ssb: Add support for block-I/O

This adds support for block based I/O to SSB.
This is needed in order to efficiently support PIO data
transfers to the card.
The block-I/O support is only compiled, if it's selected by the
weird driver that needs it. So there's no overhead for sane devices.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

5 files changed, 315 insertions, 0 deletions

diff --git a/drivers/ssb/Kconfig b/drivers/ssb/Kconfig
index 0f7cce2560d1..cd845b8acd17 100644
--- a/drivers/ssb/Kconfig
+++ b/drivers/ssb/Kconfig
@@ -24,6 +24,11 @@ config SSB
 config SSB_SPROM
         bool
 
+# Support for Block-I/O. SELECT this from the driver that needs it.
+config SSB_BLOCKIO
+        bool
+        depends on SSB
+
 config SSB_PCIHOST_POSSIBLE
         bool
         depends on SSB && (PCI = y || PCI = SSB)
diff --git a/drivers/ssb/main.c b/drivers/ssb/main.c
index 3e58db7ef608..19ddd2bd1057 100644
--- a/drivers/ssb/main.c
+++ b/drivers/ssb/main.c
@@ -555,6 +555,55 @@ static u32 ssb_ssb_read32(struct ssb_device *dev, u16 offset)
         return readl(bus->mmio + offset);
 }
 
+#ifdef CONFIG_SSB_BLOCKIO
+static void ssb_ssb_block_read(struct ssb_device *dev, void *buffer,
+                               size_t count, u16 offset, u8 reg_width)
+{
+        struct ssb_bus *bus = dev->bus;
+        void __iomem *addr;
+
+        offset += dev->core_index * SSB_CORE_SIZE;
+        addr = bus->mmio + offset;
+
+        switch (reg_width) {
+        case sizeof(u8): {
+                u8 *buf = buffer;
+
+                while (count) {
+                        *buf = __raw_readb(addr);
+                        buf++;
+                        count--;
+                }
+                break;
+        }
+        case sizeof(u16): {
+                __le16 *buf = buffer;
+
+                SSB_WARN_ON(count & 1);
+                while (count) {
+                        *buf = (__force __le16)__raw_readw(addr);
+                        buf++;
+                        count -= 2;
+                }
+                break;
+        }
+        case sizeof(u32): {
+                __le32 *buf = buffer;
+
+                SSB_WARN_ON(count & 3);
+                while (count) {
+                        *buf = (__force __le32)__raw_readl(addr);
+                        buf++;
+                        count -= 4;
+                }
+                break;
+        }
+        default:
+                SSB_WARN_ON(1);
+        }
+}
+#endif /* CONFIG_SSB_BLOCKIO */
+
 static void ssb_ssb_write8(struct ssb_device *dev, u16 offset, u8 value)
 {
         struct ssb_bus *bus = dev->bus;
@@ -579,6 +628,55 @@ static void ssb_ssb_write32(struct ssb_device *dev, u16 offset, u32 value)
         writel(value, bus->mmio + offset);
 }
 
