[PATCH] drm/amd/amdgpu: New debugfs interface for MMIO registers
Tom St Denis
tstdenis82 at gmail.com
Tue Aug 24 13:28:24 UTC 2021
hehehe I just moved it to uapi... No worries, you're the maintainer, I'll
move it back before posting v2.
Cheers,
Tom
On Tue, Aug 24, 2021 at 9:22 AM Christian König <
ckoenig.leichtzumerken at gmail.com> wrote:
> Am 24.08.21 um 14:42 schrieb Tom St Denis:
>
> The IOCTL data is in the debugfs header as it is. I could move that to
> the amdgpu_drm.h and include it from amdgpu_debugfs.h.
>
>
> Na, keep it like that and just add a comment.
>
> On second thought I don't want to raise any discussion on the mailing list
> if we should have a debugfs structure in the UAPI headers.
>
> Christian.
>
>
> I'll re-write the STATE IOCTL to use a struct and then test against what I
> have in umr.
>
> Refactoring the read/write is trivial and I'll do that no problem (with
> style fixes).
>
> Cheers,
> Tom
>
> On Tue, Aug 24, 2021 at 8:34 AM Christian König <
> ckoenig.leichtzumerken at gmail.com> wrote:
>
>> Am 24.08.21 um 14:27 schrieb StDenis, Tom:
>> > [AMD Official Use Only]
>> >
>> > What do you mean a "shared header?" How would they be shared between
>> kernel and user?
>>
>> Somewhere in the include/uapi/drm/ folder I think. Either add that to
>> amdgpu_drm.h or maybe amdgpu_debugfs.h?
>>
>> Or just keep it as a structure in amdgpu_debugfs.h with a comment that
>> it is used for an IOCTL.
>>
>> Just not something hard coded like first byte is this, second that etc....
>>
>> > As for why not read/write. Jus wanted to keep it simple. It's not
>> really performance bound. umr never does reads/writes larger than 32-bits
>> anyways. It doesn't have to be this way though but I figured the fewer LOC
>> the better.
>>
>> I think it would be cleaner if we would have separate functions for this.
>>
>> As far as I can see you also don't need the dance with the power
>> managerment etc for the IOCTL. It's just get_user() into your structure.
>>
>> BTW: In the kernel coding style put "switch" and "case" on the same
>> column, otherwise checkpatch.pl might complain.
>>
>> Christian.
>>
>> >
>> > Tom
>> >
>> > ________________________________________
>> > From: Christian König <ckoenig.leichtzumerken at gmail.com>
>> > Sent: Tuesday, August 24, 2021 08:20
>> > To: StDenis, Tom; amd-gfx at lists.freedesktop.org
>> > Subject: Re: [PATCH] drm/amd/amdgpu: New debugfs interface for MMIO
>> registers
>> >
>> >
>> >
>> > Am 24.08.21 um 14:16 schrieb Tom St Denis:
>> >> This new debugfs interface uses an IOCTL interface in order to pass
>> >> along state information like SRBM and GRBM bank switching. This
>> >> new interface also allows a full 32-bit MMIO address range which
>> >> the previous didn't. With this new design we have room to grow
>> >> the flexibility of the file as need be.
