[PATCH 0 of 2] AMD SR56x0 Erratum 64

[PATCH 0 of 2] AMD SR56x0 Erratum 64

[Andrew Cooper]

This is a series of two patches, the first a prerequisite for the second, but
functionally unrelated.

The first adds readq/writeq for 64bit MMIO, and changes the existing MMIO
accessors to use explicit bit widths.

The second patch is an errata workaround, suitable for unstable.

A slightly tweaked patch applicable for 4.2 and previously to follow very
shortly.

~Andrew

[PATCH 1 of 2] x86: Use explicit widths for MMIO read/write, and add 64bit varients

[Andrew Cooper]

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff -r 2369a9d759f0 -r 12e991b1d50b xen/include/asm-x86/io.h
--- a/xen/include/asm-x86/io.h
+++ b/xen/include/asm-x86/io.h
@@ -5,12 +5,14 @@
 #include <xen/types.h>
 #include <asm/page.h>
 
-#define readb(x) (*(volatile char *)(x))
-#define readw(x) (*(volatile short *)(x))
-#define readl(x) (*(volatile int *)(x))
-#define writeb(d,x) (*(volatile char *)(x) = (d))
-#define writew(d,x) (*(volatile short *)(x) = (d))
-#define writel(d,x) (*(volatile int *)(x) = (d))
+#define readb(x) (*(volatile uint8_t  *)(x))
+#define readw(x) (*(volatile uint16_t *)(x))
+#define readl(x) (*(volatile uint32_t *)(x))
+#define readq(x) (*(volatile uint64_t *)(x))
+#define writeb(d,x) (*(volatile uint8_t  *)(x) = (d))
+#define writew(d,x) (*(volatile uint16_t *)(x) = (d))
+#define writel(d,x) (*(volatile uint32_t *)(x) = (d))
+#define writeq(d,x) (*(volatile uint64_t *)(x) = (d))
 
 #define __OUT1(s,x) \
 static inline void out##s(unsigned x value, unsigned short port) {

[PATCH 2 of 2] AMD/iommu: SR56x0 Erratum 64 - Reset all head & tail pointers

[Andrew Cooper]

Reference at time of patch:
http://support.amd.com/us/ChipsetMotherboard_TechDocs/46303.pdf

Erratum 64 states that the head and tail pointers for the Command buffer and
Event log are only reset on a cold boot, not a warm boot.

While the erratum is limited to systems using SR56xx chipsets (such as Family
10h CPUs), resetting the pointers is a sensible action in all cases, including
the PPR log for consistency.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

--

Changes since v1:
 * Reset PPR head/tail pointer as well
 * Make use of writeq()

diff -r 12e991b1d50b -r 50eb8a3229ec xen/drivers/passthrough/amd/iommu_init.c
--- a/xen/drivers/passthrough/amd/iommu_init.c
+++ b/xen/drivers/passthrough/amd/iommu_init.c
@@ -154,6 +154,11 @@ static void register_iommu_cmd_buffer_in
                          IOMMU_CMD_BUFFER_LENGTH_MASK,
                          IOMMU_CMD_BUFFER_LENGTH_SHIFT, &entry);
     writel(entry, iommu->mmio_base+IOMMU_CMD_BUFFER_BASE_HIGH_OFFSET);
+
+    /* Reset head/tail pointer. SR56x0 Erratum 64 means this might not happen
+     * automatically for us. */
+    writeq(0, iommu->mmio_base + IOMMU_CMD_BUFFER_HEAD_OFFSET);
+    writeq(0, iommu->mmio_base + IOMMU_CMD_BUFFER_TAIL_OFFSET);
 }
 
 static void register_iommu_event_log_in_mmio_space(struct amd_iommu *iommu)
@@ -182,6 +187,11 @@ static void register_iommu_event_log_in_
                         IOMMU_EVENT_LOG_LENGTH_MASK,
                         IOMMU_EVENT_LOG_LENGTH_SHIFT, &entry);
     writel(entry, iommu->mmio_base+IOMMU_EVENT_LOG_BASE_HIGH_OFFSET);
+
+    /* Reset head/tail pointer. SR56x0 Erratum 64 means this might not happen
+     * automatically for us. */
+    writeq(0, iommu->mmio_base + IOMMU_EVENT_LOG_HEAD_OFFSET);
+    writeq(0, iommu->mmio_base + IOMMU_EVENT_LOG_TAIL_OFFSET);
 }
 
 static void register_iommu_ppr_log_in_mmio_space(struct amd_iommu *iommu)
@@ -210,6 +220,9 @@ static void register_iommu_ppr_log_in_mm
                         IOMMU_PPR_LOG_LENGTH_MASK,
                         IOMMU_PPR_LOG_LENGTH_SHIFT, &entry);
     writel(entry, iommu->mmio_base + IOMMU_PPR_LOG_BASE_HIGH_OFFSET);
+
+    writeq(0, iommu->mmio_base + IOMMU_PPR_LOG_HEAD_OFFSET);
+    writeq(0, iommu->mmio_base + IOMMU_PPR_LOG_TAIL_OFFSET);
 }

