| 0,0 → 1,253 |
|---|
| /* |
| * Copyright (c) 2008 Pavel Rimsky |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** @addtogroup sparc64 |
| * @{ |
| */ |
| /** |
| * @file |
| * @brief SGCN driver. |
| */ |
| |
| #include <arch/drivers/sgcn.h> |
| #include <genarch/ofw/ofw_tree.h> |
| #include <debug.h> |
| #include <func.h> |
| #include <print.h> |
| #include <mm/page.h> |
| #include <console/chardev.h> |
| #include <console/console.h> |
| #include <synch/spinlock.h> |
| |
| /* |
| * Physical address at which the SBBC starts. This value has been obtained |
| * by inspecting (using Simics) memory accesses made by OBP. It is valid |
| * for the Simics-simulated Serengeti machine. The author of this code is |
| * not sure whether this value is valid generally. |
| */ |
| #define SBBC_START 0x63000000000 |
| |
| /* offset of SRAM within the SBBC memory */ |
| #define SBBC_SRAM_OFFSET 0x900000 |
| |
| /* magic string contained at the beginning of SRAM */ |
| #define SRAM_TOC_MAGIC "TOCSRAM" |
| |
| /* |
| * Key into the SRAM table of contents which identifies the entry |
| * describing the OBP console buffer. It is worth mentioning |
| * that the OBP console buffer is not the only console buffer |
| * which can be used. It is, however, used because when the kernel |
| * is running, the OBP buffer is not used by OBP any more but OBP |
| * has already made neccessary arangements so that the output will |
| * be read from the OBP buffer and input will go to the OBP buffer. |
| * Therefore HelenOS needs to make no such arrangements any more. |
| */ |
| #define CONSOLE_KEY "OBPCONS" |
| |
| /* magic string contained at the beginning of the console buffer */ |
| #define SGCN_BUFFER_MAGIC "CON" |
| |
| |
| /* |
| * Returns a pointer to the object of a given type which is placed at the given |
| * offset from the SRAM beginning. |
| */ |
| #define SRAM(type, offset) ((type *) (sram_begin + (offset))) |
| |
| /* Returns a pointer to the SRAM table of contents. */ |
| #define SRAM_TOC (SRAM(iosram_toc_t, 0)) |
| |
| /* |
| * Returns a pointer to the object of a given type which is placed at the given |
| * offset from the console buffer beginning. |
| */ |
| #define SGCN_BUFFER(type, offset) \ |
| ((type *) (sgcn_buffer_begin + (offset))) |
| |
| /* Returns a pointer to the console buffer header. */ |
| #define SGCN_BUFFER_HEADER (SGCN_BUFFER(sgcn_buffer_header_t, 0)) |
| |
| |
| /* starting address of SRAM, will be set by the init_sram_begin function */ |
| static uintptr_t sram_begin; |
| |
| /* |
| * starting address of the SGCN buffer, will be set by the |
| * init_sgcn_buffer_begin function |
| */ |
| static uintptr_t sgcn_buffer_begin; |
| |
| |
| /* |
| * Ensures that writing to the buffer and consequent update of the write pointer |
| * are together one atomic operation. |
| */ |
| SPINLOCK_INITIALIZE(sgcn_output_lock); |
| |
| |
| static void sgcn_putchar(struct chardev * cd, const char c); |
| |
| /** character device operations */ |
| static chardev_operations_t sgcn_ops = { |
| .suspend = NULL, |
| .resume = NULL, |
| .write = sgcn_putchar, |
| .read = NULL |
| }; |
| |
| /** SGCN character device */ |
| chardev_t sgcn_stdout; |
| |
| /** |
| * Initializes the starting address of SRAM. |
| * |
| * The SRAM starts 0x900000 + C bytes behind the SBBC start in the |
| * physical memory, where C is the value read from the "iosram-toc" |
| * property of the "/chosen" OBP node. The sram_begin variable will |
| * be set to the virtual address which maps to the SRAM physical |
| * address. |
| */ |
| static void init_sram_begin(void) |
| { |
| ofw_tree_node_t *chosen; |
| ofw_tree_property_t *iosram_toc; |
| |
| chosen = ofw_tree_lookup("/chosen"); |