>> >>
>> >> Signed-off-by: Tom St Denis <tom.stdenis at amd.com>
>> >> ---
>> >> drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 177
>> ++++++++++++++++++++
>> >> drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.h | 32 ++++
>> >> 2 files changed, 209 insertions(+)
>> >>
>> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>> >> index 277128846dd1..ab2d92f84da5 100644
>> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
>> >> @@ -279,6 +279,173 @@ static ssize_t amdgpu_debugfs_regs_write(struct
>> file *f, const char __user *buf,
>> >> return amdgpu_debugfs_process_reg_op(false, f, (char __user
>> *)buf, size, pos);
>> >> }
>> >>
>> >> +static int amdgpu_debugfs_regs2_open(struct inode *inode, struct file
>> *file)
>> >> +{
>> >> + struct amdgpu_debugfs_regs2_data *rd;
>> >> +
>> >> + rd = kzalloc(sizeof *rd, GFP_KERNEL);
>> >> + if (!rd)
>> >> + return -ENOMEM;
>> >> + rd->adev = file_inode(file)->i_private;
>> >> + file->private_data = rd;
>> >> +
>> >> + return 0;
>> >> +}
>> >> +
>> >> +static int amdgpu_debugfs_regs2_release(struct inode *inode, struct
>> file *file)
>> >> +{
>> >> + kfree(file->private_data);
>> >> + return 0;
>> >> +}
>> >> +
>> >> +static int amdgpu_debugfs_regs2_op(struct file *f, char __user *buf,
>> int write_en)
>> >> +{
>> >> + struct amdgpu_debugfs_regs2_data *rd = f->private_data;
>> >> + struct amdgpu_device *adev = rd->adev;
>> >> + int result = 0, r;
>> >> + uint32_t value;
>> >> +
>> >> + if (rd->state.offset & 0x3)
>> >> + return -EINVAL;
>> >> +
>> >> + if (rd->state.use_grbm) {
>> >> + if (rd->state.grbm.se == 0x3FF)
>> >> + rd->state.grbm.se = 0xFFFFFFFF;
>> >> + if (rd->state.grbm.sh == 0x3FF)
>> >> + rd->state.grbm.sh = 0xFFFFFFFF;
>> >> + if (rd->state.grbm.instance == 0x3FF)
>> >> + rd->state.grbm.instance = 0xFFFFFFFF;
>> >> + }
>> >> +
>> >> + r = pm_runtime_get_sync(adev_to_drm(adev)->dev);
>> >> + if (r < 0) {
>> >> + pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
>> >> + return r;
>> >> + }
>> >> +
>> >> + r = amdgpu_virt_enable_access_debugfs(adev);
>> >> + if (r < 0) {
>> >> + pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
>> >> + return r;
>> >> + }
>> >> +
>> >> + if (rd->state.use_grbm) {
>> >> + if ((rd->state.grbm.sh != 0xFFFFFFFF && rd->
>> state.grbm.sh >= adev->gfx.config.max_sh_per_se) ||
>> >> + (rd->state.grbm.se != 0xFFFFFFFF && rd->
>> state.grbm.se >= adev->gfx.config.max_shader_engines)) {
>> >> +
>> pm_runtime_mark_last_busy(adev_to_drm(adev)->dev);
>> >> +
>> pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
>> >> + amdgpu_virt_disable_access_debugfs(adev);
>> >> + return -EINVAL;
>> >> + }
>> >> + mutex_lock(&adev->grbm_idx_mutex);
>> >> + amdgpu_gfx_select_se_sh(adev, rd->state.grbm.se,
>> >> + rd->
>> state.grbm.sh,
>> >> +
>> rd->state.grbm.instance);
>> >> + } else if (rd->state.use_grbm) {
>> >> + mutex_lock(&adev->srbm_mutex);
>> >> + amdgpu_gfx_select_me_pipe_q(adev, rd->state.srbm.me,
>> rd->state.srbm.pipe,
>> >> +
>> rd->state.srbm.queue, rd->state.srbm.vmid);
>> >> + }
>> >> +
>> >> + if (rd->state.pg_lock)
>> >> + mutex_lock(&adev->pm.mutex);
>> >> +
>> >> + if (!write_en) {
>> >> + value = RREG32(rd->state.offset >> 2);
>> >> + r = put_user(value, (uint32_t *)buf);
