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alistair23-linux/drivers/iommu/omap-iommu2.c
Suman Anna b148d5fb2e iommu/omap: Enable bus-error back on supported iommus 
The remoteproc MMUs in OMAP4+ SoCs have some additional debug
registers that can give out the PC value in addition to the
MMU fault address. The PC value can be extracted properly only
on the DSP cores, and is not available on the ARM processors
within the IPU sub-systems. Instead, the MMUs have been enhanced
to throw a bus-error response back to the IPU processors.

This functionality is programmable through the MMU_GP_REG register.
The cores are simply stalled if the MMU_GP_REG.BUS_ERR_BACK_EN bit
is not set. When set, a bus-error exception is raised allowing the
processor to handle it as a bus fault and provide additional debug
information. This feature is turned on by default by the driver on
iommus supporting it.

Signed-off-by: Subramaniam Chanderashekarapuram <subramaniam.ca@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
2014-03-04 17:02:08 +01:00

338 lines
8 KiB
C
Raw Blame History

/*
* omap iommu: omap2/3 architecture specific functions
*
* Copyright (C) 2008-2009 Nokia Corporation
*
* Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>,
* Paul Mundt and Toshihiro Kobayashi
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/err.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/omap-iommu.h>
#include <linux/slab.h>
#include <linux/stringify.h>
#include <linux/platform_data/iommu-omap.h>
#include "omap-iommu.h"
/*
* omap2 architecture specific register bit definitions
*/
#define IOMMU_ARCH_VERSION 0x00000011
/* IRQSTATUS & IRQENABLE */
#define MMU_IRQ_MULTIHITFAULT (1 << 4)
#define MMU_IRQ_TABLEWALKFAULT (1 << 3)
#define MMU_IRQ_EMUMISS (1 << 2)
#define MMU_IRQ_TRANSLATIONFAULT (1 << 1)
#define MMU_IRQ_TLBMISS (1 << 0)
#define __MMU_IRQ_FAULT \
(MMU_IRQ_MULTIHITFAULT | MMU_IRQ_EMUMISS | MMU_IRQ_TRANSLATIONFAULT)
#define MMU_IRQ_MASK \
(__MMU_IRQ_FAULT | MMU_IRQ_TABLEWALKFAULT | MMU_IRQ_TLBMISS)
#define MMU_IRQ_TWL_MASK (__MMU_IRQ_FAULT | MMU_IRQ_TABLEWALKFAULT)
#define MMU_IRQ_TLB_MISS_MASK (__MMU_IRQ_FAULT | MMU_IRQ_TLBMISS)
/* MMU_CNTL */
#define MMU_CNTL_SHIFT 1
#define MMU_CNTL_MASK (7 << MMU_CNTL_SHIFT)
#define MMU_CNTL_EML_TLB (1 << 3)
#define MMU_CNTL_TWL_EN (1 << 2)
#define MMU_CNTL_MMU_EN (1 << 1)
#define get_cam_va_mask(pgsz) \
(((pgsz) == MMU_CAM_PGSZ_16M) ? 0xff000000 : \
((pgsz) == MMU_CAM_PGSZ_1M) ? 0xfff00000 : \
((pgsz) == MMU_CAM_PGSZ_64K) ? 0xffff0000 : \
((pgsz) == MMU_CAM_PGSZ_4K) ? 0xfffff000 : 0)
/* IOMMU errors */
#define OMAP_IOMMU_ERR_TLB_MISS (1 << 0)
#define OMAP_IOMMU_ERR_TRANS_FAULT (1 << 1)
#define OMAP_IOMMU_ERR_EMU_MISS (1 << 2)
#define OMAP_IOMMU_ERR_TBLWALK_FAULT (1 << 3)
#define OMAP_IOMMU_ERR_MULTIHIT_FAULT (1 << 4)
static void __iommu_set_twl(struct omap_iommu *obj, bool on)
{
u32 l = iommu_read_reg(obj, MMU_CNTL);
if (on)
iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
else
iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
l &= ~MMU_CNTL_MASK;
if (on)
l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
else
l |= (MMU_CNTL_MMU_EN);
iommu_write_reg(obj, l, MMU_CNTL);
}
static int omap2_iommu_enable(struct omap_iommu *obj)
{
u32 l, pa;
if (!obj->iopgd || !IS_ALIGNED((u32)obj->iopgd, SZ_16K))
return -EINVAL;
pa = virt_to_phys(obj->iopgd);
if (!IS_ALIGNED(pa, SZ_16K))
return -EINVAL;
l = iommu_read_reg(obj, MMU_REVISION);
dev_info(obj->dev, "%s: version %d.%d\n", obj->name,
(l >> 4) & 0xf, l & 0xf);
iommu_write_reg(obj, pa, MMU_TTB);
if (obj->has_bus_err_back)
iommu_write_reg(obj, MMU_GP_REG_BUS_ERR_BACK_EN, MMU_GP_REG);
__iommu_set_twl(obj, true);
return 0;
}
static void omap2_iommu_disable(struct omap_iommu *obj)
{
u32 l = iommu_read_reg(obj, MMU_CNTL);
l &= ~MMU_CNTL_MASK;
iommu_write_reg(obj, l, MMU_CNTL);
dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
}
static void omap2_iommu_set_twl(struct omap_iommu *obj, bool on)
{
__iommu_set_twl(obj, false);
}
static u32 omap2_iommu_fault_isr(struct omap_iommu *obj, u32 *ra)
{
u32 stat, da;
u32 errs = 0;
stat = iommu_read_reg(obj, MMU_IRQSTATUS);
stat &= MMU_IRQ_MASK;
if (!stat) {
*ra = 0;
return 0;
}
da = iommu_read_reg(obj, MMU_FAULT_AD);
*ra = da;
if (stat & MMU_IRQ_TLBMISS)
errs |= OMAP_IOMMU_ERR_TLB_MISS;
if (stat & MMU_IRQ_TRANSLATIONFAULT)
errs |= OMAP_IOMMU_ERR_TRANS_FAULT;
if (stat & MMU_IRQ_EMUMISS)
errs |= OMAP_IOMMU_ERR_EMU_MISS;
if (stat & MMU_IRQ_TABLEWALKFAULT)
errs |= OMAP_IOMMU_ERR_TBLWALK_FAULT;
if (stat & MMU_IRQ_MULTIHITFAULT)
errs |= OMAP_IOMMU_ERR_MULTIHIT_FAULT;
iommu_write_reg(obj, stat, MMU_IRQSTATUS);
return errs;
}
static void omap2_tlb_read_cr(struct omap_iommu *obj, struct cr_regs *cr)
{
cr->cam = iommu_read_reg(obj, MMU_READ_CAM);
cr->ram = iommu_read_reg(obj, MMU_READ_RAM);
}
static void omap2_tlb_load_cr(struct omap_iommu *obj, struct cr_regs *cr)
{
iommu_write_reg(obj, cr->cam | MMU_CAM_V, MMU_CAM);
iommu_write_reg(obj, cr->ram, MMU_RAM);
}
static u32 omap2_cr_to_virt(struct cr_regs *cr)
{
u32 page_size = cr->cam & MMU_CAM_PGSZ_MASK;
u32 mask = get_cam_va_mask(cr->cam & page_size);
return cr->cam & mask;
}
static struct cr_regs *omap2_alloc_cr(struct omap_iommu *obj,
struct iotlb_entry *e)
{
struct cr_regs *cr;
if (e->da & ~(get_cam_va_mask(e->pgsz))) {
dev_err(obj->dev, "%s:\twrong alignment: %08x\n", __func__,
e->da);
return ERR_PTR(-EINVAL);
}
cr = kmalloc(sizeof(*cr), GFP_KERNEL);
if (!cr)
return ERR_PTR(-ENOMEM);
cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid;
cr->ram = e->pa | e->endian | e->elsz | e->mixed;
return cr;
}
static inline int omap2_cr_valid(struct cr_regs *cr)
{
return cr->cam & MMU_CAM_V;
}
static u32 omap2_get_pte_attr(struct iotlb_entry *e)
{
u32 attr;
attr = e->mixed << 5;
attr |= e->endian;
attr |= e->elsz >> 3;
attr <<= (((e->pgsz == MMU_CAM_PGSZ_4K) ||