+#ifdef CONFIG_SSB_BLOCKIO
+static void ssb_ssb_block_write(struct ssb_device *dev, const void *buffer,
+                                size_t count, u16 offset, u8 reg_width)
+{
+        struct ssb_bus *bus = dev->bus;
+        void __iomem *addr;
+
+        offset += dev->core_index * SSB_CORE_SIZE;
+        addr = bus->mmio + offset;
+
+        switch (reg_width) {
+        case sizeof(u8): {
+                const u8 *buf = buffer;
+
+                while (count) {
+                        __raw_writeb(*buf, addr);
+                        buf++;
+                        count--;
+                }
+                break;
+        }
+        case sizeof(u16): {
+                const __le16 *buf = buffer;
+
+                SSB_WARN_ON(count & 1);
+                while (count) {
+                        __raw_writew((__force u16)(*buf), addr);
+                        buf++;
+                        count -= 2;
+                }
+                break;
+        }
+        case sizeof(u32): {
+                const __le32 *buf = buffer;
+
+                SSB_WARN_ON(count & 3);
+                while (count) {
+                        __raw_writel((__force u32)(*buf), addr);
+                        buf++;
+                        count -= 4;
+                }
+                break;
+        }
+        default:
+                SSB_WARN_ON(1);
+        }
+}
+#endif /* CONFIG_SSB_BLOCKIO */
+
 /* Ops for the plain SSB bus without a host-device (no PCI or PCMCIA). */
 static const struct ssb_bus_ops ssb_ssb_ops = {
         .read8          = ssb_ssb_read8,
@@ -587,6 +685,10 @@ static const struct ssb_bus_ops ssb_ssb_ops = {
         .write8         = ssb_ssb_write8,
         .write16        = ssb_ssb_write16,
         .write32        = ssb_ssb_write32,
+#ifdef CONFIG_SSB_BLOCKIO
+        .block_read     = ssb_ssb_block_read,
+        .block_write    = ssb_ssb_block_write,
+#endif
 };
 
 static int ssb_fetch_invariants(struct ssb_bus *bus,
diff --git a/drivers/ssb/pci.c b/drivers/ssb/pci.c
index f1514b33cfae..904b1a8d0885 100644
--- a/drivers/ssb/pci.c
+++ b/drivers/ssb/pci.c
@@ -613,6 +613,41 @@ static u32 ssb_pci_read32(struct ssb_device *dev, u16 offset)
         return ioread32(bus->mmio + offset);
 }
 
+#ifdef CONFIG_SSB_BLOCKIO
+static void ssb_pci_block_read(struct ssb_device *dev, void *buffer,
+                               size_t count, u16 offset, u8 reg_width)
+{
+        struct ssb_bus *bus = dev->bus;
+        void __iomem *addr = bus->mmio + offset;
+
+        if (unlikely(ssb_pci_assert_buspower(bus)))
+                goto error;
+        if (unlikely(bus->mapped_device != dev)) {
+                if (unlikely(ssb_pci_switch_core(bus, dev)))
+                        goto error;
+        }
+        switch (reg_width) {
+        case sizeof(u8):
+                ioread8_rep(addr, buffer, count);
+                break;
+        case sizeof(u16):
+                SSB_WARN_ON(count & 1);
+                ioread16_rep(addr, buffer, count >> 1);
+                break;
+        case sizeof(u32):
+                SSB_WARN_ON(count & 3);
+                ioread32_rep(addr, buffer, count >> 2);
+                break;
+        default:
+                SSB_WARN_ON(1);
+        }
+
+        return;
+error:
+        memset(buffer, 0xFF, count);
+}
+#endif /* CONFIG_SSB_BLOCKIO */
+
 static void ssb_pci_write8(struct ssb_device *dev, u16 offset, u8 value)
 {
         struct ssb_bus *bus = dev->bus;
@@ -652,6 +687,37 @@ static void ssb_pci_write32(struct ssb_device *dev, u16 offset, u32 value)
         iowrite32(value, bus->mmio + offset);
 }
 