| if (!chosen) |
| panic("Can't find /chosen.\n"); |
| |
| iosram_toc = ofw_tree_getprop(chosen, "iosram-toc"); |
| if (!iosram_toc) |
| panic("Can't find property \"iosram-toc\".\n"); |
| if (!iosram_toc->value) |
| panic("Can't find SRAM TOC.\n"); |
| |
| sram_begin = hw_map( |
| SBBC_START + SBBC_SRAM_OFFSET |
| + *((uint32_t *) iosram_toc->value), |
| 128 * 1024); |
| } |
| |
| /** |
| * Initializes the starting address of the SGCN buffer. |
| * |
| * The offset of the SGCN buffer within SRAM is obtained from the |
| * SRAM table of contents. The table of contents contains |
| * information about several buffers, among which there is an OBP |
| * console buffer - this one will be used as the SGCN buffer. |
| */ |
| static void sgcn_buffer_begin_init(void) |
| { |
| init_sram_begin(); |
| |
| ASSERT(strcmp(SRAM_TOC->magic, SRAM_TOC_MAGIC) == 0); |
| |
| /* lookup TOC entry with the correct key */ |
| uint32_t i; |
| for (i = 0; i < MAX_TOC_ENTRIES; i++) { |
| if (strcmp(SRAM_TOC->keys[i].key, CONSOLE_KEY) == 0) |
| break; |
| } |
| ASSERT(i < MAX_TOC_ENTRIES); |
| |
| sgcn_buffer_begin = sram_begin + SRAM_TOC->keys[i].offset; |
| } |
| |
| /** |
| * Writes a single character to the SGCN (circular) output buffer |
| * and updates the output write pointer so that SGCN gets to know |
| * that the character has been written. |
| */ |
| static void sgcn_do_putchar(const char c) |
| { |
| uint32_t begin = SGCN_BUFFER_HEADER->out_begin; |
| uint32_t end = SGCN_BUFFER_HEADER->out_end; |
| uint32_t size = end - begin; |
| |
| /* we need pointers to volatile variables */ |
| volatile char *buf_ptr = (volatile char *) |
| SGCN_BUFFER(char, SGCN_BUFFER_HEADER->out_wrptr); |
| volatile uint32_t *out_wrptr_ptr = &(SGCN_BUFFER_HEADER->out_wrptr); |
| volatile uint32_t *out_rdptr_ptr = &(SGCN_BUFFER_HEADER->out_rdptr); |
| |
| /* |
| * Write the character and increment the write pointer modulo the |
| * output buffer size. Note that if we are to rewrite a character |
| * which has not been read by the SGCN controller yet (i.e. the output |
| * buffer is full), we need to wait until the controller reads some more |
| * characters. We wait actively, which means that all threads waiting |
| * for the lock are blocked. However, this situation is |
| * 1) rare - the output buffer is big, so filling the whole |
| * output buffer is improbable |
| * 2) short-lasting - it will take the controller only a fraction |
| * of millisecond to pick the unread characters up |
| * 3) not serious - the blocked threads are those that print something |
| * to user console, which is not a time-critical operation |
| */ |
| uint32_t new_wrptr = (((*out_wrptr_ptr) - begin + 1) % size) + begin; |
| while (*out_rdptr_ptr == new_wrptr) |
| ; |
| *buf_ptr = c; |
| *out_wrptr_ptr = new_wrptr; |
| } |
| |
| /** |
| * SGCN output operation. Prints a single character to the SGCN. If the line |
| * feed character is written ('\n'), the carriage return character ('\r') is |
| * written straight away. |
| */ |
| static void sgcn_putchar(struct chardev * cd, const char c) |
| { |
| spinlock_lock(&sgcn_output_lock); |
| |
| sgcn_do_putchar(c); |
| if (c == '\n') { |
| sgcn_do_putchar('\r'); |
| } |
| |
| spinlock_unlock(&sgcn_output_lock); |
| } |
| |
| /** |
| * A public function which initializes I/O from/to Serengeti console |
| * and sets it as a default input/output. |
| */ |
| void sgcn_init(void) |
| { |
| sgcn_buffer_begin_init(); |
| |
| chardev_initialize("sgcn_output", &sgcn_stdout, &sgcn_ops); |
| stdout = &sgcn_stdout; |
| |
| |
| printf("SGCN buffer begin = %d, in read ptr = %" PRIu32 ".", sgcn_buffer_begin, SGCN_BUFFER_HEADER->in_wrptr); |
| } |
| |
| /** @} |
| */ |