(e->pgsz == MMU_CAM_PGSZ_64K)) ? 0 : 6);
return attr;
}
static ssize_t
omap2_dump_cr(struct omap_iommu *obj, struct cr_regs *cr, char *buf)
{
char *p = buf;
/* FIXME: Need more detail analysis of cam/ram */
p += sprintf(p, "%08x %08x %01x\n", cr->cam, cr->ram,
(cr->cam & MMU_CAM_P) ? 1 : 0);
return p - buf;
}
#define pr_reg(name) \
do { \
ssize_t bytes; \
const char *str = "%20s: %08x\n"; \
const int maxcol = 32; \
bytes = snprintf(p, maxcol, str, __stringify(name), \
iommu_read_reg(obj, MMU_##name)); \
p += bytes; \
len -= bytes; \
if (len < maxcol) \
goto out; \
} while (0)
static ssize_t
omap2_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len)
{
char *p = buf;
pr_reg(REVISION);
pr_reg(IRQSTATUS);
pr_reg(IRQENABLE);
pr_reg(WALKING_ST);
pr_reg(CNTL);
pr_reg(FAULT_AD);
pr_reg(TTB);
pr_reg(LOCK);
pr_reg(LD_TLB);
pr_reg(CAM);
pr_reg(RAM);
pr_reg(GFLUSH);
pr_reg(FLUSH_ENTRY);
pr_reg(READ_CAM);
pr_reg(READ_RAM);
pr_reg(EMU_FAULT_AD);
out:
return p - buf;
}
static void omap2_iommu_save_ctx(struct omap_iommu *obj)
{
int i;
u32 *p = obj->ctx;
for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
p[i] = iommu_read_reg(obj, i * sizeof(u32));
dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
}
BUG_ON(p[0] != IOMMU_ARCH_VERSION);
}
static void omap2_iommu_restore_ctx(struct omap_iommu *obj)
{
int i;
u32 *p = obj->ctx;
for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
iommu_write_reg(obj, p[i], i * sizeof(u32));
dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
}
BUG_ON(p[0] != IOMMU_ARCH_VERSION);
}
static void omap2_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e)
{
e->da = cr->cam & MMU_CAM_VATAG_MASK;
e->pa = cr->ram & MMU_RAM_PADDR_MASK;
e->valid = cr->cam & MMU_CAM_V;
e->pgsz = cr->cam & MMU_CAM_PGSZ_MASK;
e->endian = cr->ram & MMU_RAM_ENDIAN_MASK;
e->elsz = cr->ram & MMU_RAM_ELSZ_MASK;
e->mixed = cr->ram & MMU_RAM_MIXED;
}
static const struct iommu_functions omap2_iommu_ops = {
.version = IOMMU_ARCH_VERSION,
.enable = omap2_iommu_enable,
.disable = omap2_iommu_disable,
.set_twl = omap2_iommu_set_twl,
.fault_isr = omap2_iommu_fault_isr,
.tlb_read_cr = omap2_tlb_read_cr,
.tlb_load_cr = omap2_tlb_load_cr,
.cr_to_e = omap2_cr_to_e,
.cr_to_virt = omap2_cr_to_virt,
.alloc_cr = omap2_alloc_cr,
.cr_valid = omap2_cr_valid,
.dump_cr = omap2_dump_cr,
.get_pte_attr = omap2_get_pte_attr,
.save_ctx = omap2_iommu_save_ctx,
.restore_ctx = omap2_iommu_restore_ctx,
.dump_ctx = omap2_iommu_dump_ctx,
};
static int __init omap2_iommu_init(void)
{
return omap_install_iommu_arch(&omap2_iommu_ops);
}
module_init(omap2_iommu_init);
static void __exit omap2_iommu_exit(void)
{
omap_uninstall_iommu_arch(&omap2_iommu_ops);
}
module_exit(omap2_iommu_exit);
MODULE_AUTHOR("Hiroshi DOYU, Paul Mundt and Toshihiro Kobayashi");
MODULE_DESCRIPTION("omap iommu: omap2/3 architecture specific functions");
MODULE_LICENSE("GPL v2");
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