[POWERPC] bestcomm: core bestcomm support for Freescale MPC5200

This patch adds support for the core of the BestComm API
for the Freescale MPC5200(b). The BestComm engine is a
microcode-controlled / tasks-based DMA used by several
of the onchip devices.

Setting up the tasks / memory allocation and all common
low level functions are handled by this patch.
The specifics details of each tasks and their microcode
are split-out in separate patches.

This is not the official API, but a much cleaner one.
(hopefully)

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

9 files changed, 1312 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 3724cb43d8a5..bdced1e42293 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -315,4 +315,6 @@ config FSL_ULI1575
 config CPM
         bool
 
+source "arch/powerpc/sysdev/bestcomm/Kconfig"
+
 endmenu
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index 1a6f5641ebc8..99a77d743d48 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_FSL_SOC)		+= fsl_soc.o
 obj-$(CONFIG_FSL_PCI)           += fsl_pci.o
 obj-$(CONFIG_TSI108_BRIDGE)     += tsi108_pci.o tsi108_dev.o
 obj-$(CONFIG_QUICC_ENGINE)      += qe_lib/
+obj-$(CONFIG_PPC_BESTCOMM)      += bestcomm/
 mv64x60-$(CONFIG_PCI)           += mv64x60_pci.o
 obj-$(CONFIG_MV64X60)           += $(mv64x60-y) mv64x60_pic.o mv64x60_dev.o \
                                    mv64x60_udbg.o
diff --git a/arch/powerpc/sysdev/bestcomm/Kconfig b/arch/powerpc/sysdev/bestcomm/Kconfig
new file mode 100644
index 000000000000..3366e24c10d6
--- /dev/null
+++ b/arch/powerpc/sysdev/bestcomm/Kconfig
@@ -0,0 +1,18 @@
+#
+# Kconfig options for Bestcomm
+#
+
+config PPC_BESTCOMM
+        tristate "Bestcomm DMA engine support"
+        depends on PPC_MPC52xx
+        default n
+        select PPC_LIB_RHEAP
+        help
+          BestComm is the name of the communication coprocessor found
+          on the Freescale MPC5200 family of processor. It's usage is
+          optionnal for some drivers (like ATA), but required for
+          others (like FEC).
+
+          If you want to use drivers that require DMA operations,
+          answer Y or M. Otherwise say N.
+
diff --git a/arch/powerpc/sysdev/bestcomm/Makefile b/arch/powerpc/sysdev/bestcomm/Makefile
new file mode 100644
index 000000000000..a24aa06faaf5
--- /dev/null
+++ b/arch/powerpc/sysdev/bestcomm/Makefile
@@ -0,0 +1,8 @@
+#
+# Makefile for BestComm & co
+#
+
+bestcomm-core-objs      := bestcomm.o sram.o
+
+obj-$(CONFIG_PPC_BESTCOMM)              += bestcomm-core.o
+ 
diff --git a/arch/powerpc/sysdev/bestcomm/bestcomm.c b/arch/powerpc/sysdev/bestcomm/bestcomm.c
new file mode 100644
index 000000000000..48492a83e5a7
--- /dev/null
+++ b/arch/powerpc/sysdev/bestcomm/bestcomm.c
@@ -0,0 +1,528 @@
+/*
+ * Driver for MPC52xx processor BestComm peripheral controller
+ *
+ *
+ * Copyright (C) 2006-2007 Sylvain Munaut <tnt@246tNt.com>
+ * Copyright (C) 2005      Varma Electronics Oy,
+ *                         ( by Andrey Volkov <avolkov@varma-el.com> )
+ * Copyright (C) 2003-2004 MontaVista, Software, Inc.
+ *                         ( by Dale Farnsworth <dfarnsworth@mvista.com> )
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/mpc52xx.h>
+
+#include "sram.h"
+#include "bestcomm_priv.h"
+#include "bestcomm.h"
+
+#define DRIVER_NAME "bestcomm-core"
+
+
+struct bcom_engine *bcom_eng = NULL;
+EXPORT_SYMBOL_GPL(bcom_eng);    /* needed for inline functions */
+
+
+/* ======================================================================== */
+/* Public and private API                                                   */
+/* ======================================================================== */
+
+/* Private API */
+
+struct bcom_task *
+bcom_task_alloc(int bd_count, int bd_size, int priv_size)
+{
+        int i, tasknum = -1;
+        struct bcom_task *tsk;
+
+        /* Get and reserve a task num */
+        spin_lock(&bcom_eng->lock);
+
+        for (i=0; i<BCOM_MAX_TASKS; i++)
+                if (!bcom_eng->tdt[i].stop) {   /* we use stop as a marker */
+                        bcom_eng->tdt[i].stop = 0xfffffffful; /* dummy addr */
+                        tasknum = i;
+                        break;
+                }
+
+        spin_unlock(&bcom_eng->lock);
+
+        if (tasknum < 0)
+                return NULL;
+
+        /* Allocate our structure */
+        tsk = kzalloc(sizeof(struct bcom_task) + priv_size, GFP_KERNEL);
+        if (!tsk)
+                goto error;
+
+        tsk->tasknum = tasknum;
+        if (priv_size)
+                tsk->priv = (void*)tsk + sizeof(struct bcom_task);
+
+        /* Get IRQ of that task */
+        tsk->irq = irq_of_parse_and_map(bcom_eng->ofnode, tsk->tasknum);
+        if (tsk->irq == NO_IRQ)
+                goto error;
+
+        /* Init the BDs, if needed */
+        if (bd_count) {
+                tsk->cookie = kmalloc(sizeof(void*) * bd_count, GFP_KERNEL);
+                if (!tsk->cookie)
+                        goto error;
+
+                tsk->bd = bcom_sram_alloc(bd_count * bd_size, 4, &tsk->bd_pa);
+                if (!tsk->bd)
+                        goto error;
+                memset(tsk->bd, 0x00, bd_count * bd_size);
+
+                tsk->num_bd = bd_count;
+                tsk->bd_size = bd_size;
+        }
+
+        return tsk;
+
+error:
+        if (tsk) {
+                if (tsk->irq != NO_IRQ)
+                        irq_dispose_mapping(tsk->irq);
+                bcom_sram_free(tsk->bd);
+                kfree(tsk->cookie);
+                kfree(tsk);
+        }
+
+        bcom_eng->tdt[tasknum].stop = 0;
+
+        return NULL;
+}
+EXPORT_SYMBOL_GPL(bcom_task_alloc);
+
+void
+bcom_task_free(struct bcom_task *tsk)
