[PATCH] arm/raspberrypi: Ensure that buffers used for VC mail box
Pavel Pisa
ppisa4lists at pikron.com
Sun Jun 19 13:46:54 UTC 2016
From: Pavel Pisa <ppisa at pikron.com>
---
c/src/lib/libbsp/arm/raspberrypi/misc/vc.c | 42 ++++++++++++++++++----
c/src/lib/libbsp/arm/raspberrypi/misc/vc_defines.h | 21 +++++++++++
2 files changed, 56 insertions(+), 7 deletions(-)
diff --git a/c/src/lib/libbsp/arm/raspberrypi/misc/vc.c b/c/src/lib/libbsp/arm/raspberrypi/misc/vc.c
index 54935af..91f9174 100644
--- a/c/src/lib/libbsp/arm/raspberrypi/misc/vc.c
+++ b/c/src/lib/libbsp/arm/raspberrypi/misc/vc.c
@@ -22,6 +22,7 @@
#include <bsp/raspberrypi.h>
#include <bsp/mailbox.h>
#include <bsp/vc.h>
+#include <libcpu/arm-cp15.h>
#include "vc_defines.h"
#if (RPI_L2_CACHE_ENABLE == 1)
@@ -45,6 +46,26 @@ bcm2835_mailbox_send_read_buffer(void *buf)
return 0;
}
+/*
+ * When cache is enabled then content of buffer exchanged
+ * with VideoCore has to be propagated through ARM11/Cortex-A7
+ * caches
+ */
+static inline void
+bcm2835_mailbox_buffer_flush_and_invalidate(void *buf, size_t size)
+{
+ uint32_t sctlr_val;
+
+ sctlr_val = arm_cp15_get_control();
+
+ arm_cp15_drain_write_buffer();
+ if (sctlr_val & (ARM_CP15_CTRL_C | ARM_CP15_CTRL_M)) {
+ arm_cp15_drain_write_buffer();
+ rtems_cache_flush_multiple_data_lines(buf, size);
+ rtems_cache_invalidate_multiple_data_lines(buf, size);
+ }
+}
+
#define BCM2835_MBOX_VAL_LENGTH_MASK(_val_len) \
(_val_len&(~BCM2835_MBOX_TAG_VAL_LEN_RESPONSE))
@@ -55,10 +76,11 @@ bcm2835_mailbox_get_display_size(bcm2835_get_display_size_entries *_entries)
bcm2835_mbox_buf_hdr hdr;
bcm2835_mbox_tag_display_size get_display_size;
uint32_t end_tag;
- }buffer __attribute__((aligned (16)));
+ }buffer BCM2835_MBOX_BUF_ALIGN_ATTRIBUTE;
BCM2835_MBOX_INIT_BUF(&buffer);
BCM2835_MBOX_INIT_TAG_NO_REQ(&buffer.get_display_size,
BCM2835_MAILBOX_TAG_GET_DISPLAY_SIZE);
+ bcm2835_mailbox_buffer_flush_and_invalidate(&buffer, sizeof(&buffer));
if (bcm2835_mailbox_send_read_buffer(&buffer))
return -1;
_entries->width = buffer.get_display_size.body.resp.width;
@@ -83,7 +105,7 @@ bcm2835_mailbox_init_frame_buffer(bcm2835_init_frame_buffer_entries* _entries)
bcm2835_mbox_tag_allocate_buffer allocate_buffer;
bcm2835_mbox_tag_get_pitch get_pitch;
uint32_t end_tag;
- } buffer __attribute__((aligned (16)));
+ } buffer BCM2835_MBOX_BUF_ALIGN_ATTRIBUTE;
BCM2835_MBOX_INIT_BUF(&buffer);
BCM2835_MBOX_INIT_TAG(&buffer.set_display_size,
BCM2835_MAILBOX_TAG_SET_DISPLAY_SIZE);
@@ -117,6 +139,7 @@ bcm2835_mailbox_init_frame_buffer(bcm2835_init_frame_buffer_entries* _entries)
buffer.allocate_buffer.body.req.align = 0x100;
BCM2835_MBOX_INIT_TAG_NO_REQ(&buffer.get_pitch,
BCM2835_MAILBOX_TAG_GET_PITCH);
+ bcm2835_mailbox_buffer_flush_and_invalidate(&buffer, sizeof(&buffer));
if (bcm2835_mailbox_send_read_buffer(&buffer))
return -1;
_entries->xres = buffer.set_display_size.body.resp.width;
@@ -151,10 +174,11 @@ bcm2835_mailbox_get_pitch(bcm2835_get_pitch_entries* _entries)
bcm2835_mbox_buf_hdr hdr;
bcm2835_mbox_tag_get_pitch get_pitch;
uint32_t end_tag;
- }buffer __attribute__((aligned (16)));
+ }buffer BCM2835_MBOX_BUF_ALIGN_ATTRIBUTE;
BCM2835_MBOX_INIT_BUF(&buffer);
BCM2835_MBOX_INIT_TAG_NO_REQ(&buffer.get_pitch,
BCM2835_MAILBOX_TAG_GET_PITCH);
+ bcm2835_mailbox_buffer_flush_and_invalidate(&buffer, sizeof(&buffer));
if (bcm2835_mailbox_send_read_buffer(&buffer))
return -1;
_entries->pitch = buffer.get_pitch.body.resp.pitch;
@@ -171,10 +195,11 @@ bcm2835_mailbox_get_cmdline(bcm2835_get_cmdline_entries* _entries)
bcm2835_mbox_buf_hdr hdr;
bcm2835_mbox_tag_get_cmd_line get_cmd_line;
uint32_t end_tag;
- }buffer __attribute__((aligned (16)));
+ }buffer BCM2835_MBOX_BUF_ALIGN_ATTRIBUTE;