>> >> + } else {
>> >> + r = get_user(value, (uint32_t *)buf);
>> >> + if (!r)
>> >> + amdgpu_mm_wreg_mmio_rlc(adev, rd->state.offset
>> >> 2, value);
>> >> + }
>> >> + if (r) {
>> >> + result = r;
>> >> + goto end;
>> >> + }
>> >> + result = 0;
>> >> +end:
>> >> + if (rd->state.use_grbm) {
>> >> + amdgpu_gfx_select_se_sh(adev, 0xffffffff, 0xffffffff,
>> 0xffffffff);
>> >> + mutex_unlock(&adev->grbm_idx_mutex);
>> >> + } else if (rd->state.use_srbm) {
>> >> + amdgpu_gfx_select_me_pipe_q(adev, 0, 0, 0, 0);
>> >> + mutex_unlock(&adev->srbm_mutex);
>> >> + }
>> >> +
>> >> + if (rd->state.pg_lock)
>> >> + mutex_unlock(&adev->pm.mutex);
>> >> +
>> >> + // in umr (the likely user of this) flags are set per file
>> operation
>> >> + // which means they're never "unset" explicitly. To avoid
>> breaking
>> >> + // this convention we unset the flags after each operation
>> >> + // flags are for a single call (need to be set for every
>> read/write)
>> >> + rd->state.use_grbm = 0;
>> >> + rd->state.use_srbm = 0;
>> >> + rd->state.pg_lock = 0;
>> >> +
>> >> + pm_runtime_mark_last_busy(adev_to_drm(adev)->dev);
>> >> + pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
>> >> +
>> >> + amdgpu_virt_disable_access_debugfs(adev);
>> >> + return result;
>> >> +}
>> >> +
>> >> +static long amdgpu_debugfs_regs2_ioctl(struct file *f, unsigned int
>> cmd, unsigned long data)
>> >> +{
>> >> + struct amdgpu_debugfs_regs2_data *rd = f->private_data;
>> >> + unsigned char st[32], v;
>> >> + int r, x;
>> >> +
>> >> + // always read first 4 bytes of data
>> >> + for (x = 0; x < 4; x++) {
>> >> + if ((r = get_user(v, (unsigned char *)data))) {
>> >> + return r;
>> >> + }
>> >> + ++data;
>> >> + st[x] = v;
>> >> + }
>> >> +
>> >> + // first 4 bytes are offset
>> >> + rd->state.offset = ((u32)st[0]) | ((u32)st[1] << 8) |
>> >> + ((u32)st[2] << 16) |
>> ((u32)st[3] << 24);
>> >> +
>> >> + switch (cmd) {
>> >> + case AMDGPU_DEBUGFS_REGS2_IOC_SET_STATE:
>> >> + for (x = 4; x < 32; x++) {
>> >> + if ((r = get_user(v, (unsigned char
>> *)data))) {
>> >> + return r;
>> >> + }
>> >> + ++data;
>> >> + st[x] = v;
>> >> + }
>> >> +
>> >> + // next byte contains the flag
>> >> + // we only consume the remainder of the state if
>> bit 1 is set
>> >> + // this allows the subsequent read/write
>> >> + rd->state.use_grbm = (st[4] & 1) ? 1 : 0;
>> >> + rd->state.use_srbm = (st[4] & 2) ? 1 : 0;
>> >> + rd->state.pg_lock = (st[4] & 4) ? 1 : 0;
>> >> +
>> >> + // next 6 bytes are grbm data
>> >> + rd->state.grbm.se = ((u32)st[5]) |
>> ((u32)st[6] << 8);
>> >> + rd->state.grbm.sh = ((u32)st[7]) |
>> ((u32)st[8] << 8);
>> >> + rd->state.grbm.instance = ((u32)st[9]) |
>> ((u32)st[10] << 8);
>> >> +
>> >> + // next 8 are srbm data
>> >> + rd->state.srbm.me = ((u32)st[11]) |
>> ((u32)st[12] << 8);
>> >> + rd->state.srbm.pipe = ((u32)st[13]) |
>> ((u32)st[14] << 8);
>> >> + rd->state.srbm.queue = ((u32)st[15]) |
>> ((u32)st[16] << 8);
>> >> + rd->state.srbm.vmid = ((u32)st[17]) |
>> ((u32)st[18] << 8);
>> >> + break;
>> >> + case AMDGPU_DEBUGFS_REGS2_IOC_READ:
>> >> + return amdgpu_debugfs_regs2_op(f, (char __user
>> *)data, 0);
>> >> + case AMDGPU_DEBUGFS_REGS2_IOC_WRITE:
>> >> + return amdgpu_debugfs_regs2_op(f, (char __user
>> *)data, 1);