+{
+        /* Stop the task */
+        bcom_disable_task(tsk->tasknum);
+
+        /* Clear TDT */
+        bcom_eng->tdt[tsk->tasknum].start = 0;
+        bcom_eng->tdt[tsk->tasknum].stop  = 0;
+
+        /* Free everything */
+        irq_dispose_mapping(tsk->irq);
+        bcom_sram_free(tsk->bd);
+        kfree(tsk->cookie);
+        kfree(tsk);
+}
+EXPORT_SYMBOL_GPL(bcom_task_free);
+
+int
+bcom_load_image(int task, u32 *task_image)
+{
+        struct bcom_task_header *hdr = (struct bcom_task_header *)task_image;
+        struct bcom_tdt *tdt;
+        u32 *desc, *var, *inc;
+        u32 *desc_src, *var_src, *inc_src;
+
+        /* Safety checks */
+        if (hdr->magic != BCOM_TASK_MAGIC) {
+                printk(KERN_ERR DRIVER_NAME
+                        ": Trying to load invalid microcode\n");
+                return -EINVAL;
+        }
+
+        if ((task < 0) || (task >= BCOM_MAX_TASKS)) {
+                printk(KERN_ERR DRIVER_NAME
+                        ": Trying to load invalid task %d\n", task);
+                return -EINVAL;
+        }
+
+        /* Initial load or reload */
+        tdt = &bcom_eng->tdt[task];
+
+        if (tdt->start) {
+                desc = bcom_task_desc(task);
+                if (hdr->desc_size != bcom_task_num_descs(task)) {
+                        printk(KERN_ERR DRIVER_NAME
+                                ": Trying to reload wrong task image "
+                                "(%d size %d/%d)!\n",
+                                task,
+                                hdr->desc_size,
+                                bcom_task_num_descs(task));
+                        return -EINVAL;
+                }
+        } else {
+                phys_addr_t start_pa;
+
+                desc = bcom_sram_alloc(hdr->desc_size * sizeof(u32), 4, &start_pa);
+                if (!desc)
+                        return -ENOMEM;
+
+                tdt->start = start_pa;
+                tdt->stop = start_pa + ((hdr->desc_size-1) * sizeof(u32));
+        }
+
+        var = bcom_task_var(task);
+        inc = bcom_task_inc(task);
+
+        /* Clear & copy */
+        memset(var, 0x00, BCOM_VAR_SIZE);
+        memset(inc, 0x00, BCOM_INC_SIZE);
+
+        desc_src = (u32 *)(hdr + 1);
+        var_src = desc_src + hdr->desc_size;
+        inc_src = var_src + hdr->var_size;
+
+        memcpy(desc, desc_src, hdr->desc_size * sizeof(u32));
+        memcpy(var + hdr->first_var, var_src, hdr->var_size * sizeof(u32));
+        memcpy(inc, inc_src, hdr->inc_size * sizeof(u32));
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(bcom_load_image);
+
+void
+bcom_set_initiator(int task, int initiator)
+{
+        int i;
+        int num_descs;
+        u32 *desc;
+        int next_drd_has_initiator;
+
+        bcom_set_tcr_initiator(task, initiator);
+
+        /* Just setting tcr is apparently not enough due to some problem */
+        /* with it. So we just go thru all the microcode and replace in  */
+        /* the DRD directly */
+
+        desc = bcom_task_desc(task);
+        next_drd_has_initiator = 1;
+        num_descs = bcom_task_num_descs(task);
+
+        for (i=0; i<num_descs; i++, desc++) {
+                if (!bcom_desc_is_drd(*desc))
+                        continue;
+                if (next_drd_has_initiator)
+                        if (bcom_desc_initiator(*desc) != BCOM_INITIATOR_ALWAYS)
+                                bcom_set_desc_initiator(desc, initiator);
+                next_drd_has_initiator = !bcom_drd_is_extended(*desc);
+        }
+}
+EXPORT_SYMBOL_GPL(bcom_set_initiator);
+
+
+/* Public API */
+
+void
+bcom_enable(struct bcom_task *tsk)
+{
+        bcom_enable_task(tsk->tasknum);
+}
+EXPORT_SYMBOL_GPL(bcom_enable);
+
+void
+bcom_disable(struct bcom_task *tsk)
+{
+        bcom_disable_task(tsk->tasknum);
+}
+EXPORT_SYMBOL_GPL(bcom_disable);
+
+
+/* ======================================================================== */
+/* Engine init/cleanup                                                      */
+/* ======================================================================== */
+
+/* Function Descriptor table */
+/* this will need to be updated if Freescale changes their task code FDT */
+static u32 fdt_ops[] = {
+        0xa0045670,     /* FDT[48] - load_acc()   */
+        0x80045670,     /* FDT[49] - unload_acc() */
+        0x21800000,     /* FDT[50] - and()        */
+        0x21e00000,     /* FDT[51] - or()         */
+        0x21500000,     /* FDT[52] - xor()        */
+        0x21400000,     /* FDT[53] - andn()       */
+        0x21500000,     /* FDT[54] - not()        */
+        0x20400000,     /* FDT[55] - add()        */
+        0x20500000,     /* FDT[56] - sub()        */
+        0x20800000,     /* FDT[57] - lsh()        */
+        0x20a00000,     /* FDT[58] - rsh()        */
+        0xc0170000,     /* FDT[59] - crc8()       */
+        0xc0145670,     /* FDT[60] - crc16()      */
+        0xc0345670,     /* FDT[61] - crc32()      */
+        0xa0076540,     /* FDT[62] - endian32()   */
+        0xa0000760,     /* FDT[63] - endian16()   */
+};
+
+
+static int __devinit
+bcom_engine_init(void)
+{
+        int task;
+        phys_addr_t tdt_pa, ctx_pa, var_pa, fdt_pa;
+        unsigned int tdt_size, ctx_size, var_size, fdt_size;
+
+        /* Allocate & clear SRAM zones for FDT, TDTs, contexts and vars/incs */
+        tdt_size = BCOM_MAX_TASKS * sizeof(struct bcom_tdt);
+        ctx_size = BCOM_MAX_TASKS * BCOM_CTX_SIZE;
+        var_size = BCOM_MAX_TASKS * (BCOM_VAR_SIZE + BCOM_INC_SIZE);
+        fdt_size = BCOM_FDT_SIZE;
+
+        bcom_eng->tdt = bcom_sram_alloc(tdt_size, sizeof(u32), &tdt_pa);
