Patchwork target-arm: Fixed ARMv7-M SHPR access

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Submitter Sebastian Huber
Date Dec. 16, 2011, 6:50 p.m.
Message ID <1324061437-20899-1-git-send-email-sebastian.huber@embedded-brains.de>
Download mbox | patch
Permalink /patch/131887/
State New
Headers show

Comments

Sebastian Huber - Dec. 16, 2011, 6:50 p.m.
According to "ARMv7-M Architecture Reference Manual" issue D section
"B3.2.10 System Handler Prioriy Register 1, SHPR1", "B3.2.11 System
Handler Prioriy Register 2, SHPR2", and "B3.2.12 System Handler Prioriy
Register 3, SHPR3".

Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
---
 hw/arm_gic.c     |   16 ++++++++++++++--
 hw/armv7m_nvic.c |   19 -------------------
 2 files changed, 14 insertions(+), 21 deletions(-)
Peter Maydell - Dec. 17, 2011, 12:50 a.m.
On 16 December 2011 18:50, Sebastian Huber
<sebastian.huber@embedded-brains.de> wrote:
> According to "ARMv7-M Architecture Reference Manual" issue D section
> "B3.2.10 System Handler Prioriy Register 1, SHPR1", "B3.2.11 System
> Handler Prioriy Register 2, SHPR2", and "B3.2.12 System Handler Prioriy
> Register 3, SHPR3".

This would fix the specific issue of not being able to do byte or halfword
accesses to the SHPR registers, but it doesn't do anything about other
byte-accessible registers like the CFSR.

The right fix for this is for armv7m_nvic to expose a memory region for
the system control space which implements byte and halfword accesses,
and not to try to indirect everything through a single GIC region.

-- PMM
Sebastian Huber - Dec. 18, 2011, 1:30 p.m.
On 17/12/11 01:50, Peter Maydell wrote:
> On 16 December 2011 18:50, Sebastian Huber
> <sebastian.huber@embedded-brains.de>  wrote:
>> According to "ARMv7-M Architecture Reference Manual" issue D section
>> "B3.2.10 System Handler Prioriy Register 1, SHPR1", "B3.2.11 System
>> Handler Prioriy Register 2, SHPR2", and "B3.2.12 System Handler Prioriy
>> Register 3, SHPR3".
> This would fix the specific issue of not being able to do byte or halfword
> accesses to the SHPR registers, but it doesn't do anything about other
> byte-accessible registers like the CFSR.
>
> The right fix for this is for armv7m_nvic to expose a memory region for
> the system control space which implements byte and halfword accesses,
> and not to try to indirect everything through a single GIC region.

I am primary a Qemu user and fixed the bugs only as far as it was 
necessary to run my test suites.  I used the surrounding code as a 
reference.  Maybe I find some time in the next months to clean this up.
Peter Maydell - Dec. 18, 2011, 1:54 p.m.
On 18 December 2011 13:30, Sebastian Huber
<sebastian.huber@embedded-brains.de> wrote:
> I am primary a Qemu user and fixed the bugs only as far as it was necessary
> to run my test suites.  I used the surrounding code as a reference.  Maybe I
> find some time in the next months to clean this up.

Right. Thanks for tracking down what the various problems were,
by the way; that's useful.

-- PMM

Patch

diff --git a/hw/arm_gic.c b/hw/arm_gic.c
index 9b52119..5139d95 100644
--- a/hw/arm_gic.c
+++ b/hw/arm_gic.c
@@ -356,6 +356,11 @@  static uint32_t gic_dist_readb(void *opaque, target_phys_addr_t offset)
             if (GIC_TEST_TRIGGER(irq + i))
                 res |= (2 << (i * 2));
         }
+#else
+    } else if (0xd18 <= offset && offset < 0xd24) {
+        /* System Handler Priority.  */
+        irq = offset - 0xd14;
+        res = GIC_GET_PRIORITY(irq, cpu);
 #endif
     } else if (offset < 0xfe0) {
         goto bad_reg;
@@ -387,7 +392,8 @@  static uint32_t gic_dist_readl(void *opaque, target_phys_addr_t offset)
     gic_state *s = (gic_state *)opaque;
     uint32_t addr;
     addr = offset;
-    if (addr < 0x100 || addr > 0xd00)
+    if (addr < 0x100 || (addr > 0xd00 && addr != 0xd18 && addr != 0xd1c
+        && addr != 0xd20))
         return nvic_readl(s, addr);
 #endif
     val = gic_dist_readw(opaque, offset);
@@ -528,6 +534,11 @@  static void gic_dist_writeb(void *opaque, target_phys_addr_t offset,
                 GIC_CLEAR_TRIGGER(irq + i);
             }
         }
+#else
+    } else if (0xd18 <= offset && offset < 0xd24) {
+        /* System Handler Priority.  */
+        irq = offset - 0xd14;
+        s->priority1[irq][0] = value & 0xff;
 #endif
     } else {
         /* 0xf00 is only handled for 32-bit writes.  */
@@ -553,7 +564,8 @@  static void gic_dist_writel(void *opaque, target_phys_addr_t offset,
 #ifdef NVIC
     uint32_t addr;
     addr = offset;
-    if (addr < 0x100 || (addr > 0xd00 && addr != 0xf00)) {
+    if (addr < 0x100 || (addr > 0xd00 && addr != 0xd18 && addr != 0xd1c
+        && addr != 0xd20 && addr != 0xf00)) {
         nvic_writel(s, addr, value);
         return;
     }
diff --git a/hw/armv7m_nvic.c b/hw/armv7m_nvic.c
index bf8c3c5..65b575e 100644
--- a/hw/armv7m_nvic.c
+++ b/hw/armv7m_nvic.c
@@ -195,14 +195,6 @@  static uint32_t nvic_readl(void *opaque, uint32_t offset)
     case 0xd14: /* Configuration Control.  */
         /* TODO: Implement Configuration Control bits.  */
         return 0;
-    case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority.  */
-        irq = offset - 0xd14;
-        val = 0;
-        val |= s->gic.priority1[irq++][0];
-        val |= s->gic.priority1[irq++][0] << 8;
-        val |= s->gic.priority1[irq++][0] << 16;
-        val |= s->gic.priority1[irq][0] << 24;
-        return val;
     case 0xd24: /* System Handler Status.  */
         val = 0;
         if (s->gic.irq_state[ARMV7M_EXCP_MEM].active) val |= (1 << 0);
@@ -335,17 +327,6 @@  static void nvic_writel(void *opaque, uint32_t offset, uint32_t value)
     case 0xd14: /* Configuration Control.  */
         /* TODO: Implement control registers.  */
         goto bad_reg;
-    case 0xd18: case 0xd1c: case 0xd20: /* System Handler Priority.  */
-        {
-            int irq;
-            irq = offset - 0xd14;
-            s->gic.priority1[irq++][0] = value & 0xff;
-            s->gic.priority1[irq++][0] = (value >> 8) & 0xff;
-            s->gic.priority1[irq++][0] = (value >> 16) & 0xff;
-            s->gic.priority1[irq][0] = (value >> 24) & 0xff;
-            gic_update(&s->gic);
-        }
-        break;
     case 0xd24: /* System Handler Control.  */
         /* TODO: Real hardware allows you to set/clear the active bits
            under some circumstances.  We don't implement this.  */