+#ifdef CONFIG_SSB_BLOCKIO
+static void ssb_pci_block_write(struct ssb_device *dev, const void *buffer,
+                                size_t count, u16 offset, u8 reg_width)
+{
+        struct ssb_bus *bus = dev->bus;
+        void __iomem *addr = bus->mmio + offset;
+
+        if (unlikely(ssb_pci_assert_buspower(bus)))
+                return;
+        if (unlikely(bus->mapped_device != dev)) {
+                if (unlikely(ssb_pci_switch_core(bus, dev)))
+                        return;
+        }
+        switch (reg_width) {
+        case sizeof(u8):
+                iowrite8_rep(addr, buffer, count);
+                break;
+        case sizeof(u16):
+                SSB_WARN_ON(count & 1);
+                iowrite16_rep(addr, buffer, count >> 1);
+                break;
+        case sizeof(u32):
+                SSB_WARN_ON(count & 3);
+                iowrite32_rep(addr, buffer, count >> 2);
+                break;
+        default:
+                SSB_WARN_ON(1);
+        }
+}
+#endif /* CONFIG_SSB_BLOCKIO */
+
 /* Not "static", as it's used in main.c */
 const struct ssb_bus_ops ssb_pci_ops = {
         .read8          = ssb_pci_read8,
@@ -660,6 +726,10 @@ const struct ssb_bus_ops ssb_pci_ops = {
         .write8         = ssb_pci_write8,
         .write16        = ssb_pci_write16,
         .write32        = ssb_pci_write32,
+#ifdef CONFIG_SSB_BLOCKIO
+        .block_read     = ssb_pci_block_read,
+        .block_write    = ssb_pci_block_write,
+#endif
 };
 
 static ssize_t ssb_pci_attr_sprom_show(struct device *pcidev,
diff --git a/drivers/ssb/pcmcia.c b/drivers/ssb/pcmcia.c
index dcaf2412bea7..24c2a46c1476 100644
--- a/drivers/ssb/pcmcia.c
+++ b/drivers/ssb/pcmcia.c
@@ -285,6 +285,64 @@ static u32 ssb_pcmcia_read32(struct ssb_device *dev, u16 offset)
         return (lo | (hi << 16));
 }
 
+#ifdef CONFIG_SSB_BLOCKIO
+static void ssb_pcmcia_block_read(struct ssb_device *dev, void *buffer,
+                                  size_t count, u16 offset, u8 reg_width)
+{
+        struct ssb_bus *bus = dev->bus;
+        unsigned long flags;
+        void __iomem *addr = bus->mmio + offset;
+        int err;
+
+        spin_lock_irqsave(&bus->bar_lock, flags);
+        err = select_core_and_segment(dev, &offset);
+        if (unlikely(err)) {
+                memset(buffer, 0xFF, count);
+                goto unlock;
+        }
+        switch (reg_width) {
+        case sizeof(u8): {
+                u8 *buf = buffer;
+
+                while (count) {
+                        *buf = __raw_readb(addr);
+                        buf++;
+                        count--;
+                }
+                break;
+        }
+        case sizeof(u16): {
+                __le16 *buf = buffer;
+
+                SSB_WARN_ON(count & 1);
+                while (count) {
+                        *buf = (__force __le16)__raw_readw(addr);
+                        buf++;
+                        count -= 2;
+                }
+                break;
+        }
+        case sizeof(u32): {
+                __le16 *buf = buffer;
+
+                SSB_WARN_ON(count & 3);
+                while (count) {
+                        *buf = (__force __le16)__raw_readw(addr);
+                        buf++;
+                        *buf = (__force __le16)__raw_readw(addr + 2);
+                        buf++;
+                        count -= 4;
+                }
+                break;
+        }
+        default:
+                SSB_WARN_ON(1);
+        }
+unlock:
+        spin_unlock_irqrestore(&bus->bar_lock, flags);
+}
+#endif /* CONFIG_SSB_BLOCKIO */
+
 static void ssb_pcmcia_write8(struct ssb_device *dev, u16 offset, u8 value)
 {
         struct ssb_bus *bus = dev->bus;
@@ -329,6 +387,63 @@ static void ssb_pcmcia_write32(struct ssb_device *dev, u16 offset, u32 value)
         spin_unlock_irqrestore(&bus->bar_lock, flags);
 }
 