+        bcom_eng->ctx = bcom_sram_alloc(ctx_size, BCOM_CTX_ALIGN, &ctx_pa);
+        bcom_eng->var = bcom_sram_alloc(var_size, BCOM_VAR_ALIGN, &var_pa);
+        bcom_eng->fdt = bcom_sram_alloc(fdt_size, BCOM_FDT_ALIGN, &fdt_pa);
+
+        if (!bcom_eng->tdt || !bcom_eng->ctx || !bcom_eng->var || !bcom_eng->fdt) {
+                printk(KERN_ERR "DMA: SRAM alloc failed in engine init !\n");
+
+                bcom_sram_free(bcom_eng->tdt);
+                bcom_sram_free(bcom_eng->ctx);
+                bcom_sram_free(bcom_eng->var);
+                bcom_sram_free(bcom_eng->fdt);
+
+                return -ENOMEM;
+        }
+
+        memset(bcom_eng->tdt, 0x00, tdt_size);
+        memset(bcom_eng->ctx, 0x00, ctx_size);
+        memset(bcom_eng->var, 0x00, var_size);
+        memset(bcom_eng->fdt, 0x00, fdt_size);
+
+        /* Copy the FDT for the EU#3 */
+        memcpy(&bcom_eng->fdt[48], fdt_ops, sizeof(fdt_ops));
+
+        /* Initialize Task base structure */
+        for (task=0; task<BCOM_MAX_TASKS; task++)
+        {
+                out_be16(&bcom_eng->regs->tcr[task], 0);
+                out_8(&bcom_eng->regs->ipr[task], 0);
+
+                bcom_eng->tdt[task].context     = ctx_pa;
+                bcom_eng->tdt[task].var = var_pa;
+                bcom_eng->tdt[task].fdt = fdt_pa;
+
+                var_pa += BCOM_VAR_SIZE + BCOM_INC_SIZE;
+                ctx_pa += BCOM_CTX_SIZE;
+        }
+
+        out_be32(&bcom_eng->regs->taskBar, tdt_pa);
+
+        /* Init 'always' initiator */
+        out_8(&bcom_eng->regs->ipr[BCOM_INITIATOR_ALWAYS], BCOM_IPR_ALWAYS);
+
+        /* Disable COMM Bus Prefetch, apparently it's not reliable yet */
+        /* FIXME: This should be done on 5200 and not 5200B ... */
+        out_be16(&bcom_eng->regs->PtdCntrl, in_be16(&bcom_eng->regs->PtdCntrl) | 1);
+
+        /* Init lock */
+        spin_lock_init(&bcom_eng->lock);
+
+        return 0;
+}
+
+static void
+bcom_engine_cleanup(void)
+{
+        int task;
+
+        /* Stop all tasks */
+        for (task=0; task<BCOM_MAX_TASKS; task++)
+        {
+                out_be16(&bcom_eng->regs->tcr[task], 0);
+                out_8(&bcom_eng->regs->ipr[task], 0);
+        }
+
+        out_be32(&bcom_eng->regs->taskBar, 0ul);
+
+        /* Release the SRAM zones */
+        bcom_sram_free(bcom_eng->tdt);
+        bcom_sram_free(bcom_eng->ctx);
+        bcom_sram_free(bcom_eng->var);
+        bcom_sram_free(bcom_eng->fdt);
+}
+
+
+/* ======================================================================== */
+/* OF platform driver                                                       */
+/* ======================================================================== */
+
+static int __devinit
+mpc52xx_bcom_probe(struct of_device *op, const struct of_device_id *match)
+{
+        struct device_node *ofn_sram;
+        struct resource res_bcom;
+
+        int rv;
+
+        /* Inform user we're ok so far */
+        printk(KERN_INFO "DMA: MPC52xx BestComm driver\n");
+
+        /* Get the bestcomm node */
+        of_node_get(op->node);
+
+        /* Prepare SRAM */
+        ofn_sram = of_find_compatible_node(NULL, "sram", "mpc5200-sram");
+        if (!ofn_sram) {
+                printk(KERN_ERR DRIVER_NAME ": "
+                        "No SRAM found in device tree\n");
+                rv = -ENODEV;
+                goto error_ofput;
+        }
+        rv = bcom_sram_init(ofn_sram, DRIVER_NAME);
+        of_node_put(ofn_sram);
+
+        if (rv) {
+                printk(KERN_ERR DRIVER_NAME ": "
+                        "Error in SRAM init\n");
+                goto error_ofput;
+        }
+
+        /* Get a clean struct */
+        bcom_eng = kzalloc(sizeof(struct bcom_engine), GFP_KERNEL);
+        if (!bcom_eng) {
+                printk(KERN_ERR DRIVER_NAME ": "
+                        "Can't allocate state structure\n");
+                rv = -ENOMEM;
+                goto error_sramclean;
+        }
+
+        /* Save the node */
+        bcom_eng->ofnode = op->node;
+
+        /* Get, reserve & map io */
+        if (of_address_to_resource(op->node, 0, &res_bcom)) {
+                printk(KERN_ERR DRIVER_NAME ": "
+                        "Can't get resource\n");
+                rv = -EINVAL;
+                goto error_sramclean;
+        }
+
+        if (!request_mem_region(res_bcom.start, sizeof(struct mpc52xx_sdma),
+                                DRIVER_NAME)) {
+                printk(KERN_ERR DRIVER_NAME ": "
+                        "Can't request registers region\n");
+                rv = -EBUSY;
+                goto error_sramclean;
+        }
+
+        bcom_eng->regs_base = res_bcom.start;
+        bcom_eng->regs = ioremap(res_bcom.start, sizeof(struct mpc52xx_sdma));
+        if (!bcom_eng->regs) {
+                printk(KERN_ERR DRIVER_NAME ": "
+                        "Can't map registers\n");
+                rv = -ENOMEM;
+                goto error_release;
+        }
+
+        /* Now, do the real init */
+        rv = bcom_engine_init();
+        if (rv)
+                goto error_unmap;
+
+        /* Done ! */
+        printk(KERN_INFO "DMA: MPC52xx BestComm engine @%08lx ok !\n",
+                bcom_eng->regs_base);
+
+        return 0;
+
+        /* Error path */
+error_unmap:
+        iounmap(bcom_eng->regs);
+error_release:
+        release_mem_region(res_bcom.start, sizeof(struct mpc52xx_sdma));
+error_sramclean:
+        kfree(bcom_eng);
+        bcom_sram_cleanup();
+error_ofput:
+        of_node_put(op->node);
+
+        printk(KERN_ERR "DMA: MPC52xx BestComm init failed !\n");
+
+        return rv;
+}
+
+
+static int
+mpc52xx_bcom_remove(struct of_device *op)