Re: [PATCH 0 of 2] AMD SR56x0 Erratum 64

[Keir Fraser]

On 22/05/2013 11:13, "Andrew Cooper" <andrew.cooper3@citrix.com> wrote:

> This is a series of two patches, the first a prerequisite for the second, but
> functionally unrelated.
> 
> The first adds readq/writeq for 64bit MMIO, and changes the existing MMIO
> accessors to use explicit bit widths.
> 
> The second patch is an errata workaround, suitable for unstable.
> 
> A slightly tweaked patch applicable for 4.2 and previously to follow very
> shortly.

Both are fine by me.

Acked-by: Keir Fraser <keir@xen.org>

> ~Andrew

Re: [PATCH 2 of 2] AMD/iommu: SR56x0 Erratum 64 - Reset all head & tail pointers

[Suthikulpanit, Suravee]

Acked: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

Thank you,

Suravee

-----Original Message-----
From: Andrew Cooper [mailto:andrew.cooper3@citrix.com] 
Sent: Wednesday, May 22, 2013 5:14 AM
To: xen-devel@lists.xen.org
Cc: Keir Fraser; Jan Beulich; Suthikulpanit, Suravee; Shin, Jacob
Subject: [PATCH 2 of 2] AMD/iommu: SR56x0 Erratum 64 - Reset all head & tail pointers

Reference at time of patch:
http://support.amd.com/us/ChipsetMotherboard_TechDocs/46303.pdf

Erratum 64 states that the head and tail pointers for the Command buffer and Event log are only reset on a cold boot, not a warm boot.

While the erratum is limited to systems using SR56xx chipsets (such as Family 10h CPUs), resetting the pointers is a sensible action in all cases, including the PPR log for consistency.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

--

Changes since v1:
 * Reset PPR head/tail pointer as well
 * Make use of writeq()

diff -r 12e991b1d50b -r 50eb8a3229ec xen/drivers/passthrough/amd/iommu_init.c
--- a/xen/drivers/passthrough/amd/iommu_init.c
+++ b/xen/drivers/passthrough/amd/iommu_init.c
@@ -154,6 +154,11 @@ static void register_iommu_cmd_buffer_in
                          IOMMU_CMD_BUFFER_LENGTH_MASK,
                          IOMMU_CMD_BUFFER_LENGTH_SHIFT, &entry);
     writel(entry, iommu->mmio_base+IOMMU_CMD_BUFFER_BASE_HIGH_OFFSET);
+
+    /* Reset head/tail pointer. SR56x0 Erratum 64 means this might not happen
+     * automatically for us. */
+    writeq(0, iommu->mmio_base + IOMMU_CMD_BUFFER_HEAD_OFFSET);
+    writeq(0, iommu->mmio_base + IOMMU_CMD_BUFFER_TAIL_OFFSET);
 }
 
 static void register_iommu_event_log_in_mmio_space(struct amd_iommu *iommu) @@ -182,6 +187,11 @@ static void register_iommu_event_log_in_
                         IOMMU_EVENT_LOG_LENGTH_MASK,
                         IOMMU_EVENT_LOG_LENGTH_SHIFT, &entry);
     writel(entry, iommu->mmio_base+IOMMU_EVENT_LOG_BASE_HIGH_OFFSET);
+
+    /* Reset head/tail pointer. SR56x0 Erratum 64 means this might not happen
+     * automatically for us. */
+    writeq(0, iommu->mmio_base + IOMMU_EVENT_LOG_HEAD_OFFSET);
+    writeq(0, iommu->mmio_base + IOMMU_EVENT_LOG_TAIL_OFFSET);
 }
 
 static void register_iommu_ppr_log_in_mmio_space(struct amd_iommu *iommu) @@ -210,6 +220,9 @@ static void register_iommu_ppr_log_in_mm
                         IOMMU_PPR_LOG_LENGTH_MASK,
                         IOMMU_PPR_LOG_LENGTH_SHIFT, &entry);
     writel(entry, iommu->mmio_base + IOMMU_PPR_LOG_BASE_HIGH_OFFSET);
+
+    writeq(0, iommu->mmio_base + IOMMU_PPR_LOG_HEAD_OFFSET);
+    writeq(0, iommu->mmio_base + IOMMU_PPR_LOG_TAIL_OFFSET);
 }