BCM2835_MBOX_INIT_BUF(&buffer);
BCM2835_MBOX_INIT_TAG_NO_REQ(&buffer.get_cmd_line,
BCM2835_MAILBOX_TAG_GET_CMD_LINE);
+ bcm2835_mailbox_buffer_flush_and_invalidate(&buffer, sizeof(&buffer));
if (bcm2835_mailbox_send_read_buffer(&buffer))
return -1;
for (i = 0;
@@ -196,12 +221,13 @@ bcm2835_mailbox_set_power_state(bcm2835_set_power_state_entries *_entries)
bcm2835_mbox_buf_hdr hdr;
bcm2835_mbox_tag_power_state set_power_state;
uint32_t end_tag;
- }buffer __attribute__((aligned (16)));
+ }buffer BCM2835_MBOX_BUF_ALIGN_ATTRIBUTE;
BCM2835_MBOX_INIT_BUF(&buffer);
BCM2835_MBOX_INIT_TAG(&buffer.set_power_state,
BCM2835_MAILBOX_TAG_SET_POWER_STATE);
buffer.set_power_state.body.req.dev_id = _entries->dev_id;
buffer.set_power_state.body.req.state = _entries->state;
+ bcm2835_mailbox_buffer_flush_and_invalidate(&buffer, sizeof(&buffer));
if (bcm2835_mailbox_send_read_buffer(&buffer))
return -1;
_entries->dev_id = buffer.set_power_state.body.resp.dev_id;
@@ -218,10 +244,11 @@ bcm2835_mailbox_get_arm_memory(bcm2835_get_arm_memory_entries* _entries)
bcm2835_mbox_buf_hdr hdr;
bcm2835_mbox_tag_get_arm_memory get_arm_memory;
uint32_t end_tag;
- }buffer __attribute__((aligned (16)));
+ }buffer BCM2835_MBOX_BUF_ALIGN_ATTRIBUTE;
BCM2835_MBOX_INIT_BUF(&buffer);
BCM2835_MBOX_INIT_TAG_NO_REQ(&buffer.get_arm_memory,
BCM2835_MAILBOX_TAG_GET_ARM_MEMORY);
+ bcm2835_mailbox_buffer_flush_and_invalidate(&buffer, sizeof(&buffer));
if (bcm2835_mailbox_send_read_buffer(&buffer))
return -1;
_entries->base = buffer.get_arm_memory.body.resp.base;
@@ -238,10 +265,11 @@ bcm2835_mailbox_get_vc_memory(bcm2835_get_vc_memory_entries* _entries)
bcm2835_mbox_buf_hdr hdr;
bcm2835_mbox_tag_get_vc_memory get_vc_memory;
uint32_t end_tag;
- }buffer __attribute__((aligned (16)));
+ }buffer BCM2835_MBOX_BUF_ALIGN_ATTRIBUTE;
BCM2835_MBOX_INIT_BUF(&buffer);
BCM2835_MBOX_INIT_TAG_NO_REQ(&buffer.get_vc_memory,
BCM2835_MAILBOX_TAG_GET_VC_MEMORY);
+ bcm2835_mailbox_buffer_flush_and_invalidate(&buffer, sizeof(&buffer));
if (bcm2835_mailbox_send_read_buffer(&buffer))
return -1;
_entries->base = buffer.get_vc_memory.body.resp.base;
diff --git a/c/src/lib/libbsp/arm/raspberrypi/misc/vc_defines.h b/c/src/lib/libbsp/arm/raspberrypi/misc/vc_defines.h
index 30320ae..f3d5a28 100644
--- a/c/src/lib/libbsp/arm/raspberrypi/misc/vc_defines.h
+++ b/c/src/lib/libbsp/arm/raspberrypi/misc/vc_defines.h
@@ -115,6 +115,24 @@ typedef struct {
(_t_)->tag_hdr.val_len = 0; \
}
+/*
+ * Mailbox buffers has to be aligned to 16 bytes because
+ * 4 LSB bits of the BCM2835_MBOX_WRITE and BCM2835_MBOX_READ
+ * registers are used to pass channel number.
+ *
+ * But there is another requirement for buffer allocation
+ * as well when interface is called after cache is enabled.
+ * The buffer should not share cache line with another variable
+ * which can be updated during data exchange with VideoCore.
+ * If cache is filled to satisfy another variable update
+ * during VideoCore output is stored into main memory then
+ * part of received data can be lost.
+ *
+ * Cache line length is 64 bytes for RPi2 Cortex-A7 data cache
+ * so align buffers to this value.
+ */
+#define BCM2835_MBOX_BUF_ALIGN_ATTRIBUTE __attribute__((aligned (64)))
+
/* Video Core */
#define BCM2835_MAILBOX_TAG_FIRMWARE_REVISION 0x00000001
@@ -244,6 +262,9 @@ typedef struct {
#define BCM2835_MAILBOX_TAG_GET_TRUBO 0x00030009
#define BCM2835_MAILBOX_TAG_SET_TURBO 0x00038009
+#define BCM2835_MAILBOX_TAG_GET_DOMAIN_STATE 0x00030030
+#define BCM2835_MAILBOX_TAG_SET_DOMAIN_STATE 0x00038030
+
/* Voltage */
#define BCM2835_MAILBOX_VOLTAGE_RESERVED_UVID 0x000000000
#define BCM2835_MAILBOX_VOLTAGE_CORE_UVID 0x000000001
--
1.9.1
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