+{
+        /* Clean up the engine */
+        bcom_engine_cleanup();
+
+        /* Cleanup SRAM */
+        bcom_sram_cleanup();
+
+        /* Release regs */
+        iounmap(bcom_eng->regs);
+        release_mem_region(bcom_eng->regs_base, sizeof(struct mpc52xx_sdma));
+
+        /* Release the node */
+        of_node_put(bcom_eng->ofnode);
+
+        /* Release memory */
+        kfree(bcom_eng);
+        bcom_eng = NULL;
+
+        return 0;
+}
+
+static struct of_device_id mpc52xx_bcom_of_match[] = {
+        {
+                .type           = "dma-controller",
+                .compatible     = "mpc5200-bestcomm",
+        },
+        {},
+};
+
+MODULE_DEVICE_TABLE(of, mpc52xx_bcom_of_match);
+
+
+static struct of_platform_driver mpc52xx_bcom_of_platform_driver = {
+        .owner          = THIS_MODULE,
+        .name           = DRIVER_NAME,
+        .match_table    = mpc52xx_bcom_of_match,
+        .probe          = mpc52xx_bcom_probe,
+        .remove         = mpc52xx_bcom_remove,
+        .driver         = {
+                .name   = DRIVER_NAME,
+                .owner  = THIS_MODULE,
+        },
+};
+
+
+/* ======================================================================== */
+/* Module                                                                   */
+/* ======================================================================== */
+
+static int __init
+mpc52xx_bcom_init(void)
+{
+        return of_register_platform_driver(&mpc52xx_bcom_of_platform_driver);
+}
+
+static void __exit
+mpc52xx_bcom_exit(void)
+{
+        of_unregister_platform_driver(&mpc52xx_bcom_of_platform_driver);
+}
+
+/* If we're not a module, we must make sure everything is setup before  */
+/* anyone tries to use us ... that's why we use subsys_initcall instead */
+/* of module_init. */
+subsys_initcall(mpc52xx_bcom_init);
+module_exit(mpc52xx_bcom_exit);
+
+MODULE_DESCRIPTION("Freescale MPC52xx BestComm DMA");
+MODULE_AUTHOR("Sylvain Munaut <tnt@246tNt.com>");
+MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
+MODULE_AUTHOR("Dale Farnsworth <dfarnsworth@mvista.com>");
+MODULE_LICENSE("GPL v2");
+
diff --git a/arch/powerpc/sysdev/bestcomm/bestcomm.h b/arch/powerpc/sysdev/bestcomm/bestcomm.h
new file mode 100644
index 000000000000..e802cb4eb69a
--- /dev/null
+++ b/arch/powerpc/sysdev/bestcomm/bestcomm.h
@@ -0,0 +1,190 @@
+/*
+ * Public header for the MPC52xx processor BestComm driver
+ *
+ *
+ * Copyright (C) 2006      Sylvain Munaut <tnt@246tNt.com>
+ * Copyright (C) 2005      Varma Electronics Oy,
+ *                         ( by Andrey Volkov <avolkov@varma-el.com> )
+ * Copyright (C) 2003-2004 MontaVista, Software, Inc.
+ *                         ( by Dale Farnsworth <dfarnsworth@mvista.com> )
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#ifndef __BESTCOMM_H__
+#define __BESTCOMM_H__
+
+struct bcom_bd; /* defined later on ... */
+
+
+/* ======================================================================== */
+/* Generic task managment                                                   */
+/* ======================================================================== */
+
+/**
+ * struct bcom_task - Structure describing a loaded BestComm task
+ *
+ * This structure is never built by the driver it self. It's built and
+ * filled the intermediate layer of the BestComm API, the task dependent
+ * support code.
+ *
+ * Most likely you don't need to poke around inside this structure. The
+ * fields are exposed in the header just for the sake of inline functions
+ */
+struct bcom_task {
+        unsigned int    tasknum;
+        unsigned int    flags;
+        int             irq;
+
+        struct bcom_bd  *bd;
+        phys_addr_t     bd_pa;
+        void            **cookie;
+        unsigned short  index;
+        unsigned short  outdex;
+        unsigned int    num_bd;
+        unsigned int    bd_size;
+
+        void*           priv;
+};
+
+#define BCOM_FLAGS_NONE         0x00000000ul
+#define BCOM_FLAGS_ENABLE_TASK  (1ul <<  0)
+
+/**
+ * bcom_enable - Enable a BestComm task
+ * @tsk: The BestComm task structure
+ *
+ * This function makes sure the given task is enabled and can be run
+ * by the BestComm engine as needed
+ */
+extern void bcom_enable(struct bcom_task *tsk);
+
+/**
+ * bcom_disable - Disable a BestComm task
+ * @tsk: The BestComm task structure
+ *
+ * This function disable a given task, making sure it's not executed
+ * by the BestComm engine.
+ */
+extern void bcom_disable(struct bcom_task *tsk);
+
+
+/**
+ * bcom_get_task_irq - Returns the irq number of a BestComm task
+ * @tsk: The BestComm task structure
+ */
+static inline int
+bcom_get_task_irq(struct bcom_task *tsk) {
+        return tsk->irq;
+}
+
+/* ======================================================================== */
+/* BD based tasks helpers                                                   */
+/* ======================================================================== */
+
+/**
+ * struct bcom_bd - Structure describing a generic BestComm buffer descriptor
+ * @status: The current status of this buffer. Exact meaning depends on the
+ *          task type
+ * @data: An array of u32 whose meaning depends on the task type.
+ */
+struct bcom_bd {
+        u32     status;
+        u32     data[1];        /* variable, but at least 1 */
+};
+
+#define BCOM_BD_READY   0x40000000ul
+
+/** _bcom_next_index - Get next input index.
+ * @tsk: pointer to task structure
+ *
+ * Support function; Device drivers should not call this
+ */
+static inline int
+_bcom_next_index(struct bcom_task *tsk)
+{
+        return ((tsk->index + 1) == tsk->num_bd) ? 0 : tsk->index + 1;
+}
+
+/** _bcom_next_outdex - Get next output index.
