = ipi_isr, .source_id = 2 },
+ { .func = uart_isr, .source_id = 16 },
+ { .func = spurious_isr, .source_id = 0 },
+ { .func = NULL, .source_id = 0 }
+};
+
+bool ipi_running;
+
+#define ISR "ISR XISR="
+void isr(void)
+{
+ struct isr_op *op;
+ uint32_t xirr;
+
+ assert(!ipi_running); // check we aren't reentrant
+ ipi_running = true;
+
+ xirr = xics_read32(XICS_XIRR); // read hardware irq source
+
+#ifdef DEBUG
+ putstr(ISR, strlen(ISR));
+ print_number(xirr & 0xff);
+ putstr("\r\n", 2);
+#endif
+
+ op = isr_table;
+ while (1) {
+ assert(op->func); // didn't find isr
+ if (op->source_id == (xirr & 0x00ffffff)) {
+ op->func();
+ break;
+ }
+ op++;
+ }
+
+ xics_write32(XICS_XIRR, xirr); // EOI
+
+ ipi_running = false;
+}
+
+/*****************************************/
+
+int xics_test_0(void)
+{
+ // setup
+ xics_write8(XICS_XIRR, 0x00); // mask all interrupts
+ isrs_run = 0;
+
+ xics_write8(XICS_XIRR, 0x00); // mask all interrupts
+
+ // trigger two interrupts
+ potato_uart_irq_en(); // cause 0x500 interrupt
+ xics_write8(XICS_MFRR, 0x05); // cause 0x500 interrupt
+
+ // still masked, so shouldn't happen yet
+ assert(isrs_run == 0);
+
+ // unmask IPI only
+ xics_write8(XICS_XIRR, 0x40);
+ assert(isrs_run == ISR_IPI);
+
+ // unmask UART
+ xics_write8(XICS_XIRR, 0xc0);
+ assert(isrs_run == (ISR_IPI | ISR_UART));
+
+ // cleanup
+ xics_write8(XICS_XIRR, 0x00); // mask all interrupts
+ isrs_run = 0;
+
+ return 0;
+}
+
+int xics_test_1(void)
+{
+ // setup
+ xics_write8(XICS_XIRR, 0x00); // mask all interrupts
+ isrs_run = 0;
+
+ xics_write8(XICS_XIRR, 0xff); // allow all interrupts
+
+ // should be none pending
+ assert(isrs_run == 0);
+
+ // trigger both
+ potato_uart_irq_en(); // cause 0x500 interrupt
+ xics_write8(XICS_MFRR, 0x05); // cause 0x500 interrupt
+
+ assert(isrs_run == (ISR_IPI | ISR_UART));
+
+ // cleanup
+ xics_write8(XICS_XIRR, 0x00); // mask all interrupts
+ isrs_run = 0;
+
+ return 0;
+}
+
+void mtmsrd(uint64_t val)
+{
+ __asm__ volatile("mtmsrd %0" : : "r" (val));
+}
+
+int xics_test_2(void)
+{
+ // setup
+ xics_write8(XICS_XIRR, 0x00); // mask all interrupts
+ isrs_run = 0;
+
+ // trigger interrupts with MSR[EE]=0 and show they are not run
+ mtmsrd(0x9000000000000003); // EE off
+
+ xics_write8(XICS_XIRR, 0xff); // allow all interrupts
+
+ // trigger an IPI
+ xics_write8(XICS_MFRR, 0x05); // cause 0x500 interrupt
+
+ assert(isrs_run == 0);
+
+ mtmsrd(0x9000000000008003); // EE on
+ assert(isrs_run == ISR_IPI);
+
+ // cleanup
+ xics_write8(XICS_XIRR, 0x00); // mask all interrupts
+ isrs_run = 0;
+
+ return 0;
+}
+
+#define TEST "Test "
+#define PASS "PASS\r\n"
+#define FAIL "FAIL\r\n"
+
+int (*tests[])(void) = {
+ xics_test_0,
+ xics_test_1,
+ xics_test_2,
+ NULL
+};
+
+int main(void)
+{
+ int fail = 0;
+ int i = 0;
+ int (*t)(void);
+
+ potato_uart_init();
+ ipi_running = false;
+
+ /* run the tests */
+ while (1) {
+ t = tests[i];
+ if (!t)
+ break;
+
+ putstr(TEST, strlen(TEST));
+ print_number(i);
+ putstr(": ", 1);
+ if (t() != 0) {
+ fail = 1;
+ putstr(FAIL, strlen(FAIL));
+ } else
+ putstr(PASS, strlen(PASS));
+
+ i++;
+ }
+
+ return fail;
+}
--- /dev/null
+#include <stdint.h>
+
+#define XICS_BASE 0xc0004000
+
+static uint64_t xics_base = XICS_BASE;
+
+#define XICS_XIRR_POLL 0x0
+#define XICS_XIRR 0x4
+#define XICS_RESV 0x8
+#define XICS_MFRR 0xC
+
+uint8_t xics_read8(int offset)
+{
+ uint32_t val;
+
+ __asm__ volatile("lbzcix %0,%1,%2" : "=r" (val) : "b" (xics_base), "r" (offset));
+ return val;
+}
+
+void xics_write8(int offset, uint8_t val)
+{
+ __asm__ volatile("stbcix %0,%1,%2" : : "r" (val), "b" (xics_base), "r" (offset));
+}
+
+uint32_t xics_read32(int offset)
+{
+ uint32_t val;
+
+ __asm__ volatile("lwzcix %0,%1,%2" : "=r" (val) : "b" (xics_base), "r" (offset));
+ return val;
+}
+
+void xics_write32(int offset, uint32_t val)
+{
+ __asm__ volatile("stwcix %0,%1,%2" : : "r" (val), "b" (xics_base), "r" (offset));
+}