+#ifdef CONFIG_SSB_BLOCKIO
+static void ssb_pcmcia_block_write(struct ssb_device *dev, const void *buffer,
+                                   size_t count, u16 offset, u8 reg_width)
+{
+        struct ssb_bus *bus = dev->bus;
+        unsigned long flags;
+        void __iomem *addr = bus->mmio + offset;
+        int err;
+
+        spin_lock_irqsave(&bus->bar_lock, flags);
+        err = select_core_and_segment(dev, &offset);
+        if (unlikely(err))
+                goto unlock;
+        switch (reg_width) {
+        case sizeof(u8): {
+                const u8 *buf = buffer;
+
+                while (count) {
+                        __raw_writeb(*buf, addr);
+                        buf++;
+                        count--;
+                }
+                break;
+        }
+        case sizeof(u16): {
+                const __le16 *buf = buffer;
+
+                SSB_WARN_ON(count & 1);
+                while (count) {
+                        __raw_writew((__force u16)(*buf), addr);
+                        buf++;
+                        count -= 2;
+                }
+                break;
+        }
+        case sizeof(u32): {
+                const __le16 *buf = buffer;
+
+                SSB_WARN_ON(count & 3);
+                while (count) {
+                        __raw_writew((__force u16)(*buf), addr);
+                        buf++;
+                        __raw_writew((__force u16)(*buf), addr + 2);
+                        buf++;
+                        count -= 4;
+                }
+                break;
+        }
+        default:
+                SSB_WARN_ON(1);
+        }
+unlock:
+        mmiowb();
+        spin_unlock_irqrestore(&bus->bar_lock, flags);
+}
+#endif /* CONFIG_SSB_BLOCKIO */
+
 /* Not "static", as it's used in main.c */
 const struct ssb_bus_ops ssb_pcmcia_ops = {
         .read8          = ssb_pcmcia_read8,
@@ -337,6 +452,10 @@ const struct ssb_bus_ops ssb_pcmcia_ops = {
         .write8         = ssb_pcmcia_write8,
         .write16        = ssb_pcmcia_write16,
         .write32        = ssb_pcmcia_write32,
+#ifdef CONFIG_SSB_BLOCKIO
+        .block_read     = ssb_pcmcia_block_read,
+        .block_write    = ssb_pcmcia_block_write,
+#endif
 };
 
 static int ssb_pcmcia_sprom_command(struct ssb_bus *bus, u8 command)
diff --git a/include/linux/ssb/ssb.h b/include/linux/ssb/ssb.h
index a8ca396f810a..9f95afd0e9e3 100644
--- a/include/linux/ssb/ssb.h
+++ b/include/linux/ssb/ssb.h
@@ -78,6 +78,12 @@ struct ssb_bus_ops {
         void (*write8)(struct ssb_device *dev, u16 offset, u8 value);
         void (*write16)(struct ssb_device *dev, u16 offset, u16 value);
         void (*write32)(struct ssb_device *dev, u16 offset, u32 value);
+#ifdef CONFIG_SSB_BLOCKIO
+        void (*block_read)(struct ssb_device *dev, void *buffer,
+                           size_t count, u16 offset, u8 reg_width);
+        void (*block_write)(struct ssb_device *dev, const void *buffer,
+                            size_t count, u16 offset, u8 reg_width);
+#endif
 };
 
 
@@ -374,6 +380,19 @@ static inline void ssb_write32(struct ssb_device *dev, u16 offset, u32 value)
 {
         dev->ops->write32(dev, offset, value);
 }
+#ifdef CONFIG_SSB_BLOCKIO
+static inline void ssb_block_read(struct ssb_device *dev, void *buffer,
+                                  size_t count, u16 offset, u8 reg_width)
+{
+        dev->ops->block_read(dev, buffer, count, offset, reg_width);
+}
+
+static inline void ssb_block_write(struct ssb_device *dev, const void *buffer,
+                                   size_t count, u16 offset, u8 reg_width)
+{
+        dev->ops->block_write(dev, buffer, count, offset, reg_width);
+}
+#endif /* CONFIG_SSB_BLOCKIO */
 
 
 /* Translation (routing) bits that need to be ORed to DMA