+ * @tsk: pointer to task structure
+ *
+ * Support function; Device drivers should not call this
+ */
+static inline int
+_bcom_next_outdex(struct bcom_task *tsk)
+{
+        return ((tsk->outdex + 1) == tsk->num_bd) ? 0 : tsk->outdex + 1;
+}
+
+/**
+ * bcom_queue_empty - Checks if a BestComm task BD queue is empty
+ * @tsk: The BestComm task structure
+ */
+static inline int
+bcom_queue_empty(struct bcom_task *tsk)
+{
+        return tsk->index == tsk->outdex;
+}
+
+/**
+ * bcom_queue_full - Checks if a BestComm task BD queue is full
+ * @tsk: The BestComm task structure
+ */
+static inline int
+bcom_queue_full(struct bcom_task *tsk)
+{
+        return tsk->outdex == _bcom_next_index(tsk);
+}
+
+/**
+ * bcom_buffer_done - Checks if a BestComm 
+ * @tsk: The BestComm task structure
+ */
+static inline int
+bcom_buffer_done(struct bcom_task *tsk)
+{
+        if (bcom_queue_empty(tsk))
+                return 0;
+        return !(tsk->bd[tsk->outdex].status & BCOM_BD_READY);
+}
+
+/**
+ * bcom_prepare_next_buffer - clear status of next available buffer.
+ * @tsk: The BestComm task structure
+ *
+ * Returns pointer to next buffer descriptor
+ */
+static inline struct bcom_bd *
+bcom_prepare_next_buffer(struct bcom_task *tsk)
+{
+        tsk->bd[tsk->index].status = 0; /* cleanup last status */
+        return &tsk->bd[tsk->index];
+}
+
+static inline void
+bcom_submit_next_buffer(struct bcom_task *tsk, void *cookie)
+{
+        tsk->cookie[tsk->index] = cookie;
+        mb();   /* ensure the bd is really up-to-date */
+        tsk->bd[tsk->index].status |= BCOM_BD_READY;
+        tsk->index = _bcom_next_index(tsk);
+        if (tsk->flags & BCOM_FLAGS_ENABLE_TASK)
+                bcom_enable(tsk);
+}
+
+static inline void *
+bcom_retrieve_buffer(struct bcom_task *tsk, u32 *p_status, struct bcom_bd **p_bd)
+{
+        void *cookie = tsk->cookie[tsk->outdex];
+        if (p_status)
+                *p_status = tsk->bd[tsk->outdex].status;
+        if (p_bd)
+                *p_bd = &tsk->bd[tsk->outdex];
+        tsk->outdex = _bcom_next_outdex(tsk);
+        return cookie;
+}
+
+#endif /* __BESTCOMM_H__ */
diff --git a/arch/powerpc/sysdev/bestcomm/bestcomm_priv.h b/arch/powerpc/sysdev/bestcomm/bestcomm_priv.h
new file mode 100644
index 000000000000..866a2915ef2f
--- /dev/null
+++ b/arch/powerpc/sysdev/bestcomm/bestcomm_priv.h
@@ -0,0 +1,334 @@
+/*
+ * Private header for the MPC52xx processor BestComm driver
+ *
+ * By private, we mean that driver should not use it directly. It's meant
+ * to be used by the BestComm engine driver itself and by the intermediate
+ * layer between the core and the drivers.
+ *
+ * Copyright (C) 2006      Sylvain Munaut <tnt@246tNt.com>
+ * Copyright (C) 2005      Varma Electronics Oy,
+ *                         ( by Andrey Volkov <avolkov@varma-el.com> )
+ * Copyright (C) 2003-2004 MontaVista, Software, Inc.
+ *                         ( by Dale Farnsworth <dfarnsworth@mvista.com> )
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#ifndef __BESTCOMM_PRIV_H__
+#define __BESTCOMM_PRIV_H__
+
+#include <linux/spinlock.h>
+#include <linux/of.h>
+#include <asm/io.h>
+#include <asm/mpc52xx.h>
+
+#include "sram.h"
+
+
+/* ======================================================================== */
+/* Engine related stuff                                                     */
+/* ======================================================================== */
+
+/* Zones sizes and needed alignments */
+#define BCOM_MAX_TASKS          16
+#define BCOM_MAX_VAR            24
+#define BCOM_MAX_INC            8
+#define BCOM_MAX_FDT            64
+#define BCOM_MAX_CTX            20
+#define BCOM_CTX_SIZE           (BCOM_MAX_CTX * sizeof(u32))
+#define BCOM_CTX_ALIGN          0x100
+#define BCOM_VAR_SIZE           (BCOM_MAX_VAR * sizeof(u32))
+#define BCOM_INC_SIZE           (BCOM_MAX_INC * sizeof(u32))
+#define BCOM_VAR_ALIGN          0x80
+#define BCOM_FDT_SIZE           (BCOM_MAX_FDT * sizeof(u32))
+#define BCOM_FDT_ALIGN          0x100
+
+/**
+ * struct bcom_tdt - Task Descriptor Table Entry
+ *
+ */
+struct bcom_tdt {
+        u32 start;
+        u32 stop;
+        u32 var;
+        u32 fdt;
+        u32 exec_status;        /* used internally by BestComm engine */
+        u32 mvtp;               /* used internally by BestComm engine */
+        u32 context;
+        u32 litbase;
+};
+
+/**
+ * struct bcom_engine
+ *
+ * This holds all info needed globaly to handle the engine
+ */
+struct bcom_engine {
+        struct device_node              *ofnode;
+        struct mpc52xx_sdma __iomem     *regs;
+        phys_addr_t                      regs_base;
+
+        struct bcom_tdt                 *tdt;
+        u32                             *ctx;
+        u32                             *var;
+        u32                             *fdt;
+
+        spinlock_t                      lock;
+};
+
+extern struct bcom_engine *bcom_eng;
+
+
+/* ======================================================================== */
+/* Tasks related stuff                                                      */
+/* ======================================================================== */
+
+/* Tasks image header */
+#define BCOM_TASK_MAGIC         0x4243544B      /* 'BCTK' */
+
+struct bcom_task_header {
+        u32     magic;
+        u8      desc_size;      /* the size fields     */
+        u8      var_size;       /* are given in number */
+        u8      inc_size;       /* of 32-bits words    */
+        u8      first_var;
+        u8      reserved[8];
+};
+
+/* Descriptors stucture & co */
+#define BCOM_DESC_NOP           0x000001f8
+#define BCOM_LCD_MASK           0x80000000
+#define BCOM_DRD_EXTENDED       0x40000000
+#define BCOM_DRD_INITIATOR_SHIFT        21
+
+/* Tasks pragma */
+#define BCOM_PRAGMA_BIT_RSV             7       /* reserved pragma bit */
+#define BCOM_PRAGMA_BIT_PRECISE_INC     6       /* increment 0=when possible, */
+                                                /*           1=iter end */
+#define BCOM_PRAGMA_BIT_RST_ERROR_NO    5       /* don't reset errors on */
+                                                /* task enable */
+#define BCOM_PRAGMA_BIT_PACK            4       /* pack data enable */
+#define BCOM_PRAGMA_BIT_INTEGER         3       /* data alignment */
+                                                /* 0=frac(msb), 1=int(lsb) */
+#define BCOM_PRAGMA_BIT_SPECREAD        2       /* XLB speculative read */
+#define BCOM_PRAGMA_BIT_CW              1       /* write line buffer enable */
+#define BCOM_PRAGMA_BIT_RL              0       /* read line buffer enable */
+
+        /* Looks like XLB speculative read generates XLB errors when a buffer
+         * is at the end of the physical memory. i.e. when accessing the
+         * lasts words, the engine tries to prefetch the next but there is no
+         * next ...