>> >> + default:
>> >> + return -EINVAL;
>> >> + }
>> >> + return 0;
>> >> +}
>> >>
>> >> /**
>> >> * amdgpu_debugfs_regs_pcie_read - Read from a PCIE register
>> >> @@ -1091,6 +1258,14 @@ static ssize_t
>> amdgpu_debugfs_gfxoff_read(struct file *f, char __user *buf,
>> >> return result;
>> >> }
>> >>
>> >> +static const struct file_operations amdgpu_debugfs_regs2_fops = {
>> >> + .owner = THIS_MODULE,
>> >> + .unlocked_ioctl = amdgpu_debugfs_regs2_ioctl,
>> >> + .open = amdgpu_debugfs_regs2_open,
>> >> + .release = amdgpu_debugfs_regs2_release,
>> >> + .llseek = default_llseek
>> >> +};
>> >> +
>> >> static const struct file_operations amdgpu_debugfs_regs_fops = {
>> >> .owner = THIS_MODULE,
>> >> .read = amdgpu_debugfs_regs_read,
>> >> @@ -1148,6 +1323,7 @@ static const struct file_operations
>> amdgpu_debugfs_gfxoff_fops = {
>> >>
>> >> static const struct file_operations *debugfs_regs[] = {
>> >> &amdgpu_debugfs_regs_fops,
>> >> + &amdgpu_debugfs_regs2_fops,
>> >> &amdgpu_debugfs_regs_didt_fops,
>> >> &amdgpu_debugfs_regs_pcie_fops,
>> >> &amdgpu_debugfs_regs_smc_fops,
>> >> @@ -1160,6 +1336,7 @@ static const struct file_operations
>> *debugfs_regs[] = {
>> >>
>> >> static const char *debugfs_regs_names[] = {
>> >> "amdgpu_regs",
>> >> + "amdgpu_regs2",
>> >> "amdgpu_regs_didt",
>> >> "amdgpu_regs_pcie",
>> >> "amdgpu_regs_smc",
>> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.h
>> >> index 141a8474e24f..04c81cd4bcc7 100644
>> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.h
>> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.h
>> >> @@ -22,6 +22,7 @@
>> >> * OTHER DEALINGS IN THE SOFTWARE.
>> >> *
>> >> */
>> >> +#include <linux/ioctl.h>
>> >>
>> >> /*
>> >> * Debugfs
>> >> @@ -38,3 +39,34 @@ void amdgpu_debugfs_fence_init(struct amdgpu_device
>> *adev);
>> >> void amdgpu_debugfs_firmware_init(struct amdgpu_device *adev);
>> >> void amdgpu_debugfs_gem_init(struct amdgpu_device *adev);
>> >> int amdgpu_debugfs_wait_dump(struct amdgpu_device *adev);
>> >> +
>> >> +struct amdgpu_debugfs_regs2_data {
>> >> + struct amdgpu_device *adev;
>> >> + struct {
>> >> + // regs state
>> >> + int use_srbm,
>> >> + use_grbm,
>> >> + pg_lock;
>> >> + struct {
>> >> + u32 se, sh, instance;
>> >> + } grbm;
>> >> + struct {
>> >> + u32 me, pipe, queue, vmid;
>> >> + } srbm;
>> >> + u32 offset;
>> >> + } state;
>> >> +};
>> > This stuff needs to be in some shared header then.
>> >
>> >> +
>> >> +enum AMDGPU_DEBUGFS_REGS2_CMDS {
>> >> + AMDGPU_DEBUGFS_REGS2_CMD_SET_STATE=0,
>> >> + AMDGPU_DEBUGFS_REGS2_CMD_READ,
>> >> + AMDGPU_DEBUGFS_REGS2_CMD_WRITE,
>> > Why not just using the normal read and write functions?
>> >
>> > Christian.
>> >
>> >> +};
>> >> +
>> >> +struct amdgpu_debugfs_regs2_iocdata {
>> >> + unsigned char t[32];
>> >> +};
>> >> +
>> >> +#define AMDGPU_DEBUGFS_REGS2_IOC_SET_STATE _IOWR(0x20,
>> AMDGPU_DEBUGFS_REGS2_CMD_SET_STATE, struct amdgpu_debugfs_regs2_iocdata)
>> >> +#define AMDGPU_DEBUGFS_REGS2_IOC_READ _IOWR(0x20,
>> AMDGPU_DEBUGFS_REGS2_CMD_WRITE, struct amdgpu_debugfs_regs2_iocdata)
>> >> +#define AMDGPU_DEBUGFS_REGS2_IOC_WRITE _IOWR(0x20,
>> AMDGPU_DEBUGFS_REGS2_CMD_READ, struct amdgpu_debugfs_regs2_iocdata)
>>
>>
>
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