+         */
+#define BCOM_STD_PRAGMA         ((0 << BCOM_PRAGMA_BIT_RSV)             | \
+                                 (0 << BCOM_PRAGMA_BIT_PRECISE_INC)     | \
+                                 (0 << BCOM_PRAGMA_BIT_RST_ERROR_NO)    | \
+                                 (0 << BCOM_PRAGMA_BIT_PACK)            | \
+                                 (0 << BCOM_PRAGMA_BIT_INTEGER)         | \
+                                 (0 << BCOM_PRAGMA_BIT_SPECREAD)        | \
+                                 (1 << BCOM_PRAGMA_BIT_CW)              | \
+                                 (1 << BCOM_PRAGMA_BIT_RL))
+
+#define BCOM_PCI_PRAGMA         ((0 << BCOM_PRAGMA_BIT_RSV)             | \
+                                 (0 << BCOM_PRAGMA_BIT_PRECISE_INC)     | \
+                                 (0 << BCOM_PRAGMA_BIT_RST_ERROR_NO)    | \
+                                 (0 << BCOM_PRAGMA_BIT_PACK)            | \
+                                 (1 << BCOM_PRAGMA_BIT_INTEGER)         | \
+                                 (0 << BCOM_PRAGMA_BIT_SPECREAD)        | \
+                                 (1 << BCOM_PRAGMA_BIT_CW)              | \
+                                 (1 << BCOM_PRAGMA_BIT_RL))
+
+#define BCOM_ATA_PRAGMA         BCOM_STD_PRAGMA
+#define BCOM_CRC16_DP_0_PRAGMA  BCOM_STD_PRAGMA
+#define BCOM_CRC16_DP_1_PRAGMA  BCOM_STD_PRAGMA
+#define BCOM_FEC_RX_BD_PRAGMA   BCOM_STD_PRAGMA
+#define BCOM_FEC_TX_BD_PRAGMA   BCOM_STD_PRAGMA
+#define BCOM_GEN_DP_0_PRAGMA    BCOM_STD_PRAGMA
+#define BCOM_GEN_DP_1_PRAGMA    BCOM_STD_PRAGMA
+#define BCOM_GEN_DP_2_PRAGMA    BCOM_STD_PRAGMA
+#define BCOM_GEN_DP_3_PRAGMA    BCOM_STD_PRAGMA
+#define BCOM_GEN_DP_BD_0_PRAGMA BCOM_STD_PRAGMA
+#define BCOM_GEN_DP_BD_1_PRAGMA BCOM_STD_PRAGMA
+#define BCOM_GEN_RX_BD_PRAGMA   BCOM_STD_PRAGMA
+#define BCOM_GEN_TX_BD_PRAGMA   BCOM_STD_PRAGMA
+#define BCOM_GEN_LPC_PRAGMA     BCOM_STD_PRAGMA
+#define BCOM_PCI_RX_PRAGMA      BCOM_PCI_PRAGMA
+#define BCOM_PCI_TX_PRAGMA      BCOM_PCI_PRAGMA
+
+/* Initiators number */
+#define BCOM_INITIATOR_ALWAYS    0
+#define BCOM_INITIATOR_SCTMR_0   1
+#define BCOM_INITIATOR_SCTMR_1   2
+#define BCOM_INITIATOR_FEC_RX    3
+#define BCOM_INITIATOR_FEC_TX    4
+#define BCOM_INITIATOR_ATA_RX    5
+#define BCOM_INITIATOR_ATA_TX    6
+#define BCOM_INITIATOR_SCPCI_RX  7
+#define BCOM_INITIATOR_SCPCI_TX  8
+#define BCOM_INITIATOR_PSC3_RX   9
+#define BCOM_INITIATOR_PSC3_TX  10
+#define BCOM_INITIATOR_PSC2_RX  11
+#define BCOM_INITIATOR_PSC2_TX  12
+#define BCOM_INITIATOR_PSC1_RX  13
+#define BCOM_INITIATOR_PSC1_TX  14
+#define BCOM_INITIATOR_SCTMR_2  15
+#define BCOM_INITIATOR_SCLPC    16
+#define BCOM_INITIATOR_PSC5_RX  17
+#define BCOM_INITIATOR_PSC5_TX  18
+#define BCOM_INITIATOR_PSC4_RX  19
+#define BCOM_INITIATOR_PSC4_TX  20
+#define BCOM_INITIATOR_I2C2_RX  21
+#define BCOM_INITIATOR_I2C2_TX  22
+#define BCOM_INITIATOR_I2C1_RX  23
+#define BCOM_INITIATOR_I2C1_TX  24
+#define BCOM_INITIATOR_PSC6_RX  25
+#define BCOM_INITIATOR_PSC6_TX  26
+#define BCOM_INITIATOR_IRDA_RX  25
+#define BCOM_INITIATOR_IRDA_TX  26
+#define BCOM_INITIATOR_SCTMR_3  27
+#define BCOM_INITIATOR_SCTMR_4  28
+#define BCOM_INITIATOR_SCTMR_5  29
+#define BCOM_INITIATOR_SCTMR_6  30
+#define BCOM_INITIATOR_SCTMR_7  31
+
+/* Initiators priorities */
+#define BCOM_IPR_ALWAYS         7
+#define BCOM_IPR_SCTMR_0        2
+#define BCOM_IPR_SCTMR_1        2
+#define BCOM_IPR_FEC_RX         6
+#define BCOM_IPR_FEC_TX         5
+#define BCOM_IPR_ATA_RX         4
+#define BCOM_IPR_ATA_TX         3
+#define BCOM_IPR_SCPCI_RX       2
+#define BCOM_IPR_SCPCI_TX       2
+#define BCOM_IPR_PSC3_RX        2
+#define BCOM_IPR_PSC3_TX        2
+#define BCOM_IPR_PSC2_RX        2
+#define BCOM_IPR_PSC2_TX        2
+#define BCOM_IPR_PSC1_RX        2
+#define BCOM_IPR_PSC1_TX        2
+#define BCOM_IPR_SCTMR_2        2
+#define BCOM_IPR_SCLPC          2
+#define BCOM_IPR_PSC5_RX        2
+#define BCOM_IPR_PSC5_TX        2
+#define BCOM_IPR_PSC4_RX        2
+#define BCOM_IPR_PSC4_TX        2
+#define BCOM_IPR_I2C2_RX        2
+#define BCOM_IPR_I2C2_TX        2
+#define BCOM_IPR_I2C1_RX        2
+#define BCOM_IPR_I2C1_TX        2
+#define BCOM_IPR_PSC6_RX        2
+#define BCOM_IPR_PSC6_TX        2
+#define BCOM_IPR_IRDA_RX        2
+#define BCOM_IPR_IRDA_TX        2
+#define BCOM_IPR_SCTMR_3        2
+#define BCOM_IPR_SCTMR_4        2
+#define BCOM_IPR_SCTMR_5        2
+#define BCOM_IPR_SCTMR_6        2
+#define BCOM_IPR_SCTMR_7        2
+
+
+/* ======================================================================== */
+/* API                                                                      */
+/* ======================================================================== */
+
+extern struct bcom_task *bcom_task_alloc(int bd_count, int bd_size, int priv_size);
+extern void bcom_task_free(struct bcom_task *tsk);
+extern int bcom_load_image(int task, u32 *task_image);
+extern void bcom_set_initiator(int task, int initiator);
+
+
+#define TASK_ENABLE             0x8000
+
+static inline void
+bcom_enable_task(int task)
+{
+        u16 reg;
+        reg = in_be16(&bcom_eng->regs->tcr[task]);
+        out_be16(&bcom_eng->regs->tcr[task],  reg | TASK_ENABLE);
+}
+
+static inline void
+bcom_disable_task(int task)
+{
+        u16 reg = in_be16(&bcom_eng->regs->tcr[task]);
+        out_be16(&bcom_eng->regs->tcr[task], reg & ~TASK_ENABLE);
+}
+
+
+static inline u32 *
+bcom_task_desc(int task)
+{
+        return bcom_sram_pa2va(bcom_eng->tdt[task].start);
+}
+
+static inline int
+bcom_task_num_descs(int task)
+{
+        return (bcom_eng->tdt[task].stop - bcom_eng->tdt[task].start)/sizeof(u32) + 1;
+}
+
+static inline u32 *
+bcom_task_var(int task)
+{
+        return bcom_sram_pa2va(bcom_eng->tdt[task].var);
+}
+
+static inline u32 *
+bcom_task_inc(int task)
+{
+        return &bcom_task_var(task)[BCOM_MAX_VAR];
+}
+
+
+static inline int
+bcom_drd_is_extended(u32 desc)
+{
+        return (desc) & BCOM_DRD_EXTENDED;
+}
+
+static inline int
+bcom_desc_is_drd(u32 desc)
+{
+        return !(desc & BCOM_LCD_MASK) && desc != BCOM_DESC_NOP;
+}
+
+static inline int
+bcom_desc_initiator(u32 desc)
+{
+        return (desc >> BCOM_DRD_INITIATOR_SHIFT) & 0x1f;
+}
+
+static inline void
+bcom_set_desc_initiator(u32 *desc, int initiator)
+{
+        *desc = (*desc & ~(0x1f << BCOM_DRD_INITIATOR_SHIFT)) |
+                        ((initiator & 0x1f) << BCOM_DRD_INITIATOR_SHIFT);
+}
+
+
+static inline void
+bcom_set_task_pragma(int task, int pragma)
+{
+        u32 *fdt = &bcom_eng->tdt[task].fdt;
+        *fdt = (*fdt & ~0xff) | pragma;
+}
+
+static inline void
+bcom_set_task_auto_start(int task, int next_task)
+{
+        u16 __iomem *tcr = &bcom_eng->regs->tcr[task];
+        out_be16(tcr, (in_be16(tcr) & ~0xff) | 0x00c0 | next_task);
+}
+
+static inline void
+bcom_set_tcr_initiator(int task, int initiator)
+{
+        u16 __iomem *tcr = &bcom_eng->regs->tcr[task];
+        out_be16(tcr, (in_be16(tcr) & ~0x1f00) | ((initiator & 0x1f) << 8));
+}
+
+
+#endif /* __BESTCOMM_PRIV_H__ */
+
diff --git a/arch/powerpc/sysdev/bestcomm/sram.c b/arch/powerpc/sysdev/bestcomm/sram.c
new file mode 100644
index 000000000000..99784383a843
--- /dev/null
+++ b/arch/powerpc/sysdev/bestcomm/sram.c
@@ -0,0 +1,177 @@
+/*
+ * Simple memory allocator for on-board SRAM
+ *
+ *
+ * Maintainer : Sylvain Munaut <tnt@246tNt.com>
+ *
+ * Copyright (C) 2005 Sylvain Munaut <tnt@246tNt.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/ioport.h>
+#include <linux/of.h>
+
+#include <asm/io.h>
+#include <asm/mmu.h>
+
+#include "sram.h"
+
+
+/* Struct keeping our 'state' */
+struct bcom_sram *bcom_sram = NULL;
+EXPORT_SYMBOL_GPL(bcom_sram);   /* needed for inline functions */
+
+
+/* ======================================================================== */
+/* Public API                                                               */
+/* ======================================================================== */
+/* DO NOT USE in interrupts, if needed in irq handler, we should use the
+   _irqsave version of the spin_locks */
+
+int bcom_sram_init(struct device_node *sram_node, char *owner)
+{
+        int rv;
+        const u32 *regaddr_p;
+        u64 regaddr64, size64;
+        unsigned int psize;
+
+        /* Create our state struct */
+        if (bcom_sram) {
+                printk(KERN_ERR "%s: bcom_sram_init: "
+                        "Already initialized !\n", owner);
+                return -EBUSY;
+        }
+
+        bcom_sram = kmalloc(sizeof(struct bcom_sram), GFP_KERNEL);
+        if (!bcom_sram) {
+                printk(KERN_ERR "%s: bcom_sram_init: "
+                        "Couldn't allocate internal state !\n", owner);
+                return -ENOMEM;
+        }
+
+        /* Get address and size of the sram */
+        regaddr_p = of_get_address(sram_node, 0, &size64, NULL);
+        if (!regaddr_p) {
+                printk(KERN_ERR "%s: bcom_sram_init: "
+                        "Invalid device node !\n", owner);
+                rv = -EINVAL;
+                goto error_free;
+        }
+
+        regaddr64 = of_translate_address(sram_node, regaddr_p);
+
+        bcom_sram->base_phys = (phys_addr_t) regaddr64;
+        bcom_sram->size = (unsigned int) size64;
+
+        /* Request region */
+        if (!request_mem_region(bcom_sram->base_phys, bcom_sram->size, owner)) {
+                printk(KERN_ERR "%s: bcom_sram_init: "
+                        "Couldn't request region !\n", owner);
+                rv = -EBUSY;
+                goto error_free;
+        }
+
+        /* Map SRAM */
+                /* sram is not really __iomem */
+        bcom_sram->base_virt = (void*) ioremap(bcom_sram->base_phys, bcom_sram->size);
+
+        if (!bcom_sram->base_virt) {
+                printk(KERN_ERR "%s: bcom_sram_init: "
+                        "Map error SRAM zone 0x%08lx (0x%0x)!\n",
+                        owner, bcom_sram->base_phys, bcom_sram->size );
+                rv = -ENOMEM;
+                goto error_release;
+        }
+
+        /* Create an rheap (defaults to 32 bits word alignment) */
+        bcom_sram->rh = rh_create(4);
+
+        /* Attach the free zones */
+#if 0
+        /* Currently disabled ... for future use only */
+        reg_addr_p = of_get_property(sram_node, "available", &psize);
+#else
+        regaddr_p = NULL;
+        psize = 0;
+#endif
+
+        if (!regaddr_p || !psize) {
+                /* Attach the whole zone */
+                rh_attach_region(bcom_sram->rh, 0, bcom_sram->size);
+        } else {
+                /* Attach each zone independently */
+                while (psize >= 2 * sizeof(u32)) {
+                        phys_addr_t zbase = of_translate_address(sram_node, regaddr_p);
+                        rh_attach_region(bcom_sram->rh, zbase - bcom_sram->base_phys, regaddr_p[1]);
+                        regaddr_p += 2;
+                        psize -= 2 * sizeof(u32);
+                }
+        }
+
+        /* Init our spinlock */
+        spin_lock_init(&bcom_sram->lock);
+
+        return 0;
+
+error_release:
+        release_mem_region(bcom_sram->base_phys, bcom_sram->size);
+error_free:
+        kfree(bcom_sram);
+        bcom_sram = NULL;
+
+        return rv;
+}
+EXPORT_SYMBOL_GPL(bcom_sram_init);
+
+void bcom_sram_cleanup(void)
+{
+        /* Free resources */
+        if (bcom_sram) {
+                rh_destroy(bcom_sram->rh);
+                iounmap((void __iomem *)bcom_sram->base_virt);
+                release_mem_region(bcom_sram->base_phys, bcom_sram->size);
+                kfree(bcom_sram);
+                bcom_sram = NULL;
+        }
+}
+EXPORT_SYMBOL_GPL(bcom_sram_cleanup);
+
+void* bcom_sram_alloc(int size, int align, phys_addr_t *phys)
+{
+        unsigned long offset;
+
+        spin_lock(&bcom_sram->lock);
+        offset = rh_alloc_align(bcom_sram->rh, size, align, NULL);
+        spin_unlock(&bcom_sram->lock);
+
+        if (IS_ERR_VALUE(offset))
+                return NULL;
+
+        *phys = bcom_sram->base_phys + offset;
+        return bcom_sram->base_virt + offset;
+}
+EXPORT_SYMBOL_GPL(bcom_sram_alloc);
+
+void bcom_sram_free(void *ptr)
+{
+        unsigned long offset;
+
+        if (!ptr)
+                return;
+
+        offset = ptr - bcom_sram->base_virt;
+
+        spin_lock(&bcom_sram->lock);
+        rh_free(bcom_sram->rh, offset);
+        spin_unlock(&bcom_sram->lock);
+}
+EXPORT_SYMBOL_GPL(bcom_sram_free);
+
diff --git a/arch/powerpc/sysdev/bestcomm/sram.h b/arch/powerpc/sysdev/bestcomm/sram.h
new file mode 100644
index 000000000000..b6d668963cce
--- /dev/null
+++ b/arch/powerpc/sysdev/bestcomm/sram.h
@@ -0,0 +1,54 @@
+/*
+ * Handling of a sram zone for bestcomm
+ *
+ *
+ * Copyright (C) 2007 Sylvain Munaut <tnt@246tNt.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#ifndef __BESTCOMM_SRAM_H__
+#define __BESTCOMM_SRAM_H__
+
+#include <asm/rheap.h>
+#include <asm/mmu.h>
+#include <linux/spinlock.h>
+
+
+/* Structure used internally */
+        /* The internals are here for the inline functions
+         * sake, certainly not for the user to mess with !
+         */
+struct bcom_sram {
+        phys_addr_t              base_phys;
+        void                    *base_virt;
+        unsigned int             size;
+        rh_info_t               *rh;
+        spinlock_t               lock;
+};
+
+extern struct bcom_sram *bcom_sram;
+
+
+/* Public API */
+extern int  bcom_sram_init(struct device_node *sram_node, char *owner);
+extern void bcom_sram_cleanup(void);
+
+extern void* bcom_sram_alloc(int size, int align, phys_addr_t *phys);
+extern void  bcom_sram_free(void *ptr);
+
+static inline phys_addr_t bcom_sram_va2pa(void *va) {
+        return bcom_sram->base_phys +
+                (unsigned long)(va - bcom_sram->base_virt);
+}
+
+static inline void *bcom_sram_pa2va(phys_addr_t pa) {
+        return bcom_sram->base_virt +
+                (unsigned long)(pa - bcom_sram->base_phys);
+}
+
+
+#endif  /* __BESTCOMM_SRAM_H__ */
+